feat: simplify loading plugins using patterns like karma-*

Now it's possible to load all sybling npm modules through:
plugins = ['karma-*'];

This is also the default configuration.

I hope in most of the cases, people should not have to worry about specifying plugins at all.

This commit also extracts the plugin loading logic into a separate module.

lib/config.js

@@ -217,14 +217,7 @@ var parseConfig = function(configFilePath, cliOptions) {
       dir: 'coverage/'
     },
     loggers: [ constant.CONSOLE_APPENDER ],
-    plugins: [
-      'karma-jasmine',
-      'karma-requirejs',
-      'karma-chrome-launcher',
-      'karma-firefox-launcher',
-      'karma-phantomjs-launcher',
-      'karma-coffee-preprocessor'
-    ]
+    plugins: [ 'karma-*' ]
   };
   var dsl = new KarmaDsl(config);
   try {

lib/plugin.js

@@ -0,0 +1,49 @@
+var fs = require('fs');
+var path = require('path');
+
+var helper = require('./helper');
+var log = require('./logger').create('plugin');
+
+
+exports.resolve = function(plugins) {
+  var modules = [];
+
+  var requirePlugin = function(name) {
+    log.debug('Loading plugin %s.', name);
+    try {
+      modules.push(require(name));
+    } catch (e) {
+      if (e.code === 'MODULE_NOT_FOUND' && e.message.indexOf(name) !== -1) {
+        log.warn('Cannot find plugin "%s".\n  Did you forget to install it ?\n' +
+                 '  npm install %s --save-dev', name, name);
+      } else {
+        log.warn('Error during loading "%s" plugin:\n  %s', name, e.message);
+      }
+    }
+  };
+
+  plugins.forEach(function(plugin) {
+    if (helper.isString(plugin)) {
+      if (plugin.indexOf('*') !== -1) {
+        var pluginDirectory = path.normalize(__dirname + '/../..');
+        var regexp = new RegExp('^' + plugin.replace('*', '.*'));
+
+        log.debug('Loading %s from %s', plugin, pluginDirectory);
+        fs.readdirSync(pluginDirectory).filter(function(pluginName) {
+          return regexp.test(pluginName);
+        }).forEach(function(pluginName) {
+          requirePlugin(pluginDirectory + '/' + pluginName);
+        });
+      } else {
+        requirePlugin(plugin);
+      }
+    } else if (helper.isObject(plugin)) {
+      log.debug('Loading inlined plugin (defining %s).', Object.keys(plugin).join(', '));
+      modules.push(plugin);
+    } else {
+      log.warn('Invalid plugin %s', plugin);
+    }
+  });
+
+  return modules;
+};

lib/server.js

@@ -7,6 +7,7 @@ var logger = require('./logger');
 var browser = require('./browser');
 var constant = require('./constants');
 var watcher = require('./watcher');
+var plugin = require('./plugin');
 
 var ws = require('./web-server');
 var preprocessor = require('./preprocessor');
@@ -247,25 +248,8 @@ exports.start = function(cliOptions, done) {
     capturedBrowsers: ['type', browser.Collection]
   }];
 
-  // register all plugins
-  config.plugins.forEach(function(plugin) {
-    if (helper.isString(plugin)) {
-      try {
-        modules.push(require(plugin));
-      } catch (e) {
-        if (e.code === 'MODULE_NOT_FOUND') {
-          log.warn('Cannot find plugin "%s".\n  Did you forget to install it ?\n' +
-                   '  npm install %s --save-dev', plugin, plugin);
-        } else {
-          log.warn('Error during loading "%s" plugin:\n  %s', plugin, e.message);
-        }
-      }
-    } else if (helper.isObject(plugin)) {
-      modules.push(plugin);
-    } else {
-      log.warn('Invalid plugin %s', plugin);
-    }
-  });
+  // load the plugins
+  modules = modules.concat(plugin.resolve(config.plugins));
 
   var injector = new di.Injector(modules);