Turn off echo on Windows - fixes #116 (#118)

fixtures/hello.cmd

@@ -0,0 +1 @@
+ECHO Hello World

index.js

@@ -1,4 +1,5 @@
 'use strict';
+const path = require('path');
 const childProcess = require('child_process');
 const util = require('util');
 const crossSpawn = require('cross-spawn');
@@ -59,6 +60,11 @@ function handleArgs(cmd, args, opts) {
 		opts.cleanup = false;
 	}
 
+	if (process.platform === 'win32' && path.basename(parsed.command) === 'cmd.exe') {
+		// #116
+		parsed.args.unshift('/q');
+	}
+
 	return {
 		cmd: parsed.command,
 		args: parsed.args,

test.js

@@ -17,6 +17,14 @@ test('execa()', async t => {
 	t.is(stdout, 'foo');
 });
 
+if (process.platform === 'win32') {
+	test('execa() - cmd file', async t => {
+		const {stdout} = await m('hello.cmd');
+
+		t.is(stdout, 'Hello World');
+	});
+}
+
 test('buffer', async t => {
 	const {stdout} = await m('noop', ['foo'], {encoding: null});
 	t.true(Buffer.isBuffer(stdout));