/
fromStream.js
54 lines (44 loc) · 1.24 KB
/
fromStream.js
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const Rx = require('rxjs');
function afterSubscribe(fn) {
return source => new Rx.Observable(observer => {
const subscription = source.subscribe(observer);
try {
fn();
} catch (e) {
observer.error(e);
subscription.unsubscribe();
}
return subscription;
});
}
function fromStream(stream, finishEventName, dataEventName) {
stream.pause();
finishEventName || (finishEventName = 'end');
dataEventName || (dataEventName = 'data');
return Rx.Observable.merge(
Rx.Observable.fromEvent(stream, dataEventName),
Rx.Observable.fromEvent(stream, 'error', e => { throw e; })
)
.takeUntil(Rx.Observable.fromEvent(stream, finishEventName))
.let(afterSubscribe(() => stream.resume()))
.share();
}
function fromReadableStream(stream, dataEventName) {
return fromStream(stream, 'end', dataEventName);
}
function fromReadLineStream(stream) {
return fromStream(stream, 'close', 'line');
}
function fromWritableStream(stream) {
return fromStream(stream, 'finish');
}
function fromTransformStream(stream, dataEventName) {
return fromStream(stream, 'finish', dataEventName);
}
module.exports = {
fromStream,
fromReadableStream,
fromReadLineStream,
fromWritableStream,
fromTransformStream
};