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Code coverage

Code coverage

Owned by Fabian D.
Last updated: yesterday at 9:37 am by Aaron Machin
4 min read

Overview

Code coverage is a valuable tool to identify gaps in your test suite and ensure that your code is adequately covered by tests. However, high code coverage alone does not guarantee high-quality tests. It is critical to focus on writing well-constructed tests, as this will have a greater impact than striving to cover every line of code.

PHPUnit and code coverage

PHPUnit provides built-in support for generating code coverage reports in various formats. To generate code coverage, PHPUnit relies on either XDebug or pcov. While pcov is more performant than XDebug, this guide demonstrates how to use both.

Configuring and generating code coverage reports (latest version)

This guide details how to configure and generate a code coverage report for the latest version of Totara. For older implementations, please see the Configurations for older versions section.

Step 1: Initialise PHPUnit

php test/phpunit/phpunit.php init

Step 2: Configure whitelists

To generate code coverage, you need to define a whitelist in your phpunit.xml file. Without this, you will encounter the following error:

Error: Incorrect whitelist config, no code coverage will be generated.

Add the following whitelist configuration to your phpunit.xml file directly after the </php> tag. Adjust the paths to match your project’s structure. Only directories and files included in the whitelist will appear in the coverage report.

These are just examples. Please change the whitelist so it matches your needs. Only directories and files included in the whitelist will appear in the report.

File: test/phpunit/phpunit.xml

<source> <include> <directory suffix=".php">/var/www/totara/src/SITENAME/server/totara/core/classes/local</directory> <directory suffix=".php">/var/www/totara/src/SITENAME/server/totara/core/classes/task</directory> <file>/var/www/totara/src/SITENAME/server/totara/core/classes/visibility_adviser.php</file> </include> </source>

Important notes

  • Use full paths to avoid incorrect whitelist configuration errors.

  • You can also use <exclude> tags. Please refer to the PHPUnit documentation for the full configuration details.

  • Limit the whitelist to relevant files and directories to reduce the report generation time.

  • If <source> does not work, replace it with <coverage>.

Step 3: Generate coverage reports

Using XDebug

Ensure XDebug is installed. Use the following commands to generate an HTML-formatted coverage report:

Clover XML Report

Using pcov

pcov is a high-performance alternative to XDebug. To set it up:

  1. Install pcov:

    Note the generated path to pcov.so, e.g. /usr/local/lib/php/extensions/no-debug-non-zts-20230831/pcov.so.

  2. Update php.ini. Note here also that we update the memory_limit to 8G:

  3. Generate the report:

Viewing the report using Totara docker developer environment

If using our Totara Docker Development environment - https://totara.atlassian.net/wiki/spaces/IN/pages/108151852 - you can replace the output path for the coverage report /var/www/html/coverage_report with /var/www/totara/src/coverage_report. Once you’ve done this, execute the following steps to make it accessible:

  1. On your PHP container: Once the coverage report has been created, set the permissions to allow nginx to access the generated files by running the following:

You will need to run the above each time you generate a new coverage report.

  1. On your local machine: add your new “coverage_report site” in the hosts file, so that we can access it via the browser. Replace XX with the PHP version you are currently using. For example if you’re using PHP 8.3, this will be 83. Once this step has been run, you should not need to repeat this step.

  1. Now you should be able to access your coverage report via the web browser by navigating to http://coverage_report.totaraXX, where XX is the PHP version you used in step 2.

Configurations for older versions

Totara 13

Initialisation:

Whitelist configuration:

These are just examples. Please change the whitelist so it matches your needs. Only directories and files included in the whitelist will appear in the report.

Generating coverage reports:

Totara 12

Initialisation:

Whitelist configuration:

Generating coverage reports:

pcov installation:

Install pcov/clobber which adds pcov support to PHPUnit 7:

Integration with PHPStorm

PHPStorm has the ability to run code coverage analysis in product using XDebug or pcov. The analysis is automatically loaded into the platform and displayed both in the coverage tool, and in-editor when looking at files. Their documentation on code coverage explains how to set it up.

Here are a few pointers and tips:

  • You still need to define a whitelist

  • As a product we support several different versions of PHP - if you're using php-fpm and have them installed you can configure PHPStorm so that you can choose which version you run tests and coverage on

  • When looking at a testcase file you can click on the little arrows next to test case classes and test case methods and choose to run specific tests

Common pitfalls

  1. Incorrect phpunit.xml paths: Ensure paths point to the correct Totara installation.

  2. Whitelist misconfiguration: Use pwd to verify paths and ensure full paths in your configuration.

Further reading