Add codecov reports

Author: Riimu

.github/workflows/main.yml

@@ -51,4 +51,31 @@ jobs:
       - name: Run PHP Coding Standards Fixer
         run: php-cs-fixer fix -v --dry-run --allow-risky=yes --using-cache=no
       - name: Run PHP_CodeSniffer
-        run: phpcs -p --standard=PSR12 src tests
+        run: phpcs -p --standard=PSR12 src tests --exclude=PSR12.Properties.ConstantVisibility
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Setup PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: '8.0'
+        coverage: xdebug
+    - name: Get composer cache directory
+      id: composer-cache
+      run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+    - name: Cache composer dependencies
+      uses: actions/cache@v2
+      with:
+        path: ${{ steps.composer-cache.outputs.dir }}
+        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
+        restore-keys: ${{ runner.os }}-composer-
+    - name: Install dependencies
+      run: composer install --no-progress --prefer-dist --classmap-authoritative --no-interaction
+    - name: Setup problem matchers for PHPUnit
+      run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
+    - name: Test with phpunit
+      run: vendor/bin/phpunit --coverage-clover coverage.xml
+    - name: Upload coverage
+      uses: codecov/codecov-action@v1