fix: allow [0] shorthand

Author: marionebl

@commitlint/core/src/lint.js

@@ -41,14 +41,6 @@ export default async (message, rules = {}, opts = {}) => {
 				);
 			}
 
-			if (config.length !== 2 && config.length !== 3) {
-				return new Error(
-					`config for rule ${name} must be 2 or 3 items long, received ${util.inspect(
-						config
-					)} of length ${config.length}`
-				);
-			}
-
 			const [level, when] = config;
 
 			if (typeof level !== 'number' || isNaN(level)) {
@@ -59,6 +51,18 @@ export default async (message, rules = {}, opts = {}) => {
 				);
 			}
 
+			if (level === 0 && config.length === 1) {
+				return null;
+			}
+
+			if (config.length !== 2 && config.length !== 3) {
+				return new Error(
+					`config for rule ${name} must be 2 or 3 items long, received ${util.inspect(
+						config
+					)} of length ${config.length}`
+				);
+			}
+
 			if (level < 0 || level > 2) {
 				return new RangeError(
 					`level for rule ${name} must be between 0 and 2, received ${util.inspect(

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

@@ -73,12 +73,15 @@ test('throws for invalid rule config', async t => {
 	t.true(error.message.indexOf('scope-enum must be array') > -1);
 });
 
+test('allows disable shorthand', async t => {
+	await t.notThrows(lint('foo', {'type-enum': [0], 'scope-enum': [0]}));
+});
+
 test('throws for rule with invalid length', async t => {
 	const error = await t.throws(
-		lint('type(scope): foo', {'type-enum': [], 'scope-enum': [1, 2, 3, 4]})
+		lint('type(scope): foo', {'scope-enum': [1, 2, 3, 4]})
 	);
 
-	t.true(error.message.indexOf('type-enum must be 2 or 3 items long') > -1);
 	t.true(error.message.indexOf('scope-enum must be 2 or 3 items long') > -1);
 });