Add tests

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.neon]
+indent_style = tab

.github/workflows/ci.yaml

@@ -9,20 +9,47 @@ concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}
 
 jobs:
+    tests:
+        runs-on: ubuntu-latest
+        strategy:
+            fail-fast: false
+            matrix:
+                php: [ '8.1', '8.2', '8.3', '8.4' ]
+                dependency-versions: [ lowest, highest ]
+        steps:
+            -   name: Checkout
+                uses: actions/checkout@v4
+
+            -   name: Setup PHP
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: '${{ matrix.php }}'
+                    coverage: none
+
+            -   name: Install Composer packages
+                uses: ramsey/composer-install@v3
+                with:
+                    dependency-versions: '${{ matrix.dependency-versions }}'
+
+            -   name: Run tests
+                run: vendor/bin/phpunit --colors=always
+
     phpstan:
         runs-on: ubuntu-latest
 
         steps:
-            - name: Checkout code
-              uses: actions/checkout@v4
+            -   name: Checkout code
+                uses: actions/checkout@v4
 
-            - name: Set up PHP
-              uses: shivammathur/setup-php@v2
-              with:
-                  php-version: '8.1'
+            -   name: Set up PHP
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: '8.1'
 
-            - name: Install Composer packages
-              uses: ramsey/composer-install@v3
+            -   name: Install Composer packages
+                uses: ramsey/composer-install@v3
+                with:
+                    dependency-versions: '${{ matrix.dependency-versions }}'
 
-            - name: Run PHPStan
-              run: vendor/bin/phpstan --ansi
+            -   name: Run PHPStan
+                run: vendor/bin/phpstan --ansi

.gitignore

@@ -1 +1,2 @@
 /vendor/
+/.phpunit.cache

composer.json

@@ -10,7 +10,12 @@
     "license": "MIT",
     "autoload": {
         "psr-4": {
-            "TicketSwap\\PHPstanErrorFormatter\\": "src/"
+            "TicketSwap\\PHPStanErrorFormatter\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "TicketSwap\\PHPStanErrorFormatter\\": "tests/"
         }
     },
     "extra": {
@@ -22,5 +27,8 @@
     },
     "config": {
         "sort-packages": true
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^10.5.35"
     }
 }