Add stdin/stdout/stderr options (#26)

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 = ({
+	stdin,
+	stdout,
+	stderr,
+	stdio = [stdin, stdout, stderr],
+	...options
+}) => ({
+	...options,
+	stdio,
+});
+
 const getResult = async subprocess => {
 	const result = {};
 	const onExit = waitForExit(subprocess);
@@ -57,6 +68,10 @@ const waitForExit = async subprocess => {
 };
 
 const bufferOutput = async (stream, result, streamName) => {
+	if (!stream) {
+		return;
+	}
+
 	stream.setEncoding('utf8');
 	result[streamName] = '';
 	stream.on('data', chunk => {
@@ -73,7 +88,7 @@ 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;
 

test.js

@@ -24,6 +24,54 @@ 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 array', 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('can pass options.stdio string', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdio: 'ignore'});
+	t.is(promise.subprocess.stdin, null);
+	t.is(promise.subprocess.stdout, null);
+	t.is(promise.subprocess.stderr, null);
+	t.is(promise.subprocess.stdio.length, 3);
+	await promise;
+});
+
+test('options.stdio array 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('options.stdio string has priority over options.stdout', async t => {
+	const promise = nanoSpawn('node', ['--version'], {stdio: '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 t.throwsAsync(nanoSpawn('node', {timeout: 1}));
 	t.is(exitCode, undefined);
@@ -109,6 +157,12 @@ 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);
@@ -143,6 +197,17 @@ 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");']);
 

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/);