add loadIncremental to js

automerge-js/src/index.ts

@@ -231,6 +231,20 @@ export function load<T>(data: Uint8Array, _opts?: ActorId | InitOptions<T>) : Do
   return doc
 }
 
+export function loadIncremental<T>(doc: Doc<T>, data: Uint8Array, opts?: ApplyOptions<T>) : Doc<T> {
+  if (!opts) { opts = {} }
+  const state = _state(doc)
+  if (state.heads) {
+    throw new RangeError("Attempting to change an out of date document - set at: " + _trace(doc));
+  }
+  if (_readonly(doc) === false) {
+    throw new RangeError("Calls to Automerge.change cannot be nested")
+  }
+  const heads = state.handle.getHeads()
+  state.handle.loadIncremental(data)
+  return progressDocument(doc, heads, opts.patchCallback || state.patchCallback)
+}
+
 export function save<T>(doc: Doc<T>) : Uint8Array  {
   return _state(doc).handle.save()
 }

automerge-js/test/extra_api_tests.ts

@@ -0,0 +1,20 @@
+
+import * as assert from 'assert'
+import * as Automerge from '../src'
+
+describe('Automerge', () => {
+    describe('basics', () => {
+        it('should allow you to load incrementally', () => {
+          let doc1 = Automerge.from({ foo: "bar" })
+          let doc2 = Automerge.init();
+          doc2 = Automerge.loadIncremental(doc2, Automerge.save(doc1))
+          doc1 = Automerge.change(doc1, (d) => d.foo2 = "bar2")
+          doc2 = Automerge.loadIncremental(doc2, Automerge.getBackend(doc1).saveIncremental() )
+          doc1 = Automerge.change(doc1, (d) => d.foo = "bar2")
+          doc2 = Automerge.loadIncremental(doc2, Automerge.getBackend(doc1).saveIncremental() )
+          doc1 = Automerge.change(doc1, (d) => d.x = "y")
+          doc2 = Automerge.loadIncremental(doc2, Automerge.getBackend(doc1).saveIncremental() )
+          assert.deepEqual(doc1,doc2)
+        })
+    })
+})