Use spawn instead of execFile

fixtures/error-message.js

@@ -2,4 +2,4 @@
 'use strict';
 console.log('stdout');
 console.error('stderr');
-process.exit(1);
+process.exit(2);

index.js

@@ -1,10 +1,12 @@
 'use strict';
 var childProcess = require('child_process');
+var util = require('util');
 var crossSpawnAsync = require('cross-spawn-async');
 var stripEof = require('strip-eof');
 var objectAssign = require('object-assign');
 var npmRunPath = require('npm-run-path');
 var isStream = require('is-stream');
+var _getStream = require('get-stream');
 var pathKey = require('path-key')();
 var TEN_MEBIBYTE = 1024 * 1024 * 10;
 
@@ -61,7 +63,7 @@ function handleInput(spawned, opts) {
 }
 
 function handleOutput(opts, val) {
-	if (opts.stripEof) {
+	if (val && opts.stripEof) {
 		val = stripEof(val);
 	}
 
@@ -91,32 +93,83 @@ function handleShell(fn, cmd, opts) {
 	return fn(file, args, opts);
 }
 
+function getStream(stream, encoding) {
+	if (!stream) {
+		return null;
+	}
+
+	if (encoding) {
+		return _getStream(stream, {encoding: encoding});
+	}
+	return _getStream.buffer(stream);
+}
+
+function processDone(spawned) {
+	return new Promise(function (resolve) {
+		spawned.on('exit', function (code, signal) {
+			resolve({code: code, signal: signal});
+		});
+
+		spawned.on('error', function (err) {
+			resolve({err: err});
+		});
+	});
+}
+
 module.exports = function (cmd, args, opts) {
-	var spawned;
-
-	var promise = new Promise(function (resolve, reject) {
-		var parsed = handleArgs(cmd, args, opts);
-
-		spawned = childProcess.execFile(parsed.cmd, parsed.args, parsed.opts, function (err, stdout, stderr) {
-			if (err) {
-				err.stdout = stdout;
-				err.stderr = stderr;
-				err.message += stdout;
-				reject(err);
-				return;
+	var parsed = handleArgs(cmd, args, opts);
+	var encoding = parsed.opts.encoding;
+	var spawned = childProcess.spawn(parsed.cmd, parsed.args, parsed.opts);
+
+	var promise = Promise.all([
+		processDone(spawned),
+		getStream(spawned.stdout, encoding),
+		getStream(spawned.stderr, encoding)
+	]).then(function (arr) {
+		var result = arr[0];
+		var stdout = arr[1];
+		var stderr = arr[2];
+
+		var err = result.err;
+		var code = result.code;
+		var signal = result.signal;
+
+		if (err || code !== 0 || signal !== null) {
+			var joinedCmd = cmd;
+
+			if (Array.isArray(args) && args.length) {
+				joinedCmd += ' ' + args.join(' ');
 			}
 
-			resolve({
-				stdout: handleOutput(parsed.opts, stdout),
-				stderr: handleOutput(parsed.opts, stderr)
-			});
-		});
+			if (!err) {
+				err = new Error('Command failed: ' + joinedCmd + '\n' + stderr + stdout);
+
+				// TODO: missing some timeout logic for killed
+				// https://github.com/nodejs/node/blob/master/lib/child_process.js#L203
+				// err.killed = spawned.killed || killed;
+				err.killed = spawned.killed;
+
+				// TODO: child_process applies the following logic for resolving the code:
+				// var uv = process.bind('uv');
+				// ex.code = code < 0 ? uv.errname(code) : code;
+				err.code = code;
+			}
 
-		crossSpawnAsync._enoent.hookChildProcess(spawned, parsed);
+			err.stdout = stdout;
+			err.stderr = stderr;
+			throw err;
+		}
 
-		handleInput(spawned, parsed.opts);
+		return {
+			stdout: handleOutput(parsed.opts, stdout),
+			stderr: handleOutput(parsed.opts, stderr)
+		};
 	});
 
+	crossSpawnAsync._enoent.hookChildProcess(spawned, parsed);
+
+	handleInput(spawned, parsed.opts);
+
 	spawned.then = promise.then.bind(promise);
 	spawned.catch = promise.catch.bind(promise);
 
@@ -141,14 +194,7 @@ module.exports.shell = function (cmd, opts) {
 	return handleShell(module.exports, cmd, opts);
 };
 
-module.exports.spawn = function (cmd, args, opts) {
-	var parsed = handleArgs(cmd, args, opts);
-	var spawned = childProcess.spawn(parsed.cmd, parsed.args, parsed.opts);
-
-	crossSpawnAsync._enoent.hookChildProcess(spawned, parsed);
-
-	return spawned;
-};
+module.exports.spawn = util.deprecate(module.exports, 'execa.spawn: just use execa instead.');
 
 module.exports.sync = function (cmd, args, opts) {
 	var parsed = handleArgs(cmd, args, opts);
@@ -159,10 +205,8 @@ module.exports.sync = function (cmd, args, opts) {
 
 	var result = childProcess.spawnSync(parsed.cmd, parsed.args, parsed.opts);
 
-	if (parsed.opts.stripEof) {
-		result.stdout = stripEof(result.stdout);
-		result.stderr = stripEof(result.stderr);
-	}
+	result.stdout = handleOutput(parsed.opts, result.stdout);
+	result.stderr = handleOutput(parsed.opts, result.stderr);
 
 	return result;
 };

package.json

@@ -45,6 +45,7 @@
   ],
   "dependencies": {
     "cross-spawn-async": "^2.1.1",
+    "get-stream": "^2.0.0",
     "is-stream": "^1.1.0",
     "npm-run-path": "^1.0.0",
     "object-assign": "^4.0.1",
@@ -55,7 +56,6 @@
     "ava": "*",
     "cat-names": "^1.0.2",
     "coveralls": "^2.11.9",
-    "get-stream": "^2.0.0",
     "nyc": "^6.4.0",
     "xo": "*"
   }

test.js

@@ -34,8 +34,8 @@ test('stdout/stderr available on errors', async t => {
 });
 
 test('include stdout in errors for improved debugging', async t => {
-	const err = await t.throws(m('./fixtures/error-message.js'));
-	t.true(err.message.indexOf('stdout') !== -1);
+	const err = await t.throws(m('fixtures/error-message.js'));
+	t.regex(err.message, /stdout/);
 });
 
 test('execa.shell()', async t => {
@@ -112,6 +112,11 @@ test('input option can be a Buffer - sync', async t => {
 	t.is(stdout, 'testing12');
 });
 
+test('opts.stdout:ignore - stdout will not collect data', async t => {
+	const {stdout} = await m('stdin', {input: 'hello', stdio: [null, 'ignore', null]});
+	t.is(stdout, null);
+});
+
 test('helpful error trying to provide an input stream in sync mode', t => {
 	t.throws(
 		() => m.sync('stdin', {input: new stream.PassThrough()}),