Version Compatibility in Angular

Angular is a widely used front-end framework developed by Google for building dynamic web applications. Over time, Angular has evolved from the AngularJS (1.x) to the modern Angular (2+) bringing significant improvements in performance, modularity and development.

With frequent updates ensuring version compatibility is important when maintaining or upgrading the Angular applications. This article provides an overview of Angular version compatibility, how to manage it and best practices to ensure smooth transitions between the different Angular versions.

Understanding Angular Versioning

Version compatibility in Angular refers to the ability of the different versions of Angular libraries, tools and dependencies to work together without causing errors or breaking changes. Since Angular follows Semantic Versioning understanding how each version affects your application is essential for the seamless development experience.

Angular versions are divided into:

• Major: Introduces significant changes sometimes with the breaking changes.
• Minor: Adds new features but remains backwards-compatible.
• Patch: Fix bugs while ensuring backward compatibility.

Angular Release Schedule

The Angular follows a predictable release schedule which helps developers plan upgrades and maintain compatibility. The Angular releases major updates twice a year, typically in March and September with the minor and patch releases occurring more frequently.

• Major Releases: Approximately every 6 months, introducing new features and potentially breaking changes.
• Minor Releases: Every few weeks, adding new features in a backward-compatible manner.
• Patch Releases: As needed, to address bug fixes or regressions.

Angular also provides Long-Term Support (LTS) for the previous major version, allowing developers more time to update their applications.

Version Compatibility Considerations

When upgrading or maintaining Angular projects consider the following:

Core Angular Packages

Angular's core packages include:

• @angular/core: The main package contains the core functionality.
• @angular/common: Common directives and pipes.
• @angular/compiler: The compiler for the Angular templates.
• @angular/forms: Form handling.
• @angular/router: Routing capabilities.

Each package version must be aligned with the Angular core version to the avoid compatibility issues.

Angular CLI

The Angular Command Line Interface (CLI) is used to the create and manage Angular projects. It must be compatible with the Angular core packages:

• Installation: Use npm install -g @angular/cli to install the latest CLI version.
• Version Check: Run ng --version to check the CLI version.

Angular Material and Other Libraries

The Angular Material and other third-party libraries need to be compatible with Angular core version:

• Angular Material: Check the version compatibility with the Angular on the Angular Material Release Notes.
• Third-Party Libraries: The Verify compatibility with the Angular versions in the library's documentation.

TypeScript and RxJS Versions

The Angular requires specific versions of the TypeScript and RxJS:

• TypeScript: Check the Angular documentation for the supported TypeScript version.
• RxJS: Ensure compatibility with the version required by the Angular. For Angular 13, RxJS 6.5 or higher is typically required.

Checking and Updating Angular Version Compatibility

Checking Current Versions

To check the current versions of Angular and related packages in your project, use:

ng version

This command provides a detailed list of Angular core packages, the CLI, and other dependencies, along with their versions.

Updating Angular to a New Version

Updating Angular involves upgrading both the Angular CLI and the core framework packages. Always start by updating the Angular CLI globally:

npm install -g @angular/cli@latest

Then, update your local project dependencies:

ng update @angular/core @angular/cli

Using ng update for Guided Updates

The ng update command provides guidance for the updating Angular projects:

• Basic Update: Run ng update to see a list of the outdated packages and recommended updates.
• Detailed Update: Run ng update @angular/core@latest @angular/cli@latest to the update to the latest versions.

Common Compatibility Issues and Solutions

TypeScript Version Mismatch

• Issue: The TypeScript version required by the Angular may differ from the installed version.
• Solution: Install the required TypeScript version using the npm install typescript@<version>.

npm install typescript@<version>

RxJS Compatibility Issues

• Issue: RxJS version conflicts with the Angular's required version.
• Solution: Update RxJS to a compatible version using the npm install rxjs@<version>.

npm install rxjs@<version>

Deprecated APIs and Breaking Changes

• Issue: Upgrading to a new major version may introduce breaking changes or deprecated APIs.
• Solution: Review the Angular Changelog and migration guide for the changes and update your code accordingly.

Best Practices for Version Compatibility

1. Use Angular Update Guide

The Angular provides an official update guide that helps developers upgrade from the one version to another while considering the breaking changes and compatibility issues. This tool is a great resource when transitioning between versions.

2. Keep Angular CLI and Core in Sync

Ensure that the Angular CLI and Angular Core versions are compatible. Running the following command updates both to the latest version:

ng update @angular/core @angular/cli

3. Test Third-Party Libraries

When upgrading Angular always check if third-party libraries in the project are compatible with new version. For instance, libraries like RxJS, NgRx or UI components may need updates when Angular versions change.

We can use the following command to check outdated dependencies:

npm outdated

4. Follow Semantic Versioning (Semver)

The Angular uses semantic versioning which helps in understanding the type of changes that come with the version:

• Major versions (X.0.0) may introduce breaking changes.
• Minor versions (X.Y.0) introduce new features without the breaking backward compatibility.
• Patch versions (X.Y.Z) include the backward-compatible bug fixes.

By following semver developers can better anticipate the impact of the updating versions.

5. Locking Versions

To avoid unexpected changes in dependencies lock the version of the Angular and third-party libraries in package.json. This ensures that each time the project is built the same versions of libraries are used.

Example of locking dependencies in package.json:

"dependencies": {
    "@angular/core": "^12.0.0",
    "@angular/cli": "^12.0.0",
    "rxjs": "^6.6.0"
}

6. Use LTS Versions

Always consider using the Long-Term Support (LTS) version of the Angular. The LTS versions are more stable receive critical bug fixes and have longer support periods making them ideal for the production applications.

Create Quiz