Initial commit

node_modules/execa/lib/io/output-async.js

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+import mergeStreams from '@sindresorhus/merge-streams';
+import {isStandardStream} from '../utils/standard-stream.js';
+import {incrementMaxListeners} from '../utils/max-listeners.js';
+import {TRANSFORM_TYPES} from '../stdio/type.js';
+import {pipeStreams} from './pipeline.js';
+
+// Handle `input`, `inputFile`, `stdin`, `stdout` and `stderr` options, after spawning, in async mode
+// When multiple input streams are used, we merge them to ensure the output stream ends only once each input stream has ended
+export const pipeOutputAsync = (subprocess, fileDescriptors, controller) => {
+	const pipeGroups = new Map();
+
+	for (const [fdNumber, {stdioItems, direction}] of Object.entries(fileDescriptors)) {
+		for (const {stream} of stdioItems.filter(({type}) => TRANSFORM_TYPES.has(type))) {
+			pipeTransform(subprocess, stream, direction, fdNumber);
+		}
+
+		for (const {stream} of stdioItems.filter(({type}) => !TRANSFORM_TYPES.has(type))) {
+			pipeStdioItem({
+				subprocess,
+				stream,
+				direction,
+				fdNumber,
+				pipeGroups,
+				controller,
+			});
+		}
+	}
+
+	for (const [outputStream, inputStreams] of pipeGroups.entries()) {
+		const inputStream = inputStreams.length === 1 ? inputStreams[0] : mergeStreams(inputStreams);
+		pipeStreams(inputStream, outputStream);
+	}
+};
+
+// When using transforms, `subprocess.stdin|stdout|stderr|stdio` is directly mutated
+const pipeTransform = (subprocess, stream, direction, fdNumber) => {
+	if (direction === 'output') {
+		pipeStreams(subprocess.stdio[fdNumber], stream);
+	} else {
+		pipeStreams(stream, subprocess.stdio[fdNumber]);
+	}
+
+	const streamProperty = SUBPROCESS_STREAM_PROPERTIES[fdNumber];
+	if (streamProperty !== undefined) {
+		subprocess[streamProperty] = stream;
+	}
+
+	subprocess.stdio[fdNumber] = stream;
+};
+
+const SUBPROCESS_STREAM_PROPERTIES = ['stdin', 'stdout', 'stderr'];
+
+// Most `std*` option values involve piping `subprocess.std*` to a stream.
+// The stream is either passed by the user or created internally.
+const pipeStdioItem = ({subprocess, stream, direction, fdNumber, pipeGroups, controller}) => {
+	if (stream === undefined) {
+		return;
+	}
+
+	setStandardStreamMaxListeners(stream, controller);
+
+	const [inputStream, outputStream] = direction === 'output'
+		? [stream, subprocess.stdio[fdNumber]]
+		: [subprocess.stdio[fdNumber], stream];
+	const outputStreams = pipeGroups.get(inputStream) ?? [];
+	pipeGroups.set(inputStream, [...outputStreams, outputStream]);
+};
+
+// Multiple subprocesses might be piping from/to `process.std*` at the same time.
+// This is not necessarily an error and should not print a `maxListeners` warning.
+const setStandardStreamMaxListeners = (stream, {signal}) => {
+	if (isStandardStream(stream)) {
+		incrementMaxListeners(stream, MAX_LISTENERS_INCREMENT, signal);
+	}
+};
+
+// `source.pipe(destination)` adds at most 1 listener for each event.
+// If `stdin` option is an array, the values might be combined with `merge-streams`.
+// That library also listens for `source` end, which adds 1 more listener.
+const MAX_LISTENERS_INCREMENT = 2;