Karma Webpack sourcemaps not working
The issue comes from the istanbul-instrumenter-loader.
One solution is to configure karma and webpack to skip code coverage instrumentation when running tests in watch mode.
Based on the latest version in the angular2-webpack-starter repo, you can modify the following 2 files:
karma.conf.js
/**
* @author: @AngularClass
*/
const autowatch = process.env.npm_lifecycle_script.indexOf('--auto-watch') !== -1;
module.exports = function(config) {
var testWebpackConfig = require('./webpack.test.js')({env: 'test'});
var configuration = {
// base path that will be used to resolve all patterns (e.g. files, exclude)
basePath: '',
/*
* Frameworks to use
*
* available frameworks: https://npmjs.org/browse/keyword/karma-adapter
*/
frameworks: ['jasmine'],
// list of files to exclude
exclude: [ ],
/*
* list of files / patterns to load in the browser
*
* we are building the test environment in ./spec-bundle.js
*/
files: [ { pattern: './config/spec-bundle.js', watched: false } ],
/*
* preprocess matching files before serving them to the browser
* available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
*/
// skip coverage in watch mode
preprocessors: { './config/spec-bundle.js': autowatch ? ['webpack', 'sourcemap'] : ['coverage', 'webpack', 'sourcemap'] },
// Webpack Config at ./webpack.test.js
webpack: testWebpackConfig,
// Webpack please don't spam the console when running in karma!
webpackServer: { noInfo: true },
/*
* test results reporter to use
*
* possible values: 'dots', 'progress'
* available reporters: https://npmjs.org/browse/keyword/karma-reporter
*/
reporters: [ 'mocha'],
// 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: false,
/*
* start these browsers
* available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
*/
browsers: [
'Chrome'
],
customLaunchers: {
ChromeTravisCi: {
base: 'Chrome',
flags: ['--no-sandbox']
}
},
/*
* Continuous Integration mode
* if true, Karma captures browsers, runs the tests and exits
*/
singleRun: true
};
if (process.env.TRAVIS){
configuration.browsers = ['ChromeTravisCi'];
}
// skip coverage in watch mode
if (!autowatch) {
configuration.reporters.push('coverage');
configuration.coverageReporter = {
dir : 'coverage/',
reporters: [
{ type: 'text-summary' },
{ type: 'json' },
{ type: 'html' }
]
};
}
config.set(configuration);
};
webpack.test.js
/**
* @author: @AngularClass
*/
const helpers = require('./helpers');
/**
* Webpack Plugins
*/
const ProvidePlugin = require('webpack/lib/ProvidePlugin');
const DefinePlugin = require('webpack/lib/DefinePlugin');
/**
* Webpack Constants
*/
const ENV = process.env.ENV = process.env.NODE_ENV = 'test';
const autowatch = process.env.npm_lifecycle_script.indexOf('--auto-watch') !== -1;
/**
* Webpack configuration
*
* See: http://webpack.github.io/docs/configuration.html#cli
*/
module.exports = function(options) {
let config = {
/**
* Source map for Karma from the help of karma-sourcemap-loader & karma-webpack
*
* Do not change, leave as is or it wont work.
* See: https://github.com/webpack/karma-webpack#source-maps
*/
devtool: 'inline-source-map',
/**
* Options affecting the resolving of modules.
*
* See: http://webpack.github.io/docs/configuration.html#resolve
*/
resolve: {
/**
* An array of extensions that should be used to resolve modules.
*
* See: http://webpack.github.io/docs/configuration.html#resolve-extensions
*/
extensions: ['', '.ts', '.js'],
/**
* Make sure root is src
*/
root: helpers.root('src'),
},
/**
* Options affecting the normal modules.
*
* See: http://webpack.github.io/docs/configuration.html#module
*/
module: {
/**
* An array of applied pre and post loaders.
*
* See: http://webpack.github.io/docs/configuration.html#module-preloaders-module-postloaders
*/
preLoaders: [
/**
* Tslint loader support for *.ts files
*
* See: https://github.com/wbuchwalter/tslint-loader
*/
{
test: /\.ts$/,
loader: 'tslint-loader',
exclude: [helpers.root('node_modules')]
},
/**
* Source map loader support for *.js files
* Extracts SourceMaps for source files that as added as sourceMappingURL comment.
*
* See: https://github.com/webpack/source-map-loader
*/
{
test: /\.js$/,
loader: 'source-map-loader',
exclude: [
// these packages have problems with their sourcemaps
helpers.root('node_modules/rxjs'),
helpers.root('node_modules/@angular')
]}
],
/**
* An array of automatically applied loaders.
*
* IMPORTANT: The loaders here are resolved relative to the resource which they are applied to.
* This means they are not resolved relative to the configuration file.
*
* See: http://webpack.github.io/docs/configuration.html#module-loaders
*/
loaders: [
/**
* Typescript loader support for .ts and Angular 2 async routes via .async.ts
*
* See: https://github.com/s-panferov/awesome-typescript-loader
*/
{
test: /\.ts$/,
loader: 'awesome-typescript-loader',
query: {
compilerOptions: {
// Remove TypeScript helpers to be injected
// below by DefinePlugin
removeComments: true
}
},
exclude: [/\.e2e\.ts$/]
},
/**
* Json loader support for *.json files.
*
* See: https://github.com/webpack/json-loader
*/
{ test: /\.json$/, loader: 'json-loader', exclude: [helpers.root('src/index.html')] },
/**
* Raw loader support for *.css files
* Returns file content as string
*
* See: https://github.com/webpack/raw-loader
*/
{ test: /\.css$/, loaders: ['to-string-loader', 'css-loader'], exclude: [helpers.root('src/index.html')] },
/**
* Raw loader support for *.html
* Returns file content as string
*
* See: https://github.com/webpack/raw-loader
*/
{ test: /\.html$/, loader: 'raw-loader', exclude: [helpers.root('src/index.html')] }
],
/**
* An array of applied pre and post loaders.
*
* See: http://webpack.github.io/docs/configuration.html#module-preloaders-module-postloaders
*/
postLoaders: []
},
/**
* Add additional plugins to the compiler.
*
* See: http://webpack.github.io/docs/configuration.html#plugins
*/
plugins: [
/**
* Plugin: DefinePlugin
* Description: Define free variables.
* Useful for having development builds with debug logging or adding global constants.
*
* Environment helpers
*
* See: https://webpack.github.io/docs/list-of-plugins.html#defineplugin
*/
// NOTE: when adding more properties make sure you include them in custom-typings.d.ts
new DefinePlugin({
'ENV': JSON.stringify(ENV),
'HMR': false,
'process.env': {
'ENV': JSON.stringify(ENV),
'NODE_ENV': JSON.stringify(ENV),
'HMR': false,
}
}),
],
/**
* Static analysis linter for TypeScript advanced options configuration
* Description: An extensible linter for the TypeScript language.
*
* See: https://github.com/wbuchwalter/tslint-loader
*/
tslint: {
emitErrors: false,
failOnHint: false,
resourcePath: 'src'
},
/**
* Include polyfills or mocks for various node stuff
* Description: Node configuration
*
* See: https://webpack.github.io/docs/configuration.html#node
*/
node: {
global: 'window',
process: false,
crypto: 'empty',
module: false,
clearImmediate: false,
setImmediate: false
}
};
// skip coverage in watch mode
if (!autowatch) {
config.module.postLoaders.push(/**
* Instruments JS files with Istanbul for subsequent code coverage reporting.
* Instrument only testing sources.
*
* See: https://github.com/deepsweet/istanbul-instrumenter-loader
*/
{
test: /\.(js|ts)$/, loader: 'istanbul-instrumenter-loader',
include: helpers.root('src'),
exclude: [
/\.(e2e|spec)\.ts$/,
/node_modules/
]
});
}
return config;
}
Now, you should be able to see the source Typescript file when running npm run watch:test.
This looks a whole lot like this Stack Overflow question, and so it may indeed have the same solution.
WebPack, by default, doesn't pass source maps up to Karma unless the file extension is .js (or .jsx if you're using React). In a setup like this one, Karma+WebPack just transpiles the .ts files (or .tsx) straight from TypeScript to JavaScript and serves them under the same file name.
I found a solution that worked for me on the GitHub Issues page for karma-webpack. The trick is to inject webpack.SourceMapDevToolPlugin with a widened file filter into the webpack config. For you, that should look something like this:
var webpack = require('webpack');
// in your config.set:
plugins: [
// existing plugins go here
new webpack.SourceMapDevToolPlugin({
filename: null, // if no value is provided the sourcemap is inlined
test: /\.(ts|js)($|\?)/i // process .js and .ts files only
})
]
Give that a try and see if it doesn't fix the problem.