feat(dumpers): Added mermaid dumper

src/Dumper/Dumper.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Finite\Dumper;
+
+use Finite\State;
+
+interface Dumper
+{
+    /**
+     * @param enum-string<State> $stateEnum
+     */
+    public function dump(string $stateEnum): string;
+}

src/Dumper/MermaidDumper.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Finite\Dumper;
+
+use Finite\State;
+
+class MermaidDumper implements Dumper
+{
+    /**
+     * @param enum-string<State> $stateEnum
+     */
+    public function dump(string $stateEnum): string
+    {
+        $output = [
+            '---',
+            'title: ' . $stateEnum,
+            '---',
+            'stateDiagram-v2',
+        ];
+
+        foreach ($stateEnum::getTransitions() as $transition) {
+            foreach ($transition->getSourceStates() as $state) {
+                $output[] = sprintf(
+                    '    %s --> %s: %s',
+                    $state->value,
+                    $transition->getTargetState()->value,
+                    $transition->getName()
+                );
+            }
+        }
+
+        return implode(PHP_EOL, $output);
+    }
+}

src/Transition/Transition.php

@@ -14,9 +14,9 @@ class Transition implements TransitionInterface
 {
     public function __construct(
         public readonly string $name,
-        /** @var State[] */
+        /** @var array<int,State&\BackedEnum> */
         public readonly array $sourceStates,
-        public readonly State $targetState,
+        public readonly State&\BackedEnum $targetState,
         /** @var array<string, string> */
         public readonly array $properties = []
     )
@@ -28,7 +28,7 @@ public function getSourceStates(): array
         return $this->sourceStates;
     }
 
-    public function getTargetState(): State
+    public function getTargetState(): State&\BackedEnum
     {
         return $this->targetState;
     }

src/Transition/TransitionInterface.php

@@ -12,11 +12,11 @@
 interface TransitionInterface
 {
     /**
-     * @return State[]
+     * @return array<int, \BackedEnum&State>
      */
     public function getSourceStates(): array;
 
-    public function getTargetState(): State;
+    public function getTargetState(): State&\BackedEnum;
 
     public function process(object $object): void;
 

tests/Dumper/MermaidDumperTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Finite\Tests\Dumper;
+
+use Finite\Dumper\MermaidDumper;
+use Finite\Tests\E2E\SimpleArticleState;
+use PHPUnit\Framework\TestCase;
+
+class MermaidDumperTest extends TestCase
+{
+    public function test_it_dumps(): void
+    {
+        $this->assertSame(
+            <<<MERMAID
+            ---
+            title: Finite\Tests\E2E\SimpleArticleState
+            ---
+            stateDiagram-v2
+                draft --> published: publish
+                reported --> published: clear
+                disabled --> published: clear
+                published --> reported: report
+                reported --> disabled: disable
+                published --> disabled: disable
+            MERMAID,
+            (new MermaidDumper)->dump(SimpleArticleState::class)
+        );
+    }
+}

tests/Transition/TransitionTest.php

@@ -4,6 +4,7 @@
 namespace Finite\Tests\Transition;
 
 use Finite\State;
+use Finite\Tests\E2E\SimpleArticleState;
 use Finite\Transition\Transition;
 use PHPUnit\Framework\TestCase;
 
@@ -13,12 +14,10 @@ class TransitionTest extends TestCase
 
     protected function setUp(): void
     {
-        $targetState = $this->createMock(State::class);
-
         $this->object = new Transition(
             'name',
-            ['source'],
-            $targetState,
+            [SimpleArticleState::DRAFT],
+            SimpleArticleState::PUBLISHED,
             ['property' => 'value', 'property2' => 'value2'],
         );
     }