How do I know which new javascript features are available to use in project

To determine which new JavaScript features you can use in your project, you can follow these steps:

1. Check Browser Compatibility:

   • Use tools like Can I use to check the compatibility of specific JavaScript features across different browsers and versions. This site provides detailed information on feature support for various environments.

2. Refer to ECMAScript Specifications:

   • Familiarize yourself with the latest ECMAScript (ES) specifications. The ECMAScript proposal status page on GitHub provides the current status of new features and proposals.

3. Use Modern JavaScript Documentation:

   • Sites like MDN Web Docs offer comprehensive documentation on JavaScript features, including their compatibility and usage.

4. Browser DevTools:

   • Most modern browsers have developer tools that include information on supported JavaScript features. You can check the browser's documentation for details on what is supported.

5. JavaScript Transpilers:

   • If you're using a transpiler like Babel, you can configure it to include specific plugins or presets that allow the use of newer JavaScript features while ensuring compatibility with older environments.

6. Package Managers:

   • Tools like npm and Yarn often include details about the supported JavaScript versions and environments for specific packages. Reviewing the documentation and configuration of these tools can provide insights into compatible features.

7. Environment-Specific Documentation:

   • If you're developing for a specific runtime environment like Node.js, refer to its official documentation to understand which ECMAScript features are supported in various versions.

Practical Steps

1. Identify Target Environments:

   • Determine the environments where your code will run (e.g., specific browser versions, Node.js versions).

2. Consult Compatibility Tables:

   • Use caniuse.com to look up each feature you're interested in and see its support across your target environments.

3. Use Linters and Transpilers:

   • Configure tools like ESLint with plugins that enforce compatibility rules based on your target environments.
   • Configure Babel to transpile modern JavaScript features to a version supported by your target environments.

Example: Checking Compatibility for a Feature

Suppose you want to use the optional chaining feature in your project:

1. Go to Can I use.
2. Search for "optional chaining".
3. Review the compatibility table to see which browsers and versions support this feature.
4. If necessary, configure Babel with the appropriate plugin to ensure compatibility.

Example: Using Babel for Compatibility

1. Install Babel and the necessary presets/plugins:

   npm install --save-dev @babel/core @babel/preset-env @babel/plugin-proposal-optional-chaining
   

2. Configure Babel in a .babelrc file:

   {
     "presets": ["@babel/preset-env"],
     "plugins": ["@babel/plugin-proposal-optional-chaining"]
   }
   

This configuration ensures that your code can use optional chaining and still be compatible with environments that do not support this feature natively.