Angular Webpack Configuration Customization

This challenge focuses on understanding and customizing the Webpack configuration within an Angular project. By modifying Webpack, you can gain finer control over your build process, optimize assets, and integrate custom loaders or plugins, leading to more efficient and tailored applications.

Problem Description

Your task is to modify the default Webpack configuration of an Angular project to achieve specific build customizations. Angular CLI abstracts away much of Webpack's complexity, but it also provides mechanisms for extending and overriding its configuration. You will need to integrate a custom Webpack loader to process a new file type and configure Webpack to output optimized assets.

Key Requirements:

1. Integrate a Custom Loader: Implement a custom loader (e.g., a hypothetical my-custom-loader) to process .mydata files. These files will contain simple JSON-like data. The loader should transform the content of .mydata files into JavaScript modules that export the parsed JSON data.
2. Output Optimization: Configure Webpack to generate separate CSS files for styles instead of inlining them into JavaScript bundles.
3. Environment-Specific Configuration: Ensure that your customizations are applied correctly for both development and production builds.

Expected Behavior:

• When you have a file named data.mydata in your Angular project, and you import it into a component (e.g., import myData from './data.mydata';), the myData variable should contain the parsed JavaScript object representation of the JSON data within data.mydata.
• During a production build (ng build --prod), CSS styles should be extracted into individual .css files.
• The custom loader should function correctly in both development (ng serve) and production builds.

Edge Cases to Consider:

• Handling of invalid JSON within .mydata files (though for this challenge, assume valid JSON).
• Ensuring the custom loader doesn't interfere with standard Angular build processes.

Examples

Example 1: Processing a .mydata file

Input File (src/app/data.mydata):

{
  "greeting": "Hello",
  "target": "World"
}

TypeScript Component (src/app/app.component.ts):

import { Component } from '@angular/core';
import myData from './data.mydata'; // Assuming your loader is configured to handle this

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'my-angular-app';
  message: string;

  constructor() {
    this.message = `${myData.greeting}, ${myData.target}!`;
  }
}

Expected Output (in the browser console or rendered in the template): The message property in AppComponent should be "Hello, World!".

Explanation: The custom Webpack loader intercepts the import of data.mydata, parses the JSON content, and transforms it into a JavaScript module exporting the parsed object. Angular then uses this exported object.

Example 2: CSS Output in Production Build

Input: A standard Angular project with some component-specific styles and global styles.

Command: ng build --prod

Expected Output: When inspecting the dist/your-app-name/ directory after the build, you should find separate .css files for your application's styles, rather than styles being embedded within the JavaScript bundles.

Explanation: The Webpack configuration is adjusted to use a CSS extraction plugin (like MiniCssExtractPlugin), which pulls out CSS from the JavaScript bundles and creates standalone .css files.

Constraints

• You will be working within a standard Angular CLI project.
• The custom loader should be written in TypeScript and be compatible with Webpack's loader API.
• Avoid significantly altering the core Angular CLI build process beyond what's necessary for these specific customizations.
• The solution should be efficient and not introduce substantial build time overhead.

Notes

• Angular CLI uses Webpack under the hood. You can extend its configuration by creating a webpack-config.js file in the root of your Angular project.
• Refer to the official Angular CLI documentation on extending Webpack configurations for guidance.
• You'll likely need to install additional Webpack packages (loaders and plugins).
• For the custom loader, consider how to parse the JSON and return valid JavaScript code (e.g., using module.exports = ...).
• For CSS extraction, look into mini-css-extract-plugin.