fix: error is thrown if there's no scope-{enum,type} rule at all

`type`, `scope` and `scopeOverrides` in cz-customizable config is/are
now silently ignored if `type-num`, `scope-enum` rule doesn't exist in
commitlint config.

Closes #3

Author: whizark

lib/config.js

@@ -38,22 +38,29 @@ function get(pathOrCzConfig, defaultConfig) {
     }
 
     // Converts the `scopes` and `scopeOverrides` into `scope-enum` rule.
-    if (typeof czConfig.scopes !== 'undefined' || typeof czConfig.scopeOverrides !== 'undefined') {
+    const hasScopeEnum = Object.prototype.hasOwnProperty.call(config.rules, 'scope-enum');
+
+    if (
+        hasScopeEnum &&
+        (typeof czConfig.scopes !== 'undefined' || typeof czConfig.scopeOverrides !== 'undefined')
+    ) {
         config.rules['scope-enum'][2] = Scopes.get(czConfig);
     }
 
     // Removes empty `scope-enum` rule.
-    if (!config.rules['scope-enum'][2].length) {
+    if (hasScopeEnum && !config.rules['scope-enum'][2].length) {
         delete config.rules['scope-enum'];
     }
 
     // Converts the `types` into `type-enum` rule.
-    if (typeof czConfig.types !== 'undefined') {
+    const hasTypeEnum = Object.prototype.hasOwnProperty.call(config.rules, 'type-enum');
+
+    if (hasTypeEnum && typeof czConfig.types !== 'undefined') {
         config.rules['type-enum'][2] = Types.get(czConfig);
     }
 
     // Removes empty `type-enum` rule.
-    if (!config.rules['type-enum'][2].length) {
+    if (hasTypeEnum && !config.rules['type-enum'][2].length) {
         delete config.rules['type-enum'];
     }
 

test/config.spec.js

@@ -173,5 +173,91 @@ describe('config', function () {
                 assert.deepStrictEqual(Config.get(configPath, defaultConfig), expected);
             }
         );
+
+        it('should ignore `scopes` and `scopeOverrides` when commitlint config has no `scope-enum` rule',
+            function () {
+                const configPath = path.join(__dirname, 'fixtures/.cz-config.js');
+
+                const defaultConfig = {
+                    rules: {
+                        'body-leading-blank'  : [
+                            2,
+                            'always',
+                        ],
+                        'type-enum' : [
+                            1,
+                            'never',
+                            [
+                                'type-3',
+                                'type-4',
+                            ],
+                        ],
+                    },
+                };
+
+                const expected = {
+                    rules: {
+                        'body-leading-blank'  : [
+                            2,
+                            'always',
+                        ],
+                        'type-enum' : [
+                            1,
+                            'never',
+                            [
+                                'type-1',
+                                'type-2',
+                            ],
+                        ],
+                    }
+                };
+
+                assert.deepStrictEqual(Config.get(configPath, defaultConfig), expected);
+            }
+        );
+
+        it('should ignore `types` when commitlint config has no `type-enum` rule',
+            function () {
+                const configPath = path.join(__dirname, 'fixtures/.cz-config.js');
+
+                const defaultConfig = {
+                    rules: {
+                        'body-leading-blank'  : [
+                            2,
+                            'always',
+                        ],
+                        'scope-enum': [
+                            1,
+                            'never',
+                            [
+                                'scope-4',
+                                'scope-5',
+                                'scope-6',
+                            ],
+                        ],
+                    },
+                };
+
+                const expected = {
+                    rules: {
+                        'body-leading-blank'  : [
+                            2,
+                            'always',
+                        ],
+                        'scope-enum': [
+                            1,
+                            'never',
+                            [
+                                'scope-1',
+                                'scope-2',
+                                'scope-3',
+                            ],
+                        ],
+                    }
+                };
+
+                assert.deepStrictEqual(Config.get(configPath, defaultConfig), expected);
+            }
+        );
     });
 });