Fix error thrown when options are invalid

index.js

@@ -247,13 +247,13 @@ const execa = (file, args, options) => {
 	try {
 		spawned = childProcess.spawn(parsed.file, parsed.args, parsed.options);
 	} catch (error) {
-		return Promise.reject(makeError({error, stdout: '', stderr: '', all: ''}, {
+		throw makeError({error, stdout: '', stderr: '', all: ''}, {
 			joinedCommand,
 			parsed,
 			timedOut: false,
 			isCanceled: false,
 			killed: false
-		}));
+		});
 	}
 
 	const kill = spawned.kill.bind(spawned);

readme.md

@@ -136,6 +136,8 @@ Returns a [`child_process` instance](https://nodejs.org/api/child_process.html#c
   - is also a `Promise` resolving or rejecting with a [`childProcessResult`](#childProcessResult).
   - exposes the following additional methods and properties.
 
+An [error](#childProcessResult) might also be thrown when `options` are invalid.
+
 #### kill([signal], [options])
 
 Same as the original [`child_process#kill()`](https://nodejs.org/api/child_process.html#child_process_subprocess_kill_signal) except: if `signal` is `SIGTERM` (the default value) and the child process is not terminated after 5 seconds, force it by sending `SIGKILL`.

test.js

@@ -288,8 +288,8 @@ test('execa() returns a promise with kill() and pid', t => {
 	t.is(typeof pid, 'number');
 });
 
-test('child_process.spawn() errors are propagated', async t => {
-	const {exitCodeName} = await t.throwsAsync(execa('noop', {uid: -1}));
+test('child_process.spawn() errors are propagated', t => {
+	const {exitCodeName} = t.throws(() => execa('noop', {uid: -1}));
 	t.is(exitCodeName, process.platform === 'win32' ? 'ENOTSUP' : 'EINVAL');
 });