feat: Update Relationship class constructor to public and implement custom sorting for relationships

Author: tasuku43

src/ClassDiagramRenderer/Node/Relationship/Relationship.php

@@ -8,7 +8,7 @@
 abstract class Relationship
 {
     protected const FORMAT = "%s %s %s: %s";
-    public function __construct(protected Node $from, protected Node $to)
+    public function __construct(public Node $from, public Node $to)
     {
     }
 

src/ClassDiagramRenderer/Node/Relationship/Relationships.php

@@ -34,7 +34,11 @@ public function getAll(): array
 
     public function sort(): void
     {
-        Relationship::sortRelationships($this->relationships);
+        usort($this->relationships, function (Relationship $a, Relationship $b) {
+            $aKey = $a->from->nodeName() . ' ' . $a->to->nodeName();
+            $bKey = $b->from->nodeName() . ' ' . $b->to->nodeName();
+            return strcmp($aKey, $bKey);
+        });
     }
 
     public function filter(RenderOptions $options): self

tests/ClassDiagramRenderer/Node/Relationship/RelationshipsTest.php

@@ -0,0 +1,55 @@
+<?php
+declare(strict_types=1);
+
+namespace Tasuku43\Tests\MermaidClassDiagram\ClassDiagramRenderer\Node\Relationship;
+
+use PHPUnit\Framework\TestCase;
+use Tasuku43\MermaidClassDiagram\ClassDiagramRenderer\Node\Node;
+use Tasuku43\MermaidClassDiagram\ClassDiagramRenderer\Node\Relationship\Dependency;
+use Tasuku43\MermaidClassDiagram\ClassDiagramRenderer\Node\Relationship\Inheritance;
+use Tasuku43\MermaidClassDiagram\ClassDiagramRenderer\Node\Relationship\Realization;
+use Tasuku43\MermaidClassDiagram\ClassDiagramRenderer\Node\Relationship\Relationships;
+
+class RelationshipsTest extends TestCase
+{
+    public function testSort(): void
+    {
+        $a = $this->mockNode('A');
+        $b = $this->mockNode('B');
+        $c = $this->mockNode('C');
+
+        $relationships = Relationships::empty();
+
+        // Intentionally add in non-sorted order by (from, to)
+        $relationships->add(new Inheritance($c, $b));    // key: "C B"
+        $relationships->add(new Dependency($a, $c));     // key: "A C"
+        $relationships->add(new Realization($b, $a));    // key: "B A"
+
+        $relationships->sort();
+        $sorted = $relationships->getAll();
+
+        $this->assertCount(3, $sorted);
+        $this->assertInstanceOf(Dependency::class, $sorted[0]);   // A C
+        $this->assertSame('A', $sorted[0]->from->nodeName());
+        $this->assertSame('C', $sorted[0]->to->nodeName());
+
+        $this->assertInstanceOf(Realization::class, $sorted[1]); // B A
+        $this->assertSame('B', $sorted[1]->from->nodeName());
+        $this->assertSame('A', $sorted[1]->to->nodeName());
+
+        $this->assertInstanceOf(Inheritance::class, $sorted[2]); // C B
+        $this->assertSame('C', $sorted[2]->from->nodeName());
+        $this->assertSame('B', $sorted[2]->to->nodeName());
+    }
+
+    private function mockNode(string $name): Node
+    {
+        return new class($name) extends Node {
+            public function render(): string
+            {
+                return "class {$this->name} {}";
+            }
+        };
+    }
+}
+