[10.x] Improve test cases and achieve 100% code coverage (#48360)

* Add test case method for checking all registered namespace Return Properly

* Add test case method for checking all added jsonPaths return properly

* Add test case method for checking expected exception when invalid json provide

* Fix some coding style!

tests/Translation/TranslationFileLoaderTest.php

@@ -121,4 +121,35 @@ public function testLoadMethodForJSONProperlyCallsLoaderForMultiplePaths()
 
         $this->assertEquals(['foo' => 'bar', 'baz' => 'backagesplash'], $loader->load('en', '*', '*'));
     }
+
+    public function testLoadMethodThrowExceptionWhenProvideInvalidJSON()
+    {
+        $loader = new FileLoader($files = m::mock(Filesystem::class), __DIR__);
+        $loader->addJsonPath(__DIR__.'/invalid');
+
+        $invalidJsonString = '.{"foo":"cricket", "baz": "football"}';
+        $files->shouldReceive('exists')->once()->with(__DIR__.'/invalid/en.json')->andReturn(true);
+        $files->shouldReceive('get')->once()->with(__DIR__.'/invalid/en.json')->andReturn($invalidJsonString);
+
+        $this->expectException(\RuntimeException::class);
+        $loader->load('en', '*', '*');
+    }
+
+    public function testAllRegisteredNamespaceReturnProperly()
+    {
+        $loader = new FileLoader(m::mock(Filesystem::class), __DIR__);
+        $loader->addNamespace('namespace', 'foo');
+        $loader->addNamespace('namespace2', 'bar');
+        $this->assertEquals(['namespace' => 'foo', 'namespace2' => 'bar'], $loader->namespaces());
+    }
+
+    public function testAllAddedJsonPathsReturnProperly()
+    {
+        $loader = new FileLoader(m::mock(Filesystem::class), __DIR__);
+        $path1 = __DIR__.'/another';
+        $path2 = __DIR__.'/another2';
+        $loader->addJsonPath($path1);
+        $loader->addJsonPath($path2);
+        $this->assertEquals([$path1, $path2], $loader->jsonPaths());
+    }
 }