From cf0875fd1b6320329af9c04b389b5691009b8a02 Mon Sep 17 00:00:00 2001
From: ehmicky <ehmicky@gmail.com>
Date: Sun, 18 Aug 2024 15:40:40 +0100
Subject: [PATCH] Add `stdin`/`stdout`/`stderr` options

---
 index.js     | 19 +++++++++++++++++--
 test.js      | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 utilities.js |  4 ++++
 3 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 0e2215f..4e5ac85 100644
--- a/index.js
+++ b/index.js
@@ -8,7 +8,7 @@ export default function nanoSpawn(command, commandArguments = [], options = {})
 		? [commandArguments, options]
 		: [[], commandArguments];
 
-	const subprocess = spawn(command, commandArguments, options);
+	const subprocess = spawn(command, commandArguments, getOptions(options));
 
 	const promise = getResult(subprocess);
 
@@ -22,6 +22,17 @@ export default function nanoSpawn(command, commandArguments = [], options = {})
 	});
 }
 
+const getOptions = ({
+	stdio,
+	stdin,
+	stdout,
+	stderr,
+	...options
+}) => ({
+	...options,
+	stdio: stdio === undefined ? [stdin, stdout, stderr] : stdio,
+});
+
 const getResult = async subprocess => {
 	const result = {};
 	const onExit = waitForExit(subprocess);
@@ -55,6 +66,10 @@ const waitForExit = async subprocess => {
 };
 
 const bufferOutput = async (stream, result, streamName) => {
+	if (!stream) {
+		return;
+	}
+
 	stream.setEncoding('utf8');
 	result[streamName] = '';
 	stream.on('data', chunk => {
@@ -71,6 +86,6 @@ const getOutput = ({exitCode, signalCode}, {stdout, stderr}) => ({
 	stderr: stripNewline(stderr),
 });
 
-const stripNewline = input => input.at(-1) === '\n'
+const stripNewline = input => input?.at(-1) === '\n'
 	? input.slice(0, input.at(-2) === '\r' ? -2 : -1)
 	: input;
diff --git a/test.js b/test.js
index 79a26f8..2247e61 100644
--- a/test.js
+++ b/test.js
@@ -19,6 +19,39 @@ test('can pass options.argv0', async t => {
 	t.is(stdout, testString);
 });
 
+test('can pass options.stdin', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdin: 'ignore'});
+	t.is(promise.subprocess.stdin, null);
+	await promise;
+});
+
+test('can pass options.stdout', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdout: 'ignore'});
+	t.is(promise.subprocess.stdout, null);
+	await promise;
+});
+
+test('can pass options.stderr', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stderr: 'ignore'});
+	t.is(promise.subprocess.stderr, null);
+	await promise;
+});
+
+test('can pass options.stdio', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdio: ['ignore', 'pipe', 'pipe', 'pipe']});
+	t.is(promise.subprocess.stdin, null);
+	t.not(promise.subprocess.stdout, null);
+	t.not(promise.subprocess.stderr, null);
+	t.not(promise.subprocess.stdio[3], null);
+	await promise;
+});
+
+test('options.stdio has priority over options.stdout', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdio: ['pipe', 'pipe', 'pipe'], stdout: 'ignore'});
+	t.not(promise.subprocess.stdout, null);
+	await promise;
+});
+
 test('can pass options object without any arguments', async t => {
 	const {exitCode, signalName} = await nanoSpawn('node', {timeout: 1});
 	t.is(exitCode, undefined);
@@ -83,6 +116,12 @@ test('result.stderr strips Windows newline', async t => {
 	t.is(stderr, '.');
 });
 
+test('result.stdout is undefined if options.stdout "ignore"', async t => {
+	const {stdout, stderr} = await nanoSpawn('node', ['-e', 'console.log("."); console.error(".");'], {stdout: 'ignore'});
+	t.is(stdout, undefined);
+	t.is(stderr, '.');
+});
+
 const multibyteString = '.\u{1F984}.';
 const multibyteUint8Array = new TextEncoder().encode(multibyteString);
 const multibyteFirstHalf = multibyteUint8Array.slice(0, 3);
@@ -117,6 +156,17 @@ test('promise.stderr can be iterated', async t => {
 	t.is(stderr, 'a\nb');
 });
 
+test('promise.stdout has no iterations if options.stdout "ignore"', async t => {
+	const promise = nanoSpawn('node', ['-e', 'console.log("."); console.error(".");'], {stdout: 'ignore'});
+	const [stdoutLines, stderrLines] = await Promise.all([arrayFromAsync(promise.stdout), arrayFromAsync(promise.stderr)]);
+	t.deepEqual(stdoutLines, []);
+	t.deepEqual(stderrLines, ['.']);
+
+	const {stdout, stderr} = await promise;
+	t.is(stdout, undefined);
+	t.is(stderr, '.');
+});
+
 test('promise can be iterated with both stdout and stderr', async t => {
 	const promise = nanoSpawn('node', ['-e', 'console.log("a"); console.error("b"); console.log("c"); console.error("d");']);
 
diff --git a/utilities.js b/utilities.js
index e98e466..2bcc148 100644
--- a/utilities.js
+++ b/utilities.js
@@ -21,6 +21,10 @@ export async function * combineAsyncIterators(iterator1, iterator2) {
 }
 
 export async function * lineIterator(iterable) {
+	if (!iterable) {
+		return;
+	}
+
 	let buffer = '';
 	for await (const chunk of iterable) {
 		const lines = `${buffer}${chunk}`.split(/\r?\n/);