feat: dynamic secondary entry points

Author: DavidParks8

.gitignore

@@ -63,4 +63,5 @@ jspm_packages/
 
 # Angular Build directory
 .ng_build/
+.ng_pkg_build/
 dist/

README.md

@@ -79,6 +79,56 @@ in the `ngPackage` field:
 
 Note: the JSON `$schema` reference enables JSON editing support (autocompletion) for the custom `ngPackage` property in an IDE like [VSCode](https://github.com/Microsoft/vscode).
 
+#### Secondary Entry-Points
+
+Besides the primary entry point, a package can contain one or more secondary entry points (e.g. `@angular/core/testing`).
+These contain symbols that we don't want to group together with the symbols in the main entry point.
+Module ID of an import for a secondary entry point directs a module loader to a directory by the secondary entry point’s name.
+For instance, “@angular/core/testing” resolves to a directory by the same name, “@angular/core/testing”.
+This directory contains a package.json file that directs the loader to the correct location for what it’s looking for.
+To that end, secondary entry points are dynamically discovered by searching for `package.json`
+files within sub directories of the main `package.json` file's folder.
+
+##### So how do I use it?
+
+All you have to do is create a `package.json` file and put it where you want a secondary entry
+point to be created. One way this can be done is by mimicking the folder structure of the 
+following example which has a testing entry point in addition to it's main entry point.
+
+```
+src  
+├── testing   
+│   ├── *.ts   
+│   ├── public_api.ts  
+│   └── package.json  
+├── *.ts  
+├── public_api.ts  
+├── ng-package.json   
+└── package.json   
+```
+
+The contents of the secondary `package.json` can be as simple as:
+```json
+{}
+```
+
+No, that is not a typo. No name is required. No version is required. It's all handled for you by ng-packagr!
+When built, the secondary bundles would be accessible as `$(your-primary-package-name)/testing`.
+##### What if I don't like `public_api.ts`?
+
+You can change the entry point file by using the `ngPackage` configuration field in your secondary `package.json`.
+For example, the following would use `index.ts` as the secondary entry point:
+
+```json
+{
+  "ngPackage": {
+    "lib": {
+      "entryFile": "index.ts"
+    }
+  }
+}
+```
+
 #### More Examples
 
 Nikolas LeBlanc has written a story on medium.com on [Building an Angular 4 Component Library with the Angular CLI and ng-packagr](https://medium.com/@ngl817/building-an-angular-4-component-library-with-the-angular-cli-and-ng-packagr-53b2ade0701e)
@@ -99,6 +149,8 @@ We keep track of user questions in GitHub's issue tracker and try to build a doc
    - :dancer: Creates type definitions (`.d.ts`)
    - :runner: Generates [Ahead-of-Time](https://angular.io/guide/aot-compiler#why-do-aot-compilation) metadata (`.metadata.json`)
  - :surfer: Inlines Templates and Stylesheets
+ - :trophy: Supports dynamic discovery and bundling of secondary entry points
+ - :mag_right: Supports scoped, and non-scoped packages
  - :sparkles: CSS Features
    - :camel: Runs [SCSS](http://sass-lang.com/guide) preprocessor, supporting the [relative `~` import syntax](https://github.com/webpack-contrib/sass-loader#imports)
    - :elephant: Runs [less](http://lesscss.org/#getting-started) preprocessor

integration/samples.js

@@ -1,4 +1,4 @@
-const fs = require('fs');
+const fs = require('fs-extra');
 const path = require('path');
 process.env.DEBUG = true;
 

integration/samples/custom/specs/package.ts

@@ -29,12 +29,12 @@ describe(`sample-custom`, () => {
       expect(PACKAGE['main']).to.equal('bundles/sample-custom.umd.js');
     });
 
-    it(`should reference "module" bundle (FESM5, also FESM2014)`, () => {
-      expect(PACKAGE['module']).to.equal('sample-custom/sample-custom.es5.js');
+    it(`should reference "module" bundle (FESM5, also FESM2015)`, () => {
+      expect(PACKAGE['module']).to.equal('sample-custom.es5.js');
     });
 
     it(`should reference "es2015" bundle (FESM2015)`, () => {
-      expect(PACKAGE['es2015']).to.equal('sample-custom/sample-custom.js');
+      expect(PACKAGE['es2015']).to.equal('sample-custom.js');
     });
 
     it(`should reference "typings" files`, () => {

integration/samples/secondary/.browserslistrc

@@ -0,0 +1,3 @@
+last 2 Chrome versions
+iOS > 10
+Safari > 10

integration/samples/secondary/README.md

@@ -0,0 +1,4 @@
+Sample library: Configuration in package.json
+======================================
+
+The configuration in this sample resides inside `package.json`.

integration/samples/secondary/baz/baz.component.html

@@ -0,0 +1 @@
+<h1 class="baz">baz!</h1>

integration/samples/secondary/baz/baz.component.scss

@@ -0,0 +1,5 @@
+@import '~node-sass/test/fixtures/include-files/file-not-processed-by-loader';
+
+.baz {
+    color: $variable-defined-by-file-not-processed-by-loader;
+}

integration/samples/secondary/baz/baz.component.ts

@@ -0,0 +1,9 @@
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'baz-component',
+  templateUrl: './baz.component.html',
+  styleUrls: ['./baz.component.scss']
+})
+export class BazComponent {
+}

integration/samples/secondary/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "@sample/secondary-lib",
+  "description": "A sample library with configuration in package.json",
+  "version": "1.0.0-pre.0",
+  "private": true,
+  "repository": "https://github.com/dherges/ng-packagr.git",
+  "peerDependencies": {
+    "@angular/core": "^4.1.2",
+    "@angular/common": "^4.1.2"
+  },
+  "ngPackage": {
+    "$schema": "../../../src/lib/ng-package.schema.json",
+    "lib": {
+      "entryFile": "public_api.ts"
+    }
+  }
+}