Merge pull request #4058 from yiminghe/className_contains

fix className check in scryRenderedDOMComponentsWithClass when encounter new line

src/test/ReactTestUtils.js

@@ -174,7 +174,7 @@ var ReactTestUtils = {
         var instClassName = React.findDOMNode(inst).className;
         return (
           instClassName &&
-          (' ' + instClassName + ' ').indexOf(' ' + className + ' ') !== -1
+          (('' + instClassName).split(/\s+/)).indexOf(className) !== -1
         );
       }
       return false;

src/test/__tests__/ReactTestUtils-test.js

@@ -187,6 +187,17 @@ describe('ReactTestUtils', function() {
 
   });
 
+  it('Test scryRenderedDOMComponentsWithClass with className contains \\n', function() {
+    var renderedComponent = ReactTestUtils.renderIntoDocument(
+      <div>Hello <span className={'x\ny'}>Jim</span></div>
+    );
+    var scryResults = ReactTestUtils.scryRenderedDOMComponentsWithClass(
+      renderedComponent,
+      'x'
+    );
+    expect(scryResults.length).toBe(1);
+  });
+
   it('traverses children in the correct order', function() {
     var container = document.createElement('div');