feature #142 Feature configure manifest options (Bruno BOUTAREL)

This PR was squashed before being merged into the master branch (closes #142).

Discussion
----------

Feature configure manifest options

This PR adds `configureManifestPlugin()` as discussed in #125

**Example:**
```javascript
Encore.configureManifestPlugin({
    fileName: '../../var/assets/manifest.json'
})
```

These options will override any default option.

Commits
-------

de061a5 Feature configure manifest options

Author: weaverryan

index.js

@@ -102,6 +102,25 @@ const publicApi = {
         return this;
     },
 
+    /**
+     * Allows to set ManifestPlugin options and override default options
+     * List of available options can be found at https://github.com/danethurber/webpack-manifest-plugin
+     *
+     * For example:
+     *
+     *      Encore.configureManifestPlugin(function(options){
+     *          options.fileName: '../../var/assets/manifest.json'
+     *      })
+     *
+     * @param {function} manifestPluginOptionsCallback
+     * @returns {exports}
+     */
+    configureManifestPlugin(manifestPluginOptionsCallback = () => {}) {
+        webpackConfig.configureManifestPlugin(manifestPluginOptionsCallback);
+
+        return this;
+    },
+
     /**
      * Adds a JavaScript file that should be webpacked:
      *

lib/WebpackConfig.js

@@ -63,6 +63,7 @@ class WebpackConfig {
         this.useImagesLoader = true;
         this.useFontsLoader = true;
         this.configuredFilenames = {};
+        this.manifestPluginOptionsCallback = function() {};
     }
 
     getContext() {
@@ -117,6 +118,14 @@ class WebpackConfig {
         this.manifestKeyPrefix = manifestKeyPrefix;
     }
 
+    configureManifestPlugin(manifestPluginOptionsCallback = () => {}) {
+        if (typeof manifestPluginOptionsCallback !== 'function') {
+            throw new Error('Argument 1 to configureManifestPlugin() must be a callback function');
+        }
+
+        this.manifestPluginOptionsCallback = manifestPluginOptionsCallback;
+    }
+
     /**
      * Returns the value that should be used as the publicPath,
      * which can be overridden by enabling the webpackDevServer

lib/plugins/manifest.js

@@ -24,11 +24,18 @@ module.exports = function(plugins, webpackConfig) {
         manifestPrefix = webpackConfig.publicPath.replace(/^\//, '');
     }
 
-    plugins.push(new ManifestPlugin({
+    const manifestPluginOptions = {
         basePath: manifestPrefix,
         // guarantee the value uses the public path (or CDN public path)
         publicPath: webpackConfig.getRealPublicPath(),
         // always write a manifest.json file, even with webpack-dev-server
         writeToFileEmit: true,
-    }));
+    };
+
+    webpackConfig.manifestPluginOptionsCallback.apply(
+        manifestPluginOptions,
+        [manifestPluginOptions]
+    );
+
+    plugins.push(new ManifestPlugin(manifestPluginOptions));
 };

test/WebpackConfig.js

@@ -163,6 +163,26 @@ describe('WebpackConfig object', () => {
         });
     });
 
+    describe('configureManifestPlugin', () => {
+        it('Setting custom options', () => {
+            const config = createConfig();
+            const callback = () => {};
+            config.configureManifestPlugin(callback);
+
+            // fileName option overridden
+            expect(config.manifestPluginOptionsCallback).to.equal(callback);
+        });
+
+        it('Setting invalid custom options argument', () => {
+            const config = createConfig();
+            const callback = 'invalid';
+
+            expect(() => {
+                config.configureManifestPlugin(callback);
+            }).to.throw('Argument 1 to configureManifestPlugin() must be a callback function');
+        });
+    });
+
     describe('addEntry', () => {
         it('Calling with a duplicate name throws an error', () => {
             const config = createConfig();