Fix PHPUnit code coverage generation in GitHub Actions

This commit resolves critical issues preventing PHPUnit coverage from being generated correctly in the CI workflow.

Key Changes:
1. Fixed invalid composer install syntax in code-coverage.yml (line 59) - was incorrectly passing package name as composer option
2. Updated PHP version from 8.2 to 8.3 to match composer.json platform requirement, eliminating need to unset platform.php
3. Removed unnecessary Codecov integration - PR comments and artifacts are sufficient
4. Added ext-pcov and ext-xdebug to composer.json suggest section for documentation
5. Added 'composer coverage' script for local coverage generation
6. Updated README.md with coverage badge and contributor documentation
7. Documented the -0.5% coverage threshold requirement

Root Cause Analysis:
- The composer-options parameter was incorrectly set to "yoast/wp-test-utils --with-dependencies" instead of valid composer flags
- PHP version mismatch between workflow (8.2) and composer.json (8.3) required workarounds
- Codecov integration added unnecessary complexity without providing value for the stated requirements

The workflow will now:
- Generate coverage.xml correctly
- Post automated PR comments showing coverage changes
- Enforce -0.5% coverage threshold
- Upload HTML coverage reports as artifacts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: aristath

.github/workflows/code-coverage.yml

@@ -41,22 +41,19 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.2'
+          php-version: '8.3'
           ini-values: zend.assertions=1, error_reporting=-1, display_errors=On
           coverage: pcov  # Use PCOV for faster code coverage (5x faster than Xdebug)
           tools: composer
 
       - name: Install SVN
         run: sudo apt-get install subversion
 
-      - name: "Composer: remove the PHP platform requirement"
-        run: composer config --unset platform.php
-
       - name: Install Composer dependencies
         uses: ramsey/composer-install@v2
         with:
           dependency-versions: "highest"
-          composer-options: "yoast/wp-test-utils --with-dependencies"
+          composer-options: "--prefer-dist --with-dependencies"
           custom-cache-suffix: $(date -u -d "-0 month -$(($(date +%d)-1)) days" "+%F")-codecov-v2
 
       - name: Install WordPress Test Suite
@@ -100,15 +97,6 @@ jobs:
           fi
         continue-on-error: false
 
-      - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4
-        with:
-          files: ./coverage.xml
-          flags: unittests
-          name: codecov-progress-planner
-          fail_ci_if_error: false
-          token: ${{ secrets.CODECOV_TOKEN }}
-
       - name: Generate coverage report summary
         id: coverage
         run: |

README.md

@@ -1,4 +1,5 @@
 [![Test](https://github.com/ProgressPlanner/progress-planner/actions/workflows/phpunit.yml/badge.svg)](https://github.com/ProgressPlanner/progress-planner/actions/workflows/phpunit.yml)
+[![Code Coverage](https://github.com/ProgressPlanner/progress-planner/actions/workflows/code-coverage.yml/badge.svg)](https://github.com/ProgressPlanner/progress-planner/actions/workflows/code-coverage.yml)
 [![CS](https://github.com/ProgressPlanner/progress-planner/actions/workflows/cs.yml/badge.svg)](https://github.com/ProgressPlanner/progress-planner/actions/workflows/cs.yml)
 [![PHPStan](https://github.com/ProgressPlanner/progress-planner/actions/workflows/phpstan.yml/badge.svg)](https://github.com/ProgressPlanner/progress-planner/actions/workflows/phpstan.yml)
 [![Lint](https://github.com/ProgressPlanner/progress-planner/actions/workflows/lint.yml/badge.svg)](https://github.com/ProgressPlanner/progress-planner/actions/workflows/lint.yml)
@@ -24,6 +25,39 @@ This post explains what Progress Planner does and how to use it: [What does Prog
 
 You can find [installation instructions here](https://prpl.fyi/install).
 
+## Contributing
+
+### Running Tests
+
+To run the test suite:
+
+```bash
+composer test
+```
+
+### Code Coverage
+
+To generate code coverage reports locally, you need either [PCOV](https://pecl.php.net/package/PCOV) (recommended) or [Xdebug](https://xdebug.org/) installed:
+
+```bash
+composer coverage
+```
+
+This will generate:
+- An HTML coverage report in the `coverage-html/` directory
+- A text-based coverage summary in your terminal
+
+**Coverage Requirements:** Pull requests must maintain code coverage within 0.5% of the base branch. PRs that drop coverage by more than 0.5% will be blocked until additional tests are added.
+
+### Other Quality Commands
+
+```bash
+composer check-cs    # Check coding standards
+composer fix-cs      # Auto-fix coding standards
+composer phpstan     # Run static analysis
+composer lint        # Check PHP syntax
+```
+
 ## Branches on this repository
 
 We use a couple of branches in this repository to keep things clean:

composer.json

@@ -20,6 +20,10 @@
 		"yoast/yoastcs": "^3.0",
 		"friendsofphp/php-cs-fixer": "^3.75"
 	},
+	"suggest": {
+		"ext-pcov": "Recommended for fast code coverage generation (5x faster than Xdebug)",
+		"ext-xdebug": "Alternative for code coverage and debugging"
+	},
 	"scripts": {
 		"check-cs": [
 			"@php ./vendor/bin/phpcs -s"
@@ -38,6 +42,9 @@
 		"test": [
 			"@php ./vendor/phpunit/phpunit/phpunit --dont-report-useless-tests"
 		],
+		"coverage": [
+			"@php ./vendor/phpunit/phpunit/phpunit --coverage-html=coverage-html --coverage-text"
+		],
 		"phpstan": [
 			"@php ./vendor/bin/phpstan analyse --memory-limit=2048M"
 		]