Fixes #6153 Add case typechecking to provided props against propTypes

scripts/fiber/tests-passing.txt

@@ -312,6 +312,7 @@ src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js
 * should not warn for valid values
 * should be implicitly optional and not warn without values
 * should warn for missing required values
+* should warn for mismatched case of passed values to types
 * should should accept any value
 * should be implicitly optional and not warn without values
 * should warn for missing required values

src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js

@@ -153,6 +153,28 @@ describe('ReactPropTypes', () => {
     it('should warn for missing required values', () => {
       typeCheckFailRequiredValues(PropTypes.string.isRequired);
     });
+
+    it('should warn for mismatched case of passed values to types', function() {
+      spyOn(console, 'error');
+      Component = React.createClass({
+        propTypes: {
+          onAction: PropTypes.func,
+          label: PropTypes.string,
+        },
+
+        render: function() {
+          return <div>{this.props.label}</div>;
+        },
+      });
+      var node = <Component onaction={() => alert('hello')} label="HelloWorld" />;
+      var node2 = <Component onaction={() => alert('hello')} label="HelloWorld" />;
+      ReactTestUtils.renderIntoDocument(node);
+      ReactTestUtils.renderIntoDocument(node2);
+      expect(console.error.calls.argsFor(0)[0]).toBe(
+        'Warning: Provided prop onaction is not defined in propTypes, did you mean onAction?',
+      );
+      expect(console.error.calls.count()).toBe(1);
+    });
   });
 
   describe('Any type', () => {

src/shared/types/checkReactTypeSpec.js

@@ -34,6 +34,7 @@ if (
 }
 
 var loggedTypeFailures = {};
+var mistypedPropFailures = {};
 
 /**
  * Assert that the values match with the type specs.
@@ -57,6 +58,9 @@ function checkReactTypeSpec(
   // only during reconciliation (begin and complete phase).
   workInProgressOrDebugID,
 ) {
+  // values can be undefined, at least in pre existing test cases, so default to empty array
+  const mismatched = values ? Object.keys(values).filter(x => Object.keys(typeSpecs).indexOf(x) === -1) : [];
+  const lowercase = mismatched.map(i => i.toLowerCase());
   for (var typeSpecName in typeSpecs) {
     if (typeSpecs.hasOwnProperty(typeSpecName)) {
       var error;
@@ -126,6 +130,16 @@ function checkReactTypeSpec(
           componentStackInfo
         );
       }
+      if (lowercase.indexOf(typeSpecName.toLowerCase()) !== -1 && !mistypedPropFailures[typeSpecName]) {
+        const mismatch = mismatched[lowercase.indexOf(typeSpecName.toLowerCase())];
+        warning(
+          false,
+          'Provided prop %s is not defined in propTypes, did you mean %s?',
+          mismatch,
+          typeSpecName,
+        );
+        mistypedPropFailures[typeSpecName] = true;
+      }
     }
   }
 }