angular-cn/aio/content/guide/setup-systemjs-anatomy.md

Anatomy of the Setup Project

The documentation setup procedures install a lot of files. Most of them can be safely ignored.

Application files inside the src/ and e2e/ folders matter most to developers.

Files outside those folders condition the development environment. They rarely change and you may never view or modify them. If you do, this page can help you understand their purpose.

<th>
  File
</th>

<th>
  Purpose
</th>

<td>
  <code>src/app/</code>
</td>

<td>


  Angular application files go here.

  Ships with the "Hello Angular" sample's
  `AppComponent`, `AppModule`, a component unit test (`app.component.spec.ts`), and
  the bootstrap file, `main.ts`.

  Try the <live-example name="setup">sample application</live-example>
  and the <live-example name="setup" stackblitz="quickstart-specs">unit test</live-example>
  as _live examples_.
</td>

<td>
  <code>e2e/</code>
</td>

<td>


  _End-to-end_ (e2e) tests of the application,
  written in Jasmine and run by the
  <a href="http://www.protractortest.org/" title="Protractor: end-to-end testing for Angular">protractor</a>
  e2e test runner.

  Initialized with an e2e test for the "Hello Angular" sample.
</td>

<td>
  <code>node_modules/</code>
</td>

<td>


  The _npm_ packages installed with the `npm install` command.
</td>

<td>
  <code>.editorconfig<br>

.git/
.gitignore
.travis.yml

<td>


  Tooling configuration files and folders.
  Ignore them until you have a compelling reason to do otherwise.
</td>

<td>
  <code>CHANGELOG.md</code>
</td>

<td>


  The history of changes to the _QuickStart_ repository.
  Delete or ignore.
</td>

<td>
  <code>favicon.ico</code>
</td>

<td>


  The application icon that appears in the browser tab.
</td>

<td>
  <code>index.html</code>
</td>

<td>


  The application host page.
  It loads a few essential scripts in a prescribed order.
  Then it boots the application, placing the root `AppComponent`
  in the custom `<my-app>` body tag.

  The same `index.html` satisfies all documentation application samples.
</td>

<td>
  <code>karma.conf.js</code>
</td>

<td>


  Configuration for the <a href="https://karma-runner.github.io/1.0/index.html" title="Karma unit test runner">karma</a>
  test runner described in the [Testing](guide/testing) guide.
</td>

<td>
  <code>karma-test-shim.js</code>
</td>

<td>


  Script to run <a href="https://karma-runner.github.io/1.0/index.html" title="Karma unit test runner">karma</a>
  with SystemJS as described in the [Testing](guide/testing) guide.
</td>

<td>
  <code>non-essential-files.txt</code>
</td>

<td>


  A list of files that you can delete if you want to purge your setup of the
  original QuickStart Seed testing and git maintenance artifacts.
  See instructions in the optional
  [_Deleting non-essential files_](guide/setup#non-essential "Setup: Deleting non-essential files") section.
  *Do this only in the beginning to avoid accidentally deleting your own tests and git setup!*
</td>

<td>
  <code>LICENSE</code>
</td>

<td>


  The open source MIT license to use this setup code in your application.
</td>

<td>
  <code>package.json</code>
</td>

<td>


  Identifies `npm `package dependencies for the project.

  Contains command scripts for running the application,
  running tests, and more. Enter `npm run` for a listing.
  <a href="https://github.com/angular/quickstart/blob/master/README.md#npm-scripts"
     title="npm scripts for Angular documentation samples">Read more</a> about them.
</td>

<td>
  <code>protractor.config.js</code>
</td>

<td>


  Configuration for the
  <a href="http://www.protractortest.org/" title="Protractor: end-to-end testing for Angular">protractor</a>
  _end-to-end_ (e2e) test runner.
</td>

<td>
  <code>README.md</code>
</td>

<td>


  Instruction for using this git repository in your project.
  Worth reading before deleting.
</td>

<td>
  <code>styles.css</code>
</td>

<td>


  Global styles for the application. Initialized with an `<h1>` style for the QuickStart demo.

</td>

<td>
  <code>systemjs<br>.config.js</code>
</td>

<td>


  Tells the **SystemJS** module loader where to find modules
  referenced in JavaScript `import` statements. For example:
  <code-example language="ts">
    import { Component } from '@angular/core;
  </code-example>


  Don't touch this file unless you are fully versed in SystemJS configuration.
</td>

<td>
  <code>systemjs<br>.config.extras.js</code>
</td>

<td>


  Optional extra SystemJS configuration.
  A way to add SystemJS mappings, such as for application _barrels_,
  without changing the original `system.config.js`.
</td>

<td>
  <code>tsconfig.json</code>
</td>

<td>


  Tells the TypeScript compiler how to transpile TypeScript source files
  into JavaScript files that run in all modern browsers.
</td>

<td>
  <code>tslint.json</code>
</td>

<td>


  The `npm` installed TypeScript linter inspects your TypeScript code
  and complains when you violate one of its rules.

  This file defines linting rules favored by the
  [Angular style guide](guide/styleguide) and by the authors of the documentation.
</td>