This section provides a step-by-step guide focused on the configuration options for the development environment of the helixml/demo-recipes.

Configuration Files

1. TypeScript Configuration (tsconfig.json)

The TypeScript configuration file manages the TypeScript compiler’s options. Here’s a standard example:

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules"]
}

• target: Specifies the ECMAScript target version.
• module: Specifies the module code generation.
• strict: Enables all strict type-checking options.
• esModuleInterop: Enables emit interoperability between CommonJS and ES Modules.
• skipLibCheck: Skips type checking of declaration files.
• forceConsistentCasingInFileNames: Disallows inconsistently-cased references to the same file.

2. CSS Preprocessor Configuration

If CSS preprocessors like SASS or LESS are used, a configuration file (webpack.config.js or equivalent) is generally needed. Here’s an example configuration for SASS:

const path = require('path');

module.exports = {
  entry: './src/styles/main.scss',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader'
        ]
      }
    ]
  }
};

• This configuration handles SASS files and compiles them into a bundled CSS file.

3. HTML Template Configuration

If you are using a templating engine, ensure the configuration specifies the entry point. Here’s an example for using HTML with a template engine like Pug:

const express = require('express');
const app = express();

app.set('view engine', 'pug');
app.set('views', './views');

app.get('/', (req, res) => {
  res.render('index', { title: 'Demo Recipes' });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

• The set method establishes the view engine and the directory for views.
• res.render constructs the response using the specified template.

4. Shell Environment Configuration

For shell configuration, environment variables can be declared in a .env file, which can be used with Node.js applications. An example .env:

DATABASE_URL=mongodb://localhost:27017/demo
API_KEY=your_api_key_here

• To utilize these variables in a Node.js application, the dotenv package can be used:

require('dotenv').config();

const dbUrl = process.env.DATABASE_URL;
const apiKey = process.env.API_KEY;

console.log(`Connecting to database at ${dbUrl}`);

5. JavaScript Configuration (Webpack)

JavaScript tooling may be set up using Webpack. An example of a simple webpack.config.js is provided below:

const path = require('path');

module.exports = {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env']
          }
        }
      }
    ]
  }
};

• This configuration sets the entry point for the application and specifies output settings.
• Babel is used to transpile modern JavaScript into a backwards-compatible version.

6. Running the Development Server

To start the development server, typically a script is added to the package.json. An example script might look like this:

"scripts": {
  "start": "webpack serve --open --mode development"
}

• The command webpack serve runs the application using Webpack’s development server.

Conclusion

The configuration of the development environment in helixml/demo-recipes requires careful attention to type safety, asset handling, and environment variables. The options provided above ensure that developers can efficiently manage the setup for various languages and environments.

Sources:

• Official TypeScript documentation.
• Webpack documentation.
• Express.js documentation.