How to Use the Command 'composer-require-checker' (with Examples)

Composer Require Checker is a useful tool for PHP developers who want to ensure that their project’s Composer dependencies are correctly defined and utilized. The tool analyzes a project’s composer.json file to identify “soft dependencies” or those dependencies that your code might rely on but aren’t explicitly declared in your composer.json. This is especially crucial for maintaining robust and clean codebases, as it helps avoid unexpected dependency issues during deployment or development.

Use Case 1: Analyzing a Composer JSON File

Code:

composer-require-checker check path/to/composer.json

Motivation:

The primary motivation for using this straightforward example is to verify the dependencies of a PHP project as defined in a composer.json file, ensuring that all necessary dependencies are explicitly declared. This helps prevent issues related to missing dependencies, which might occur if your code indirectly uses packages that are not specified in the composer.json, leading to potential runtime errors.

Explanation:

• composer-require-checker: This initiates the Composer Require Checker tool.
• check: The mode of operation that specifies you’re analyzing the composer.json.
• path/to/composer.json: The file path where your composer.json is located. This tells composer-require-checker which file to analyze for dependency checks.

Example Output:

ComposerRequireChecker 3.4.0
There is 1 unknown symbol and 0 errors.
The following unknown symbols were found:
+-------------------------------------------------------------------------------------------------+
| ClassName                                                                                       |
+-------------------------------------------------------------------------------------------------+
| Some\Missing\Dependency                                                                         |
+-------------------------------------------------------------------------------------------------+

The output provides a list of symbols (like classes or functions) that are used in the project but aren’t included in any declared dependency. This feedback can guide developers to declare these dependencies explicitly, thereby making the codebase more robust.

Use Case 2: Analyzing a Composer JSON File with a Specific Configuration

Code:

composer-require-checker check --config-file path/to/config.json path/to/composer.json

Motivation:

Sometimes, a project might need a customized configuration when checking dependencies. Perhaps certain dependencies are conditionally used, or the project has particular constraints. By using a specific configuration file, developers can manage these exceptions and provide rules that Composer Require Checker should follow during the analysis. This customization offers a flexible approach to cater for unique project needs without altering the global behavior of the checker universally.

Explanation:

• composer-require-checker: The tool used to check the composer dependencies.
• check: Again indicates the operation mode is checking the dependencies.
• --config-file: This option tells the tool to use a specific configuration file that contains custom rules or exceptions for dependency checking.
• path/to/config.json: Specifies the path to the custom configuration file, which might include exceptions or particular settings for the dependency analysis.
• path/to/composer.json: The location of the composer.json file which is the target of the dependency check.

Example Output:

ComposerRequireChecker 3.4.0
Checking with custom configuration from config.json
There are no unknown symbols or errors.

This indicates that when using a custom configuration, the project has no undisclosed dependencies, validating the project setup in line with the specified configurations.

Conclusion:

Composer Require Checker is a significant tool for any PHP developer aiming to maintain a clean and reliable dependency structure within their projects. By using the examples and understanding the motivations for different use cases, developers can ensure that their projects avoid pitfalls related to undeclared dependencies, which could hinder development or deployment processes. Whether using the basic check or incorporating custom configurations, Composer Require Checker enables better dependency management and a more stable codebase.