#Type Coverage

Source code: github.com/pestphp/pest-plugin-type-coverage

Type Coverage is a metric used to measure the percentage of code that is covered by type declarations. This helps you identify parts of your code that may not be fully typed, indicating a potential risk for bugs and other issues.

To get started with Pest's Type Coverage plugin, you may require the plugin via Composer:

1composer require pestphp/pest-plugin-type-coverage --dev

Once you have required the plugin, you may use the --type-coverage option to generate a report of your type coverage:

1./vendor/bin/pest --type-coverage

Unlike code coverage, type coverage does not require you to write any tests. Instead, it analyzes your codebase and generates a report of your type coverage. This report will display a list of files along with their corresponding type coverage results.

If any of your files are missing type declarations, they will be highlighted in yellow and displayed using their respective line numbers, along with the type of declaration that is missing.

For example, rt31 means that the return type of the function on line 31 is missing. On the other hand, pa31 means that the parameter type of the function on line 31 is missing.

#Ignoring Errors

Sometimes you may wish to ignore a specific error or line of code. To accomplish this, you may use the @pest-ignore-type annotation:

1    protected $except = [ // @pest-ignore-type
2        // ...
3    ];
4}

#Compact Output

Often, when checking type coverage, you only want to see the files that do not currently have 100% type coverage. To do this, you may use the --compact option:

1./vendor/bin/pest --type-coverage --compact

#Minimum Threshold Enforcement

As with code coverage, type coverage may also be enforced. To ensure any code that is added to your application is fully typed, you may use the --type-coverage and --min options to define the minimum threshold values for type coverage results. If the specified thresholds are not met, Pest will report a failure:

1./vendor/bin/pest --type-coverage --min=100

#Different Formats

In addition, Pest supports reporting your type coverage to a specific file:

1./vendor/bin/pest --type-coverage --min=100 --type-coverage-json=my-report.json

In this chapter, we have discussed Pest's Type Coverage plugin and how you may use it to measure the percentage of code that is covered by type declarations. In the following chapter, we explain how you may use mutation testing to improve the quality of your tests: Mutation Testing →