quick-js-datepatch/src/console.rs
2023-02-05 18:22:56 +01:00

138 lines
4 KiB
Rust

//! Javascript console integration.
//! See the [ConsoleBackend] trait for more info.
use super::JsValue;
/// Log level of a log message sent via the console.
/// These levels represent the different functions defined in the spec:
/// <https://s3.amazonaws.com/temp.michaelfbryan.com/callbacks/index.html>
#[allow(missing_docs)]
#[derive(PartialEq, Eq, Clone, Copy, Debug)]
pub enum Level {
Trace,
Debug,
Log,
Info,
Warn,
Error,
}
impl std::fmt::Display for Level {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
use Level::*;
let v = match self {
Trace => "trace",
Debug => "debug",
Log => "log",
Info => "info",
Warn => "warn",
Error => "error",
};
write!(f, "{v}")
}
}
/// A console backend that handles console messages sent from JS via
/// console.{log,debug,trace,...} functions.
///
/// A backend has to be registered via the `ContextBuilder::console` method.
///
/// A backend that forwads to the `log` crate is available with the `log` feature.
///
/// Note that any closure of type `Fn(Level, Vec<JsValue>)` implements this trait.
///
/// A very simple logger that just prints to stderr could look like this:
///
/// ```rust
/// use quick_js::{Context, JsValue, console::Level};
///
/// Context::builder()
/// .console(|level: Level, args: Vec<JsValue>| {
/// eprintln!("{}: {:?}", level, args);
/// })
/// .build()
/// # .unwrap();
/// ```
///
pub trait ConsoleBackend: std::panic::RefUnwindSafe + 'static {
/// Handle a log message.
fn log(&self, level: Level, values: Vec<JsValue>);
}
impl<F> ConsoleBackend for F
where
F: Fn(Level, Vec<JsValue>) + std::panic::RefUnwindSafe + 'static,
{
fn log(&self, level: Level, values: Vec<JsValue>) {
(self)(level, values);
}
}
#[cfg(feature = "log")]
mod log {
use super::{JsValue, Level};
/// A console implementation that logs messages via the `log` crate.
///
/// Only available with the `log` feature.
pub struct LogConsole;
fn print_value(value: JsValue) -> String {
match value {
JsValue::Undefined => "undefined".to_string(),
JsValue::Null => "null".to_string(),
JsValue::Bool(v) => v.to_string(),
JsValue::Int(v) => v.to_string(),
JsValue::Float(v) => v.to_string(),
JsValue::String(v) => v,
JsValue::Array(values) => {
let parts = values
.into_iter()
.map(print_value)
.collect::<Vec<_>>()
.join(", ");
format!("[{parts}]")
}
JsValue::Object(map) => {
let parts = map
.into_iter()
.map(|(key, value)| format!("{}: {}", key, print_value(value)))
.collect::<Vec<_>>()
.join(", ");
format!("{{{parts}}}")
}
#[cfg(feature = "chrono")]
JsValue::Date(v) => v.to_string(),
#[cfg(feature = "bigint")]
JsValue::BigInt(v) => v.to_string(),
JsValue::__NonExhaustive => unreachable!(),
}
}
impl super::ConsoleBackend for LogConsole {
fn log(&self, level: Level, values: Vec<JsValue>) {
if values.is_empty() {
return;
}
let log_level = match level {
Level::Trace => log::Level::Trace,
Level::Debug => log::Level::Debug,
Level::Log => log::Level::Info,
Level::Info => log::Level::Info,
Level::Warn => log::Level::Warn,
Level::Error => log::Level::Error,
};
let msg = values
.into_iter()
.map(print_value)
.collect::<Vec<_>>()
.join(" ");
log::log!(log_level, "{}", msg);
}
}
}
#[cfg(feature = "log")]
pub use self::log::LogConsole;