test: cover tr() function

psalm-baseline.xml

@@ -204,7 +204,7 @@
       <code><![CDATA[new \SplQueue()]]></code>
     </MixedPropertyTypeCoercion>
   </file>
-  <file src="src/Support/ProtobufCaster.php">
+  <file src="src/Support/Caster/ProtobufCaster.php">
     <MixedArgument>
       <code><![CDATA[$ed->getClass()]]></code>
       <code><![CDATA[$value]]></code>

tests/Unit/Client/FunctionTrapTest.php

@@ -4,15 +4,14 @@
 
 namespace Buggregator\Trap\Tests\Unit\Client;
 
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\RunInSeparateProcess;
 use PHPUnit\Framework\TestCase;
 
 final class FunctionTrapTest extends TestCase
 {
-    /**
-     * @runInSeparateProcess
-     *
-     * @group phpunit-only
-     */
+    #[RunInSeparateProcess]
+    #[Group('phpunit-only')]
     public function testLeak(): void
     {
         $object = new \stdClass();

tests/Unit/Client/TrTest.php

@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Buggregator\Trap\Tests\Unit\Client;
+
+use Buggregator\Trap\Client\TrapHandle\Dumper;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\RunInSeparateProcess;
+use Symfony\Component\VarDumper\Dumper\DataDumperInterface;
+
+final class TrTest extends Base
+{
+    public function testLabel(): void
+    {
+        tr(FooName: 'foo-value');
+        self::assertSame('FooName', self::$lastData->getContext()['label']);
+    }
+
+    /**
+     * Check the stacktrace contains three items and it begins with the right function name.
+     */
+    #[RunInSeparateProcess]
+    #[Group('phpunit-only')]
+    public function testTrAsStackTrace(): void
+    {
+        tr();
+
+        // 3 Stack Trace items
+        self::assertCount(3, self::$lastData->getValue());
+        self::assertStringMatchesFormat('Trace #0  -.---  %fM', self::$lastData->getType());
+        $firstLineKey = \array_key_first(self::$lastData->getValue());
+        self::assertStringContainsString('tr()', $firstLineKey);
+
+        tr();
+
+        self::assertCount(3, self::$lastData->getValue());
+        self::assertStringMatchesFormat('Trace #1  +%fms  %fM', self::$lastData->getType());
+        $firstLineKey = \array_key_first(self::$lastData->getValue());
+        self::assertStringContainsString('tr()', $firstLineKey);
+    }
+
+    /**
+     * After calling {@see tr()} the dumped data isn't stored in the memory.
+     */
+    public function testLeak(): void
+    {
+        $object = new \stdClass();
+        $ref = \WeakReference::create($object);
+
+        tr($object, $object);
+        unset($object);
+
+        $this->assertNull($ref->get());
+    }
+
+    public function testReturn(): void
+    {
+        $this->assertSame(42, tr(42));
+        $this->assertSame(42, tr(named: 42));
+        $this->assertSame(42, tr(42, 43));
+        $this->assertSame('foo', tr(...['0' => 'foo', 42 => 90]));
+        $this->assertNull(tr(null));
+    }
+
+    public function testReturnSendsDumpOnce(): void
+    {
+        $dumper = $this->getMockBuilder(DataDumperInterface::class)
+            ->getMock();
+        $dumper->expects($this->once())
+            ->method('dump')
+            ->willReturnArgument(1);
+        Dumper::setDumper($dumper);
+
+        $this->assertSame(42, tr(42));
+    }
+}