test(core): add superficial tests for lint()

Author: marionebl

@commitlint/core/src/lint.test.js

@@ -0,0 +1,36 @@
+import test from 'ava';
+import lint from './lint';
+
+test('throws without params', t => {
+	t.throws(() => lint());
+});
+
+test('throws with empty message', t => {
+	t.throws(() => lint(''));
+});
+
+test('positive on stub message and no rule', t => {
+	const actual = lint('foo: bar');
+	t.true(actual.valid);
+});
+
+test('positive on stub message and adhered rule', t => {
+	const actual = lint('foo: bar', {
+		'type-enum': [2, 'always', ['foo']]
+	});
+	t.true(actual.valid);
+});
+
+test('negative on stub message and broken rule', t => {
+	const actual = lint('foo: bar', {
+		'type-enum': [2, 'never', ['foo']]
+	});
+	t.false(actual.valid);
+});
+
+test('positive on ignored message and broken rule', t => {
+	const actual = lint('Revert "some bogus commit"', {
+		'type-empty': [2, 'never']
+	});
+	t.true(actual.valid);
+});