feat(infrastructure): add tsconfig, tslint, and build setup (#4241)

Author: Matt Goo

.eslintrc.yaml

@@ -15,6 +15,7 @@ rules:
   quotes: [error, single, {"avoidEscape": true}]
   no-var: error
   curly: error
+  eol-last: [error, "always"]
   no-floating-decimal: error
   no-unused-vars:
     - error

.gitignore

@@ -8,3 +8,5 @@ out
 .idea
 *.sw*
 .closure-tmp
+.vscode
+.typescript-tmp

.travis.yml

@@ -12,6 +12,7 @@ branches:
   # This prevents excessive resource usage and CI slowness.
   only:
     - master
+    - feat/typescript
 
 before_install:
   # Source the scripts to export their env vars. See https://superuser.com/a/176788/62792
@@ -48,17 +49,10 @@ matrix:
     addons:
       sauce_connect: true
     script:
-      - if has_testable_files; then npm run test:unit && npm run posttest; else log_untestable_files; fi
+      - if has_testable_files; then npm run test:unit; else log_untestable_files; fi
     after_success:
       - codecov
 
-  - node_js: 8
-    env:
-      - TEST_SUITE=closure
-      - CLOSURE=1
-    script:
-      - if has_testable_files; then npm run test:closure; else log_untestable_files; fi
-
   - node_js: 8
     env:
       - TEST_SUITE=site-generator

CONTRIBUTING.md

@@ -99,9 +99,8 @@ npm run fix # Runs both of the above commands in parallel
 
 npm run test:watch # Runs karma on Chrome, re-running when source files change
 
-npm test # Lints all files, runs karma, runs closure tests, and then runs coverage enforcement checks.
+npm test # Lints all files, runs karma, runs typescript tests, and then runs coverage enforcement checks.
 npm run test:unit # Only runs the karma tests
-npm run test:closure # Runs closure build tests against all closurized files
 ```
 
 #### Running Tests across browsers

closure_externs.js

@@ -762,13 +762,6 @@ would override what's been assigned in `initialize()`.
 
 While this may seem very foreign coming from outside of closure, it is a [common idiom used by closure code](https://github.com/google/closure-compiler/wiki/Types-in-the-Closure-Type-System#typedefs).
 
-## Handling third-party code
-
-Some of our components rely on third-party modules. These modules must be typed as **externs**
-within `closure_externs.js`. In most cases, you will not need to worry about doing this, as a core
-team member will most likely assist you with it. However, the details of typing these modules can
-be found within that file.
-
 ## Where to go for more help
 
 If you're working on an issue for MDC Web and find yourself wrestling with closure, please don't

docs/closure-compiler.md

@@ -50,6 +50,18 @@ const SAUCE_LAUNCHERS = {
 
 const customLaunchers = Object.assign({}, USING_SL ? SAUCE_LAUNCHERS : {}, HEADLESS_LAUNCHERS);
 const browsers = USING_TRAVISCI ? Object.keys(customLaunchers) : ['Chrome'];
+const istanbulInstrumenterLoader = {
+  use: [{
+    loader: 'istanbul-instrumenter-loader',
+    options: {esModules: true},
+  }],
+  exclude: [
+    /node_modules/,
+    /adapter.[jt]s$/,
+    /constants.[jt]s$/,
+  ],
+  include: path.resolve('./packages'),
+};
 
 module.exports = function(config) {
   config.set({
@@ -61,7 +73,7 @@ module.exports = function(config) {
     preprocessors: {
       'test/unit/index.js': ['webpack', 'sourcemap'],
     },
-    reporters: ['dots', 'coverage'],
+    reporters: ['dots', 'coverage-istanbul'],
     port: 9876,
     colors: true,
     logLevel: config.LOG_INFO,
@@ -72,13 +84,21 @@ module.exports = function(config) {
     concurrency: USING_SL ? 4 : Infinity,
     customLaunchers: customLaunchers,
 
-    coverageReporter: {
-      dir: 'coverage',
-      reporters: [
-        {type: 'lcovonly', subdir: '.'},
-        {type: 'json', subdir: '.', file: 'coverage.json'},
-        {type: 'html'},
-      ],
+    coverageIstanbulReporter: {
+      'dir': 'coverage',
+      'reports': ['html', 'lcovonly', 'json'],
+      'report-config': {
+        lcovonly: {subdir: '.'},
+        json: {subdir: '.', file: 'coverage.json'},
+      },
+      // 'emitWarning' causes the tests to fail if the thresholds are not met
+      'emitWarning': false,
+      'thresholds': {
+        statements: 95,
+        branches: 95,
+        lines: 95,
+        functions: 95,
+      },
     },
 
     client: {
@@ -93,20 +113,15 @@ module.exports = function(config) {
     },
 
     webpack: Object.assign({}, webpackConfig, {
-      devtool: 'inline-source-map',
       module: Object.assign({}, webpackConfig.module, {
         // Cover source files when not debugging tests. Otherwise, omit coverage instrumenting to get
         // uncluttered source maps.
-        rules: webpackConfig.module.rules.concat([config.singleRun ? {
+        rules: webpackConfig.module.rules.concat(config.singleRun ? [Object.assign({
+          enforce: 'post',
+          test: /\.ts$/,
+        }, istanbulInstrumenterLoader), Object.assign({
           test: /\.js$/,
-          include: path.resolve('./packages'),
-          exclude: [
-            /node_modules/,
-            /adapter.js/,
-          ],
-          loader: 'istanbul-instrumenter-loader',
-          query: {esModules: true},
-        } : undefined]).filter(Boolean),
+        }, istanbulInstrumenterLoader)] : []),
       }),
     }),