[TASK] Add trait for getArrayRepresentation to populate class

Part of #1440.

Author: JakeQZ

src/ArrayRepresentationClassProvider.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS;
+
+/**
+ * Provides a reusable implementation of `getArrayRepresentation()` which will populate the `class` element with the
+ * short name of the actual class.
+ * It is expected that this will be `use`d by (possibly-abstract) base classes, with extended classes calling on to the
+ * parent implementation then further populating the array.
+ * If a base class using this trait needs to further populate the array, the trait method can be `use`d `as`.
+ *
+ * @internal
+ *
+ * @phpstan-require-implements Renderable
+ */
+trait ArrayRepresentationClassProvider
+{
+    /**
+     * @return array<string, bool|int|float|string|list<array<string, mixed>>>
+     *
+     * @internal
+     */
+    public function getArrayRepresentation(): array
+    {
+        $reflect = new \ReflectionClass($this);
+
+        return ['class' => $reflect->getShortName()];
+    }
+}

tests/Unit/ArrayRepresentationClassProviderTest.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Position;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Tests\Unit\Fixtures\ConcreteArrayRepresentationClassProvider;
+
+/**
+ * @covers \Sabberworm\CSS\ArrayRepresentationClassProvider
+ */
+final class ArrayRepresentationClassProviderTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function getArrayRepresentationIncludesClassName(): void
+    {
+        $subject = new ConcreteArrayRepresentationClassProvider();
+
+        $result = $subject->getArrayRepresentation();
+
+        self::assertArrayHasKey('class', $result);
+        self::assertSame('ConcreteArrayRepresentationClassProvider', $result['class']);
+    }
+}

tests/Unit/Fixtures/ConcreteArrayRepresentationClassProvider.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Fixtures;
+
+use Sabberworm\CSS\ArrayRepresentationClassProvider;
+use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Renderable;
+
+final class ConcreteArrayRepresentationClassProvider implements Renderable
+{
+    use ArrayRepresentationClassProvider;
+
+    /**
+     * @return never
+     */
+    public function render(OutputFormat $outputFormat): string
+    {
+        throw new \BadMethodCallException('Nothing to see here :/', 1767308395);
+    }
+}