fix: use ES Modules by default for config files

BREAKING CHANGE:
drop ts-node, coffee and live script for config

.codeclimate.yml

@@ -2,15 +2,12 @@
 engines:
   rubocop:
     enabled: false
-  coffeelint:
-    enabled: true
   eslint:
     enabled: true
   csslint:
     enabled: true
 ratings:
   paths:
-  - "**.coffee"
   - "**.js"
   - "**.css"
 exclude_paths:

.npmignore

@@ -12,7 +12,6 @@ karma-integration-tests
 
 TODO.md
 CONTRIBUTING.md
-Gruntfile.coffee
 credentials
 Karma.sublime-*
 

docs/config/01-configuration-file.md

@@ -6,16 +6,12 @@ is by using the `karma init` command. This page lists all of the available confi
 Note: Most of the framework adapters, reporters, preprocessors and launchers need to be loaded as [plugins].
 
 
-The Karma configuration file can be written in JavaScript, CoffeeScript, or TypeScript and is loaded as a regular Node.js module.
+The Karma configuration file can be written in JavaScript and is loaded as a regular Node.js module.
 
 Unless provided as argument, the Karma CLI will look for a configuration file at
 
 * `./karma.conf.js`
-* `./karma.conf.coffee`
-* `./karma.conf.ts`
 * `./.config/karma.conf.js`
-* `./.config/karma.conf.coffee`
-* `./.config/karma.conf.ts`
 
 in that order.
 
@@ -33,24 +29,15 @@ module.exports = function(config) {
 };
 ```
 
-```coffeescript
-# karma.conf.coffee
-module.exports = (config) ->
-  config.set
-    basePath: '../..'
-    frameworks: ['jasmine']
-    # ...
-```
-
-```typescript
-// karma.conf.ts
-module.exports = (config) => {
+```javascript
+// karma.conf.js
+exports default function(config) {
   config.set({
     basePath: '../..',
     frameworks: ['jasmine'],
     //...
   });
-}
+};
 ```
 
 Alternatively, you can use an `async` function instead (since v6.3).
@@ -66,21 +53,6 @@ module.exports = async (config) => {
 };
 ```
 
-
-### Customized TypeScript Configuration
-Under the hood Karma uses ts-node to transpile TypeScript to JavaScript. If the resolved `tsconfig.json` has `module` configured as `ES` formats. You might get errors like `SyntaxError: Unexpected token`. This is due that in Node `ES` module formats are not supported. To overcome this issue you need to configure ts-node to use `commonjs` module format.
-
-Create a JavaScript configuration file that overrides the module format.
-```javascript
-// karma.conf.js
-require('ts-node').register({
-  compilerOptions: {
-    module: 'commonjs'
-  }
-});
-require('./karma.conf.ts');
-```
-
 ## File Patterns
 All of the configuration options, which specify file paths, use the [minimatch][minimatch] library to facilitate flexible
 but concise file expressions so you can easily list all of the files you want to include and exclude.

docs/intro/02-configuration.md

@@ -43,15 +43,12 @@ Press tab to list possible options.
 Config file generated at "/Users/vojta/Code/karma/my.conf.js".
 ```
 
-The configuration file can be written in CoffeeScript as well.
-In fact, if you execute `karma init` with a `*.coffee` extension such as `karma init karma.conf.coffee`, it will generate a CoffeeScript file.
-
 Of course, you can write the config file by hand or copy-paste it from another project ;-)
 
 ## Starting Karma
 When starting Karma, the configuration file path can be passed in as the first argument.
 
-By default, Karma will look for `karma.conf.js` or `karma.conf.coffee` in the current directory.
+By default, Karma will look for `karma.conf.js` in the current directory.
 ```bash
 # Start Karma using your configuration:
 $ karma start my.conf.js

lib/cli.js

@@ -102,14 +102,10 @@ function processArgs (argv, options, fs, path) {
     // default config file (if exists)
     if (fs.existsSync('./karma.conf.js')) {
       configFile = './karma.conf.js'
-    } else if (fs.existsSync('./karma.conf.coffee')) {
-      configFile = './karma.conf.coffee'
     } else if (fs.existsSync('./karma.conf.ts')) {
       configFile = './karma.conf.ts'
     } else if (fs.existsSync('./.config/karma.conf.js')) {
       configFile = './.config/karma.conf.js'
-    } else if (fs.existsSync('./.config/karma.conf.coffee')) {
-      configFile = './.config/karma.conf.coffee'
     } else if (fs.existsSync('./.config/karma.conf.ts')) {
       configFile = './.config/karma.conf.ts'
     }

lib/config.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const path = require('path')
+const url = require('url')
 const assert = require('assert')
 
 const logger = require('./logger')
@@ -10,27 +11,6 @@ const constant = require('./constants')
 
 const _ = require('lodash')
 
-let COFFEE_SCRIPT_AVAILABLE = false
-let LIVE_SCRIPT_AVAILABLE = false
-let TYPE_SCRIPT_AVAILABLE = false
-
-try {
-  require('coffeescript').register()
-  COFFEE_SCRIPT_AVAILABLE = true
-} catch {}
-
-// LiveScript is required here to enable config files written in LiveScript.
-// It's not directly used in this file.
-try {
-  require('LiveScript')
-  LIVE_SCRIPT_AVAILABLE = true
-} catch {}
-
-try {
-  require('ts-node')
-  TYPE_SCRIPT_AVAILABLE = true
-} catch {}
-
 class Pattern {
   constructor (pattern, served, included, watched, nocache, type, isBinary, integrity) {
     this.pattern = pattern
@@ -391,32 +371,19 @@ async function parseConfig (configFilePath, cliOptions = {}) {
     throw new Error(args.join(' '))
   }
 
-  let configModule
+  let configModule = () => {} // if no config file path is passed, we define a dummy config module.
   if (configFilePath) {
     try {
-      if (path.extname(configFilePath) === '.ts' && TYPE_SCRIPT_AVAILABLE) {
-        require('ts-node').register()
-      }
-      configModule = require(configFilePath)
+      configModule = await import(url.pathToFileURL(configFilePath))
       if (typeof configModule === 'object' && typeof configModule.default !== 'undefined') {
         configModule = configModule.default
       }
     } catch (e) {
-      const extension = path.extname(configFilePath)
-      if (extension === '.coffee' && !COFFEE_SCRIPT_AVAILABLE) {
-        log.error('You need to install CoffeeScript.\n  npm install coffeescript --save-dev')
-      } else if (extension === '.ls' && !LIVE_SCRIPT_AVAILABLE) {
-        log.error('You need to install LiveScript.\n  npm install LiveScript --save-dev')
-      } else if (extension === '.ts' && !TYPE_SCRIPT_AVAILABLE) {
-        log.error('You need to install TypeScript.\n  npm install typescript ts-node --save-dev')
-      }
       return fail('Error in config file!\n  ' + e.stack || e)
     }
     if (!helper.isFunction(configModule)) {
       return fail('Config file must export a function!\n' + CONFIG_SYNTAX_HELP)
     }
-  } else {
-    configModule = () => {} // if no config file path is passed, we define a dummy config module.
   }
 
   const config = new Config()

lib/init.js

@@ -3,7 +3,6 @@
 const readline = require('readline')
 const path = require('path')
 const { globSync } = require('glob')
-const { minimatch: mm } = require('minimatch')
 const exec = require('child_process').exec
 
 const helper = require('./helper')
@@ -115,7 +114,7 @@ var questions = [{
 }, {
   id: 'generateTestMain',
   question: 'Do you wanna generate a bootstrap file for RequireJS?',
-  hint: 'This will generate test-main.js/coffee that configures RequireJS and starts the tests.',
+  hint: 'This will generate test-main.js that configures RequireJS and starts the tests.',
   options: ['no', 'yes'],
   boolean: true,
   condition: (answers) => answers.requirejs
@@ -185,12 +184,6 @@ function processAnswers (answers, basePath, testMainFile) {
     }
   }
 
-  const allPatterns = answers.files.concat(answers.includedFiles || [])
-  if (allPatterns.some((pattern) => mm(pattern, '**/*.coffee'))) {
-    installPackage('karma-coffee-preprocessor')
-    processedAnswers.preprocessors['**/*.coffee'] = ['coffee']
-  }
-
   return processedAnswers
 }
 
@@ -217,17 +210,12 @@ exports.init = function (config) {
   sm.process(questions, function (answers) {
     const cwd = process.cwd()
     const configFile = config.configFile || 'karma.conf.js'
-    const isCoffee = path.extname(configFile) === '.coffee'
-    const testMainFile = isCoffee ? 'test-main.coffee' : 'test-main.js'
+    const testMainFile = 'test-main.js'
     const formatter = formatters.createForPath(configFile)
     const processedAnswers = processAnswers(answers, getBasePath(configFile, cwd), testMainFile)
     const configFilePath = path.resolve(cwd, configFile)
     const testMainFilePath = path.resolve(cwd, testMainFile)
 
-    if (isCoffee) {
-      installPackage('coffeescript')
-    }
-
     if (processedAnswers.generateTestMain) {
       formatter.writeRequirejsConfigFile(testMainFilePath)
       console.log(colorScheme.success(`RequireJS bootstrap file generated at "${testMainFilePath}".`))

lib/init/formatters.js

@@ -72,45 +72,7 @@ class JavaScriptFormatter {
   }
 }
 
-class CoffeeFormatter extends JavaScriptFormatter {
-  constructor () {
-    super()
-    this.TEMPLATE_FILE_PATH = getConfigPath('config.tpl.coffee')
-    this.REQUIREJS_TEMPLATE_FILE = getConfigPath('requirejs.config.tpl.coffee')
-  }
-}
-
-class LiveFormatter extends JavaScriptFormatter {
-  constructor () {
-    super()
-    this.TEMPLATE_FILE_PATH = getConfigPath('config.tpl.ls')
-  }
-}
-
-class TypeFormatter extends JavaScriptFormatter {
-  constructor () {
-    super()
-    this.TEMPLATE_FILE_PATH = getConfigPath('config.tpl.ts')
-  }
-}
-
 exports.JavaScript = JavaScriptFormatter
-exports.Coffee = CoffeeFormatter
-exports.Live = LiveFormatter
-exports.Type = TypeFormatter
-
 exports.createForPath = function (path) {
-  if (/\.coffee$/.test(path)) {
-    return new CoffeeFormatter()
-  }
-
-  if (/\.ls$/.test(path)) {
-    return new LiveFormatter()
-  }
-
-  if (/\.ts$/.test(path)) {
-    return new TypeFormatter()
-  }
-
   return new JavaScriptFormatter()
 }