Adds enum unit tests

.github/workflows/php-test.yml

@@ -0,0 +1,61 @@
+name: Unit Tests
+
+on:
+  push:
+    branches:
+      - trunk
+      - 'feature/**'
+      - 'release/**'
+    # Only run if PHP-related files changed.
+    paths:
+      - '.github/workflows/php-test.yml'
+      - '**.php'
+      - 'phpunit.xml.dist'
+      - 'composer.json'
+      - 'composer.lock'
+  pull_request:
+    # Only run if PHP-related files changed.
+    paths:
+      - '.github/workflows/php-test.yml'
+      - '**.php'
+      - 'phpunit.xml.dist'
+      - 'composer.json'
+      - 'composer.lock'
+    types:
+      - opened
+      - reopened
+      - synchronize
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version: ['7.4', '8.0', '8.4']
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: ${{ matrix.php-version }}
+        coverage: xdebug
+
+    - name: Validate composer.json and composer.lock
+      run: composer validate --strict
+
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v3
+      with:
+        path: vendor
+        key: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-php-${{ matrix.php-version }}-
+
+    - name: Install dependencies
+      run: composer install --prefer-dist --no-progress
+
+    - name: Run unit tests
+      run: composer phpunit

.gitignore

@@ -21,3 +21,9 @@ vendor/
 CLAUDE.md
 .cursor/
 GEMINI.md
+
+############
+## PHPUnit
+############
+
+.phpunit.cache/

phpunit.xml.dist

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         cacheResultFile=".phpunit.cache/test-results"
+         executionOrder="depends,defects"
+         forceCoversAnnotation="true"
+         beStrictAboutCoversAnnotation="true"
+         beStrictAboutOutputDuringTests="true"
+         beStrictAboutTodoAnnotatedTests="true"
+         failOnRisky="true"
+         failOnWarning="true"
+         verbose="true"
+         colors="true">
+    <testsuites>
+        <testsuite name="unit">
+            <directory suffix="Test.php">tests/unit</directory>
+        </testsuite>
+    </testsuites>
+
+    <coverage cacheDirectory=".phpunit.cache/code-coverage"
+              processUncoveredFiles="true">
+        <include>
+            <directory suffix=".php">src</directory>
+        </include>
+    </coverage>
+</phpunit>

tests/mocks/Enums/InvalidNameTestEnum.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WordPress\AiClient\Tests\mocks\Enums;
+
+use WordPress\AiClient\Common\AbstractEnum;
+
+/**
+ * Invalid test enum with lowercase constant name.
+ */
+class InvalidNameTestEnum extends AbstractEnum
+{
+    public const VALID_NAME = 'valid';
+    // phpcs:ignore Generic.NamingConventions.UpperCaseConstantName.ClassConstantNotUpperCase
+    public const invalid_name = 'invalid'; // This should cause an exception
+}

tests/mocks/Enums/InvalidTypeTestEnum.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WordPress\AiClient\Tests\mocks\Enums;
+
+use WordPress\AiClient\Common\AbstractEnum;
+
+/**
+ * Invalid test enum with float value.
+ */
+class InvalidTypeTestEnum extends AbstractEnum
+{
+    public const VALID_VALUE = 'valid';
+    public const INT_VALUE = 42; // This should cause an exception
+}

tests/mocks/Enums/ValidTestEnum.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WordPress\AiClient\Tests\mocks\Enums;
+
+use WordPress\AiClient\Common\AbstractEnum;
+
+/**
+ * Valid test enum for testing AbstractEnum functionality.
+ *
+ * @method static self firstName() Creates an instance for FIRST_NAME.
+ * @method static self lastName() Creates an instance for LAST_NAME.
+ * @method bool isFirstName() Checks if the value is FIRST_NAME.
+ * @method bool isLastName() Checks if the value is LAST_NAME.
+ */
+class ValidTestEnum extends AbstractEnum
+{
+    public const FIRST_NAME = 'first';
+    public const LAST_NAME = 'last';
+}