title: karma - Cannot find plugin
body: <p>I am trying to run js test cases using karma. But Always getting plugin not found error. And funny part is the same config file, working fine for other co-worker of mine</p>
  
  <p>Here is logs :</p>
  
  <pre><code>$ karma start karma.conf.js 
  04 10 2016 17:51:24.755:ERROR [plugin]: Cannot find plugin "karma-babel-preprocessor".
    Did you forget to install it?
    npm install karma-babel-preprocessor --save-dev
  04 10 2016 17:51:24.769:ERROR [plugin]: Cannot find plugin "karma-mocha".
    Did you forget to install it?
    npm install karma-mocha --save-dev
  04 10 2016 17:51:24.778:ERROR [plugin]: Cannot find plugin "karma-chrome-launcher".
    Did you forget to install it?
    npm install karma-chrome-launcher --save-dev
  04 10 2016 17:51:24.791:ERROR [preprocess]: Can not load "babel", it is not registered!
    Perhaps you are missing some plugin?
  /usr/local/lib/node_modules/karma/node_modules/di/lib/injector.js:9
        throw error('No provider for "' + name + '"!');
        ^
  
  Error: No provider for "framework:mocha"! (Resolving: framework:mocha)
      at error (/usr/local/lib/node_modules/karma/node_modules/di/lib/injector.js:22:12)
      at Object.parent.get (/usr/local/lib/node_modules/karma/node_modules/di/lib/injector.js:9:13)
      at get (/usr/local/lib/node_modules/karma/node_modules/di/lib/injector.js:54:19)
      at /usr/local/lib/node_modules/karma/lib/server.js:143:20
      at Array.forEach (native)
      at Server._start (/usr/local/lib/node_modules/karma/lib/server.js:142:21)
      at invoke (/usr/local/lib/node_modules/karma/node_modules/di/lib/injector.js:75:15)
      at Server.start (/usr/local/lib/node_modules/karma/lib/server.js:103:18)
      at Object.exports.run (/usr/local/lib/node_modules/karma/lib/cli.js:280:26)
      at Object.&lt;anonymous&gt; (/usr/local/lib/node_modules/karma/bin/karma:3:23)
      at Module._compile (module.js:409:26)
      at Object.Module._extensions..js (module.js:416:10)
      at Module.load (module.js:343:32)
      at Function.Module._load (module.js:300:12)
      at Function.Module.runMain (module.js:441:10)
      at startup (node.js:139:18)
  </code></pre>
  
  <p>Here is karma.config.js</p>
  
  <pre><code>// Karma configuration
  // Generated on Thu Jan 28 2016 12:33:59 GMT-0500 (EST)
  
  module.exports = function(config) {
    config.set({
  
      // base path that will be used to resolve all patterns (eg. files, exclude)
      basePath: '',
  
      plugins: [
        'karma-babel-preprocessor', 
        'karma-mocha',
        'karma-chrome-launcher',
      ],
  
      // frameworks to use
      // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
      frameworks: ['mocha', 'chai'],
  
  
      // list of files / patterns to load in the browser
      files: [
        '.venv/lib/python2.7/site-packages/xstatic/pkg/jquery/data/jquery.min.js',
        '.venv/lib/python2.7/site-packages/horizon/static/horizon/js/horizon.js',
        '.venv/lib/python2.7/site-packages/horizon/static/horizon/js/horizon.quota.js',
        '.venv/lib/python2.7/site-packages/horizon/static/horizon/js/horizon.instances.js',
        'myapp/static/comp/js/pricing.js',
        'myapp/test/js/**/*.js'
      ],
  
  
      // list of files to exclude
      exclude: [
      ],
  
  
      // preprocess matching files before serving them to the browser
      // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
      preprocessors: {
        'myapp/test/js/**/*.js': ['babel']
      },
  
      babelPreprocessor: {
        options: {
          presets: ['es2015'],
          sourceMap: 'inline'
        },
        filename: function (file) {
          return file.originalPath.replace(/\.js$/, '.es5.js');
        },
        sourceFileName: function (file) {
          return file.originalPath;
        }
      },
  
  
      // test results reporter to use
      // possible values: 'dots', 'progress'
      // available reporters: https://npmjs.org/browse/keyword/karma-reporter
      reporters: ['progress'],
  
  
      // web server port
      port: 9876,
  
  
      // enable / disable colors in the output (reporters and logs)
      colors: true,
  
  
      // level of logging
      // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
      logLevel: config.LOG_INFO,
  
  
      // enable / disable watching file and executing tests whenever any file changes
      autoWatch: true,
  
  
      // start these browsers
      // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
      browsers: ['Chrome'],
  
  
      // Continuous Integration mode
      // if true, Karma captures browsers, runs the tests and exits
      singleRun: true,
  
      // Concurrency level
      // how many browser should be started simultaneous
      concurrency: Infinity
    })
  }
  </code></pre>
  
  <p>Here is package.json</p>
  
  <pre><code>{
    "name": "comp_horizon",
    "version": "1.0.0",
    "description": "some description",
    "main": "index.js",
    "scripts": {
      "test": "node node_modules/karma/bin/karma start karma.conf.js --single-run"
    },
    "repository": {
      "type": "git",
      "url": "git+https://github.com/priverepo/comp_horizon.git"
    },
    "author": "",
    "license": "ISC",
    "bugs": {
      "url": "https://github.com/priverepo/comp_horizon/issues"
    },
    "homepage": "https://github.com/priverepo/comp_horizon#readme",
    "devDependencies": {
      "babel": "^6.3.26",
      "babel-core": "^6.4.5",
      "babel-loader": "^6.2.1",
      "babel-preset-es2015": "^6.3.13",
      "chai": "^3.4.1",
      "karma": "^0.13.19",
      "karma-babel-preprocessor": "^6.0.1",
      "karma-chai": "^0.1.0",
      "karma-chrome-launcher": "^2.0.0",
      "karma-coverage": "0.3.1",
      "karma-mocha": "^1.2.0",
      "mocha": "^3.1.0",
      "webpack": "^1.12.12",
      "webpack-bundle-tracker": "0.0.93"
    },
    "dependencies": {
      "babel-polyfill": "^6.3.14"
    }
  }
  </code></pre>
  
  <p>For can not file plugin error, I am installing that plugin. But error still persist. e.g. for Cannot find plugin "karma-babel-preprocessor", I did npm install karma-babel-preprocessor --save-dev. It went find. But still getting error.</p>
  
  <p>Thanks</p>