[11.x] Add some tests in RepositoryTest.php (#51041)

* Enhance test coverage by adding tests for the offsetExists method

* Enhance test coverage by adding tests for the offsetSet method

* Fix assertion order in testItGetsAsString method

Author: saMahmoudzadeh

tests/Config/RepositoryTest.php

@@ -221,8 +221,21 @@ public function testAll()
 
     public function testOffsetExists()
     {
+        $data = [
+            'foo' => 'bar',
+            'null_value' => null,
+            'empty_string' => '',
+            'numeric_value' => 123,
+        ];
+        $this->repository->set($data);
+
         $this->assertTrue(isset($this->repository['foo']));
         $this->assertFalse(isset($this->repository['not-exist']));
+        $this->assertTrue(isset($this->repository['null_value']));
+        $this->assertTrue(isset($this->repository['empty_string']));
+        $this->assertTrue(isset($this->repository['numeric_value']));
+        $this->assertFalse(isset($this->repository[-1]));
+        $this->assertFalse(isset($this->repository['non_numeric']));
     }
 
     public function testOffsetGet()
@@ -242,6 +255,18 @@ public function testOffsetSet()
         $this->repository['key'] = 'value';
 
         $this->assertSame('value', $this->repository['key']);
+
+        $this->repository['key'] = 'new_value';
+        $this->assertSame('new_value', $this->repository['key']);
+
+        $this->repository['new_key'] = null;
+        $this->assertNull($this->repository['new_key']);
+
+        $this->repository[''] = 'value';
+        $this->assertSame('value', $this->repository['']);
+
+        $this->repository[123] = '123';
+        $this->assertSame('123', $this->repository[123]);
     }
 
     public function testOffsetUnset()
@@ -267,7 +292,7 @@ public function testsItIsMacroable()
     public function testItGetsAsString(): void
     {
         $this->assertSame(
-            $this->repository->string('a.b'), 'c'
+            'c', $this->repository->string('a.b')
         );
     }