Introduce PHPUnit integration and initial test suite

.gitattributes

@@ -10,6 +10,7 @@
 /.gitattributes export-ignore
 /.gitignore export-ignore
 /phpstan.neon export-ignore
+/phpunit.xml export-ignore
 
 # Explicit text file types
 *.php    text

.github/workflows/PHPUnit.yml

@@ -0,0 +1,18 @@
+name: PHPUnit
+
+on:
+  pull_request:
+
+permissions: read-all
+
+jobs:
+  build:
+    uses: The-FireHub-Project/.github/.github/workflows/RunCommandOnMatrix.yml@master
+    with:
+      title: "Run PHPUnit"
+      phpVersions: ${{ vars.PHP_VERSIONS }}
+      phpExtensions: ${{ vars.PHP_EXTENSIONS }}
+      tools: "phpunit:13.x"
+      command: "phpunit"
+    secrets:
+      GH_TOKEN: ${{ secrets.GH_TOKEN }}

README.md

@@ -23,19 +23,19 @@
 </h1>
 
 <p>
-  <a href="https://github.com/The-FireHub-Project/Core-Standard/commits/develop/">
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/commits/feature/phpunit-integration-and-initial-tests/">
     <img
-      src="https://img.shields.io/github/last-commit/The-FireHub-Project/Core-Standard/develop?style=flat&logo=github&logoColor=959da5&label=last%20commit%20(branch)&labelColor=31373e"
+      src="https://img.shields.io/github/last-commit/The-FireHub-Project/Core-Standard/feature/phpunit-integration-and-initial-tests?style=flat&logo=github&logoColor=959da5&label=last%20commit%20(branch)&labelColor=31373e"
       alt="GitHub last commit (branch)"
   /></a>
-  <a href="https://github.com/The-FireHub-Project/Core-Standard/commits/develop/">
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/commits/feature/phpunit-integration-and-initial-tests/">
     <img
-      src="https://img.shields.io/github/commit-activity/m/The-FireHub-Project/Core-Standard/develop?style=flat&logo=github&logoColor=959da5&label=commit%20activity%20(branch)&labelColor=31373e"
+      src="https://img.shields.io/github/commit-activity/m/The-FireHub-Project/Core-Standard/feature/phpunit-integration-and-initial-tests?style=flat&logo=github&logoColor=959da5&label=commit%20activity%20(branch)&labelColor=31373e"
       alt="GitHub activity (branch)"
   /></a>
-  <a href="https://github.com/The-FireHub-Project/Core-Standard/compare/master...develop/">
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/compare/develop...feature/phpunit-integration-and-initial-tests/">
     <img
-      src="https://img.shields.io/github/commits-difference/The-FireHub-Project/Core-Standard?base=master&head=develop&style=flat&logo=github&logoColor=959da5&label=ahead%20master&labelColor=31373e"
+      src="https://img.shields.io/github/commits-difference/The-FireHub-Project/Core-Standard?base=develop&head=feature/phpunit-integration-and-initial-tests&style=flat&logo=github&logoColor=959da5&label=ahead%20develop&labelColor=31373e"
       alt="GitHub commit difference between two branches"
   /></a>
 </p>
@@ -45,47 +45,82 @@ Standard provides the base classes, kernel, domain layer, and minimal runtime ut
 
 ---
 
-## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Development Branch
+## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> PHPUnit testing infrastructure – Development Branch
 
-⚠️ **This is the `develop` branch**
+⚠️ **This is the `development` branch**
 
 - Unstable
 - APIs may change without notice
 - Not intended for production use
 
+### Related
+
+- Milestone: **Development v1**
+- Target Release: **v0.0.0**
+- Repository: FireHub Core Standard
+
+### Pull request
+
+<p>
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/pull/6/">
+    <img
+      src="https://img.shields.io/github/pulls/detail/title/The-FireHub-Project/Core-Standard/6?style=flat&logo=github&logoColor=959da5&label=title&labelColor=31373e"
+      alt="GitHub pull request title"
+  /></a>
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/pull/6/">
+    <img
+      src="https://img.shields.io/github/pulls/detail/author/The-FireHub-Project/Core-Standard/6?style=flat&logo=github&logoColor=959da5&labelColor=31373e"
+      alt="GitHub pull request author"
+  /></a>
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/pull/6/">
+    <img
+      src="https://img.shields.io/github/pulls/detail/age/The-FireHub-Project/Core-Standard/6?style=flat&logo=github&logoColor=959da5&labelColor=31373e"
+      alt="GitHub pull request created"
+  /></a>
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/pull/6/">
+    <img
+      src="https://img.shields.io/github/pulls/detail/comments/The-FireHub-Project/Core-Standard/6?style=flat&logo=github&logoColor=959da5&labelColor=31373e"
+      alt="GitHub pull request comments"
+  /></a>
+</p>
+
+### Milestone
+
+<p>
+  <a href="https://github.com/The-FireHub-Project/Core-Standard/milestone/1/">
+    <img
+      src="https://img.shields.io/github/milestones/progress-percent/The-FireHub-Project/Core-Standard/1?style=flat&logo=github&logoColor=959da5&labelColor=31373e"
+      alt="GitHub milestone details"
+  /></a>
+</p>
+
 ## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Branch Purpose
 
-The `develop` branch is the **primary integration branch** for all ongoing development.
+This branch introduces the PHPUnit testing infrastructure and initial Core test coverage for the FireHub ecosystem.
+
+It establishes the foundational testing layer required to validate Core behavior across:
 
-It serves as the staging area where:
-- Feature branches are merged
-- Bug fixes are integrated
-- Experimental work is stabilized
-- Code is prepared for upcoming releases
+- Core Standard
+- Core Professional
+- Core Enterprise 
+- Runtime Foundation (consumers only)
 
-All **release branches** are created **from `develop`**.
+This includes PHPUnit configuration, bootstrap alignment, and first executable test cases for Core contracts.
 
-## Stability Guarantee
+## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Architectural Goal
 
-❌ No backward compatibility guarantee  
-❌ APIs may change without notice  
-❌ Behavior may be incomplete or inconsistent  
-❌ Breaking changes are expected
+Introduce a standardized testing layer for Core validation that:
 
-This branch is intended **only for contributors and advanced testers**.
+- Ensures Core contracts behave deterministically
+- Provides automated verification of architectural rules
+- Enables CI-level validation of Core stability
+- Establishes testing as a first-class governance layer in FireHub
 
-## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Composer Usage (Not Recommended)
+## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Core Concept
 
-For internal testing only:
+A FireHub testing layer is:
 
-```json
-{
-  "require": {
-    "the-firehub-project/core-standard": "dev-develop"
-  }
-}
-```
-⚠️ Never use dev-develop in production.
+> A deterministic validation system that ensures Core contracts and architectural rules behave as specified, independent of runtime implementation details.
 
 ## <img src="https://raw.githubusercontent.com/The-FireHub-Project/the-firehub-project.github.io/master/resources/graphics/icons/firehub.svg" width="15" alt="FireHub Icon"> Authors and Contributors
 
@@ -102,4 +137,4 @@ Architecture guidelines, design principles, and ecosystem documentation are avai
 
 This software is licensed under the Apache-2.0 License.
 
-For more details, read the full license [here](./LICENSE).
+For more details, read the full license [here](./LICENSE).

composer.json

@@ -10,9 +10,21 @@
   },
   "require-dev": {
     "phpstan/phpstan": "^2.0",
-    "the-firehub-project/phpstan-rules": "dev-develop"
+    "the-firehub-project/phpstan-rules": "dev-develop",
+
+    "the-firehub-project/testing": "dev-develop"
   },
   "minimum-stability": "stable",
+  "autoload": {
+    "psr-4": {
+      "FireHub\\Core\\": "src"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "FireHub\\Tests\\Core\\": "tests/"
+    }
+  },
   "authors": [
     {
       "name": "Danijel Galić",

phpstan.neon

@@ -1,5 +1,5 @@
 includes:
-  - vendor/the-firehub-project/phpstan-rules/src/config/base.neon
+  - vendor/the-firehub-project/phpstan-rules/src/Config/base.neon
 
 parameters:
   paths:

phpunit.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit bootstrap="vendor/autoload.php"
+         colors="true"
+         cacheDirectory=".build/phpunit/cache"
+         displayDetailsOnTestsThatTriggerWarnings="true">
+  <testsuites>
+    <testsuite name="unit">
+      <directory>tests/Unit</directory>
+    </testsuite>
+  </testsuites>
+  <source>
+    <include>
+      <directory suffix=".php">src</directory>
+    </include>
+  </source>
+</phpunit>

src/type/firehub.ValueObject.php → src/Type/ValueObject.php

@@ -44,16 +44,16 @@ abstract public function value ():mixed;
      *
      * Compares this Value Object with another instance of the same type using strict
      * class comparison and value equality semantics.
-     * @since 1.0.0
-     *
-     * @uses \FireHub\Core\Type\ValueObject::sameAs() To compare the VO types.
-     * @uses \FireHub\Core\Type\ValueObject::value() To compare the VO values.
-     *
      * @param self<TValue> $other <p>
      * The Value Object to compare against.
      * </p>
      *
      * @return bool True if the VOs are equal, false otherwise.
+     *@uses \FireHub\Core\Type\ValueObject::value() To compare the VO values.
+     *
+     * @since 1.0.0
+     *
+     * @uses \FireHub\Core\Type\ValueObject::sameAs() To compare the VO types.
      */
     final public function equals (self $other):bool {
 
@@ -66,13 +66,13 @@ final public function equals (self $other):bool {
      * ### Checks strict identity equality of a Value Object type
      *
      * Ensures both objects are of the same concrete class without comparing values.
-     * @since 1.0.0
-     *
      * @param \FireHub\Core\Type\ValueObject<TValue> $other <p>
      * The Value Object to compare against.
      * </p>
      *
      * @return bool True if the objects are of the same type, false otherwise.
+     *@since 1.0.0
+     *
      */
     final public function sameAs (self $other):bool {
 

tests/Stubs/Type/DummyIntVO.php

@@ -0,0 +1,55 @@
+<?php declare(strict_types = 1);
+
+/**
+ * This file is part of the FireHub Project ecosystem
+ *
+ * @author Danijel Galić <danijel.galic@outlook.com>
+ * @copyright 2026-present The FireHub Project - All rights reserved
+ * @license https://opensource.org/license/Apache-2-0 Apache License, Version 2.0
+ *
+ * @php-version >=8.2
+ * @package Core\Tests
+ */
+
+namespace FireHub\Tests\Core\Stubs\Type;
+
+use FireHub\Core\Type\ValueObject;
+use InvalidArgumentException;
+
+/**
+ * ### Dummy int Value Object
+ * @since 1.0.0
+ */
+readonly class DummyIntVO extends ValueObject {
+
+    /**
+     * ### Constructor
+     * @since 1.0.0
+     *
+     * @param int $value
+     *
+     * @return void
+     */
+    public function __construct (
+        private int $value = 1
+    ) {
+
+        $this->guard(
+            fn() => $this->value > 0,
+            fn() => new InvalidArgumentException('Value must be positive.')
+        );
+
+    }
+
+    /**
+     * @inheritDoc
+     *
+     * @since 1.0.0
+     */
+    public function value ():int {
+
+        return $this->value;
+
+    }
+
+}

tests/Stubs/Type/DummyStringVO.php

@@ -0,0 +1,55 @@
+<?php declare(strict_types = 1);
+
+/**
+ * This file is part of the FireHub Project ecosystem
+ *
+ * @author Danijel Galić <danijel.galic@outlook.com>
+ * @copyright 2026-present The FireHub Project - All rights reserved
+ * @license https://opensource.org/license/Apache-2-0 Apache License, Version 2.0
+ *
+ * @php-version >=8.2
+ * @package Core\Tests
+ */
+
+namespace FireHub\Tests\Core\Stubs\Type;
+
+use FireHub\Core\Type\ValueObject;
+use InvalidArgumentException;
+
+/**
+ * ### Dummy string Value Object
+ * @since 1.0.0
+ */
+readonly class DummyStringVO extends ValueObject {
+
+    /**
+     * ### Constructor
+     * @since 1.0.0
+     *
+     * @param string $value
+     *
+     * @return void
+     */
+    public function __construct (
+        private string $value = 'default'
+    ) {
+
+        $this->guard(
+            fn() => $this->value !== '',
+            fn() => new InvalidArgumentException('Value cannot be empty.')
+        );
+
+    }
+
+    /**
+     * @inheritDoc
+     *
+     * @since 1.0.0
+     */
+    public function value ():string {
+
+        return $this->value;
+
+    }
+
+}