feat(preprocessor): free instrumenter

Allow any Istanbul instrumenter to be used in the karma-coverage.
Will help karma-runner#120

Closes karma-runner#101 karma-runner#49

BREAKING CHANGE: Karma-coverage does not ship with additional instrumenter. You need to explicitly install the instrumenter you need.

Removed **Ibrik** instrumenter that need to be installed explicitly.

Quick list of known community instrumenters :
- [Ibrik](https://github.com/Constellation/ibrik) (CoffeeScript files instrumenter).
- [Ismailia](https://github.com/Spote/ismailia) (ES6 files instrumenter using Traceur).
- [Isparta](https://github.com/douglasduteil/isparta) (ES6 files instrumenter using 6to5).

Author: douglasduteil

README.md

@@ -206,26 +206,47 @@ coverageReporter: {
 ```
 
 #### instrumenter
-Karma-coverage infers the instrumenter regarding of the file extension.
-  The `.coffee` files are by default covered using
-  [Ibrik](https://github.com/Constellation/ibrik) (an
-  [Istanbul](https://github.com/gotwarlost/istanbul) analog for
-  CoffeeScript files). It is possible to override this behavior and point out an
+Karma-coverage can infers the instrumenter regarding of the file extension.
+  It is possible to override this behavior and point out an
   instrumenter for the files matching a specific pattern.
   To do so, you need to declare an object under with the keys represents the
   pattern to match, and the instrumenter to apply. The matching will be done
   using [minimatch](https://github.com/isaacs/minimatch).
   If two patterns match, the last one will take the precedence.
 
+For example you can use [Ibrik](https://github.com/Constellation/ibrik) (an
+  [Istanbul](https://github.com/gotwarlost/istanbul) analog for
+  CoffeeScript files) with:
+
 ```javascript
 coverageReporter: {
+  instrumenters: { ibrik : require('ibrik') }
   instrumenter: {
-    '**/*.coffee': 'istanbul' // Force the use of the Istanbul instrumenter to cover CoffeeScript files
+    '**/*.coffee': 'ibrik'
   },
   // ...
 }
 ```
 
+You can pass options additional options to specific instrumenter with:
+
+```javascript
+var to5Options = { experimental: true };
+
+// [...]
+
+coverageReporter: {
+  instrumenters: { isparta : require('isparta') },
+  instrumenter: {
+    '**/*.js': 'isparta'
+  },
+  instrumenterOptions: {
+    isparta: { to5 : to5Options }
+  }
+}
+```
+
+
 ----
 
 For more information on Karma see the [homepage].

lib/preprocessor.js

@@ -1,13 +1,17 @@
 var istanbul  = require('istanbul'),
-    ibrik     = require('ibrik'),
     minimatch = require('minimatch'),
-    globalSourceCache = require('./sourceCache');
+    globalSourceCache = require('./sourceCache'),
+    extend = require('util')._extend;
 
 var createCoveragePreprocessor = function(logger, basePath, reporters, coverageReporter) {
   var log = logger.create('preprocessor.coverage');
   var instrumenterOverrides = (coverageReporter && coverageReporter.instrumenter) || {};
-  var instrumenters = {istanbul: istanbul, ibrik: ibrik};
+  var instrumenters = extend({istanbul: istanbul}, (coverageReporter && coverageReporter.instrumenters));
   var sourceCache = globalSourceCache.getByBasePath(basePath);
+  var instrumentersOptions = Object.keys(instrumenters).reduce(function getInstumenterOptions(memo, instrumenterName){
+    memo[instrumenterName] = (coverageReporter && coverageReporter.instrumenterOptions && coverageReporter.instrumenterOptions[instrumenterName]) || {};
+    return memo;
+  }, {});
 
   // if coverage reporter is not used, do not preprocess the files
   if (reporters.indexOf('coverage') === -1) {
@@ -20,8 +24,8 @@ var createCoveragePreprocessor = function(logger, basePath, reporters, coverageR
   function checkInstrumenters() {
     var literal;
     for (var pattern in instrumenterOverrides) {
-      literal = String(instrumenterOverrides[pattern]).toLowerCase();
-      if (literal !== 'istanbul' && literal !== 'ibrik') {
+      literal = String(instrumenterOverrides[pattern]);
+      if (Object.keys(instrumenters).indexOf(literal) < 0) {
         log.error('Unknown instrumenter: %s', literal);
         return false;
       }
@@ -38,25 +42,23 @@ var createCoveragePreprocessor = function(logger, basePath, reporters, coverageR
     log.debug('Processing "%s".', file.originalPath);
 
     var jsPath = file.originalPath.replace(basePath + '/', './');
-    var instrumenterLiteral = jsPath.match(/\.coffee$/) ? 'ibrik' : 'istanbul';
+    // default instrumenters
+    var instrumenterLiteral = 'istanbul';
 
     for (var pattern in instrumenterOverrides) {
       if (minimatch(file.originalPath, pattern, {dot: true})) {
-        instrumenterLiteral = String(instrumenterOverrides[pattern]).toLowerCase();
+        instrumenterLiteral = String(instrumenterOverrides[pattern]);
       }
     }
 
-    var instrumenter = new instrumenters[instrumenterLiteral].Instrumenter();
+    var instrumenter = new instrumenters[instrumenterLiteral].Instrumenter(instrumentersOptions[instrumenterLiteral] || {});
 
     instrumenter.instrument(content, jsPath, function(err, instrumentedCode) {
+
       if (err) {
         log.error('%s\n  at %s', err.message, file.originalPath);
       }
 
-      if (instrumenterLiteral === 'ibrik') {
-        file.path = file.path.replace(/\.coffee$/, '.js');
-      }
-
       // remember the actual immediate instrumented JS for given original path
       sourceCache[jsPath] = content;
 

package.json

@@ -20,7 +20,6 @@
   "author": "SATO taichi <ryushi@gmail.com>",
   "dependencies": {
     "istanbul": "~0.3.0",
-    "ibrik": "~2.0.0",
     "dateformat": "~1.0.6",
     "minimatch": "~0.3.0"
   },

test/preprocessor.spec.coffee

@@ -57,20 +57,50 @@ describe 'preprocessor', ->
       expect(sandbox.__coverage__).to.have.ownProperty './file.js'
       done()
 
-  it 'should preprocess the coffee code', (done) ->
-    process = createPreprocessor mockLogger, '/base/path', ['coverage', 'progress'], {}
-    file = new File '/base/path/file.coffee'
+  it 'should preprocess the fake code', (done) ->
+    fakeInstanbulLikeInstrumenter  = ->
+    fakeInstanbulLikeInstrumenter::instrument = (_a, _b, callback) ->
+      callback()
+      return
+    process = createPreprocessor mockLogger, '/base/path', ['coverage', 'progress'],
+      instrumenters:
+       fakeInstanbulLike :
+          Instrumenter : fakeInstanbulLikeInstrumenter
+      instrumenter:
+        '**/*.fake': 'fakeInstanbulLike'
+    file = new File '/base/path/file.fake'
 
     process ORIGINAL_COFFEE_CODE, file, (preprocessedCode) ->
       sandbox =
         a: true
         something: ->
 
       vm.runInNewContext preprocessedCode, sandbox
-      expect(file.path).to.equal '/base/path/file.js'
-      expect(sandbox.__coverage__).to.have.ownProperty './file.coffee'
+      expect(file.path).to.equal '/base/path/file.fake'
       done()
 
+  it 'should preprocess the fake code with the config options', (done) ->
+    fakeInstanbulLikeInstrumenter = (options) ->
+      expect(options.experimental).to.be.ok
+      return
+    fakeInstanbulLikeInstrumenter::instrument = (_a, _b, callback) ->
+      callback()
+      return
+
+    process = createPreprocessor mockLogger, '/base/path', ['coverage', 'progress'],
+      instrumenters:
+        fakeInstanbulLike:
+          Instrumenter: fakeInstanbulLikeInstrumenter
+      instrumenterOptions:
+        fakeInstanbulLike:
+          experimental: yes
+      instrumenter:
+        '**/*.fake': 'fakeInstanbulLike'
+
+    file = new File '/base/path/file.fake'
+
+    process ORIGINAL_COFFEE_CODE, file, done
+
   it 'should not preprocess the coffee code', (done) ->
     process = createPreprocessor mockLogger, '/base/path', ['coverage', 'progress'],
       instrumenter: