test: kill PublicVisibility mutation in TextTrait::setText

Create TextTraitTestClass fixture that uses TextTrait directly without
aliasing the setText method. This allows testing the trait's method
visibility, which kills the PublicVisibility mutation. The existing
tests using PostData don't catch this mutation because PostData aliases
setText as traitSetText and provides its own public override.

Author: claude

tests/src/Fixtures/TextTraitTestClass.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Deviantintegral\Har\Tests\Fixtures;
+
+use Deviantintegral\Har\SharedFields\TextTrait;
+
+/**
+ * Test fixture class that uses TextTrait directly without aliasing.
+ *
+ * This class is used to test the visibility of the trait's methods.
+ * Unlike PostData and Content which alias setText as traitSetText
+ * and override with their own public method, this class uses the
+ * trait's setText directly.
+ *
+ * @internal Test fixture only
+ */
+final class TextTraitTestClass
+{
+    use TextTrait;
+}

tests/src/Unit/SharedFields/TextTraitTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Deviantintegral\Har\Tests\Unit\SharedFields;
+
+use Deviantintegral\Har\Tests\Fixtures\TextTraitTestClass;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers \Deviantintegral\Har\SharedFields\TextTrait
+ */
+class TextTraitTest extends TestCase
+{
+    public function testSetTextIsPublic(): void
+    {
+        // This test kills the PublicVisibility mutation in TextTrait::setText
+        // by using a class that uses the trait WITHOUT aliasing/overriding.
+        //
+        // Unlike PostData and Content which alias setText as traitSetText
+        // and provide their own public setText, TextTraitTestClass uses
+        // the trait's method directly. If the trait's method becomes
+        // protected, this test will fail with a fatal error.
+        $instance = new TextTraitTestClass();
+
+        // Calling setText from outside the class - would fail if protected
+        $result = $instance->setText('test content');
+
+        // Verify method chaining works (returns self)
+        $this->assertSame($instance, $result);
+
+        // Verify the text was set
+        $this->assertTrue($instance->hasText());
+        $this->assertEquals('test content', $instance->getText());
+    }
+
+    public function testSetTextWithNull(): void
+    {
+        $instance = new TextTraitTestClass();
+        $instance->setText('initial');
+        $this->assertTrue($instance->hasText());
+
+        // Setting null should clear the text
+        $instance->setText(null);
+        $this->assertFalse($instance->hasText());
+        $this->assertNull($instance->getText());
+    }
+
+    public function testHasText(): void
+    {
+        $instance = new TextTraitTestClass();
+
+        // Initially no text
+        $this->assertFalse($instance->hasText());
+
+        // After setting text
+        $instance->setText('content');
+        $this->assertTrue($instance->hasText());
+
+        // After clearing text
+        $instance->setText(null);
+        $this->assertFalse($instance->hasText());
+    }
+
+    public function testGetText(): void
+    {
+        $instance = new TextTraitTestClass();
+
+        // Initially null
+        $this->assertNull($instance->getText());
+
+        // After setting
+        $instance->setText('some text');
+        $this->assertEquals('some text', $instance->getText());
+    }
+}