Only add frontend code coverage instrumentation when generating coverage report

.babelrc

+{
+  "presets": [
+    ["latest", { "es2015": { "modules": false } }],
+    "stage-2"
+  ],
+  "env": {
+    "coverage": {
+      "plugins": [
+        ["istanbul", {
+          "exclude": [
+            "app/assets/javascripts/droplab/**/*",
+            "spec/javascripts/**/*"
+          ]
+        }],
+        ["transform-define", {
+          "process.env.BABEL_ENV": "coverage"
+        }]
+      ]
+    }
+  }
+}

.gitlab-ci.yml

@@ -277,6 +277,8 @@ rake karma:
   stage: test
   <<: *use-db
   <<: *dedicated-runner
+  variables:
+    BABEL_ENV: "coverage"
   script:
     - bundle exec rake karma
   artifacts:

changelogs/unreleased/make-karma-fast-again.yml

+---
+title: Only add code coverage instrumentation when generating coverage report
+merge_request: 9987
+author:

config/karma.config.js

@@ -3,17 +3,6 @@ var webpack = require('webpack');
 var webpackConfig = require('./webpack.config.js');
 var ROOT_PATH = path.resolve(__dirname, '..');
 
-// add coverage instrumentation to babel config
-if (webpackConfig.module && webpackConfig.module.rules) {
-  var babelConfig = webpackConfig.module.rules.find(function (rule) {
-    return rule.loader === 'babel-loader';
-  });
-
-  babelConfig.options = babelConfig.options || {};
-  babelConfig.options.plugins = babelConfig.options.plugins || [];
-  babelConfig.options.plugins.push('istanbul');
-}
-
 // remove problematic plugins
 if (webpackConfig.plugins) {
   webpackConfig.plugins = webpackConfig.plugins.filter(function (plugin) {
@@ -27,7 +16,8 @@ if (webpackConfig.plugins) {
 // Karma configuration
 module.exports = function(config) {
   var progressReporter = process.env.CI ? 'mocha' : 'progress';
-  config.set({
+
+  var karmaConfig = {
     basePath: ROOT_PATH,
     browsers: ['PhantomJS'],
     frameworks: ['jasmine'],
@@ -38,14 +28,20 @@ module.exports = function(config) {
     preprocessors: {
       'spec/javascripts/**/*.js': ['webpack', 'sourcemap'],
     },
-    reporters: [progressReporter, 'coverage-istanbul'],
-    coverageIstanbulReporter: {
+    reporters: [progressReporter],
+    webpack: webpackConfig,
+    webpackMiddleware: { stats: 'errors-only' },
+  };
+
+  if (process.env.BABEL_ENV === 'coverage' || process.env.NODE_ENV === 'coverage') {
+    karmaConfig.reporters.push('coverage-istanbul');
+    karmaConfig.coverageIstanbulReporter = {
       reports: ['html', 'text-summary'],
       dir: 'coverage-javascript/',
       subdir: '.',
       fixWebpackSourcePaths: true
-    },
-    webpack: webpackConfig,
-    webpackMiddleware: { stats: 'errors-only' },
-  });
+    };
+  }
+
+  config.set(karmaConfig);
 };

config/webpack.config.js

@@ -59,13 +59,7 @@ var config = {
       {
         test: /\.js$/,
         exclude: /(node_modules|vendor\/assets)/,
-        loader: 'babel-loader',
-        options: {
-          presets: [
-            ["es2015", {"modules": false}],
-            'stage-2'
-          ]
-        }
+        loader: 'babel-loader'
       },
       {
         test: /\.svg$/,

package.json

@@ -6,6 +6,7 @@
     "eslint-fix": "eslint --max-warnings 0 --ext .js --fix .",
     "eslint-report": "eslint --max-warnings 0 --ext .js --format html --output-file ./eslint-report.html .",
     "karma": "karma start config/karma.config.js --single-run",
+    "karma-coverage": "BABEL_ENV=coverage karma start config/karma.config.js --single-run",
     "karma-start": "karma start config/karma.config.js",
     "webpack": "webpack --config config/webpack.config.js",
     "webpack-prod": "NODE_ENV=production webpack --config config/webpack.config.js"
@@ -13,7 +14,8 @@
   "dependencies": {
     "babel-core": "^6.22.1",
     "babel-loader": "^6.2.10",
-    "babel-preset-es2015": "^6.22.0",
+    "babel-plugin-transform-define": "^1.2.0",
+    "babel-preset-latest": "^6.24.0",
     "babel-preset-stage-2": "^6.22.0",
     "bootstrap-sass": "^3.3.6",
     "compression-webpack-plugin": "^0.3.2",
@@ -57,12 +59,5 @@
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^2.0.2",
     "webpack-dev-server": "^2.3.0"
-  },
-  "nyc": {
-    "exclude": [
-      "spec/javascripts/test_bundle.js",
-      "spec/javascripts/**/*_spec.js",
-      "app/assets/javascripts/droplab/**/*"
-    ]
   }
 }

spec/javascripts/test_bundle.js

@@ -32,10 +32,11 @@ testsContext.keys().forEach(function (path) {
   }
 });
 
-// workaround: include all source files to find files with 0% coverage
-// see also https://github.com/deepsweet/istanbul-instrumenter-loader/issues/15
-describe('Uncovered files', function () {
-  // the following files throw errors because of undefined variables
+// if we're generating coverage reports, make sure to include all files so
+// that we can catch files with 0% coverage
+// see: https://github.com/deepsweet/istanbul-instrumenter-loader/issues/15
+if (process.env.BABEL_ENV === 'coverage') {
+  // exempt these files from the coverage report
   const troubleMakers = [
     './blob_edit/blob_edit_bundle.js',
     './cycle_analytics/components/stage_plan_component.js',
@@ -48,7 +49,8 @@ describe('Uncovered files', function () {
     './network/branch_graph.js',
   ];
 
-  const sourceFiles = require.context('~', true, /^\.\/(?!application\.js).*\.js$/);
+  describe('Uncovered files', function () {
+    const sourceFiles = require.context('~', true, /\.js$/);
     sourceFiles.keys().forEach(function (path) {
       // ignore if there is a matching spec file
       if (testsContext.keys().indexOf(`${path.replace(/\.js$/, '')}_spec`) > -1) {
@@ -65,4 +67,5 @@ describe('Uncovered files', function () {
         }
       });
     });
-});
+  });
+}

yarn.lock

@@ -473,6 +473,13 @@ babel-plugin-transform-decorators@^6.22.0:
     babel-template "^6.22.0"
     babel-types "^6.22.0"
 
+babel-plugin-transform-define@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-define/-/babel-plugin-transform-define-1.2.0.tgz#f036bda05162f29a542e434f585da1ccf1e7ec6a"
+  dependencies:
+    lodash.get "4.4.2"
+    traverse "0.6.6"
+
 babel-plugin-transform-es2015-arrow-functions@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-arrow-functions/-/babel-plugin-transform-es2015-arrow-functions-6.22.0.tgz#452692cb711d5f79dc7f85e440ce41b9f244d221"
@@ -549,17 +556,17 @@ babel-plugin-transform-es2015-literals@^6.22.0:
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-transform-es2015-modules-amd@^6.22.0:
-  version "6.22.0"
-  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-amd/-/babel-plugin-transform-es2015-modules-amd-6.22.0.tgz#bf69cd34889a41c33d90dfb740e0091ccff52f21"
+babel-plugin-transform-es2015-modules-amd@^6.24.0:
+  version "6.24.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-amd/-/babel-plugin-transform-es2015-modules-amd-6.24.0.tgz#a1911fb9b7ec7e05a43a63c5995007557bcf6a2e"
   dependencies:
-    babel-plugin-transform-es2015-modules-commonjs "^6.22.0"
+    babel-plugin-transform-es2015-modules-commonjs "^6.24.0"
     babel-runtime "^6.22.0"
     babel-template "^6.22.0"
 
-babel-plugin-transform-es2015-modules-commonjs@^6.22.0:
-  version "6.23.0"
-  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-commonjs/-/babel-plugin-transform-es2015-modules-commonjs-6.23.0.tgz#cba7aa6379fb7ec99250e6d46de2973aaffa7b92"
+babel-plugin-transform-es2015-modules-commonjs@^6.24.0:
+  version "6.24.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-commonjs/-/babel-plugin-transform-es2015-modules-commonjs-6.24.0.tgz#e921aefb72c2cc26cb03d107626156413222134f"
   dependencies:
     babel-plugin-transform-strict-mode "^6.22.0"
     babel-runtime "^6.22.0"
@@ -574,11 +581,11 @@ babel-plugin-transform-es2015-modules-systemjs@^6.22.0:
     babel-runtime "^6.22.0"
     babel-template "^6.23.0"
 
-babel-plugin-transform-es2015-modules-umd@^6.22.0:
-  version "6.23.0"
-  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-umd/-/babel-plugin-transform-es2015-modules-umd-6.23.0.tgz#8d284ae2e19ed8fe21d2b1b26d6e7e0fcd94f0f1"
+babel-plugin-transform-es2015-modules-umd@^6.24.0:
+  version "6.24.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-es2015-modules-umd/-/babel-plugin-transform-es2015-modules-umd-6.24.0.tgz#fd5fa63521cae8d273927c3958afd7c067733450"
   dependencies:
-    babel-plugin-transform-es2015-modules-amd "^6.22.0"
+    babel-plugin-transform-es2015-modules-amd "^6.24.0"
     babel-runtime "^6.22.0"
     babel-template "^6.23.0"
 
@@ -669,9 +676,9 @@ babel-plugin-transform-strict-mode@^6.22.0:
     babel-runtime "^6.22.0"
     babel-types "^6.22.0"
 
-babel-preset-es2015@^6.22.0:
-  version "6.22.0"
-  resolved "https://registry.yarnpkg.com/babel-preset-es2015/-/babel-preset-es2015-6.22.0.tgz#af5a98ecb35eb8af764ad8a5a05eb36dc4386835"
+babel-preset-es2015@^6.24.0:
+  version "6.24.0"
+  resolved "https://registry.yarnpkg.com/babel-preset-es2015/-/babel-preset-es2015-6.24.0.tgz#c162d68b1932696e036cd3110dc1ccd303d2673a"
   dependencies:
     babel-plugin-check-es2015-constants "^6.22.0"
     babel-plugin-transform-es2015-arrow-functions "^6.22.0"
@@ -684,10 +691,10 @@ babel-preset-es2015@^6.22.0:
     babel-plugin-transform-es2015-for-of "^6.22.0"
     babel-plugin-transform-es2015-function-name "^6.22.0"
     babel-plugin-transform-es2015-literals "^6.22.0"
-    babel-plugin-transform-es2015-modules-amd "^6.22.0"
-    babel-plugin-transform-es2015-modules-commonjs "^6.22.0"
+    babel-plugin-transform-es2015-modules-amd "^6.24.0"
+    babel-plugin-transform-es2015-modules-commonjs "^6.24.0"
     babel-plugin-transform-es2015-modules-systemjs "^6.22.0"
-    babel-plugin-transform-es2015-modules-umd "^6.22.0"
+    babel-plugin-transform-es2015-modules-umd "^6.24.0"
     babel-plugin-transform-es2015-object-super "^6.22.0"
     babel-plugin-transform-es2015-parameters "^6.22.0"
     babel-plugin-transform-es2015-shorthand-properties "^6.22.0"
@@ -698,6 +705,27 @@ babel-preset-es2015@^6.22.0:
     babel-plugin-transform-es2015-unicode-regex "^6.22.0"
     babel-plugin-transform-regenerator "^6.22.0"
 
+babel-preset-es2016@^6.22.0:
+  version "6.22.0"
+  resolved "https://registry.yarnpkg.com/babel-preset-es2016/-/babel-preset-es2016-6.22.0.tgz#b061aaa3983d40c9fbacfa3743b5df37f336156c"
+  dependencies:
+    babel-plugin-transform-exponentiation-operator "^6.22.0"
+
+babel-preset-es2017@^6.22.0:
+  version "6.22.0"
+  resolved "https://registry.yarnpkg.com/babel-preset-es2017/-/babel-preset-es2017-6.22.0.tgz#de2f9da5a30c50d293fb54a0ba15d6ddc573f0f2"
+  dependencies:
+    babel-plugin-syntax-trailing-function-commas "^6.22.0"
+    babel-plugin-transform-async-to-generator "^6.22.0"
+
+babel-preset-latest@^6.24.0:
+  version "6.24.0"
+  resolved "https://registry.yarnpkg.com/babel-preset-latest/-/babel-preset-latest-6.24.0.tgz#a68d20f509edcc5d7433a48dfaebf7e4f2cd4cb7"
+  dependencies:
+    babel-preset-es2015 "^6.24.0"
+    babel-preset-es2016 "^6.22.0"
+    babel-preset-es2017 "^6.22.0"
+
 babel-preset-stage-2@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-preset-stage-2/-/babel-preset-stage-2-6.22.0.tgz#ccd565f19c245cade394b21216df704a73b27c07"
@@ -2900,6 +2928,10 @@ lodash.deburr@^4.0.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/lodash.deburr/-/lodash.deburr-4.1.0.tgz#ddb1bbb3ef07458c0177ba07de14422cb033ff9b"
 
+lodash.get@4.4.2:
+  version "4.4.2"
+  resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"
+
 lodash.get@^3.7.0:
   version "3.7.0"
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-3.7.0.tgz#3ce68ae2c91683b281cc5394128303cbf75e691f"
@@ -4271,6 +4303,10 @@ tough-cookie@~2.3.0:
   dependencies:
     punycode "^1.4.1"
 
+traverse@0.6.6:
+  version "0.6.6"
+  resolved "https://registry.yarnpkg.com/traverse/-/traverse-0.6.6.tgz#cbdf560fd7b9af632502fed40f918c157ea97137"
+
 trim-right@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/trim-right/-/trim-right-1.0.1.tgz#cb2e1203067e0c8de1f614094b9fe45704ea6003"