Fix an uncaught error when a file target cannot be opened and the subprocess fails to spawn

Author: sindresorhus

lib/stdio/handle.js

@@ -241,12 +241,15 @@ const addStreamProperties = ({stdioItem, addProperties, direction, options, file
 // We need to create those streams before subprocess spawning, in case their creation fails, e.g. when passing an invalid generator as argument.
 // Like this, an exception would be thrown, which would prevent spawning a subprocess.
 export const cleanupCustomStreams = fileDescriptors => {
-	for (const {stdioItems} of fileDescriptors) {
-		for (const {stream} of stdioItems) {
-			if (stream !== undefined && !isStandardStream(stream)) {
-				stream.destroy();
-			}
+	for (const {stream} of fileDescriptors.flatMap(({stdioItems}) => stdioItems)) {
+		if (stream === undefined || isStandardStream(stream)) {
+			continue;
 		}
+
+		// The stream can still error after being destroyed, e.g. when its file cannot be opened.
+		// That error would be uncaught and crash the current process, although it is irrelevant since execa already fails with its own error.
+		stream.on('error', () => {});
+		stream.destroy();
 	}
 };
 

test/fixtures/early-error-file.js

@@ -0,0 +1,8 @@
+#!/usr/bin/env node
+import process from 'node:process';
+import {execa} from '../../index.js';
+import {earlyErrorOptions} from '../helpers/early-error.js';
+
+// The file cannot be opened, since its directory does not exist
+const {code} = await execa('empty.js', {...earlyErrorOptions, [process.argv[2]]: {file: '/nonexistent-directory-for-execa/file'}, reject: false});
+console.log(code);

test/fixtures/invalid-stdio-file.js

@@ -0,0 +1,10 @@
+#!/usr/bin/env node
+import {execa} from '../../index.js';
+
+// The file cannot be opened, since its directory does not exist.
+// Its stream is created before the next item is rejected, which throws before spawning.
+try {
+	execa('empty.js', {stdout: [{file: '/nonexistent-directory-for-execa/file'}, ['foo']]});
+} catch (error) {
+	console.log(error.message);
+}

test/return/early-error.js

@@ -98,6 +98,21 @@ test('child_process.spawn() early errors are propagated', async () => {
 	await assertRejects(getEarlyErrorSubprocess(), expectedEarlyError);
 });
 
+// File targets are opened before spawning, then closed since the subprocess did not spawn.
+// Failing to open them must not be an uncaught exception, which would crash the current process.
+const testEarlyErrorFile = async optionName => {
+	const {stdout} = await execa('early-error-file.js', [optionName]);
+	assert.equal(stdout, expectedEarlyError.code);
+};
+
+test('child_process.spawn() early errors do not crash if an output file cannot be opened', () => testEarlyErrorFile('stdout'));
+test('child_process.spawn() early errors do not crash if an input file cannot be opened', () => testEarlyErrorFile('stdin'));
+
+test('Invalid stdio options do not crash if an output file cannot be opened', async () => {
+	const {stdout} = await execa('invalid-stdio-file.js');
+	assert.equal(stdout, 'The `stdout` option cannot be an iterable.');
+});
+
 test('child_process.spawn() early errors are returned', async () => {
 	const {failed} = await getEarlyErrorSubprocess({reject: false});
 	assert.equal(failed, true);