How to use the command web-ext (with examples)

Web-ext is a command-line tool developed by Mozilla that is used for managing web extension development. It provides a set of commands for running, testing, building, and packaging web extensions for various browsers.

Use case 1: Run the web extension in the current directory in Firefox

Code:

web-ext run

Motivation: When developing a web extension, it is important to be able to quickly test and iterate on the code. By running the web extension in Firefox, developers can easily see how the extension behaves and make necessary adjustments.

Explanation: The run command is used to run the web extension in the current directory. When executed without any arguments, it automatically detects the browser and runs the extension in it.

Example output: The web extension is launched in Firefox and can be interacted with by the user.

Use case 2: Run a web extension from a specific directory in Firefox

Code:

web-ext run --source-dir path/to/directory

Motivation: In some cases, developers may have the web extension code stored in a different directory than the one they are currently in. By specifying the source directory, the run command allows developers to run the web extension from that directory.

Explanation: The --source-dir argument is used to specify the path to the directory containing the web extension code.

Example output: The web extension from the specified directory is launched in Firefox and can be interacted with by the user.

Use case 3: Display verbose execution output

Code:

web-ext run --verbose

Motivation: When debugging or troubleshooting issues with a web extension, it can be helpful to see detailed execution output. By enabling verbose output, developers can get more information about what is happening during the execution of the web extension.

Explanation: The --verbose argument is used to enable verbose output, which provides additional information during the execution of the web extension.

Example output: The command output includes detailed information about the execution of the web extension, such as which files are being loaded and any errors that occur.

Use case 4: Run a web extension in Firefox Android

Code:

web-ext run --target firefox-android

Motivation: Testing web extensions on mobile devices is an important part of the development process. By using the --target argument with the value firefox-android, developers can run the web extension in Firefox on an Android device.

Explanation: The --target argument is used to specify the target platform or browser for running the web extension. In this case, the value firefox-android is used to indicate that the extension should be run in Firefox on an Android device.

Example output: The web extension is launched in Firefox on the Android device and can be interacted with by the user.

Use case 5: Lint the manifest and source files for errors

Code:

web-ext lint

Motivation: To ensure that a web extension is free of errors and follows best practices, it is important to perform linting. By running the lint command, developers can check the manifest file and source code for errors and potential issues.

Explanation: The lint command is used to analyze the manifest file and source code of the web extension for errors and warnings. It checks for common issues such as invalid or missing properties in the manifest file, syntax errors, and potential security vulnerabilities.

Example output: The command output displays any issues found in the manifest file and source code, along with suggestions for how to fix them.

Use case 6: Build and package the extension

Code:

web-ext build

Motivation: Once a web extension is ready for distribution, it needs to be built and packaged into a format that can be installed by users. By running the build command, developers can create a packaged version of the web extension.

Explanation: The build command is used to create a packaged version of the web extension. It compiles the source code, includes any necessary dependencies, and creates a distributable package in a format such as a zip file.

Example output: The command output indicates that the web extension has been successfully built and provides the path to the packaged file.

Use case 7: Display verbose build output

Code:

web-ext build --verbose

Motivation: Similar to displaying verbose execution output, it can be beneficial to see detailed output during the build process. By enabling verbose build output, developers can get more information about the steps being performed during the build.

Explanation: The --verbose argument is used to enable verbose output during the build process.

Example output: The command output includes detailed information about the steps being performed during the build, such as which files are being included and any errors that occur.

Use case 8: Sign a package for self-hosting

Code:

web-ext sign --api-key api_key --api-secret api_secret

Motivation: In some cases, developers may want to self-host their web extension and distribute it outside of browser extension stores. By signing the package with an API key and secret, developers can ensure the authenticity and integrity of the extension.

Explanation: The sign command is used to sign a package for self-hosting. The --api-key and --api-secret arguments are used to specify the API key and secret required for signing the package.

Example output: The command output indicates that the package has been successfully signed and provides the path to the signed package.

Conclusion:

The web-ext command-line tool provides a wide range of functionality for managing web extension development. From running and testing extensions to building and signing them for distribution, web-ext simplifies the development workflow and provides a convenient way to manage web extension projects.