60 changed files with 3527 additions and 4237 deletions
--- a/.eslintignore
+++ b/.eslintignore
@ -1,9 +1,7 @@
 node_modules/
 /.*cache/
 /.tmp/
 /coverage/
 /dist/
 /packages/*/bin/
 /packages/*/coverage/
 /packages/*/dist/
 /packages/*/lib/
--- a/.eslintrc.js
+++ b/.eslintrc.js
@ -1,6 +1,4 @@
 const tsconfigs = [
  'tsconfig.json',
  '*/tsconfig.json',
  'packages/*/tsconfig.json',
  'packages/*/test/tsconfig.json',
 ]
@ -20,14 +18,15 @@ module.exports = {
  },
  settings: {
    'import/resolver': {
-      // Use eslint-import-resolver-typescript to obey "paths" in tsconfig.json.
+      // Use eslint-import-resolver-ts to obey "paths" in tsconfig.json.
-      typescript: {
+      ts: {
        directory: tsconfigs,
      },
    },
  },
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/eslint-recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:@typescript-eslint/recommended-requiring-type-checking',
    'standard-with-typescript',
@ -36,63 +35,48 @@ module.exports = {
  ],
  rules: {
    'comma-dangle': ['error', 'always-multiline'],
    // Disable in favour of TypeScript rule.
    'func-call-spacing': 'off',
    'linebreak-style': ['error', 'unix'],
-    // Changed from error to warn and enabled ignoreEOLComments.
+    'lines-between-class-members': 'off',
    // Disable in favour of TypeScript rule.
    'no-extra-semi': 'off',
    'no-multi-spaces': ['warn', {
      ignoreEOLComments: true,
    }],
    // Changed from error to warn and adjusted options.
    'no-multiple-empty-lines': ['warn', {
      max: 2,
      maxEOF: 1,
      maxBOF: 1,
    }],
    'no-template-curly-in-string': 'off',
    // Changed from 'after' to 'before'.
    'operator-linebreak': ['error', 'before'],
    // Changed from error and all 'never' to warn and switches 'never'.
    'padded-blocks': ['warn', {
      switches: 'never',
    }],
    // Changed from 'as-needed' to 'consistent-as-needed'.
    'quote-props': ['error', 'consistent-as-needed'],
    // Disable in favour of TypeScript rule.
    'semi': 'off',
    // Import
    // Some packages have wrong type declarations.
    'import/default': 'off',
    'import/newline-after-import': 'warn',
    'import/no-absolute-path': 'error',
    // This rule disallows using both wildcard and selective imports from the same module.
    'import/no-duplicates': 'off',
-    // Some packages have it wrong in type declarations (e.g. katex, marked).
+    // Some packages has it wrong in type declarations (e.g. katex, marked).
    'import/no-named-as-default-member': 'off',
    // TypeScript
    // Changed options.
    '@typescript-eslint/ban-types': ['error', {
      // Allow to use {} and object - they are actually useful.
      types: {
        '{}': false,
        'object': false,
      },
      extendDefaults: true,
    }],
    '@typescript-eslint/class-literal-property-style': ['error', 'fields'],
    // Changed from error to off.
    '@typescript-eslint/consistent-type-definitions': 'off',
    // Changed from error to off.
    '@typescript-eslint/explicit-function-return-type': 'off',
-    '@typescript-eslint/explicit-member-accessibility': ['error', {
+    '@typescript-eslint/explicit-member-accessibility': ['warn', {
      accessibility: 'no-public',
      overrides: {
        parameterProperties: 'off',
      },
    }],
-    // Changed from warn to error and adjusted options.
+    '@typescript-eslint/func-call-spacing': ['error', 'never'],
    '@typescript-eslint/explicit-module-boundary-types': ['error', {
      allowArgumentsExplicitlyTypedAsAny: true,
    }],
    '@typescript-eslint/indent': ['error', 2, {
      SwitchCase: 1,
      VariableDeclarator: 1,
@ -111,58 +95,31 @@ module.exports = {
      flatTernaryExpressions: true,
      ignoreComments: false,
    }],
    // Changed from error to warn.
    '@typescript-eslint/lines-between-class-members': 'warn',
    // Changed delimiter for type literals from none to comma.
    // The reason is just aesthetic symmetry with object literals.
    '@typescript-eslint/member-delimiter-style': ['error', {
      multiline: { delimiter: 'comma', requireLast: true },
      singleline: { delimiter: 'comma', requireLast: false },
      overrides: {
        interface: {
          multiline: { delimiter: 'none' },
        },
      },
    }],
    '@typescript-eslint/member-ordering': 'warn',
    // Changed from warn to off.
    '@typescript-eslint/no-explicit-any': 'off',
    // Changed from error to warn.
    '@typescript-eslint/no-extra-semi': 'warn',
    // It disallows using void even in valid cases.
    '@typescript-eslint/no-invalid-void-type': 'off',
    // Changed from error to warn.
    '@typescript-eslint/no-namespace': 'warn',
    // Changed from error to warn.
    '@typescript-eslint/no-non-null-assertion': 'warn',
    '@typescript-eslint/no-require-imports': 'error',
-    // Changed from error to warn.
+    '@typescript-eslint/no-unused-vars': ['error', {
-    '@typescript-eslint/no-unsafe-assignment': 'warn',
+      argsIgnorePattern: '^_',
-    // Changed from error to warn.
+    }],
    '@typescript-eslint/no-unsafe-member-access': 'warn',
    // Disabled in favour of the next rule.
    '@typescript-eslint/no-unused-vars': 'off',
    '@typescript-eslint/no-unused-vars-experimental': 'error',
    // Changed options.
    '@typescript-eslint/no-use-before-define': ['error', {
      classes: true,
      functions: false,
      typedefs: false,
      variables: true,
    }],
    '@typescript-eslint/prefer-for-of': 'warn',
    // Changed from error to warn.
    '@typescript-eslint/prefer-includes': 'warn',
    // Changed from error to warn.
    '@typescript-eslint/prefer-regexp-exec': 'warn',
    '@typescript-eslint/prefer-string-starts-ends-with': 'warn',
-    // It has too many false positives.
+    '@typescript-eslint/promise-function-async': ['error', {
-    '@typescript-eslint/restrict-template-expressions': 'off',
+      allowAny: true,
    // Changed from error to off.
    '@typescript-eslint/strict-boolean-expressions': 'off',
    '@typescript-eslint/switch-exhaustiveness-check': 'error',
    // Changed from error to warn and adjusted options.
    '@typescript-eslint/unbound-method': ['warn', {
      ignoreStatic: true,
    }],
    '@typescript-eslint/semi': ['error', 'never'],
    '@typescript-eslint/strict-boolean-expressions': 'off',
  },
  overrides: [
    {
@ -170,14 +127,7 @@ module.exports = {
      rules: {
        // Allow to format arrays for parametrized tests as tables.
        'array-bracket-spacing': 'off',
-        'comma-dangle': ['error', {
+        'comma-spacing': 'off',
          arrays: 'always-multiline',
          objects: 'always-multiline',
          imports: 'always-multiline',
          exports: 'always-multiline',
          // Changed to not require comma in a multiline expect().
          functions: 'only-multiline',
        }],
        'object-curly-spacing': 'off',
        'no-multi-spaces': 'off',
        'standard/array-bracket-even-spacing': 'off',
@ -185,10 +135,7 @@ module.exports = {
        'space-in-parens': 'off',
        // jest.mock() must be above imports.
        'import/first': 'off',
-        '@typescript-eslint/comma-spacing': 'off',
+        '@typescript-eslint/no-non-null-assertion': 'off',
        // False positive on expect() functions.
        '@typescript-eslint/no-unsafe-call': 'off',
        '@typescript-eslint/no-unsafe-return': 'warn',
      },
    },
  ],
--- a/.github/FUNDING.yml
+++ b/.github/FUNDING.yml
@ -1,3 +0,0 @@
 # These are supported funding model platforms
 github: jirutka
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -1,68 +0,0 @@
 name: CI
 on:
  - push
  - pull_request
 jobs:
  test:
    name: Test on Node.js ${{ matrix.node-version }}
    runs-on: ubuntu-20.04
    strategy:
      matrix:
        node-version: [10, 12, 13, 14]
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0  # fetch all history to make `git describe` work
      - name: Setup Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v2
        with:
          node-version: ${{ matrix.node-version }}
      - run: yarn install
      - run: yarn build
      - run: yarn bundle
      - run: yarn test
      - run: yarn lint
  publish:
    name: Publish to npmjs and GitHub Releases
    needs: [test]
    if: startsWith(github.ref, 'refs/tags/v')
    runs-on: ubuntu-20.04
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0  # fetch all history to make `git describe` work
      - run: sudo apt-get install asciidoctor pandoc
      - uses: actions/setup-node@v2
        with:
          node-version: 14
          registry-url: https://registry.npmjs.org
      - run: yarn install
      - name: Generate source tarball
        run: ./scripts/create-src-tarball dist/ipynb2html-${GITHUB_REF/refs\/tags\//}-src.tar.gz
      - run: yarn build
      - run: yarn bundle
      - name: Publish packages to npmjs
        run: yarn publish-all --non-interactive
        env:
          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
      - name: Upload tarballs to Releases
        uses: softprops/action-gh-release@v1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          fail_on_unmatched_files: true
          files: |
            dist/*.tar.gz
            packages/ipynb2html-cli/dist/*.tar.gz
            packages/ipynb2html-cli/dist/*.zip
--- a/.gitignore
+++ b/.gitignore
@ -7,7 +7,6 @@
 /.*cache/
 /.tmp/
 node_modules/
 .eslintcache
 .tsbuildinfo
 tsconfig.tsbuildinfo
 *.log
--- a/.travis.yml
+++ b/.travis.yml
@ -0,0 +1,54 @@
 dist: bionic
 language: node_js
 node_js:
  - '10'
  - '12'
  - node
 addons:
  apt:
    packages:
      - asciidoctor
      - pandoc
 env:
  global:
    - secure: "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"  # NPM_TOKEN=ceed......2bf2
 cache: yarn
 install:
  - yarn install
  - test -z "$TRAVIS_TAG" || ./scripts/create-src-tarball dist/ipynb2html-$TRAVIS_TAG-src.tar.gz
 script:
  - yarn run build
  - yarn run bundle
  - yarn run test
  - yarn run lint
 before_deploy:
  - echo '//registry.npmjs.org/:_authToken=${NPM_TOKEN}' >> "$HOME"/.npmrc
 deploy:
  - provider: script
    script: yarn publish-all --non-interactive
    skip_cleanup: true
    on:
      repo: jirutka/ipynb2html
      tags: true
      node_js: '10'
  - provider: releases
    api_key:
      secure: j5Ks+lUUE2NkUKKC4A+FRKVia3oRyanMKp25jZwF2jLOQxZp0/BggNOduw7zMLzPizmMbz7CkYV/pLyXH+rwCjOdQPnSGLorzfp6ztzG49SqPUK5i5PdSctYT7+C2HdYR25xtw6f06HXzLWTIeYb0JG+5pUCkI4R+z1JEqZhx3PMOkAx9Ec9UoYNKcbHe1E78y8zH0pDccVJ1ejrbmizEqZALpYNR+qCWhTfLVbwYlpJJGIKCIXVYI9tU/3y/6JOO+gCX2m8jqNVBPrwWWD//gGExn2lR6BK0WiXTE71FbM7GyVjoeh93Zg1WifF+7DBtaTI9qs+928afLn28AcWqB6P/HgoRgt/4oLvJU2hkdkIoNqQONqYZeglW1A5qYp6T3nURLpcn1cg2yBD6vNi8cet4ntgOsPu9Soa8pzsm9xcITMJNUlFOEWyYPyvgTXHUjZwbZvrZHRVYeHrDOuq9EEAz+11u1FYG49uSBZf3+H6CmL7n2qeoYhlMhT94bgIkF4ByFmP+OTUcMcWvDdA7uD8JqPMaxQI0hhjrszxPT7C5YNXsJ1Q0vU2zZSMF74fygsXlnr6VeqwxSzgF/6mAAuSwtKSg/pFPPLdevIeehw4oLCz+ZdxVk5kpfymKvqvueDdMMoV4Fse4Yhv81Z76tAPM35TtqJa77DJwqOVOCE=
    file_glob: true
    file:
      - dist/*.tar.gz
      - packages/ipynb2html-cli/dist/*.tar.gz
      - packages/ipynb2html-cli/dist/*.zip
    skip_cleanup: true
    on:
      repo: jirutka/ipynb2html
      tags: true
      node_js: '10'
--- a/2
+++ b/2
@ -1,6 +1,6 @@
 The MIT License
-Copyright 2019-2020 Jakub Jirutka <jakub@jirutka.cz>.
+Copyright 2019 Jakub Jirutka <jakub@jirutka.cz>.
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/README.adoc
+++ b/README.adoc
@ -2,15 +2,15 @@
 :npm-name: ipynb2html
 :gh-name: jirutka/{npm-name}
 :gh-branch: master
-:version: 0.3.0
+:version: 0.1.0-beta.8
-:ansiup-version: 5.0.1
+:ansiup-version: 4.0.4
-:hljs-version: 10.7.3
+:hljs-version: 9.15.10
-:katex-version: 0.13.11
+:katex-version: 0.11.1
-:marked-version: 2.0.7
+:marked-version: 0.7.0
 :vs-marketplace-uri: https://marketplace.visualstudio.com/items?itemName=
 ifdef::env-github[]
-image:https://github.com/{gh-name}/workflows/CI/badge.svg[CI Status, link=https://github.com/{gh-name}/actions?query=workflow%3A%22CI%22]
+image:https://travis-ci.com/{gh-name}.svg?branch={gh-branch}[Build Status, link="https://travis-ci.com/{gh-name}"]
 endif::env-github[]
 {npm-name} is a converter (renderer) of the https://nbformat.readthedocs.io/en/stable/[Jupyter Notebook Format] 4.0+ to static HTML.
@ -47,8 +47,6 @@ This package builds on the {npm-name}-core and provides a complete, ready-to-go
 * https://github.com/IonicaBizau/anser[anser] as ANSI sequences renderer,
 * https://github.com/highlightjs/highlight.js[highlight.js] as syntax highlighter.
 It also provides a reference stylesheet which you can find in `dist/notebook.min.css` (or non-minified link:packages/{npm-name}/styles/notebook.css[`styles/notebook.css`]).
 === {npm-name}-cli
@ -60,8 +58,6 @@ endif::env-github[]
 This package provides a CLI interface for {npm-name}.
 ifndef::npm-readme[]
 == Installation
 All the <<Packages, packages>> can be installed using `npm` or `yarn` from https://www.npmjs.com/[npmjs.com].
@ -77,8 +73,6 @@ It requires only Node.js (version 10 or newer) to be installed on the system.
 The archive also contains source maps (useful for debugging).
 endif::[]
 == Usage
@ -132,7 +126,6 @@ You can link it from https://www.jsdelivr.com/[jsDelivr CDN], for example:
 <html>
  <head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/{npm-name}@{version}/dist/notebook.min.css" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@{katex-version}/dist/katex.min.css" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@{hljs-version}/build/styles/default.min.css" crossorigin="anonymous">
    <script src="https://cdn.jsdelivr.net/npm/{npm-name}@{version}/dist/{npm-name}-full.min.js" crossorigin="anonymous"></script>
@ -153,7 +146,6 @@ document.body.appendChild(element)
 <html>
  <head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/{npm-name}@{version}/dist/notebook.min.css" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@{katex-version}/dist/katex.min.css" crossorigin="anonymous">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@{hljs-version}/build/styles/default.min.css" crossorigin="anonymous">
    <script defer src="https://cdn.jsdelivr.net/npm/{npm-name}@{version}/dist/{npm-name}-full.min.js" crossorigin="anonymous"
--- a/examples/bundle-full.html
+++ b/examples/bundle-full.html
@ -4,14 +4,17 @@
    <meta charset="utf-8" lang="cs">
    <meta name="viewport" content="initial-scale=1">
    <title>Example using ipynb2html-full.js</title>
    <link rel="stylesheet" href="../packages/ipynb2html/dist/notebook.min.css">
    <link
      rel="stylesheet"
-      href="https://cdn.jsdelivr.net/npm/katex@0.13.11/dist/katex.min.css"
+      href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css"
      crossorigin="anonymous">
    <link
      rel="stylesheet"
-      href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.7.3/build/styles/default.min.css"
+      href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.15.10/build/styles/default.min.css"
      crossorigin="anonymous">
    <link
      rel="stylesheet"
      href="https://cdn.jsdelivr.net/gh/jsvine/nbpreview@c54381b/css/vendor/notebook.css"
      crossorigin="anonymous">
    <script defer src="../packages/ipynb2html/dist/ipynb2html-full.js" onload="ipynb2html.autoRender();"></script>
    <style>
--- a/examples/bundle.html
+++ b/examples/bundle.html
@ -4,19 +4,22 @@
    <meta charset="utf-8" lang="cs">
    <meta name="viewport" content="initial-scale=1">
    <title>Example using ipynb2html.js</title>
    <link rel="stylesheet" href="../packages/ipynb2html/dist/notebook.min.css">
    <link
      rel="stylesheet"
-      href="https://cdn.jsdelivr.net/npm/katex@0.13.11/dist/katex.min.css"
+      href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css"
      crossorigin="anonymous">
    <link
      rel="stylesheet"
-      href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.7.3/build/styles/default.min.css"
+      href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.15.10/build/styles/default.min.css"
      crossorigin="anonymous">
-    <script src="https://cdn.jsdelivr.net/npm/marked@2.0.7/marked.min.js" crossorigin="anonymous"></script>
+    <link
-    <script src="https://cdn.jsdelivr.net/npm/ansi_up@5.0.1/ansi_up.js" crossorigin="anonymous"></script>
+      rel="stylesheet"
-    <script src="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.7.3/build/highlight.min.js" crossorigin="anonymous"></script>
+      href="https://cdn.jsdelivr.net/gh/jsvine/nbpreview@c54381b/css/vendor/notebook.css"
-    <script src="https://cdn.jsdelivr.net/npm/katex@0.13.11/dist/katex.min.js" crossorigin="anonymous"></script>
+      crossorigin="anonymous">
    <script src="https://cdn.jsdelivr.net/npm/marked@0.7.0/marked.min.js" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/ansi_up@4.0.4/ansi_up.js" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.15.10/build/highlight.min.js" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.js" crossorigin="anonymous"></script>
    <script defer src="../packages/ipynb2html/dist/ipynb2html.js" onload="ipynb2html.autoRender();"></script>
    <style>
      html, body {
--- a/jest.config.base.js
+++ b/jest.config.base.js
@ -63,7 +63,7 @@ module.exports = {
  globals: {
    'ts-jest': {
      compiler: 'ttypescript',
-      tsConfig: '<rootDir>/test/tsconfig.json',
+      tsConfig: '<rootDir>/tsconfig.json',
    },
  },
--- a/package.json
+++ b/package.json
@ -1,12 +1,12 @@
 {
  "name": "ipynb2html-parent",
-  "version": "0.3.0",
+  "version": "0.1.0-beta.8",
  "private": true,
  "scripts": {
    "build": "ttsc --build",
    "bundle": "wsrun --exclude-missing bundle",
-    "clean": "rimraf coverage/ dist/ lib/ .eslintcache *.log && wsrun clean",
+    "clean": "rimraf coverage/ dist/ lib/ *.log && wsrun clean",
-    "lint": "eslint --cache --ext .ts,.tsx,.js .",
+    "lint": "eslint --ext .ts,.tsx,.js .",
    "postinstall": "patch-package && run-s build",
    "publish-all": "wsrun --serial publish",
    "test": "jest --detectOpenHandles --coverage --verbose",
@ -17,52 +17,55 @@
    "node": ">=10.13.0"
  },
  "devDependencies": {
-    "@babel/core": "^7.10.3",
+    "@babel/core": "^7.6.3",
-    "@babel/preset-env": "^7.10.3",
+    "@babel/preset-env": "^7.6.3",
    "@rollup/plugin-babel": "^5.0.3",
    "@rollup/plugin-commonjs": "^13.0.0",
    "@rollup/plugin-node-resolve": "^8.0.1",
    "@types/dedent": "^0.7.0",
-    "@types/jest": "^24.9.1",
+    "@types/highlightjs": "^9.12.0",
-    "@types/node": "^10.17.25",
+    "@types/jest": "^24.0.18",
-    "@typescript-eslint/eslint-plugin": "^3.3.0",
+    "@types/katex": "^0.10.2",
-    "@typescript-eslint/parser": "^3.3.0",
+    "@types/marked": "^0.6.5",
    "@types/node": "^10.13.0",
    "@typescript-eslint/eslint-plugin": "^2.4.0",
    "@typescript-eslint/parser": "^2.4.0",
    "ansi_up": "^4.0.4",
    "arrify": "^2.0.1",
-    "common-path-prefix": "^3.0.0",
+    "common-path-prefix": "^2.0.0",
-    "core-js": "^3.6.5",
+    "core-js": "^3.2.1",
    "csso-cli": "^3.0.0",
    "dedent": "^0.7.0",
-    "eslint": "^7.3.0",
+    "eslint": "^6.5.1",
-    "eslint-config-standard-with-typescript": "^18.0.2",
+    "eslint-config-standard-with-typescript": "^10.0.0",
-    "eslint-import-resolver-typescript": "^2.0.0",
+    "eslint-import-resolver-ts": "^0.4.0",
-    "eslint-plugin-import": "^2.21.2",
+    "eslint-plugin-import": "^2.18.0",
-    "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-node": "^10.0.0",
    "eslint-plugin-promise": "^4.2.1",
    "eslint-plugin-standard": "^4.0.0",
    "fs-extra": "^8.1.0",
-    "jest": "^25.5.4",
+    "jest": "^24.9.0",
-    "jest-chain": "^1.1.5",
+    "jest-chain": "^1.1.2",
    "node-html-parser": "^1.2.19",
    "nodom": "^2.3.0",
    "npm-run-all": "^4.1.5",
-    "patch-package": "^6.2.2",
+    "patch-package": "^6.2.0",
-    "postinstall-postinstall": "^2.1.0",
+    "postinstall-postinstall": "^2.0.0",
-    "rimraf": "^3.0.2",
+    "rimraf": "^3.0.0",
-    "rollup": "^2.17.1",
+    "rollup": "^1.23.0",
-    "rollup-plugin-add-git-msg": "^1.1.0",
+    "rollup-plugin-add-git-msg": "^1.0.3",
-    "rollup-plugin-executable": "^1.6.0",
+    "rollup-plugin-babel": "^4.3.3",
-    "rollup-plugin-node-externals": "^2.2.0",
+    "rollup-plugin-commonjs": "^10.1.0",
    "rollup-plugin-executable": "^1.5.1",
    "rollup-plugin-node-externals": "^2.0.1",
    "rollup-plugin-node-license": "^0.2.0",
-    "rollup-plugin-terser": "^6.1.0",
+    "rollup-plugin-node-resolve": "^5.2.0",
-    "rollup-plugin-typescript2": "^0.27.1",
+    "rollup-plugin-strip-shebang": "^1.2.7",
-    "tar": "^5.0.10",
+    "rollup-plugin-terser": "^5.1.2",
-    "ts-jest": "^25.5.1",
+    "rollup-plugin-typescript2": "^0.24.3",
-    "ts-node": "^8.10.2",
+    "tar": "^5.0.5",
    "ts-jest": "^24.1.0",
    "ts-node": "^8.4.1",
    "ts-transformer-export-default-name": "^0.1.0",
    "ts-transformer-inline-file": "^0.1.1",
-    "ttypescript": "^1.5.10",
+    "ttypescript": "^1.5.7",
-    "typescript": "~3.9.5",
+    "typescript": "~3.6.4",
-    "wsrun": "^5.2.1",
+    "wsrun": "^5.0.2",
    "yarn-version-bump": "^0.0.3",
    "yazl": "^2.5.1"
  },
--- a/packages/ipynb2html-cli/bin/ipynb2html
+++ b/packages/ipynb2html-cli/bin/ipynb2html
@ -1,2 +0,0 @@
 #!/usr/bin/env node
 require('../lib/index').default(process.argv.slice(2))
--- a/packages/ipynb2html-cli/package.json
+++ b/packages/ipynb2html-cli/package.json
@ -1,6 +1,6 @@
 {
  "name": "ipynb2html-cli",
-  "version": "0.3.0",
+  "version": "0.1.0-beta.8",
  "description": "CLI tool for converting Jupyter Notebooks to static HTML",
  "author": "Jakub Jirutka <jakub@jirutka.cz>",
  "license": "MIT",
@ -19,20 +19,19 @@
    "notebook"
  ],
  "bin": {
-    "ipynb2html": "bin/ipynb2html"
+    "ipynb2html": "lib/index.js"
  },
  "main": "lib/index.js",
  "types": "lib/index.d.ts",
  "files": [
    "bin",
    "lib",
    "src"
  ],
  "scripts": {
    "build": "ttsc --build",
    "bundle": "rollup -c && ./scripts/pack-bundle",
-    "clean": "rimraf coverage/ dist/ lib/ .eslintcache .tsbuildinfo",
+    "clean": "rimraf coverage/ dist/ lib/ .tsbuildinfo",
-    "lint": "PKGDIR=$PWD; cd ../../ && eslint --cache --ext .ts,.tsx,.js $PKGDIR",
+    "lint": "eslint --ext .ts,.tsx,.js .",
    "prepublishOnly": "run-s readme2md",
    "readme2md": "../../scripts/adoc2md -a npm-readme ../../README.adoc > README.md",
    "watch-ts": "ttsc --build --watch"
@ -41,14 +40,14 @@
    "node": ">=10.13.0"
  },
  "dependencies": {
-    "ipynb2html": "0.3.0",
+    "ipynb2html": "0.1.0-beta.8",
-    "minimist": "^1.2.6",
+    "minimist": "^1.2.0",
    "minimist-options": "^4.0.2",
    "nodom": "^2.3.0",
-    "source-map-support": "^0.5.16"
+    "source-map-support": "^0.5.13"
  },
  "devDependencies": {
    "@types/minimist": "^1.2.0",
-    "@types/source-map-support": "^0.5.1"
+    "@types/source-map-support": "^0.5.0"
  }
 }
--- a/packages/ipynb2html-cli/rollup.config.js
+++ b/packages/ipynb2html-cli/rollup.config.js
@ -1,11 +1,12 @@
 import addGitMsg from 'rollup-plugin-add-git-msg'
-import commonjs from '@rollup/plugin-commonjs'
+import commonjs from 'rollup-plugin-commonjs'
 import executable from 'rollup-plugin-executable'
 import externals from 'rollup-plugin-node-externals'
 import license from 'rollup-plugin-node-license'
-import resolve from '@rollup/plugin-node-resolve'
+import resolve from 'rollup-plugin-node-resolve'
 import { terser } from 'rollup-plugin-terser'
 import typescript from 'rollup-plugin-typescript2'
 import stripShebang from 'rollup-plugin-strip-shebang'
 import ttypescript from 'ttypescript'
 import pkg from './package.json'
@ -14,6 +15,10 @@ import pkg from './package.json'
 export default {
  input: 'src/index.ts',
  plugins: [
    // Rollup doesn't like shebangs, let's strip it.
    stripShebang({
      include: 'src/index.ts',
    }),
    // Transpile TypeScript sources to JS.
    typescript({
      typescript: ttypescript,
@ -26,6 +31,9 @@ export default {
          incremental: true,
        },
      },
      // This is needed for node-license plugin. :(
      // https://github.com/ezolenko/rollup-plugin-typescript2#plugins-using-asyncawait
      objectHashIgnoreUnknownHack: true,
      clean: true,
    }),
    // Make node builtins external.
--- a/packages/ipynb2html-cli/src/cli.ts
+++ b/packages/ipynb2html-cli/src/cli.ts
@ -3,17 +3,14 @@ import minimist from 'minimist'
 import minimistOptions from 'minimist-options'
 import { Document } from 'nodom'
 import { exit } from 'process'
-import { $INLINE_FILE, $INLINE_JSON } from 'ts-transformer-inline-file'
+import { $INLINE_JSON } from 'ts-transformer-inline-file'
 import * as ipynb2html from 'ipynb2html'
-import renderPage from './page'
+import template from './template'
 // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
 const { version, bugs: bugsUrl } = $INLINE_JSON('../package.json')
 const notebookCss = $INLINE_FILE('../../ipynb2html/styles/notebook.css')
 const pageCss = $INLINE_FILE('./page.css')
 const progName = 'ipynb2html'
 const helpMsg = `\
@ -28,14 +25,7 @@ Arguments:
 Options:
  -d --debug       Print debug messages.
  -s --style <file,...>  Comma separated stylesheet(s) to embed into the output
                         HTML. The stylesheet may be a path to a CSS file,
                         "@base" for the base ipynb2html style, or "@default"
                         for the default full page style. Default is @default.
  -h --help        Show this message and exit.
  -V --version     Print version and exit.
 Exit Codes:
@ -49,14 +39,9 @@ function logErr (msg: string): void {
  console.error(`${progName}: ${msg}`)
 }
 function arrify <T> (obj: T | T[]): T[] {
  return Array.isArray(obj) ? obj : [obj]
 }
 function parseCliArgs (argv: string[]) {
  const opts = minimist(argv, minimistOptions({
    debug: { alias: 'd', type: 'boolean' },
    style: { alias: 's', type: 'string', default: '@default' },
    version: { alias: 'V', type: 'boolean' },
    help: { alias: 'h', type: 'boolean' },
    arguments: 'string',
@ -88,35 +73,24 @@ function parseCliArgs (argv: string[]) {
  const [input, output] = opts._
  return {
    styles: arrify(opts.style).join(',').split(/,\s*/),
    debug: opts.debug as boolean,
    input: input === '-' ? 0 : input,  // 0 = stdin
    output,
  }
 }
 function loadStyle (name: string): string {
  switch (name) {
    case '@base': return notebookCss
    case '@default': return pageCss + notebookCss
    default: return fs.readFileSync(name, 'utf8')
  }
 }
 export default (argv: string[]): void => {
  const opts = parseCliArgs(argv)
  try {
    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
    const notebook = JSON.parse(fs.readFileSync(opts.input, 'utf-8'))
    const style = opts.styles.map(loadStyle).join('\n')
    const title = ipynb2html.readNotebookTitle(notebook) || 'Notebook'
-    const renderNotebook = ipynb2html.createRenderer(new Document())
+    const render = ipynb2html.createRenderer(new Document())
-    const contents = renderNotebook(notebook).outerHTML
+    const contents = render(notebook).outerHTML
-    const html = renderPage({ contents, title, style })
+    const html = template(contents, title)
    if (opts.output) {
      fs.writeFileSync(opts.output, html)
@ -127,7 +101,7 @@ export default (argv: string[]): void => {
    if (opts.debug) {
      console.debug(err)
    } else {
-      logErr((err as Error).message)
+      logErr(err.message)
    }
    return exit(1)
  }
--- a/packages/ipynb2html-cli/src/index.ts
+++ b/packages/ipynb2html-cli/src/index.ts
@ -1,9 +1,10 @@
 #!/usr/bin/env node
 import sourceMapSupport from 'source-map-support'
 import cli from './cli'
 // Allow to disable sourcemap when running from pkg bundle.
-if (!/^(0|disable|false|no|off)$/i.test(process.env.NODE_SOURCEMAP ?? '')) {
+if (!/^(0|disable|false|no|off)$/i.test(process.env.NODE_SOURCEMAP || '')) {
  sourceMapSupport.install({ environment: 'node' })
 }
--- a/packages/ipynb2html-cli/src/page.css
+++ b/packages/ipynb2html-cli/src/page.css
@ -1,95 +0,0 @@
 html, body {
  margin: 0;
  padding: 0;
  background-color: #dedede;
  color: #2a2a2a;
  font-family: sans-serif;
 }
 code,
 pre {
  font-size: 0.85rem;
 }
 h1, h2, h3, h4, h5, h6 {
  margin-top: 1.6em;
  position: relative;
 }
 h1 {
  font-size: 2em;
 }
 h1 .anchor,
 h2 .anchor,
 h3 .anchor,
 h4 .anchor,
 h5 .anchor,
 h6 .anchor {
  display: block;
  width: 1em;
  left: -1em;
  height: 100%;
  position: absolute;
 }
 h1:hover .anchor,
 h2:hover .anchor,
 h3:hover .anchor,
 h4:hover .anchor,
 h5:hover .anchor,
 h6:hover .anchor {
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'%3E%3Cg fill='none' stroke='%23000' stroke-width='3'%3E%3Cpath d='M26.1 22a5.8 5.8 0 00-8.1 0l-9.6 9.5a5.8 5.8 0 008.2 8.2l5.8-5.9'/%3E%3Cpath d='M23.6 28a5.8 5.8 0 008.2 0l9.5-9.5a5.8 5.8 0 00-8.1-8.2l-5.8 5.9'/%3E%3C/g%3E%3C/svg%3E") no-repeat 100% center;
 }
 table {
  border-collapse: collapse;
  border: 1px solid #cfcfcf;
 }
 th {
  font-weight: 600;
 }
 td,
 th {
  padding: 0.2em 0.4em;
  border: 1px solid #cfcfcf;
 }
 thead tr,
 tbody tr:nth-child(even) {
  background-color: #f7f7f7;
 }
 thead tr:hover,
 tbody tr:hover {
  background-color: #cfcfcf;
 }
 .nb-notebook {
  max-width: 45rem;
  margin: 1rem auto;
  padding: 3rem 6rem;
  background-color: white;
  box-shadow: 4px 4px 8px #cfcfcf, -4px -4px 8px #cfcfcf;
 }
 .nb-output table {
  font-size: 0.9em;
 }
@media (max-width: 900px) {
  .nb-notebook {
    margin: 0;
    padding-left: 5rem;
    padding-right: 3rem;
    max-width: none;
    box-shadow: none;
  }
 }
@media (max-width: 768px) {
  .nb-notebook {
    padding: 1rem 5% 2rem 5%;
  }
 }
--- a/packages/ipynb2html-cli/src/page.ts
+++ b/packages/ipynb2html-cli/src/page.ts
@ -1,34 +0,0 @@
 import { version } from 'ipynb2html'
 export type Options = {
  contents: string,
  title: string,
  style: string,
 }
 export default ({ contents, title, style }: Options): string => `\
 <!DOCTYPE html>
 <html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="initial-scale=1">
    <meta name="generator" content="ipynb2html ${version}">
    <title>${title}</title>
    <link rel="stylesheet"
        href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@10.7.3/build/styles/default.min.css"
        integrity="sha384-s4RLYRjGGbVqKOyMGGwfxUTMOO6D7r2eom7hWZQ6BjK2Df4ZyfzLXEkonSm0KLIQ"
        crossorigin="anonymous">
    <link rel="stylesheet"
        href="https://cdn.jsdelivr.net/npm/katex@0.13.11/dist/katex.min.css"
        integrity="sha384-Um5gpz1odJg5Z4HAmzPtgZKdTBHZdw8S29IecapCSB31ligYPhHQZMIlWLYQGVoc"
        crossorigin="anonymous">
    <style>
 ${style.replace(/\n\n/g, '\n').replace(/\n$/, '').replace(/^/gm, '      ')}
    </style>
  </head>
  <body>
 ${contents}
  </body>
 </html>
 `
--- a/packages/ipynb2html-cli/src/template.ts
+++ b/packages/ipynb2html-cli/src/template.ts
@ -0,0 +1,38 @@
 export default (contents: string, title: string): string => `\
 <!DOCTYPE html>
 <html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="initial-scale=1">
    <title>${title}</title>
    <link rel="stylesheet"
        href="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.15.10/build/styles/default.min.css"
        integrity="sha384-ut3ELVx81ErZQaaMTknSmGb0CEGAKoBFTamRcY1ddG4guN0aoga4C+B6B7Kv1Ll1"
        crossorigin="anonymous">
    <link rel="stylesheet"
        href="https://cdn.jsdelivr.net/npm/katex@0.11.0/dist/katex.min.css"
        integrity="sha384-BdGj8xC2eZkQaxoQ8nSLefg4AV4/AwB3Fj+8SUSo7pnKP6Eoy18liIKTPn9oBYNG"
        crossorigin="anonymous">
    <link rel="stylesheet"
        href="https://cdn.jsdelivr.net/gh/jsvine/nbpreview@c54381b/css/vendor/notebook.css"
        integrity="sha384-8nb3et+RBCn64rFFK06Oie9mX/D8c59Kg5hha4g9uUehuzCn9DFXGPZ94WYEBb9Z"
        crossorigin="anonymous">
    <style>
      html, body {
        margin: 0;
        padding: 0;
      }
      .nb-notebook {
        width: 99%;
        max-width: 750px;
        margin: 0 auto;
        padding: 3em 6em 1em 6em;
        background-color: white;
      }
    </style>
  </head>
  <body>
 ${contents}
  </body>
 </html>
 `
--- a/packages/ipynb2html-cli/tsconfig.json
+++ b/packages/ipynb2html-cli/tsconfig.json
@ -5,6 +5,11 @@
    "outDir": "./lib",
    "tsBuildInfoFile": "./.tsbuildinfo",
    "baseUrl": ".",
    "paths": {
      "*": ["../../types/*"],
      "@/*": ["./src/*"],
      "~/*": ["../../*"],
    },
  },
  "include": [
    "./src",
--- a/packages/ipynb2html-core/package.json
+++ b/packages/ipynb2html-core/package.json
@ -1,6 +1,6 @@
 {
  "name": "ipynb2html-core",
-  "version": "0.3.0",
+  "version": "0.1.0-beta.8",
  "description": "Convert Jupyter Notebook to static HTML",
  "author": "Jakub Jirutka <jakub@jirutka.cz>",
  "license": "MIT",
@ -25,8 +25,8 @@
  ],
  "scripts": {
    "build": "ttsc --build",
-    "clean": "rimraf coverage/ lib/ .eslintcache .tsbuildinfo",
+    "clean": "rimraf coverage/ lib/ .tsbuildinfo",
-    "lint": "PKGDIR=$PWD; cd ../../ && eslint --cache --ext .ts,.tsx,.js $PKGDIR",
+    "lint": "eslint --ext .ts,.tsx,.js .",
    "prepublishOnly": "run-s readme2md",
    "test": "jest --detectOpenHandles --coverage --verbose",
    "readme2md": "../../scripts/adoc2md -a npm-readme ../../README.adoc > README.md",
--- a/packages/ipynb2html-core/src/elementCreator.ts
+++ b/packages/ipynb2html-core/src/elementCreator.ts
@ -4,8 +4,8 @@ type Attributes = { [k: string]: string }
 // for this module's function.
 export type MinimalElement = {
  innerHTML: string,
-  setAttribute: (name: string, value: string) => void,
+  setAttribute (name: string, value: string): void,
-  appendChild: (child: any) => unknown,
+  appendChild (child: any): any,
 }
 export type ElementCreator<TElement = HTMLElement> =
--- a/packages/ipynb2html-core/src/htmlRenderer.ts
+++ b/packages/ipynb2html-core/src/htmlRenderer.ts
@ -16,7 +16,7 @@ export default <TElement> (opts: Options<TElement>): DataRenderer<TElement> => {
  const { elementCreator: el, mathRenderer: renderMath } = opts
  return (data: string): TElement => {
-    const math = (extractMathRx.exec(data) ?? [])[1]
+    const math = (extractMathRx.exec(data) || [])[1]
    return math
      ? el('div', ['latex-output'], renderMath(math))
      : el('div', ['html-output'], data)
--- a/packages/ipynb2html-core/src/index.ts
+++ b/packages/ipynb2html-core/src/index.ts
@ -3,6 +3,6 @@ import * as mathExtractor from './mathExtractor'
 export { default as createElementCreator, ElementCreator, MinimalElement } from './elementCreator'
 export { default as createHtmlRenderer } from './htmlRenderer'
 export * from './nbformat'
-export { default as NbRenderer, DataRenderer, NbRendererOpts } from './renderer'
+export { default as createNbRenderer, DataRenderer, NbRenderer, Options as NbRendererOpts } from './renderer'
 export { mathExtractor }
 export { default as version } from './version'
--- a/packages/ipynb2html-core/src/internal/utils.ts
+++ b/packages/ipynb2html-core/src/internal/utils.ts
@ -1,53 +1,36 @@
-const htmlEntities: Record<string, string> = {
+const htmlEntities = {
  '&': '&amp;',
  '<': '&lt;',
  '>': '&gt;',
 }
-type Callable = (...args: any[]) => any
+/**
 * Creates a "callable object" with the given properties. In fact, it creates
 * a function that calls `obj[funcName]` and copies all the enumerable
 * properties of the *template* to the created function.
 *
 * @param {string} funcName Name of the function property of the *template*.
 * @param {Object} template The source object from which to copy enumerable properties.
 * @return A function with all enumerable properties of the *template*.
 */
 export function callableObject <T, K extends keyof T> (
  funcName: K,
  template: T,
 ): T[K] extends Function ? T & T[K] : never {
-type CallableConstructor = new <T> () => T extends { __call__: Callable }
+  const fn = function (...args: any[]) {
-  ? T['__call__']
+    return (template[funcName] as any)(...args)
-  : 'subclass does not implement method __call__'
+  }
-
+  return Object.assign(fn, template) as any
 /* eslint-disable @typescript-eslint/no-unsafe-assignment,
                  @typescript-eslint/no-unsafe-member-access,
                  @typescript-eslint/ban-types */
 export const CallableInstance: CallableConstructor = function Callable (
  this: object,
 ): Callable {
  const func = this.constructor.prototype.__call__ as Callable
  const cls = function (...args: any[]) {
    return func.apply(cls, args) as unknown
 }
  Object.setPrototypeOf(cls, this.constructor.prototype)
  Object.defineProperties(cls, {
    name: {
      value: this.constructor.name,
      configurable: true,
    },
    length: {
      value: func.length,
      configurable: true,
    },
  })
  return cls
 } as any
 CallableInstance.prototype = Object.create(Function.prototype)
 /* eslint-enable @typescript-eslint/no-unsafe-assignment,
                 @typescript-eslint/no-unsafe-member-access,
                 @typescript-eslint/ban-types */
 /**
 * Escapes characters with special meaning in HTML with the corresponding
 * HTML entities.
 */
 export function escapeHTML (str: string): string {
-  return str.replace(/[&<>]/g, c => htmlEntities[c])
+  return str.replace(/[&<>]/g, c => (htmlEntities as any)[c])
 }
 /**
--- a/packages/ipynb2html-core/src/mathExtractor.ts
+++ b/packages/ipynb2html-core/src/mathExtractor.ts
@ -191,7 +191,7 @@ export function extractMath (text: string): [string, MathExpression[]] {
    }
  }
  if (lastIdx) {
-    processMath(unescape, math, blocks, startIdx ?? 0, lastIdx)
+    processMath(unescape, math, blocks, startIdx || 0, lastIdx)
    startIdx = endDelim = lastIdx = null
  }
  return [unescape(blocks.join('')), math.map(parseDelimitedMath)]
@ -204,6 +204,6 @@ export function extractMath (text: string): [string, MathExpression[]] {
 */
 export function restoreMath (text: string, math: string[]): string {
  return text
-    .replace(/@@([1-9][0-9]*)@@/g, (_, n) => math[Number(n) - 1] ?? '')
+    .replace(/@@([1-9][0-9]*)@@/g, (_, n) => math[Number(n) - 1])
    .replace(/@@0(\d+)@@/g, (_, n) => `@@${n}@@`)
 }
--- a/packages/ipynb2html-core/src/nbformat.ts
+++ b/packages/ipynb2html-core/src/nbformat.ts
@ -1,79 +1,78 @@
 // These types are based on https://github.com/jupyter/nbformat/blob/b6b5a18e5a40d37f1cc0f71f65108288bdec9bb7/nbformat/v4/nbformat.v4.schema.json.
 // This file was originally generated using json-schema-to-typescript 7.0.0 and
 // then manually polished.
 /* eslint-disable @typescript-eslint/member-ordering */
 /** Jupyter Notebook v4.3. */
 export interface Notebook {
  /** Notebook root-level metadata. */
-  metadata: NotebookMetadata
+  metadata: NotebookMetadata,
  /** Notebook format (minor number). Incremented for backward compatible changes to the notebook format. */
-  nbformat_minor: number
+  nbformat_minor: number,
  /** Notebook format (major number). Incremented between backwards incompatible changes to the notebook format. */
-  nbformat: 4
+  nbformat: 4,
  /** Array of cells of the current notebook. */
-  cells: Cell[]
+  cells: Cell[],
 }
 /** Notebook root-level metadata. */
 export interface NotebookMetadata {
  /** Kernel information. */
-  kernelspec?: KernelSpec
+  kernelspec?: KernelSpec,
  /** Kernel information. */
-  language_info?: LanguageInfo
+  language_info?: LanguageInfo,
  /** Original notebook format (major number) before converting the notebook between versions. This should never be written to a file. */
-  orig_nbformat?: number
+  orig_nbformat?: number,
  /** The title of the notebook document */
-  title?: string
+  title?: string,
  /** The author(s) of the notebook document */
-  authors?: any[]
+  authors?: any[],
  /** Extra properties. */
-  [key: string]: any
+  [key: string]: any,
 }
 /** Kernel information. */
 export interface KernelSpec {
  /** Name of the kernel specification. */
-  name: string
+  name: string,
  /** Name to display in UI. */
-  display_name: string
+  display_name: string,
  /** Extra properties. */
-  [key: string]: any
+  [key: string]: any,
 }
 /** Kernel information. */
 export interface LanguageInfo {
  /** The programming language which this kernel runs. */
-  name: string
+  name: string,
  /** The codemirror mode to use for code in this language. */
-  codemirror_mode?: string | { [k: string]: any }
+  codemirror_mode?: string | { [k: string]: any },
  /** The file extension for files in this language. */
-  file_extension?: string
+  file_extension?: string,
  /** The mimetype corresponding to files in this language. */
-  mimetype?: string
+  mimetype?: string,
  /** The pygments lexer to use for code in this language. */
-  pygments_lexer?: string
+  pygments_lexer?: string,
  /** Extra properties. */
-  [key: string]: any
+  [key: string]: any,
 }
@ -90,46 +89,46 @@ export enum CellType {
 interface BaseCell {
  /** String identifying the type of cell. */
-  cell_type: CellType
+  cell_type: CellType,
  /** Cell-level metadata. */
-  metadata: CellMetadata
+  metadata: CellMetadata,
  /** Contents of the cell, represented as an array of lines. */
-  source: MultilineString
+  source: MultilineString,
 }
 /** Notebook raw nbconvert cell. */
 export interface RawCell extends BaseCell {
  /** String identifying the type of cell. */
-  cell_type: CellType.Raw
+  cell_type: CellType.Raw,
  /** Cell-level metadata. */
  metadata: CellMetadata & {
    /** Raw cell metadata format for nbconvert. */
    format?: string,
-  }
+  },
  /** Media attachments (e.g. inline images), stored as mimebundle keyed by filename. */
-  attachments?: MediaAttachments
+  attachments?: MediaAttachments,
 }
 /** Notebook markdown cell. */
 export interface MarkdownCell extends BaseCell {
  /** String identifying the type of cell. */
-  cell_type: CellType.Markdown
+  cell_type: CellType.Markdown,
  /** Media attachments (e.g. inline images), stored as mimebundle keyed by filename. */
-  attachments?: MediaAttachments
+  attachments?: MediaAttachments,
 }
 /** Notebook code cell. */
 export interface CodeCell extends BaseCell {
  /** String identifying the type of cell. */
-  cell_type: CellType.Code
+  cell_type: CellType.Code,
  /** Cell-level metadata. */
  metadata: CellMetadata & {
@ -139,38 +138,38 @@ export interface CodeCell extends BaseCell {
    /** Whether the cell's output is scrolled, unscrolled, or autoscrolled. */
    scrolled?: true | false | 'auto',
-  }
+  },
  /** Execution, display, or stream outputs. */
-  outputs: Output[]
+  outputs: Output[],
  /** The code cell's prompt number. Will be null if the cell has not been run. */
-  execution_count: number | null
+  execution_count: number | null,
 }
 export interface CellMetadata {
  /** Official Jupyter Metadata for Raw Cells */
-  jupyter?: { [k: string]: any }
+  jupyter?: { [k: string]: any },
  /**
   * The cell's name. If present, must be a non-empty string. Cell names are expected to be unique
   * across all the cells in a given notebook. This criterion cannot be checked by the json schema
   * and must be established by an additional check.
   */
-  name?: string
+  name?: string,
  /** The cell's tags. Tags must be unique, and must not contain commas. */
-  tags?: string[]
+  tags?: string[],
  /** Extra properties. */
-  [key: string]: any
+  [key: string]: any,
 }
 export interface MediaAttachments {
  /** The attachment's data stored as a mimebundle. */
-  [filename: string]: MimeBundle
+  [filename: string]: MimeBundle,
 }
@ -189,62 +188,62 @@ export enum OutputType {
 export interface ExecuteResult {
  /** Type of cell output. */
-  output_type: OutputType.ExecuteResult
+  output_type: OutputType.ExecuteResult,
  /** A result's prompt number. */
-  execution_count: number | null
+  execution_count: number | null,
  /** A mime-type keyed dictionary of data */
-  data: MimeBundle
+  data: MimeBundle,
  /** Cell output metadata. */
  metadata: {
    [k: string]: any,
-  }
+  },
 }
 /** Data displayed as a result of code cell execution. */
 export interface DisplayData {
  /** Type of cell output. */
-  output_type: OutputType.DisplayData
+  output_type: OutputType.DisplayData,
  /** A mime-type keyed dictionary of data */
-  data: MimeBundle
+  data: MimeBundle,
  /** Cell output metadata. */
  metadata: {
    [k: string]: any,
-  }
+  },
 }
 /** Stream output from a code cell. */
 export interface StreamOutput {
  /** Type of cell output. */
-  output_type: OutputType.Stream
+  output_type: OutputType.Stream,
  /** The name of the stream (stdout, stderr). */
-  name: string
+  name: string,
  /** The stream's text output, represented as an array of strings. */
-  text: MultilineString
+  text: MultilineString,
 }
 /** Output of an error that occurred during code cell execution. */
 export interface ErrorOutput {
  /** Type of cell output. */
-  output_type: OutputType.Error
+  output_type: OutputType.Error,
  /** The name of the error. */
-  ename: string
+  ename: string,
  /** The value, or message, of the error. */
-  evalue: string
+  evalue: string,
  /** The error's traceback, represented as an array of strings. */
-  traceback: string[]
+  traceback: string[],
 }
@ -253,7 +252,7 @@ export interface ErrorOutput {
 export interface MimeBundle {
  /** mimetype output (e.g. text/plain), represented as either an array of strings or a string. */
-  [mediaType: string]: MultilineString
+  [mediaType: string]: MultilineString,
 }
 export type MultilineString = string | string[]
--- a/packages/ipynb2html-core/src/renderer.ts
+++ b/packages/ipynb2html-core/src/renderer.ts
@ -1,6 +1,6 @@
 // This code is originally based on notebookjs 0.4.2 distributed under the MIT license.
 import { ElementCreator } from './elementCreator'
-import { CallableInstance, escapeHTML, identity } from './internal/utils'
+import { callableObject, escapeHTML, identity } from './internal/utils'
 import {
  Cell,
  CellType,
@ -17,18 +17,18 @@ import {
 } from './nbformat'
-export type NbRendererOpts<TElement = HTMLElement> = {
+export type Options<TElement = HTMLElement> = {
  /**
   * An object with additional data renderers indexed by a media type.
   */
  dataRenderers?: DataRenderers<TElement>,
  /**
-   * An array of the supported MIME types in the priority order. When a cell
+   * An array of the supported media types in the priority order. When a cell
   * contains multiple representations of the data, the one with the media type
   * that has the lowest index in this array will be rendered. The default is
   * `Object.keys({ ...dataRenderers, ...builtinRenderers })`.
   */
-  dataTypesPriority?: string[],
+  dataRenderersOrder?: string[],
  /**
   * A function for converting ANSI escape sequences in the given *text* to HTML.
   * It gets the text from the cell as-is, without prior escaping, so it must
@ -48,7 +48,7 @@ export type NbRendererOpts<TElement = HTMLElement> = {
  markdownRenderer?: (markup: string) => string,
 }
-export type DataRenderer<TElement = HTMLElement> = (this: NbRenderer<TElement> | void, data: string) => TElement
+export type DataRenderer<TElement = HTMLElement> = (data: string) => TElement
 type DataRenderers<TElement> = { [mediaType: string]: DataRenderer<TElement> }
@ -83,173 +83,155 @@ function executionCountAttrs ({ execution_count: count }: CodeCell): { [k: strin
 }
 function notebookLanguage ({ metadata: meta }: Notebook): string {
-  return meta.language_info?.name ?? 'python'
+  return (meta.language_info && meta.language_info.name) || 'python'
 }
 class NbRenderer <TElement> extends CallableInstance<NbRenderer<TElement>> {
  readonly el: ElementCreator<TElement>
  readonly renderMarkdown: NonNullable<NbRendererOpts['markdownRenderer']>
  readonly renderAnsiCodes: NonNullable<NbRendererOpts['ansiCodesRenderer']>
  readonly highlightCode: NonNullable<NbRendererOpts['codeHighlighter']>
  readonly dataRenderers: DataRenderers<TElement>
  readonly dataTypesPriority: string[]
 /**
-   * Creates a Notebook renderer with the given options. The constructed object
+ * Builds a Notebook renderer function with the given options. It returns a
-   * is "callable", i.e. you can treat it as a function.
+ * "callable object" that exposes a renderer function for each of the
-   *
+ * Notebook's AST node. You can easily replace any of the functions to modify
-   * @example
+ * behaviour of the renderer.
   *   const renderer = new NbRenderer(document.createElement.bind(document))
   *   console.log(renderer(notebook).outerHTML)
 *
 * @param {ElementCreator} elementCreator The function that will be used for
 *   building all HTML elements.
-   * @param {NbRendererOpts} opts The renderer's options.
+ * @param {Options} opts
 * @return {NbRenderer}
 * @template TElement Type of the element object that *elementCreator* produces.
 */
-  constructor (elementCreator: ElementCreator<TElement>, opts: NbRendererOpts<TElement> = {}) {
+function buildRenderer <TElement> (elementCreator: ElementCreator<TElement>, opts: Options<TElement> = {}) {
-    super()
+  const renderMarkdown = opts.markdownRenderer || identity
  const renderAnsiCodes = opts.ansiCodesRenderer || escapeHTML
  const highlightCode = opts.codeHighlighter || escapeHTML
-    this.el = elementCreator
+  const el = elementCreator
-    this.renderMarkdown = opts.markdownRenderer ?? identity
+  const el2 = (tag: string, classes: string[]) => (data: string) => el(tag, classes, data)
    this.renderAnsiCodes = opts.ansiCodesRenderer ?? escapeHTML
    this.highlightCode = opts.codeHighlighter ?? escapeHTML
-    const el2 = (tag: string, classes: string[]) => (data: string) => this.el(tag, classes, data)
+  const embeddedImageEl = (format: string) => (data: string) => el('img', {
    const embeddedImageEl = (format: string) => (data: string) => this.el('img', {
    class: 'image-output',
    src: `data:image/${format};base64,${data.replace(/\n/g, '')}`,
  })
  // opts.dataRenderers is intentionally included twice; to get the user's
-    // provided renderers in the default dataTypesPriority before the built-in
+  // provided renderers in the default dataRenderersOrder before the built-in
  // renderers and at the same time allow to override any built-in renderer.
-    this.dataRenderers = {
+  const dataRenderers: DataRenderers<TElement> = {
    ...opts.dataRenderers,
    'image/png': embeddedImageEl('png'),
    'image/jpeg': embeddedImageEl('jpeg'),
    'image/svg+xml': el2('div', ['svg-output']),
-      'text/svg+xml': (data) => this.dataRenderers['image/svg+xml'].call(this, data),
+    'text/svg+xml': (data) => dataRenderers['image/svg+xml'](data),
    'text/html': el2('div', ['html-output']),
-      'text/markdown': (data) => this.el('div', ['html-output'], this.renderMarkdown(data)),
+    'text/markdown': (data) => dataRenderers['text/html'](renderMarkdown(data)),
    'text/latex': el2('div', ['latex-output']),
    'application/javascript': el2('script', []),
-      'text/plain': (data) => this.el('pre', ['text-output'], escapeHTML(data)),
+    'text/plain': (data) => el('pre', ['text-output'], escapeHTML(data)),
    ...opts.dataRenderers,
  }
-    this.dataTypesPriority = opts.dataTypesPriority ?? Object.keys(this.dataRenderers)
+  const dataRenderersOrder = opts.dataRenderersOrder || Object.keys(dataRenderers)
  const resolveDataType = (output: DisplayData | ExecuteResult) => {
    return dataRenderersOrder.find(type => output.data[type] && dataRenderers[type])
  }
-  /**
+  const r = callableObject('Notebook', {
-   * Renders the given Jupyter *notebook*.
+    Notebook: (notebook: Notebook): TElement => {
-   */
+      const children = notebook.cells.map(cell => r.Cell(cell, notebook))
-  __call__ (notebook: Notebook): TElement {
+      // Class "worksheet" is for backward compatibility with notebook.js.
-    return this.render(notebook)
+      return el('div', ['notebook', 'worksheet'], children)
-  }
+    },
-  /**
+    Cell: (cell: Cell, notebook: Notebook): TElement => {
   * Renders the given Jupyter *notebook*.
   */
  render (notebook: Notebook): TElement {
    const children = notebook.cells.map(cell => this.renderCell(cell, notebook))
    return this.el('div', ['notebook'], children)
  }
  renderCell (cell: Cell, notebook: Notebook): TElement {
      switch (cell.cell_type) {
-      case CellType.Code: return this.renderCodeCell(cell, notebook)
+        case CellType.Code: return r.CodeCell(cell, notebook)
-      case CellType.Markdown: return this.renderMarkdownCell(cell, notebook)
+        case CellType.Markdown: return r.MarkdownCell(cell, notebook)
-      case CellType.Raw: return this.renderRawCell(cell, notebook)
+        case CellType.Raw: return r.RawCell(cell, notebook)
-      default: return this.el('div', [], '<!-- Unsupported cell type -->')
+        default: return el('div', [], '<!-- Unsupported cell type -->')
    }
      }
    },
-  renderMarkdownCell (cell: MarkdownCell, _notebook: Notebook): TElement {
+    MarkdownCell: (cell: MarkdownCell, _notebook: Notebook): TElement => {
-    return this.el('section', ['cell', 'markdown-cell'], this.renderMarkdown(joinText(cell.source)))
+      return el('div', ['cell', 'markdown-cell'], renderMarkdown(joinText(cell.source)))
-  }
+    },
-  renderRawCell (cell: RawCell, _notebook: Notebook): TElement {
+    RawCell: (cell: RawCell, _notebook: Notebook): TElement => {
-    return this.el('section', ['cell', 'raw-cell'], joinText(cell.source))
+      return el('div', ['cell', 'raw-cell'], joinText(cell.source))
-  }
+    },
-  renderCodeCell (cell: CodeCell, notebook: Notebook): TElement {
+    CodeCell: (cell: CodeCell, notebook: Notebook): TElement => {
      const source = cell.source.length > 0
-      ? this.renderSource(cell, notebook)
+        ? r.Source(cell, notebook)
-      : this.el('div')
+        : el('div')
-    const outputs = coalesceStreams(cell.outputs ?? [])
+      const outputs = coalesceStreams(cell.outputs || [])
-      .map(output => this.renderOutput(output, cell))
+        .map(output => r.Output(output, cell))
-    return this.el('section', ['cell', 'code-cell'], [source, ...outputs])
+      return el('div', ['cell', 'code-cell'], [source, ...outputs])
-  }
+    },
-  renderSource (cell: CodeCell, notebook: Notebook): TElement {
+    Source: (cell: CodeCell, notebook: Notebook): TElement => {
      const lang = notebookLanguage(notebook)
-    const html = this.highlightCode(joinText(cell.source), lang)
+      const html = highlightCode(joinText(cell.source), lang)
-    const codeEl = this.el('code', { 'class': `lang-${lang}`, 'data-language': lang }, html)
+      const codeEl = el('code', { 'class': `lang-${lang}`, 'data-language': lang }, html)
-    const preEl = this.el('pre', [], [codeEl])
+      const preEl = el('pre', [], [codeEl])
      // Class "input" is for backward compatibility with notebook.js.
      const attrs = { ...executionCountAttrs(cell), class: 'source input' }
-    return this.el('div', attrs, [preEl])
+      return el('div', attrs, [preEl])
-  }
+    },
-  renderOutput (output: Output, cell: CodeCell): TElement {
+    Output: (output: Output, cell: CodeCell): TElement => {
      const innerEl = (() => {
        switch (output.output_type) {
-        case OutputType.DisplayData: return this.renderDisplayData(output)
+          case OutputType.DisplayData: return r.DisplayData(output)
-        case OutputType.ExecuteResult: return this.renderExecuteResult(output)
+          case OutputType.ExecuteResult: return r.ExecuteResult(output)
-        case OutputType.Stream: return this.renderStream(output)
+          case OutputType.Stream: return r.Stream(output)
-        case OutputType.Error: return this.renderError(output)
+          case OutputType.Error: return r.Error(output)
-        default: return this.el('div', [], '<!-- Unsupported output type -->')
+          default: return el('div', [], '<!-- Unsupported output type -->')
        }
      })()
      const attrs = { ...executionCountAttrs(cell), class: 'output' }
-    return this.el('div', attrs, [innerEl])
+      return el('div', attrs, [innerEl])
-  }
+    },
-  renderDisplayData (output: DisplayData): TElement {
+    DisplayData: (output: DisplayData): TElement => {
-    const type = this.resolveDataType(output)
+      const type = resolveDataType(output)
      if (type) {
-      return this.renderData(type, joinText(output.data[type]))
+        return dataRenderers[type](joinText(output.data[type]))
    }
    return this.el('div', ['empty-output'])
      }
      return el('div', ['empty-output'])
    },
-  renderExecuteResult (output: ExecuteResult): TElement {
+    ExecuteResult: (output: ExecuteResult): TElement => {
-    const type = this.resolveDataType(output)
+      const type = resolveDataType(output)
      if (type) {
-      return this.renderData(type, joinText(output.data[type]))
+        return dataRenderers[type](joinText(output.data[type]))
    }
    return this.el('div', ['empty-output'])
      }
      return el('div', ['empty-output'])
    },
-  renderError (error: ErrorOutput): TElement {
+    Error: (error: ErrorOutput): TElement => {
-    const html = this.renderAnsiCodes(error.traceback.join('\n'))
+      const html = renderAnsiCodes(error.traceback.join('\n'))
      // Class "pyerr" is for backward compatibility with notebook.js.
-    return this.el('pre', ['error', 'pyerr'], html)
+      return el('pre', ['error', 'pyerr'], html)
    },
    Stream: (stream: StreamOutput): TElement => {
      const html = renderAnsiCodes(joinText(stream.text))
      return el('pre', [stream.name], html)
    },
  })
  return r
 }
-  renderStream (stream: StreamOutput): TElement {
+export default buildRenderer
    const html = this.renderAnsiCodes(joinText(stream.text))
    return this.el('pre', [stream.name], html)
  }
-  renderData (mimeType: string, data: string): TElement {
+// XXX: An ugly hack to infer return type of generic function that returns
-    const render = this.dataRenderers[mimeType]
+// generalized object.
-    if (!render) {
+abstract class DummyClass<T> {
-      throw RangeError(`missing renderer for MIME type: ${mimeType}`)
+  renderer = buildRenderer<T>(this.elementCreator())
  abstract elementCreator (): ElementCreator<T>
 }
-    return render.call(this, data)
+export type NbRenderer<TElement> = DummyClass<TElement>['renderer']
  }
  resolveDataType (output: DisplayData | ExecuteResult): string | undefined {
    return this.dataTypesPriority.find(type => output.data[type])
  }
 }
 export default NbRenderer
--- a/packages/ipynb2html-core/src/version.ts
+++ b/packages/ipynb2html-core/src/version.ts
@ -1,6 +1,5 @@
 import { $INLINE_JSON } from 'ts-transformer-inline-file'
 // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
 const { version } = $INLINE_JSON('../package.json')
 export default version as string
--- a/packages/ipynb2html-core/test/internal/utils.test.ts
+++ b/packages/ipynb2html-core/test/internal/utils.test.ts
@ -1,64 +1,31 @@
-import { CallableInstance, escapeHTML, identity } from '@/internal/utils'
+import { callableObject, escapeHTML, identity } from '@/internal/utils'
-describe('CallableInstance', () => {
+describe('.callableObject', () => {
-  class FixtureCallable extends CallableInstance<FixtureCallable> {
+  describe('returned value', () => {
-    readonly salutation: string
+    const template = {
-
+      str: 'allons-y!',
-    constructor (salutation: string) {
+      func1: jest.fn().mockReturnValue(1),
-      super()
+      func2: jest.fn().mockReturnValue(2),
      this.salutation = salutation
    }
    const subject = callableObject('func1', template)
-    __call__ (name: string) {
+    it('is a function that calls the specified template function', () => {
-      return this.salute(name)
+      expect( subject ).toBeInstanceOf(Function)
-    }
+      expect( subject('a', 'b') ).toBe(1)
-
+      expect( template.func1 ).toBeCalledWith('a', 'b')
    salute (name: string) {
      return `${this.salutation}, ${name}!`
    }
  }
  describe('subclass', () => {
    it('can be instantiated using new', () => {
      expect(() => new FixtureCallable('Hello') ).not.toThrow()
    })
    })
-  describe('subclass instance', () => {
+    it('is not the same function as the specified template function', () => {
-    let instance: FixtureCallable
+      expect( subject ).not.toBe(template.func1)
    beforeEach(() => {
      instance = new FixtureCallable('Hello')
    })
-    it('is an instance of its class', () => {
+    it('has all enumerable properties of the given template', () => {
-      expect( instance ).toBeInstanceOf(FixtureCallable)
+      expect( subject )
-      expect( instance.salutation ).toBe('Hello')
+        .toHaveProperty('str', template.str)
-      expect( instance.salute('world') ).toBe('Hello, world!')
+        .toHaveProperty('func1', template.func1)
-    })
+        .toHaveProperty('func2', template.func2)
    it('is an instance of Function', () => {
      expect( instance ).toBeInstanceOf(Function)
    })
    it('is a typeof function', () => {
      expect( typeof instance ).toBe('function')
    })
    it('has function property "name" that equals the class name', () => {
      expect( instance.name ).toBe('FixtureCallable')
    })
    it('has function property "length" that equals number of arguments of the __call__ method', () => {
      expect( instance.length ).toBe(1)
    })
    it('can be called, redirects to the method __call__', () => {
      expect( instance('world') ).toBe('Hello, world!')
      expect( instance.apply(null, ['world']) ).toBe('Hello, world!')  // eslint-disable-line no-useless-call
      expect( instance.call(null, 'world') ).toBe('Hello, world!')  // eslint-disable-line no-useless-call
    })
  })
 })
--- a/packages/ipynb2html-core/test/mathExtractor.test.ts
+++ b/packages/ipynb2html-core/test/mathExtractor.test.ts
@ -20,7 +20,7 @@ describe('.extractMath', () => {
        it('extracts and substitutes math expression in the given text', () => {
          expect(
-            extractMath(`Let's define ${raw}.`),
+            extractMath(`Let's define ${raw}.`)
          ).toEqual(["Let's define @@1@@.", [{ displayMode, raw, value }]])
        })
      })
@ -31,7 +31,7 @@ describe('.extractMath', () => {
        it('extracts and substitutes math expression in the given text', () => {
          expect(
-            extractMath(`Let's define ${raw}.`),
+            extractMath(`Let's define ${raw}.`)
          ).toEqual(["Let's define @@1@@.", [{ displayMode, raw, value }]])
        })
      })
@ -43,7 +43,7 @@ describe('.extractMath', () => {
    it('extracts and substitutes math expression in the given text', () => {
      expect(
-        extractMath(`Let's define ${raw}.`),
+        extractMath(`Let's define ${raw}.`)
      ).toEqual(["Let's define @@1@@.", [{ displayMode: true, raw, value: raw }]])
    })
  })
@ -52,14 +52,14 @@ describe('.extractMath', () => {
    it('escapes @@[0-9]+@@ as @@0[0-9]+@@', () => {
      expect(
-        extractMath('This @@02@@ is not our marker'),
+        extractMath('This @@02@@ is not our marker')
      ).toEqual(['This @@002@@ is not our marker', []])
    })
  })
  it('ignores math delimiters inside `inline code`', () => {
    expect(
-      extractMath('`$x$` and ``$`x`$`` is a code, $x$ is not'),
+      extractMath('`$x$` and ``$`x`$`` is a code, $x$ is not')
    ).toEqual([
      '`$x$` and ``$`x`$`` is a code, @@1@@ is not',
      [{ displayMode: false, raw: '$x$', value: 'x' }],
@ -68,7 +68,7 @@ describe('.extractMath', () => {
  it('ignores math delimiters inside `inline code` with line breaks', () => {
    expect(
-      extractMath('`$x\n$` and ``\n$`x`$\n`` is a code, `$x$\n\nis` not'),
+      extractMath('`$x\n$` and ``\n$`x`$\n`` is a code, `$x$\n\nis` not')
    ).toEqual([
      '`$x\n$` and ``\n$`x`$\n`` is a code, `@@1@@\n\nis` not',
      [{ displayMode: false, raw: '$x$', value: 'x' }],
@ -135,13 +135,13 @@ describe('.restoreMath', () => {
    repl[21] = 'second'
    expect(
-      restoreMath("Let's define @@1@@ and @@22@@.", repl),
+      restoreMath("Let's define @@1@@ and @@22@@.", repl)
    ).toEqual("Let's define first and second.")
  })
  it('unescapes marker-like sequences', () => {
    expect(
-      restoreMath('This @@001@@ is not our marker, nor @@01@@, but @@1@@ is.', ['this one']),
+      restoreMath('This @@001@@ is not our marker, nor @@01@@, but @@1@@ is.', ['this one'])
    ).toEqual('This @@01@@ is not our marker, nor @@1@@, but this one is.')
  })
 })
--- a/packages/ipynb2html-core/test/renderer.test.tsx
+++ b/packages/ipynb2html-core/test/renderer.test.tsx
@ -1,20 +1,19 @@
 /* eslint-disable @typescript-eslint/unbound-method */
 import '~/test/setup'  // setupFilesAfterEnv doesn't work here
 import arrify from 'arrify'
 import { Document, HTMLElement } from 'nodom'
 import buildElementCreator from '@/elementCreator'
-import NbRenderer, { NbRendererOpts } from '@/renderer'
+import buildRenderer, { NbRenderer, Options as RendererOpts } from '@/renderer'
 import { DisplayData, MimeBundle, MultilineString, Notebook } from '@/nbformat'
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 import { Anything } from '~/test/support/matchers/toMatchElement'
 import { mockLastResult, mockResults } from '~/test/support/helpers'
-import * as fixtures from './support/fixtures/notebook'
+import * as _fixtures from './support/fixtures/notebook'
 const document = new Document()
 const fixtures = _fixtures  // workaround to allow indexed access
 describe('built renderer', () => {
@ -28,7 +27,7 @@ describe('built renderer', () => {
  const dataRenderers = {
    'text/custom': rendererMock('DisplayData'),
  }
-  const rendererOpts: NbRendererOpts<HTMLElement> = {
+  const rendererOpts: RendererOpts<HTMLElement> = {
    ansiCodesRenderer,
    codeHighlighter,
    markdownRenderer,
@ -38,46 +37,45 @@ describe('built renderer', () => {
  beforeEach(() => {
-    renderer = new NbRenderer(elementCreator, rendererOpts)
+    renderer = buildRenderer(elementCreator, rendererOpts)
  })
-  describe('.render', () => {
+  describe('.Notebook', () => {
    beforeEach(() => {
-      renderer.renderCell = rendererMock('Cell')
+      renderer.Cell = rendererMock('Cell')
    })
-    it('returns div.notebook', () => {
+    it('returns div.notebook.worksheet', () => {
-      expect( renderer.render({ ...notebook, cells: [] }) ).toHtmlEqual(
+      expect( renderer.Notebook({ ...notebook, cells: [] }) ).toHtmlEqual(
-        <div class="notebook"></div>
+        <div class="notebook worksheet"></div>
      )
    })
-    it('returns element with $cells converted using .renderCell() as the children', () => {
+    it('returns element with $cells converted using .Cell() as the children', () => {
-      const result = renderer.render(notebook)
+      const result = renderer.Notebook(notebook)
      notebook.cells.forEach((cell, idx) => {
-        expect( renderer.renderCell ).toHaveBeenNthCalledWith(idx + 1, cell, notebook)
+        expect( renderer.Cell ).toHaveBeenNthCalledWith(idx + 1, cell, notebook)
      })
-      expect( result.children ).toHtmlEqual(mockResults(renderer.renderCell))
+      expect( result.children ).toHtmlEqual(mockResults(renderer.Cell))
    })
  })
-  describe('.renderCell', () => {
+  describe('.Cell', () => {
    describe.each([
-      'renderCodeCell', 'renderMarkdownCell', 'renderRawCell',
+      'CodeCell', 'MarkdownCell', 'RawCell',
-    ] as const)('with %s', (funcName) => {
+    ] as const)('with %s', (type) => {
-      const type = funcName.replace('render', '')
+      const cell = fixtures[type]
      const cell = (fixtures as any)[type]
-      it(`returns result of calling .${funcName}() with the given cell`, () => {
+      it(`returns result of calling .${type}() with the given cell`, () => {
        const expected = stubElement(type)
-        const rendererFunc = (renderer as any)[funcName] = jest.fn(() => expected)
+        renderer[type] = jest.fn(() => expected)
-        expect( renderer.renderCell(cell, notebook) ).toBe(expected)
+        expect( renderer.Cell(cell, notebook) ).toBe(expected)
-        expect( rendererFunc ).toBeCalledWith(cell, notebook)
+        expect( renderer[type] ).toBeCalledWith(cell, notebook)
      })
    })
@ -88,7 +86,7 @@ describe('built renderer', () => {
      } as any
      it('returns div with comment "Unsupported cell type"', () => {
-        expect( renderer.renderCell(cell, notebook) ).toHtmlEqual(
+        expect( renderer.Cell(cell, notebook) ).toHtmlEqual(
          <div>
            {{__html: '<!-- Unsupported cell type -->' }}
          </div>
@ -98,15 +96,15 @@ describe('built renderer', () => {
  })
-  describe('.renderMarkdownCell', () => {
+  describe('.MarkdownCell', () => {
    eachMultilineVariant(fixtures.MarkdownCell, 'source', (cell) => {
      const source = join(cell.source)
-      it('returns section.cell.markdown-cell with the $source converted using markdownRenderer() as content', () => {
+      it('returns div.cell.markdown-cell with the $source converted using markdownRenderer() as content', () => {
-        expect( renderer.renderMarkdownCell(cell, notebook) ).toHtmlEqual(
+        expect( renderer.MarkdownCell(cell, notebook) ).toHtmlEqual(
-          <section class="cell markdown-cell">
+          <div class="cell markdown-cell">
            {{__html: mockLastResult(markdownRenderer) }}
-          </section>
+          </div>
        )
        expect( markdownRenderer ).toBeCalledWith(source)
      })
@ -114,48 +112,48 @@ describe('built renderer', () => {
  })
-  describe('.renderRawCell', () => {
+  describe('.RawCell', () => {
    eachMultilineVariant(fixtures.RawCell, 'source', (cell) => {
-      it('returns section.cell.raw-cell with the $source as content', () => {
+      it('returns div.cell.raw-cell with the $source as content', () => {
-        expect( renderer.renderRawCell(cell, notebook) ).toHtmlEqual(
+        expect( renderer.RawCell(cell, notebook) ).toHtmlEqual(
-          <section class="cell raw-cell">
+          <div class="cell raw-cell">
            {{__html: join(cell.source) }}
-          </section>
+          </div>
        )
      })
    })
  })
-  describe('.renderCodeCell', () => {
+  describe('.CodeCell', () => {
    const cell = fixtures.CodeCell
    let result: HTMLElement
    beforeEach(() => {
-      renderer.renderSource = rendererMock('Source')
+      renderer.Source = rendererMock('Source')
-      renderer.renderOutput = rendererMock('Output')
+      renderer.Output = rendererMock('Output')
-      result = renderer.renderCodeCell(cell, notebook)
+      result = renderer.CodeCell(cell, notebook)
    })
-    it('returns section.cell.code-cell', () => {
+    it('returns div.cell.code-cell', () => {
      expect( result ).toMatchElement(
-        <section class="cell code-cell"><Anything /></section>
+        <div class="cell code-cell"><Anything /></div>
      )
    })
    describe('with non-empty $source', () => {
-      it('returns element with $source rendered using .renderSource() as children[0]', () => {
+      it('returns element with $source rendered using .Source() as children[0]', () => {
-        expect( renderer.renderSource ).toBeCalledWith(cell, notebook)
+        expect( renderer.Source ).toBeCalledWith(cell, notebook)
-        expect( result.children[0] ).toHtmlEqual(mockLastResult(renderer.renderSource)!)
+        expect( result.children[0] ).toHtmlEqual(mockLastResult(renderer.Source))
      })
    })
    describe('with empty $source', () => {
      beforeEach(() => {
-        result = renderer.renderCodeCell({ ...cell, source: [] }, notebook)
+        result = renderer.CodeCell({ ...cell, source: [] }, notebook)
      })
      it('returns element with empty div as children[0]', () => {
@ -165,22 +163,22 @@ describe('built renderer', () => {
      })
    })
-    it('returns element with $outputs rendered using .renderOutput() as children[1+]', () => {
+    it('returns element with $outputs rendered using .Output() as children[1+]', () => {
      cell.outputs.forEach((output, idx) => {
-        expect( renderer.renderOutput ).toHaveBeenNthCalledWith(idx + 1, output, cell)
+        expect( renderer.Output ).toHaveBeenNthCalledWith(idx + 1, output, cell)
      })
-      expect( result.children.slice(1) ).toHtmlEqual(mockResults(renderer.renderOutput))
+      expect( result.children.slice(1) ).toHtmlEqual(mockResults(renderer.Output))
    })
  })
-  describe('.renderSource', () => {
+  describe('.Source', () => {
    const cell = fixtures.CodeCell
    const notebookLang = notebook.metadata.language_info!.name
    let result: HTMLElement
    beforeEach(() => {
-      result = renderer.renderSource(cell, notebook)
+      result = renderer.Source(cell, notebook)
    })
    it('returns div > pre > code', () => {
@ -208,7 +206,7 @@ describe('built renderer', () => {
        const myCell = { ...cell, execution_count: 2 }
        it('has data-execution-count and data-prompt-number attributes', () => {
-          const result = renderer.renderSource(myCell, notebook)
+          const result = renderer.Source(myCell, notebook)
          expect( result.attributes ).toMatchObject({
            'data-execution-count': String(myCell.execution_count),
@ -221,7 +219,7 @@ describe('built renderer', () => {
        const myCell = { ...cell, execution_count: null }
        it('has data-execution-count and data-prompt-number attributes', () => {
-          const result = renderer.renderSource(myCell, notebook)
+          const result = renderer.Source(myCell, notebook)
          expect( result.attributes )
            .not.toHaveProperty('data-execution-count')
@ -234,7 +232,7 @@ describe('built renderer', () => {
      let codeEl: HTMLElement
      beforeEach(() => {
-        codeEl = renderer.renderSource(cell, notebook).firstChild!.firstChild as HTMLElement
+        codeEl = renderer.Source(cell, notebook).firstChild!.firstChild as HTMLElement
      })
      it("has class lang-<lang> where lang is the notebook's language", () => {
@ -256,7 +254,7 @@ describe('built renderer', () => {
      const notebookLang = 'python'
      it('uses the default language: python', () => {
-        const result = renderer.renderSource(cell, myNotebook)
+        const result = renderer.Source(cell, myNotebook)
        const codeEl = result.firstChild!.firstChild as HTMLElement
        expect( codeEl.getAttribute('data-language') ).toBe(notebookLang)
@ -267,20 +265,19 @@ describe('built renderer', () => {
  })
-  describe('.renderOutput', () => {
+  describe('.Output', () => {
    const cell = { ...fixtures.CodeCell, execution_count: null }
    describe.each([
-      'renderDisplayData', 'renderExecuteResult', 'renderStream', 'renderError',
+      'DisplayData', 'ExecuteResult', 'Stream', 'Error',
-    ] as const)('with %s output', (funcName) => {
+    ] as const)('with %s output', (type) => {
-      const type = funcName.replace('render', '')
+      const output = fixtures[type]
      const output = (fixtures as any)[type]
      let result: HTMLElement
      beforeEach(() => {
-        renderer[funcName] = rendererMock(type)
+        renderer[type] = rendererMock(type)
-        result = renderer.renderOutput(output, cell)
+        result = renderer.Output(output, cell)
      })
      it('returns div.output', () => {
@ -289,16 +286,16 @@ describe('built renderer', () => {
        )
      })
-      it(`returns element with the output rendered using .${funcName}() as the only child`, () => {
+      it(`returns element with the output rendered using .${type}() as the only child`, () => {
-        expect( renderer[funcName] ).toBeCalledWith(output)
+        expect( renderer[type] ).toBeCalledWith(output)
-        expect( result.children ).toHtmlEqual([mockLastResult(renderer[funcName])!])
+        expect( result.children ).toHtmlEqual([mockLastResult(renderer[type])])
      })
      describe('when the cell has non-null execution_count', () => {
        const cell = { ...fixtures.CodeCell, execution_count: 2 }
        it('returns element with attributes data-execution-count and data-prompt-number', () => {
-          const result = renderer.renderOutput(output, cell)
+          const result = renderer.Output(output, cell)
          expect( result.attributes ).toMatchObject({
            'data-execution-count': String(cell.execution_count),
@ -320,7 +317,7 @@ describe('built renderer', () => {
      }
      it('returns div with comment "Unsupported output type"', () => {
-        expect( renderer.renderOutput(output, cell) ).toHtmlEqual(
+        expect( renderer.Output(output, cell) ).toHtmlEqual(
          <div class="output">
            <div>
              {{__html: '<!-- Unsupported output type -->' }}
@ -332,7 +329,7 @@ describe('built renderer', () => {
  })
-  describe('.renderDisplayData', () => {
+  describe('.DisplayData', () => {
    function displayDataWith (data: MimeBundle): DisplayData {
      return { ...fixtures.DisplayData, data }
@ -361,7 +358,7 @@ describe('built renderer', () => {
      const displayData = displayDataWith({ 'text/non-sense': 'whaat' })
      it('returns div.empty-output', () => {
-        expect( renderer.renderDisplayData(displayData) ).toHtmlEqual(
+        expect( renderer.DisplayData(displayData) ).toHtmlEqual(
          <div class="empty-output"></div>
        )
      })
@ -373,7 +370,7 @@ describe('built renderer', () => {
        withMimeData(mimeType, ['aW1hZ2Ug\n', 'ZGF0YQ=='], (output) => {
          it('returns img.image-output with the data in the src attribute', () => {
-            expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+            expect( renderer.DisplayData(output) ).toHtmlEqual(
              <img class="image-output" src={`data:${mimeType};base64,aW1hZ2UgZGF0YQ==`}></img>
            )
          })
@ -391,7 +388,7 @@ describe('built renderer', () => {
        withMimeData(mimeType, '<stub>data</stub>', (output, data) => {
          it(`returns div${classes.map(x => `.${x}`)} with the data as content`, () => {
-            expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+            expect( renderer.DisplayData(output) ).toHtmlEqual(
              <div class={ classes.join(' ') }>
                {{__html: join(data) }}
              </div>
@ -403,7 +400,7 @@ describe('built renderer', () => {
      withMimeData('text/markdown', ['Lorem\n', 'ipsum'], (output, data) => {
        it('returns div.html-output with the data converted using markdownRenderer() as content', () => {
-          expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+          expect( renderer.DisplayData(output) ).toHtmlEqual(
            <div class="html-output">
              {{__html: mockLastResult(markdownRenderer) }}
            </div>
@ -415,7 +412,7 @@ describe('built renderer', () => {
      withMimeData('text/plain', '>_<', (output) => {
        it('returns pre.text-output with html-escaped data', () => {
-          expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+          expect( renderer.DisplayData(output) ).toHtmlEqual(
            <pre class="text-output">{ '>_<' }</pre>
          )
        })
@ -424,7 +421,7 @@ describe('built renderer', () => {
      withMimeData('application/javascript', 'alert("Hello &!")', (output, data) => {
        it('returns script with the data', () => {
-          expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+          expect( renderer.DisplayData(output) ).toHtmlEqual(
            <script>{{__html: join(data) }}</script>
          )
        })
@ -436,8 +433,8 @@ describe('built renderer', () => {
      withMimeData('text/custom', 'Lorem ipsum', (output, data) => {
        it('renders the data using the associated external renderer', () => {
-          expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+          expect( renderer.DisplayData(output) ).toHtmlEqual(
-            mockLastResult(dataRenderers['text/custom'])!
+            mockLastResult(dataRenderers['text/custom'])
          )
          expect( dataRenderers['text/custom'] ).toBeCalledWith(join(data))
        })
@ -453,7 +450,7 @@ describe('built renderer', () => {
      const output = displayDataWith(mimeBundle)
      it('renders the data of the MIME type with a higher priority', () => {
-        expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+        expect( renderer.DisplayData(output) ).toHtmlEqual(
          <div class="html-output">
            {{__html: mimeBundle['text/html'] }}
          </div>
@ -467,8 +464,8 @@ describe('built renderer', () => {
        }
        const output = displayDataWith(mimeBundle)
-        expect( renderer.renderDisplayData(output) ).toHtmlEqual(
+        expect( renderer.DisplayData(output) ).toHtmlEqual(
-          mockLastResult(dataRenderers['text/custom'])!
+          mockLastResult(dataRenderers['text/custom'])
        )
      })
    })
@ -477,7 +474,7 @@ describe('built renderer', () => {
      const dataRenderer = rendererMock('DisplayData')
      beforeEach(() => {
-        renderer = new NbRenderer(elementCreator, {
+        renderer = buildRenderer(elementCreator, {
          ...rendererOpts,
          dataRenderers: { 'text/plain': dataRenderer },
        })
@ -487,19 +484,19 @@ describe('built renderer', () => {
        const data = 'allons-y!'
        const output = displayDataWith({ 'text/plain': [data] })
-        expect( renderer.renderDisplayData(output) ).toBe(mockLastResult(dataRenderer))
+        expect( renderer.DisplayData(output) ).toBe(mockLastResult(dataRenderer))
        expect( dataRenderer ).toBeCalledWith(data)
      })
    })
  })
-  describe('.renderError', () => {
+  describe('.Error', () => {
    const error = fixtures.Error
    const traceback = error.traceback.join('\n')
    it('returns pre.error.pyerr with inner $traceback converted using ansiCodesRenderer', () => {
-      expect( renderer.renderError(error) ).toHtmlEqual(
+      expect( renderer.Error(error) ).toHtmlEqual(
        <pre class="error pyerr">
          {{__html: mockLastResult(ansiCodesRenderer) }}
        </pre>
@ -509,12 +506,12 @@ describe('built renderer', () => {
  })
-  describe('.renderStream', () => {
+  describe('.Stream', () => {
    eachMultilineVariant(fixtures.Stream, 'text', (stream) => {
      const text = join(stream.text)
      it('returns pre.$name with inner $text converted using ansiCodesRenderer', () => {
-        expect( renderer.renderStream(stream) ).toHtmlEqual(
+        expect( renderer.Stream(stream) ).toHtmlEqual(
          <pre class={ stream.name }>
            {{__html: mockLastResult(ansiCodesRenderer) }}
          </pre>
--- a/packages/ipynb2html-core/test/tsconfig.json
+++ b/packages/ipynb2html-core/test/tsconfig.json
@ -1,9 +1,5 @@
 // This file is needed only for VSCode, see https://github.com/palmerhq/tsdx/issues/84.
 {
-  "extends": "../../../tsconfig.test.json",
+  "extends": "../tsconfig.json",
-  "compilerOptions": {
+  "include": ["."],
    "baseUrl": ".",
  },
  "references": [
    { "path": "../" },
  ],
 }
--- a/packages/ipynb2html-core/tsconfig.json
+++ b/packages/ipynb2html-core/tsconfig.json
@ -5,6 +5,11 @@
    "outDir": "./lib",
    "tsBuildInfoFile": "./.tsbuildinfo",
    "baseUrl": ".",
    "paths": {
      "*": ["../../types/*"],
      "@/*": ["./src/*"],
      "~/*": ["../../*"],
    },
  },
  "include": [
    "./src",
--- a/packages/ipynb2html/package.json
+++ b/packages/ipynb2html/package.json
@ -1,6 +1,6 @@
 {
  "name": "ipynb2html",
-  "version": "0.3.0",
+  "version": "0.1.0-beta.8",
  "description": "Convert Jupyter Notebook to static HTML",
  "author": "Jakub Jirutka <jakub@jirutka.cz>",
  "license": "MIT",
@ -23,18 +23,15 @@
  "files": [
    "dist/ipynb2html.min.js*",
    "dist/ipynb2html-full.min.js*",
    "dist/notebook.min.css*",
    "lib",
-    "src",
+    "src"
    "styles"
  ],
  "scripts": {
    "build": "ttsc --build",
    "bundle": "rollup -c",
-    "clean": "rimraf coverage/ dist/ lib/ .eslintcache .tsbuildinfo",
+    "clean": "rimraf coverage/ dist/ lib/ .tsbuildinfo",
-    "lint": "PKGDIR=$PWD; cd ../../ && eslint --cache --ext .ts,.tsx,.js $PKGDIR",
+    "lint": "eslint --ext .ts,.tsx,.js .",
-    "minify-css": "csso styles/notebook.css -o dist/notebook.min.css -s dist/notebook.min.css.map",
+    "prepublishOnly": "run-p bundle readme2md",
    "prepublishOnly": "run-p bundle minify-css readme2md",
    "test": "jest --detectOpenHandles --coverage --verbose",
    "readme2md": "../../scripts/adoc2md -a npm-readme ../../README.adoc > README.md",
    "watch-ts": "ttsc --build --watch"
@ -44,15 +41,10 @@
  },
  "dependencies": {
    "anser": "^1.4.9",
-    "highlight.js": "^10.7.3",
+    "highlightjs": "^9.12.0",
-    "ipynb2html-core": "0.3.0",
+    "ipynb2html-core": "0.1.0-beta.8",
-    "katex": "^0.13.11",
+    "katex": "^0.11.0",
-    "marked": "^2.0.7"
+    "marked": "^0.7.0"
  },
  "devDependencies": {
    "@types/katex": "^0.11.0",
    "@types/marked": "^2.0.3",
    "ansi_up": "^5.0.1"
  },
  "peerDependencies": {
    "nodom": "^2.3.0"
--- a/packages/ipynb2html/rollup.config.js
+++ b/packages/ipynb2html/rollup.config.js
@ -1,8 +1,8 @@
 import addGitMsg from 'rollup-plugin-add-git-msg'
-import babel from '@rollup/plugin-babel'
+import babel from 'rollup-plugin-babel'
-import commonjs from '@rollup/plugin-commonjs'
+import commonjs from 'rollup-plugin-commonjs'
 import license from 'rollup-plugin-node-license'
-import resolve from '@rollup/plugin-node-resolve'
+import resolve from 'rollup-plugin-node-resolve'
 import { terser } from 'rollup-plugin-terser'
 import ttypescript from 'ttypescript'
 import typescript from 'rollup-plugin-typescript2'
@ -13,10 +13,10 @@ import pkg from './package.json'
 const extensions = ['.mjs', '.js', '.ts']
 const globals = {
-  'anser': 'anser',
+  anser: 'anser',
-  'highlight.js': 'hljs',
+  highlightjs: 'hljs',
-  'katex': 'katex',
+  katex: 'katex',
-  'marked': 'marked',
+  marked: 'marked',
 }
 const plugins = [
@ -33,6 +33,9 @@ const plugins = [
        incremental: true,
      },
    },
    // This is needed for node-license plugin. :(
    // https://github.com/ezolenko/rollup-plugin-typescript2#plugins-using-asyncawait
    objectHashIgnoreUnknownHack: true,
    clean: true,
  }),
  // Resolve node modules.
@ -45,7 +48,6 @@ const plugins = [
  // Transpile all sources for older browsers and inject needed polyfills.
  babel({
    babelrc: false,
    babelHelpers: 'bundled',
    // To avoid Babel injecting core-js polyfills into core-js.
    exclude: [/node_modules\/core-js\//],
    extensions,
@ -70,23 +72,22 @@ const plugins = [
  }),
  // Generate table of the bundled packages at top of the file.
  license({ format: 'table' }),
-]
+  // Minify JS.
-
+  terser({
 const output = (filename, extra = {}) => [false, true].map(minify => ({
  name: pkg.name,
  file: `${filename}${minify ? '.min.js' : '.js'}`,
  format: 'umd',
  sourcemap: true,
  plugins: [
    // Minify JS when building .min.js file.
    minify && terser({
    ecma: 5,
    include: [/^.+\.min\.js$/],
    output: {
      // Preserve comment injected by addGitMsg and license.
      comments: RegExp(`(?:\\$\\{${pkg.name}\\}|Bundled npm packages)`),
    },
  }),
-  ].filter(Boolean),
+]
 const output = (filename, extra = {}) => ['.js', '.min.js'].map(ext => ({
  name: pkg.name,
  file: `${filename}${ext}`,
  format: 'umd',
  sourcemap: true,
  ...extra,
 }))
--- a/packages/ipynb2html/src/browser.ts
+++ b/packages/ipynb2html/src/browser.ts
@ -7,7 +7,7 @@ function unescapeHTML (input: string): string {
  return new DOMParser()
    .parseFromString(input, 'text/html')
    .documentElement
-    .textContent ?? ''
+    .textContent || ''
 }
 /**
@ -39,7 +39,6 @@ export function autoRender (opts: NbRendererOpts = {}): void {
  document.querySelectorAll(selector).forEach(script => {
    if (script.textContent && script.parentElement) {
      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
      const notebook = JSON.parse(unescapeHTML(script.textContent))
      const nbElement = render(notebook)
      script.parentElement.replaceChild(nbElement, script)
--- a/packages/ipynb2html/src/global.d.ts
+++ b/packages/ipynb2html/src/global.d.ts
@ -2,5 +2,6 @@
 // via global variable. It's an alternative to Anser that doesn't provide
 // bundle for browsers.
 declare class AnsiUp {
  // eslint-disable-next-line @typescript-eslint/camelcase
  ansi_to_html (input: string): string
 }
--- a/packages/ipynb2html/src/index.ts
+++ b/packages/ipynb2html/src/index.ts
@ -1,18 +1,19 @@
 import anser from 'anser'
-import hljs from 'highlight.js'
+import hljs from 'highlightjs'
 import katex, { KatexOptions } from 'katex'
-import marked from 'marked'
+import marked, { MarkedOptions } from 'marked'
 import {
  createElementCreator,
  createHtmlRenderer,
  createNbRenderer,
  MinimalElement,
  NbRenderer,
  NbRendererOpts as BaseOptions,
  Notebook,
 } from 'ipynb2html-core'
-import buildMarkdownRenderer, { MarkedOptions } from './markdownRenderer'
+import buildMarkdownRenderer from './markdownRenderer'
 export { default as version } from './version'
@ -42,7 +43,7 @@ export type NbRendererOpts<TElement = HTMLElement> = BaseOptions<TElement> & {
 * for this module's function.
 */
 type MinimalDocument<TElement extends MinimalElement> = {
-  createElement: (tag: string) => TElement,
+  createElement (tag: string): TElement,
 }
 const defaultKatexOpts: KatexOptions = {
@ -50,14 +51,9 @@ const defaultKatexOpts: KatexOptions = {
  throwOnError: false,
 }
 const defaultMarkedOpts: MarkedOptions = {
  headerAnchors: true,
  headerIdsStripAccents: true,
 }
 function hljsCodeHighlighter (code: string, lang: string): string {
  return hljs.getLanguage(lang)
-    ? hljs.highlight(code, { language: lang }).value
+    ? hljs.highlight(lang, code).value
    : code
 }
@ -120,15 +116,18 @@ export function createRenderer <TElement extends MinimalElement> (
    codeHighlighter = hljsCodeHighlighter
  }
  if (!markdownRenderer && marked) {
-    const markedOpts = { ...defaultMarkedOpts, ...opts.markedOpts }
+    if (katex) {
-    markdownRenderer = buildMarkdownRenderer(markedOpts, katexOpts)
+      markdownRenderer = buildMarkdownRenderer(opts.markedOpts, katexOpts)
    } else {
      markdownRenderer = (text) => marked.parse(text, opts.markedOpts)
    }
  }
  if (!dataRenderers['text/html'] && katex) {
    const mathRenderer = (tex: string) => katex.renderToString(tex, katexOpts)
    dataRenderers['text/html'] = createHtmlRenderer({ elementCreator, mathRenderer })
  }
-  return new NbRenderer(elementCreator, {
+  return createNbRenderer(elementCreator, {
    ansiCodesRenderer,
    codeHighlighter,
    dataRenderers,
--- a/packages/ipynb2html/src/markdownRenderer.ts
+++ b/packages/ipynb2html/src/markdownRenderer.ts
@ -1,62 +1,32 @@
-import hljs from 'highlight.js'
+import hljs from 'highlightjs'
 import katex, { KatexOptions } from 'katex'
-import marked, { Slugger } from 'marked'
+import marked, { MarkedOptions } from 'marked'
 import { mathExtractor } from 'ipynb2html-core'
 export type MarkdownRenderer = (markdown: string) => string
 export interface MarkedOptions extends marked.MarkedOptions {
  /** Generate heading anchors (this implies headingIds). */
  headerAnchors?: boolean
  headerIdsStripAccents?: boolean
 }
 // Removes accents from the given string.
 const stripAccents = (text: string) => text.normalize('NFD').replace(/[\u0300-\u036f]/g, '')
 // Removes math markers from the given string.
 const stripMath = (text: string) => mathExtractor.restoreMath(text, []).trim()
 class Renderer extends marked.Renderer {
  heading (text: string, level: 1 | 2 | 3 | 4 | 5 | 6, raw: string, slugger: Slugger): string {
    const opts = this.options as MarkedOptions
    if (!opts.headerIds && !opts.headerAnchors) {
      return super.heading(text, level, raw, slugger)
    }
    let id = (opts.headerPrefix ?? '') + slugger.slug(stripMath(raw))
    if (opts.headerIdsStripAccents) {
      id = stripAccents(id)
    }
    if (opts.headerAnchors) {
      text = `<a class="anchor" href="#${id}" aria-hidden="true"></a>${text}`
    }
    return `<h${level} id="${id}">${text}</h${level}>`
  }
  link (href: string | null, title: string | null, text: string): string {
    return super.link(href && stripMath(href), title && stripMath(title), text)
  }
  image (href: string | null, title: string | null, text: string): string {
    return super.image(href && stripMath(href), title && stripMath(title), stripMath(text))
  }
 }
 function highlight (code: string, lang: string): string {
  return hljs.getLanguage(lang)
-    ? hljs.highlight(code, { language: lang, ignoreIllegals: true }).value
+    ? hljs.highlight(lang, code, true).value
    : code
 }
-const renderer = (markedOpts: MarkedOptions) => (markdown: string) => marked.parse(markdown, markedOpts)
+/**
 * Returns a pre-configured marked parser with math support (using KaTeX)
 * and code highlighter (highlight.js).
 *
 * @param {MarkedOptions} markedOpts Options for the marked Markdown renderer.
 * @param {KatexOptions} katexOpts Options for the KaTeX math renderer.
 */
 export default (markedOpts: MarkedOptions = {}, katexOpts: KatexOptions = {}) => {
  if (hljs) {  // highlightjs may be an optional dependency (in browser bundle)
    markedOpts = { highlight, ...markedOpts }
  }
-const rendererWithMath = (markedOpts: MarkedOptions, katexOpts: KatexOptions) => (markdown: string) => {
+  /**
   * Converts the given *markdown* into HTML.
   */
  return (markdown: string): string => {
    const [text, math] = mathExtractor.extractMath(markdown)
    const html = marked.parse(text, markedOpts)
@ -65,22 +35,4 @@ const rendererWithMath = (markedOpts: MarkedOptions, katexOpts: KatexOptions) =>
    })
    return mathExtractor.restoreMath(html, mathHtml)
  }
 /**
 * Returns a pre-configured marked parser with (optional) math support (using
 * KaTeX) and code highlighter (highlight.js).
 *
 * @param {MarkedOptions} markedOpts Options for the marked Markdown renderer.
 * @param {KatexOptions} katexOpts Options for the KaTeX math renderer.
 */
 export default (markedOpts: MarkedOptions = {}, katexOpts: KatexOptions = {}): MarkdownRenderer => {
  markedOpts = { renderer: new Renderer(markedOpts), ...markedOpts }
  if (hljs) {  // highlight.js may be an optional dependency (in browser bundle)
    markedOpts = { highlight, ...markedOpts }
  }
  return katex  // katex may be an optional dependency (in browser bundle)
    ? rendererWithMath(markedOpts, katexOpts)
    : renderer(markedOpts)
 }
--- a/packages/ipynb2html/src/readNotebookTitle.ts
+++ b/packages/ipynb2html/src/readNotebookTitle.ts
@ -3,18 +3,18 @@ import marked from 'marked'
 import { Notebook } from 'ipynb2html-core'
-class EmptyRenderer extends marked.Renderer {}
+class EmptyRenderer extends marked.Renderer {
-// Override all the EmptyRenderer's methods inherited from marked.Renderer to
+  constructor (options?: marked.MarkedOptions) {
-// always return an empty string.
+    super(options)
-/* eslint-disable @typescript-eslint/no-unsafe-member-access */
+
-const RendererProto = marked.Renderer.prototype
+    for (const prop in this) {
-for (const prop of Object.getOwnPropertyNames(RendererProto)) {
+      if (this[prop] instanceof Function) {
-  if (prop !== 'constructor' && typeof (RendererProto as any)[prop] === 'function') {
+        (this as any)[prop] = () => ''
-    (EmptyRenderer.prototype as any)[prop] = () => ''
+      }
    }
  }
 }
 /* eslint-enable @typescript-eslint/no-unsafe-member-access */
 class MainTitleRenderer extends EmptyRenderer {
  _titleFound = false
--- a/packages/ipynb2html/src/version.ts
+++ b/packages/ipynb2html/src/version.ts
@ -1,6 +1,5 @@
 import { $INLINE_JSON } from 'ts-transformer-inline-file'
 // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
 const { version } = $INLINE_JSON('../package.json')
 export default version as string
--- a/packages/ipynb2html/styles/notebook.css
+++ b/packages/ipynb2html/styles/notebook.css
@ -1,86 +0,0 @@
 /* Reference styles for ipynb2html */
 .nb-notebook {
  line-height: 1.5;
 }
 .nb-cell + .nb-cell {
  margin-top: 1.4rem;
 }
 .nb-raw-cell {
  font-family: monospace;
  white-space: pre-wrap;
 }
 .nb-code-cell {
  position: relative;
 }
 .nb-source::before,
 .nb-output::before {
  position: absolute;
  font-family: monospace;
  color: #999;
  left: -7.5em;
  width: 7em;
  text-align: right;
 }
 .nb-source::before {
  content: "In [" attr(data-execution-count) "]:";
 }
 .nb-output::before {
  content: "Out[" attr(data-execution-count) "]:";
 }
 .nb-source + .nb-output,
 .nb-output + .nb-output {
  margin-top: 1.4rem;
 }
 .nb-source > pre {
  background-color: #f7f7f7;
  border: 1px solid #cfcfcf;
  border-radius: 2px;
  padding: 0.5em;
  margin: 0;
  overflow-x: auto;
 }
 .nb-output {
  min-height: 1em;
  width: 100%;
 }
 .nb-output > pre {
  padding: 0.5em;
  margin: 0;
  overflow-x: auto;
 }
 .nb-output > img {
  max-width: 100%;
 }
 .nb-stdout,
 .nb-stderr {
  white-space: pre-wrap;
 }
 .nb-error,
 .nb-stderr {
  background-color: #fdd;
  border-radius: 2px;
 }
@media (max-width: 768px) {
  .nb-source::before,
  .nb-output::before {
    display: block;
    position: relative;
    left: 0;
    padding-bottom: 0.5em;
    text-align: left;
  }
 }
--- a/packages/ipynb2html/test/global.d.ts
+++ b/packages/ipynb2html/test/global.d.ts
@ -1 +0,0 @@
 ../src/global.d.ts
--- a/packages/ipynb2html/test/markdownRenderer.test.tsx
+++ b/packages/ipynb2html/test/markdownRenderer.test.tsx
@ -1,152 +0,0 @@
 import { KatexOptions } from 'katex'
 import parseHtml from 'node-html-parser'
 import markdownRenderer, { MarkedOptions } from '@/markdownRenderer'
 import '~/test/setup'  // setupFilesAfterEnv doesn't work here
 import { Anything } from '~/test/support/matchers/toMatchElement'
 let katexOpts: KatexOptions
 let markedOpts: MarkedOptions
 beforeEach(() => {
  katexOpts = {
    displayMode: true,
    throwOnError: false,
  }
  markedOpts = {}
 })
 describe('headings', () => {
  it('renders h tag without anchor', () => {
    expect( render('## Some Title') ).toHtmlEqual(
      <h2 id="some-title">Some Title</h2>
    )
  })
  it('renders math in text, but strips it in id', () => {
    expect( render('## Integers $\\mathbb{Z}$') ).toMatchElement(
      <h2 id="integers">
        Integers <span class="katex"><Anything /></span>
      </h2>
    )
  })
  describe('when headerAnchors is true', () => {
    beforeEach(() => {
      markedOpts = { headerAnchors: true }
    })
    it('renders h tag with anchor', () => {
      expect( render('## Some Title') ).toHtmlEqual(
        <h2 id="some-title">
          <a class="anchor" href="#some-title" aria-hidden="true"></a>Some Title
        </h2>
      )
    })
    it('renders math in text, but strips it in href and id', () => {
      expect( render('## Integers $\\mathbb{Z}$') ).toMatchElement(
        <h2 id="integers">
          <a class="anchor" href="#integers" aria-hidden="true"></a>
          Integers <span class="katex"><Anything /></span>
        </h2>
      )
    })
  })
  describe('when headerIds is false', () => {
    beforeEach(() => {
      markedOpts = { headerIds: false }
    })
    it('renders h tag without id and anchor', () => {
      expect( render('## Some Title') ).toHtmlEqual(
        <h2>Some Title</h2>
      )
    })
  })
  describe('when headerIdsStripAccents is true', () => {
    beforeEach(() => {
      markedOpts = { headerIdsStripAccents: true }
    })
    it('strips accents in generated id', () => {
      expect( render('## Příliš žluťoučký kůň') ).toHtmlEqual(
        <h2 id="prilis-zlutoucky-kun">
          Příliš žluťoučký kůň
        </h2>
      )
    })
  })
 })
 describe('link', () => {
  it('strips math in title', () => {
    expect( render('[link](https://example.org "This is $\\TeX$!")') ).toHtmlEqual(
      <p><a href="https://example.org" title="This is !">link</a></p>
    )
  })
  it('strips math in href', () => {
    expect( render('[link](https://example.org/$\\TeX$)') ).toHtmlEqual(
      <p><a href="https://example.org/">link</a></p>
    )
  })
  it('renders math in text', () => {
    expect( render('[This is $\\TeX$!](https://example.org/)') ).toMatchElement(
      <p><a href="https://example.org/">This is <span class="katex"><Anything /></span>!</a></p>
    )
  })
 })
 describe('image', () => {
  it('strips math in title', () => {
    expect( render('![x](https://example.org/img.png "This is $\\TeX$!")') ).toHtmlEqual(
      <p><img src="https://example.org/img.png" alt="x" title="This is !" /></p>
    )
  })
  it('strips math in href', () => {
    expect( render('![image](https://example.org/$\\TeX$.png)') ).toHtmlEqual(
      <p><img src="https://example.org/.png" alt="image" /></p>
    )
  })
  it('strips math in alt text', () => {
    expect( render('![This is $\\TeX$!](https://example.org/img.png)') ).toHtmlEqual(
      <p><img src="https://example.org/img.png" alt="This is !" /></p>
    )
  })
 })
 describe('code', () => {
  it('highlights fenced code block', () => {
    // Note: We use `backticks` in this example to avoid problem that JSX
    // implicitly decodes HTML entities, but node-html-parser does not.
    expect( render('```js\nconsole.log(`Hello, world!`)\n```') ).toHtmlEqual(
      <pre>
        <code class="language-js">
          <span class="hljs-built_in">console</span>.log(<span class="hljs-string">`Hello, world!`</span>)
        </code>
      </pre>
    )
  })
 })
 function render (text: string) {
  const html = markdownRenderer(markedOpts, katexOpts)(text).replace(/\n/, '')
  return parseHtml(html, { pre: true }).childNodes[0]
 }
--- a/packages/ipynb2html/test/readNotebookTitle.test.ts
+++ b/packages/ipynb2html/test/readNotebookTitle.test.ts
@ -1,7 +1,7 @@
 import { Notebook, CellType, MarkdownCell } from 'ipynb2html-core'
 import readNotebookTitle from '@/readNotebookTitle'
 import { Notebook, CellType, MarkdownCell } from 'ipynb2html-core'
 const markdownCell = (source: string | string[]): MarkdownCell => ({
  cell_type: CellType.Markdown,
--- a/packages/ipynb2html/test/tsconfig.json
+++ b/packages/ipynb2html/test/tsconfig.json
@ -1,9 +1,5 @@
 // This file is needed only for VSCode, see https://github.com/palmerhq/tsdx/issues/84.
 {
-  "extends": "../../../tsconfig.test.json",
+  "extends": "../tsconfig.json",
-  "compilerOptions": {
+  "include": ["."],
    "baseUrl": ".",
  },
  "references": [
    { "path": "../" },
  ],
 }
--- a/packages/ipynb2html/tsconfig.json
+++ b/packages/ipynb2html/tsconfig.json
@ -5,6 +5,11 @@
    "outDir": "./lib",
    "tsBuildInfoFile": "./.tsbuildinfo",
    "baseUrl": ".",
    "paths": {
      "*": ["../../types/*"],
      "@/*": ["./src/*"],
      "~/*": ["../../*"],
    },
  },
  "include": [
    "./src",
--- a/patches/rollup-plugin-add-git-msg+1.0.3.patch
+++ b/patches/rollup-plugin-add-git-msg+1.0.3.patch
@ -0,0 +1,30 @@
 TODO: Remove after https://github.com/oplinjie/rollup-plugin-add-git-msg/pull/1 is merged.
 diff --git a/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.es.js b/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.es.js
 index 184a00e..fb3fde4 100644
 --- a/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.es.js
 +++ b/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.es.js
@@ -73,7 +73,8 @@ Banner.prototype.getHeaderArray = function getHeaderArray (opt) {
   if (opt.showTag) {
     var tag = runGitCommand(TAG_COMMAND);
     if (tag) {
 -      gitMsg = gitMsg.concat(("v" + tag + " - "));
 +      var prefix = tag.indexOf("v") === 0 ? "" : "v"
 +      gitMsg = gitMsg.concat((prefix + tag + " - "));
     }
   }
 diff --git a/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.js b/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.js
 index 7d16072..f288638 100644
 --- a/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.js
 +++ b/node_modules/rollup-plugin-add-git-msg/dist/rollup-plugin-add-git-msg.js
@@ -77,7 +77,8 @@ Banner.prototype.getHeaderArray = function getHeaderArray (opt) {
   if (opt.showTag) {
     var tag = runGitCommand(TAG_COMMAND);
     if (tag) {
 -      gitMsg = gitMsg.concat(("v" + tag + " - "));
 +      var prefix = tag.indexOf("v") === 0 ? "" : "v"
 +      gitMsg = gitMsg.concat((prefix + tag + " - "));
     }
   }
--- a/patches/yarn-version-bump+0.0.3.patch
+++ b/patches/yarn-version-bump+0.0.3.patch
@ -1,15 +0,0 @@
 TODO: Remove after https://github.com/chrisdarroch/yarn-bump/pull/1 is merged and released.
 diff --git a/node_modules/yarn-version-bump/src/workspace.js b/node_modules/yarn-version-bump/src/workspace.js
 index 28b1dd1..0cf2ecb 100644
 --- a/node_modules/yarn-version-bump/src/workspace.js
 +++ b/node_modules/yarn-version-bump/src/workspace.js
@@ -9,7 +9,7 @@ class Workspace {
     get workspaceSnapshot() {
         return runCommand('yarn',
 -            ['workspaces', 'info', '--silent'],
 +            ['--silent', 'workspaces', 'info'],
             { cwd: this.root }
         )
         .then(data => JSON.parse(data))
--- a/scripts/adoc2md
+++ b/scripts/adoc2md
@ -1,4 +1,4 @@
 #!/bin/sh -e
 ( set -o pipefail 2>/dev/null ) && set -o pipefail
-asciidoctor -o - -b docbook "$@" | pandoc -f docbook -t markdown_github --base-header-level 2 -o -
+asciidoctor -o - -b docbook "$@" | pandoc -f docbook -t markdown_github -o -
--- a/test/support/helpers.ts
+++ b/test/support/helpers.ts
@ -1,5 +1,5 @@
-type Callable = (...args: any[]) => unknown
+type Callable = (...args: any[]) => any
 export type Mock<F extends Callable> = jest.Mock<ReturnType<F>, Parameters<F>>
@ -13,9 +13,9 @@ export function asMock <F extends Callable> (fn: F): Mock<F> {
 export function mockResults <F extends Callable> (fn: F): Array<ReturnType<F>> {
  return asMock(fn).mock.results
    .filter(x => x.type === 'return')
-    .map(x => x.value as ReturnType<F>)
+    .map(x => x.value)
 }
-export function mockLastResult <F extends Callable> (fn: F): ReturnType<F> | undefined {
+export function mockLastResult <F extends Callable> (fn: F): ReturnType<F> {
-  return mockResults(fn).pop()
+  return mockResults(fn).pop() as ReturnType<F>
 }
--- a/test/support/jsx.ts
+++ b/test/support/jsx.ts
@ -60,8 +60,7 @@ export function createElement (
    } else if (child instanceof NNode) {
      el.appendChild(child)
    } else if (typeof child === 'object' && '__html' in child) {
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+      el.innerHTML = child.__html
      el.innerHTML = child.__html as string
    } else {
      el.appendChild(document.createTextNode(String(child)))
    }
@ -69,7 +68,6 @@ export function createElement (
  return el
 }
 // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
 (global as any).JSX = {
  createElement,
 }
--- a/test/support/matchers/toHtmlEqual.ts
+++ b/test/support/matchers/toHtmlEqual.ts
@ -6,8 +6,8 @@ type MatcherResult = jest.CustomMatcherResult
 declare global {
  // eslint-disable-next-line @typescript-eslint/no-namespace
  namespace jest {
-    interface Matchers<R, T> {
+    interface Matchers<R> {
-      toHtmlEqual: (expected: HTMLElement | string | Array<HTMLElement | string>) => R
+      toHtmlEqual (expected: HTMLElement | string | Array<HTMLElement | string>): R,
    }
  }
 }
--- a/test/support/matchers/toMatchElement.ts
+++ b/test/support/matchers/toMatchElement.ts
@ -10,41 +10,33 @@ type Options = {
 declare global {
  // eslint-disable-next-line @typescript-eslint/no-namespace
  namespace jest {
-    interface Matchers<R, T> {
+    interface Matchers<R> {
-      toMatchElement: (expected: HTMLElement, opts?: Options) => R
+      toMatchElement (expected: HTMLElement, opts?: Options): R,
    }
  }
 }
 export const AnythingNode = new class extends Node {
  render () { return '<!--Anything-->' }
  toString () { return this.render() }
 }()
-export const Anything = (): Node => AnythingNode
+export const Anything = () => AnythingNode
 function isWritable (obj: any, prop: string): boolean {
  const desc = Object.getOwnPropertyDescriptor(obj, prop)
  // eslint-disable-next-line @typescript-eslint/unbound-method
  return !!desc?.writable || !!desc?.set
 }
 function filterWildcardChildren (rec: Node, exp: Node): void {
  if (exp.firstChild === AnythingNode
-      && exp.childNodes.length === 1
+      && exp.children.length === 1
-      && (rec as HTMLElement).innerHTML
+      && rec instanceof HTMLElement
      && rec.innerHTML
  ) {
-    if (isWritable(rec, 'innerHTML')) {
+    rec.innerHTML = ''
-      (rec as HTMLElement).innerHTML = ''
+    rec.children.splice(0, rec.children.length, AnythingNode)
    }
    rec.childNodes.splice(0, rec.childNodes.length, AnythingNode)
    return
  }
-  for (let i = 0; i < exp.childNodes.length && i < rec.childNodes.length; i++) {
+  for (let i = 0; i < exp.children.length && i < rec.children.length; i++) {
-    if (exp.childNodes[i] === AnythingNode) {
+    if (exp.children[i] === AnythingNode) {
-      rec.childNodes[i] = AnythingNode
+      rec.children[i] = AnythingNode
    } else {
-      filterWildcardChildren(rec.childNodes[i], exp.childNodes[i])
+      filterWildcardChildren(exp.children[i], rec.children[i])
    }
  }
 }
@ -54,15 +46,13 @@ function clearAttributes (node: Node): void {
    node.attributes = {}
    node.className = ''
  }
-  node.childNodes.forEach(clearAttributes)
+  node.children.forEach(clearAttributes)
 }
 export function toMatchElement (received: HTMLElement, expected: HTMLElement, opts?: Options): MatcherResult {
  if (received.cloneNode) {
  received = received.cloneNode(true) as HTMLElement
  }
-  if (opts?.ignoreAttrs) {
+  if (opts && opts.ignoreAttrs) {
    clearAttributes(received)
  }
  filterWildcardChildren(received, expected)
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@ -1,6 +0,0 @@
 {
  "extends": "../tsconfig.test.json",
  "compilerOptions": {
    "baseUrl": ".",
  },
 }
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@ -42,9 +42,7 @@
    /* Module Resolution Options */
    "moduleResolution": "node",               /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
-    "paths": {                                /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
      "*": ["../../types/*"],                 /* This path is relative from baseUrl which is defined in tsconfig.json that includes this file inside each project. */
    },
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    "typeRoots": [                            /* List of folders to include type definitions from. */
      "./types",
--- a/tsconfig.test.json
+++ b/tsconfig.test.json
@ -1,16 +0,0 @@
 {
  "extends": "./tsconfig.base.json",
  "compilerOptions": {
    "declaration": false,
    "declarationMap": false,
    "sourceMap": false,
    "composite": false,
    "noEmit": true,
    "paths": {
      // These paths are relative from baseUrl which is defined in
      // tsconfig.json that includes this file inside each project.
      "@/*": ["../src/*"],
      "~/*": ["../../../*"],
    },
  },
 }
--- a/yarn.lock
+++ b/yarn.lock
		`@ -1,3 +0,0 @@`
			`# These are supported funding model platforms`

			`github: jirutka`
		`@ -1,2 +0,0 @@`
			`#!/usr/bin/env node`
			`require('../lib/index').default(process.argv.slice(2))`