add cli test to confirm syntactically invalid js will cause a non-zero exit code

Author: Jake Champion

integration-tests/cli/invalid.test.js

@@ -0,0 +1,18 @@
+import test from 'brittle';
+import { getBinPath } from 'get-bin-path'
+import { prepareEnvironment } from '@gmrchk/cli-testing-library';
+
+const cli = await getBinPath()
+
+test('should bail on syntax errors', async function (t) {
+    const { execute, cleanup, writeFile } = await prepareEnvironment();
+    await writeFile('./bin/index.js', '@')
+    const { code } = await execute(
+        'node',
+        cli
+    );
+
+    t.is(code, 1);
+
+    await cleanup();
+});