Add test

Author: xepozz

src/CompositeException.php

@@ -15,7 +15,7 @@ final class CompositeException extends Exception
     /**
      * @var Throwable[]
      */
-    public array $rest;
+    private array $rest;
 
     public function __construct(
         private Throwable $first,

tests/CompositeExceptionTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\ErrorHandler\Tests;
+
+use PHPUnit\Framework\TestCase;
+
+final class CompositeExceptionTest extends TestCase
+{
+    public function testExceptions()
+    {
+        $exception1 = new \Exception('Exception 1', 123, new \Exception('Previous exception'));
+        $exception2 = new \Exception('Exception 2');
+        $exception = new \Yiisoft\ErrorHandler\CompositeException(
+            $exception1,
+            $exception2,
+        );
+
+        $this->assertSame('Exception 1', $exception->getMessage());
+        $this->assertSame(123, $exception->getCode());
+        $this->assertSame($exception1, $exception->getPrevious());
+        $this->assertSame($exception1, $exception->getFirstException());
+        $this->assertSame([$exception2], $exception->getPreviousExceptions());
+    }
+
+    public function testOnlyOneException()
+    {
+        $exception1 = new \Exception('Exception 1', 123, new \Exception('Previous exception'));
+        $exception = new \Yiisoft\ErrorHandler\CompositeException($exception1);
+
+        $this->assertSame('Exception 1', $exception->getMessage());
+        $this->assertSame(123, $exception->getCode());
+        $this->assertSame($exception1, $exception->getPrevious());
+        $this->assertSame($exception1, $exception->getFirstException());
+        $this->assertSame([], $exception->getPreviousExceptions());
+    }
+}