Add tests

Author: SerafimArts

.github/workflows/main.yml

@@ -148,3 +148,54 @@ jobs:
             # Execution
             - name: Check Coding Standards
               run: vendor/bin/phpcs --standard=phpcs.xml
+
+    test:
+        name: Build (${{matrix.php}}, ${{ matrix.os }}, ${{ matrix.stability }})
+        runs-on: ${{ matrix.os }}
+
+        strategy:
+            fail-fast: false
+            matrix:
+                php: [ '7.4', '8.0', '8.1' ]
+                os: [ ubuntu-latest, macos-latest, windows-latest ]
+                stability: [ prefer-lowest, prefer-stable ]
+
+        steps: # General Steps
+            - name: Set Git To Use LF
+              run: |
+                  git config --global core.autocrlf false
+                  git config --global core.eol lf
+            - name: Checkout
+              uses: actions/checkout@v2
+
+            # Install PHP Dependencies
+            - name: Setup PHP ${{ matrix.php }}
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: ${{ matrix.php }}
+                  # PHP Extras
+                  coverage: pcov
+                  tools: pecl
+                  ini-values: "memory_limit=-1"
+            - name: Validate Composer
+              run: composer validate
+            - name: Get Composer Cache Directory
+                # Docs: <https://github.com/actions/cache/blob/master/examples.md#php---composer>
+              id: composer-cache
+              run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+            - name: Restore Composer Cache
+              uses: actions/cache@v1
+              with:
+                  path: ${{ steps.composer-cache.outputs.dir }}
+                  key: ${{ runner.os }}-${{ matrix.php }}-composer-${{ hashFiles('**/composer.json') }}
+                  restore-keys: ${{ runner.os }}-${{ matrix.php }}-composer-
+            - name: Install Dependencies
+              uses: nick-invision/retry@v1
+              with:
+                  timeout_minutes: 5
+                  max_attempts: 5
+                  command: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress
+
+            # Execution
+            - name: Execute Tests
+              run: vendor/bin/phpunit