Fix: Issue with summary formatter always being used

Fix #1273
Close #1290

packages/hint/docs/user-guide/concepts/configurations.md

@@ -45,3 +45,13 @@ the `summary` formatter:
     "formatters": ["summary"]
 }
 ```
+
+Notes:
+
+* If you define the property `formatters` when extending
+  a configuration, the formatters in the configuration will be
+  replaced with the value you have defined.
+
+* If you define the property `parsers` when extending a
+  configuration, the parsers in the configuration will be appended
+  to the values you have defined.

packages/hint/src/lib/config.ts

@@ -18,7 +18,7 @@ import * as os from 'os';
 import * as path from 'path';
 
 import * as browserslist from 'browserslist';
-import { merge } from 'lodash';
+import { mergeWith } from 'lodash';
 
 import { UserConfig, IgnoredUrl, CLIOptions, ConnectorConfig, HintsConfigObject } from './types';
 import { debug as d } from './utils/debug';
@@ -88,13 +88,19 @@ const composeConfig = (userConfig: UserConfig) => {
         return composeConfig(loadedConfiguration);
     });
 
-    const finalConfig: UserConfig = merge({}, ...configurations, userConfig);
+    const finalConfig: UserConfig = mergeWith({}, ...configurations, userConfig, (objValue, srcValue) => {
+        // Arrays need to be concatented, not merged.
+        if (Array.isArray(objValue) && Array.isArray(srcValue)) {
+            return objValue.concat(srcValue);
+        }
 
-    // Otherwise the output could be double or we could trigger double events
-    if (finalConfig.formatters) {
-        finalConfig.formatters = Array.from(new Set(finalConfig.formatters));
-    }
+        return void 0;
+    });
+
+    // The formatters defined by the user has to overwritte the one in the extends.
+    finalConfig.formatters = userConfig.formatters ? userConfig.formatters : finalConfig.formatters;
 
+    // Otherwise the output could be double or we could trigger double events
     if (finalConfig.parsers) {
         finalConfig.parsers = Array.from(new Set(finalConfig.parsers));
     }

packages/hint/tests/lib/config.ts

@@ -217,6 +217,7 @@ test.serial(`if the configuration file contains an extends property, it should c
     t.is((configuration.connector as ConnectorConfig).name, 'chrome');
     t.is(configuration.hints['disallowed-headers'], 'error');
     t.is(configuration.formatters.length, 1);
+    t.is(configuration.parsers.length, 2);
 });
 
 

packages/hint/tests/lib/fixtures/valid/package.json

@@ -10,6 +10,9 @@
     "formatters": [
       "json"
     ],
+    "parsers": [
+      "javascript"
+    ],
     "hints": {
       "disallowed-headers": ["warning", {}],
       "manifest-exists": "warning",

packages/hint/tests/lib/fixtures/valid/withextends.json

@@ -11,6 +11,9 @@
     "formatters": [
         "json"
     ],
+    "parsers": [
+        "typescript"
+    ],
     "hints": {
         "disallowed-headers": "error"
     }