TASK: Turn all Domain\* name objects into flyweights

Author: grebaldi

src/Domain/AttributeName/AttributeName.php

@@ -24,13 +24,18 @@
 
 final class AttributeName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 }

src/Domain/ComponentName/ComponentName.php

@@ -26,14 +26,19 @@
 
 final class ComponentName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 
     public function toTypeName(): TypeName

src/Domain/EnumMemberName/EnumMemberName.php

@@ -24,13 +24,18 @@
 
 final class EnumMemberName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 }

src/Domain/EnumName/EnumName.php

@@ -26,14 +26,19 @@
 
 final class EnumName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 
     public function toTypeName(): TypeName

src/Domain/PropertyName/PropertyName.php

@@ -26,14 +26,19 @@
 
 final class PropertyName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 
     public function toEnumMemberName(): EnumMemberName

src/Domain/StructName/StructName.php

@@ -26,14 +26,19 @@
 
 final class StructName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 
     public function toTypeName(): TypeName

src/Domain/TagName/TagName.php

@@ -24,13 +24,18 @@
 
 final class TagName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 }

src/Domain/TypeName/TypeName.php

@@ -26,14 +26,19 @@
 
 final class TypeName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 
     public function toVariableName(): VariableName

src/Domain/VariableName/VariableName.php

@@ -24,13 +24,18 @@
 
 final class VariableName
 {
+    /**
+     * @var array<string,self>
+     */
+    private static array $instances = [];
+
     private function __construct(
         public readonly string $value
     ) {
     }
 
     public static function from(string $string): self
     {
-        return new self($string);
+        return self::$instances[$string] ??= new self($string);
     }
 }

test/Unit/Domain/AttributeName/AttributeNameTest.php

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * PackageFactory.ComponentEngine - Universal View Components for PHP
+ *   Copyright (C) 2023 Contributors of PackageFactory.ComponentEngine
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace PackageFactory\ComponentEngine\Test\Unit\Domain\AttributeName;
+
+use PackageFactory\ComponentEngine\Domain\AttributeName\AttributeName;
+use PHPUnit\Framework\TestCase;
+
+final class AttributeNameTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function isFlyweight(): void
+    {
+        $this->assertSame(AttributeName::from('foo'), AttributeName::from('foo'));
+        $this->assertSame(AttributeName::from('bar'), AttributeName::from('bar'));
+        $this->assertSame(AttributeName::from('data-baz'), AttributeName::from('data-baz'));
+
+        $this->assertNotSame(AttributeName::from('foo'), AttributeName::from('bar'));
+    }
+}