feat: warn on empty config

@commitlint/cli/fixtures/default/commitlint.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+	rules: {
+		'type-enum': [2, 'never', ['foo']]
+	}
+};

@commitlint/cli/fixtures/husky/integration/commitlint.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+	rules: {
+		'type-enum': [2, 'never', ['foo']]
+	}
+};

@commitlint/cli/src/cli.js

@@ -150,6 +150,26 @@ async function main(options) {
 		messages.map(message => lint(message, loaded.rules, opts))
 	);
 
+	if (Object.keys(loaded.rules).length === 0) {
+		results.push({
+			valid: false,
+			errors: [
+				{
+					level: 2,
+					valid: false,
+					name: 'empty-rules',
+					message: [
+						'Please add rules to your `commitlint.config.js`',
+						'    - Getting started guide: https://git.io/fpUzJ',
+						'    - Example config: https://git.io/fpUzm'
+					].join('\n')
+				}
+			],
+			warnings: [],
+			input: ''
+		});
+	}
+
 	const report = results.reduce(
 		(info, result) => {
 			info.valid = result.valid ? info.valid : false;
@@ -270,7 +290,7 @@ function selectParserOpts(parserPreset) {
 }
 
 function loadFormatter(config, flags) {
-	const moduleName = flags.format || config.formatter;
+	const moduleName = flags.format || config.formatter || '@commitlint/format';
 	const modulePath =
 		resolveFrom.silent(__dirname, moduleName) ||
 		resolveFrom.silent(flags.cwd, moduleName) ||

@commitlint/cli/src/cli.test.js

@@ -21,34 +21,40 @@ const cli = (args, options) => {
 };
 
 test('should throw when called without [input]', async t => {
-	const cwd = await git.bootstrap('fixtures/empty');
+	const cwd = await git.bootstrap('fixtures/default');
 	const actual = await cli([], {cwd})();
 	t.is(actual.code, 1);
 });
 
 test('should reprint input from stdin', async t => {
-	const cwd = await git.bootstrap('fixtures/empty');
+	const cwd = await git.bootstrap('fixtures/default');
 	const actual = await cli([], {cwd})('foo: bar');
 	t.true(actual.stdout.includes('foo: bar'));
 });
 
 test('should produce no success output with --quiet flag', async t => {
-	const cwd = await git.bootstrap('fixtures/empty');
+	const cwd = await git.bootstrap('fixtures/default');
 	const actual = await cli(['--quiet'], {cwd})('foo: bar');
 	t.is(actual.stdout, '');
 	t.is(actual.stderr, '');
 });
 
 test('should produce no success output with -q flag', async t => {
-	const cwd = await git.bootstrap('fixtures/empty');
+	const cwd = await git.bootstrap('fixtures/default');
 	const actual = await cli(['-q'], {cwd})('foo: bar');
 	t.is(actual.stdout, '');
 	t.is(actual.stderr, '');
 });
 
-test('should succeed for input from stdin without rules', async t => {
+test('should fail for input from stdin without rules', async t => {
 	const cwd = await git.bootstrap('fixtures/empty');
 	const actual = await cli([], {cwd})('foo: bar');
+	t.is(actual.code, 1);
+});
+
+test('should succeed for input from stdin with rules', async t => {
+	const cwd = await git.bootstrap('fixtures/default');
+	const actual = await cli([], {cwd})('type: bar');
 	t.is(actual.code, 0);
 });
 
@@ -152,7 +158,7 @@ test('should work with husky via commitlint -e %HUSKY_GIT_PARAMS%', async () =>
 });
 
 test('should allow reading of environment variables for edit file, succeeding if valid', async t => {
-	const cwd = await git.bootstrap();
+	const cwd = await git.bootstrap('fixtures/simple');
 	await sander.writeFile(cwd, 'commit-msg-file', 'foo');
 	const actual = await cli(['--env', 'variable'], {
 		cwd,
@@ -254,8 +260,8 @@ test('should print full commit message when input from stdin fails', async t =>
 });
 
 test('should not print full commit message when input succeeds', async t => {
-	const cwd = await git.bootstrap('fixtures/empty');
-	const message = 'foo: bar\n\nFoo bar bizz buzz.\n\nCloses #123.';
+	const cwd = await git.bootstrap('fixtures/default');
+	const message = 'type: bar\n\nFoo bar bizz buzz.\n\nCloses #123.';
 	const actual = await cli([], {cwd})(message);
 
 	t.false(actual.stdout.includes(message));