Initial commit

node_modules/execa/lib/transform/run-async.js

@@ -0,0 +1,60 @@
+import {callbackify} from 'node:util';
+
+// Applies a series of generator functions asynchronously
+export const pushChunks = callbackify(async (getChunks, state, getChunksArguments, transformStream) => {
+	state.currentIterable = getChunks(...getChunksArguments);
+
+	try {
+		for await (const chunk of state.currentIterable) {
+			transformStream.push(chunk);
+		}
+	} finally {
+		delete state.currentIterable;
+	}
+});
+
+// For each new chunk, apply each `transform()` method
+export const transformChunk = async function * (chunk, generators, index) {
+	if (index === generators.length) {
+		yield chunk;
+		return;
+	}
+
+	const {transform = identityGenerator} = generators[index];
+	for await (const transformedChunk of transform(chunk)) {
+		yield * transformChunk(transformedChunk, generators, index + 1);
+	}
+};
+
+// At the end, apply each `final()` method, followed by the `transform()` method of the next transforms
+export const finalChunks = async function * (generators) {
+	for (const [index, {final}] of Object.entries(generators)) {
+		yield * generatorFinalChunks(final, Number(index), generators);
+	}
+};
+
+const generatorFinalChunks = async function * (final, index, generators) {
+	if (final === undefined) {
+		return;
+	}
+
+	for await (const finalChunk of final()) {
+		yield * transformChunk(finalChunk, generators, index + 1);
+	}
+};
+
+// Cancel any ongoing async generator when the Transform is destroyed, e.g. when the subprocess errors
+export const destroyTransform = callbackify(async ({currentIterable}, error) => {
+	if (currentIterable !== undefined) {
+		await (error ? currentIterable.throw(error) : currentIterable.return());
+		return;
+	}
+
+	if (error) {
+		throw error;
+	}
+});
+
+const identityGenerator = function * (chunk) {
+	yield chunk;
+};