docs(docs-infra): add testing-code-coverage.md.en.md for the english version and translate testing-code-coverage.md for spanish

Fixes #226

aio/content/guide/testing-code-coverage.en.md

@@ -0,0 +1,57 @@
+{@a code-coverage}
+
+# Find out how much code you're testing
+
+The CLI can run unit tests and create code coverage reports.
+Code coverage reports show you any parts of your code base that may not be properly tested by your unit tests.
+
+<div class="alert is-helpful">
+
+  For the sample app that the testing guides describe, see the <live-example name="testing" embedded-style noDownload>sample app</live-example>.
+
+  For the tests features in the testing guides, see <live-example name="testing" stackblitz="specs" noDownload>tests</live-example>.
+
+</div>
+
+
+To generate a coverage report run the following command in the root of your project.
+
+<code-example language="sh" class="code-shell">
+  ng test --no-watch --code-coverage
+</code-example>
+
+When the tests are complete, the command creates a new `/coverage` folder in the project. Open the `index.html` file to see a report with your source code and code coverage values.
+
+If you want to create code-coverage reports every time you test, you can set the following option in the CLI configuration file, `angular.json`:
+
+```
+  "test": {
+    "options": {
+      "codeCoverage": true
+    }
+  }
+```
+
+## Code coverage enforcement
+
+The code coverage percentages let you estimate how much of your code is tested.
+If your team decides on a set minimum amount to be unit tested, you can enforce this minimum with the Angular CLI.
+
+For example, suppose you want the code base to have a minimum of 80% code coverage.
+To enable this, open the [Karma](https://karma-runner.github.io) test platform configuration file, `karma.conf.js`, and add the following in the `coverageIstanbulReporter:` key.
+
+```
+coverageIstanbulReporter: {
+  reports: [ 'html', 'lcovonly' ],
+  fixWebpackSourcePaths: true,
+  thresholds: {
+    statements: 80,
+    lines: 80,
+    branches: 80,
+    functions: 80
+  }
+}
+```
+
+The `thresholds` property causes the tool to enforce a minimum of 80% code coverage when the unit tests are run in the project.
+