test: add missing test cases for ensure and is-ignored (#987)

* test(esnure): add tests for untested code paths

* test(is-ignored): add test case for untested code path

@commitlint/ensure/src/enum.test.ts

@@ -5,6 +5,11 @@ test('false for no params', () => {
 	expect(actual).toBe(false);
 });
 
+test('false for not array enums', () => {
+	const actual = ensure('a', 'a' as any);
+	expect(actual).toBe(false);
+});
+
 test('true for a against a', () => {
 	const actual = ensure('a', ['a']);
 	expect(actual).toBe(true);

@commitlint/is-ignored/src/is-ignored.test.ts

@@ -150,7 +150,7 @@ test('should throw error if ignores is not an array', () => {
 		isIgnored(ignoredString, {
 			ignores: 'throws error'
 		} as any);
-	}).toThrow();
+	}).toThrow('ignores must be of type array, received ');
 });
 
 test('should return true for custom ignores as function', () => {
@@ -161,3 +161,12 @@ test('should return true for custom ignores as function', () => {
 		})
 	).toBe(true);
 });
+
+test('should throw error if any element of ignores is not a function', () => {
+	const ignoredString = 'this should be ignored';
+	expect(() => {
+		isIgnored(ignoredString, {
+			ignores: ['throws error']
+		} as any);
+	}).toThrow('ignores must be array of type function, received items of type:');
+});