diff --git a/.gitea/workflows/test.yml b/.gitea/workflows/test.yml
new file mode 100644
index 0000000..1f8b49b
--- /dev/null
+++ b/.gitea/workflows/test.yml
@@ -0,0 +1,26 @@
+name: Run Unit Tests
+
+on:
+  push:
+    branches:
+      - main
+      - develop
+  pull_request:
+
+jobs:
+  test:
+    runs-on: phpunit_test
+    container: php:8.1-cli-alpine
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          apk add --no-cache git unzip
+          curl -sS https://getcomposer.org/installer  | php -- --install-dir=/usr/local/bin --filename=composer
+          composer install --no-interaction --prefer-dist
+
+      - name: Run PHPUnit tests
+        run: |
+          vendor/bin/phpunit --configuration phpunit.xml
\ No newline at end of file
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..c02fbe0
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,19 @@
+{
+    "name": "example/php-woodpecker-demo",
+    "require-dev": {
+        "phpunit/phpunit": "^9.5"
+    },
+    "autoload": {
+        "psr-4": {
+            "App\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Tests\\": "tests/"
+        }
+    },
+    "scripts": {
+        "test": "phpunit"
+    }
+}
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..46f3c9d
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit bootstrap="vendor/autoload.php"
+         colors="true"
+         verbose="true">
+    <testsuites>
+        <testsuite name="Default">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <coverage processUncoveredFiles="true">
+        <include>
+            <directory>./src</directory>
+        </include>
+        <report>
+            <clover outputFile="coverage.xml"/>
+        </report>
+    </coverage>
+</phpunit>
diff --git a/src/Calculator.php b/src/Calculator.php
new file mode 100644
index 0000000..164ba7d
--- /dev/null
+++ b/src/Calculator.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace App;
+
+class Calculator
+{
+    public function add($a, $b)
+    {
+        return $a + $b;
+    }
+
+    public function subtract($a, $b)
+    {
+        $a = 1111;
+        return $a - $b;
+    }
+}
diff --git a/tests/CalculatorTest.php b/tests/CalculatorTest.php
new file mode 100644
index 0000000..5b28347
--- /dev/null
+++ b/tests/CalculatorTest.php
@@ -0,0 +1,13 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use App\Calculator;
+
+class CalculatorTest extends TestCase
+{
+    public function testAdd()
+    {
+        $calc = new Calculator();
+        $this->assertEquals(5, $calc->add(2, 3));
+    }
+}