Merge pull request #20 from reactjs/revert-breaking-change

Revert accidental breaking change for 15.5

README.md

@@ -25,11 +25,42 @@ If you prefer a `<script>` tag, you can get it from `window.PropTypes` global:
 <script src="https://unpkg.com/prop-types/prop-types.min.js"></script>
 ```
 
-## Difference from `React.PropTypes`: Development and Production Versions
+## Difference from `React.PropTypes`: Don’t Call Validator Functions
 
-In production, **all validator functions are replaced with empty functions that throw an error**. This is done to optimize the bundle size. This is new behavior, and you will only encounter it when you migrate from `React.PropTypes` to the `prop-types` package. For the vast majority of components, this doesn’t matter, and if you didn’t see [this warning](https://facebook.github.io/react/warnings/dont-call-proptypes.html) in your components, your code is safe to migrate. This is not a breaking change in React because you are only opting into this change for a component by explicitly changing your imports to use `prop-types`.
+When you migrate components to use the standalone `prop-types`, **all validator functions will start throwing an error if you call them directly**. This makes sure that nobody relies on them in production code, and it is safe to strip their implementations to optimize the bundle size.
 
-Don’t call the validator functions manually in your code. React automatically calls `PropTypes` validators declared on your components in development version, and it won’t call them in production. **If you absolutely need to trigger the validation manually**, call `PropTypes.checkPropTypes(propTypes, props, location, componentName)`. Unlike the validators themselves, this function is safe to call in production, as it will be replaced by an empty function.
+Code like this is still fine:
+
+```js
+MyComponent.propTypes = {
+  myProp: PropTypes.bool
+};
+```
+
+However, code like this will not work with the `prop-types` package:
+
+```js
+// Will not work with `prop-types` package!
+var errorOrNull = PropTypes.bool(42, 'myProp', 'MyComponent', 'prop');
+```
+
+It will throw an error:
+
+```
+Calling PropTypes validators directly is not supported by the `prop-types` package.
+Use PropTypes.checkPropTypes() to call them.
+```
+
+This is new behavior, and you will only encounter it when you migrate from `React.PropTypes` to the `prop-types` package. For the vast majority of components, this doesn’t matter, and if you didn’t see [this warning](https://facebook.github.io/react/warnings/dont-call-proptypes.html) in your components, your code is safe to migrate. This is not a breaking change in React because you are only opting into this change for a component by explicitly changing your imports to use `prop-types`. If you temporarily need the old behavior, you can keep using `React.PropTypes` until React 16.
+
+**If you absolutely need to trigger the validation manually**, call `PropTypes.checkPropTypes()`. Unlike the validators themselves, this function is safe to call in production, as it will be replaced by an empty function:
+
+```js
+// Works with standalone PropTypes
+PropTypes.checkPropTypes(MyComponent.propTypes, props, 'prop', 'MyComponent');
+```
+
+**You might also see this error** if you’re calling a `PropTypes` validator from your own custom `PropTypes` validator. In this case, the fix is to make sure that you are passing *all* of the arguments to the inner function. There is a more in-depth explanation of how to fix it [on this page](https://facebook.github.io/react/warnings/dont-call-proptypes.html#fixing-the-false-positive-in-third-party-proptypes). Alternatively, you can temporarily keep using `React.PropTypes` until React 16, as it would still only warn in this case.
 
 If you use a bundler like Browserify or Webpack, don’t forget to [follow these instructions](https://facebook.github.io/react/docs/installation.html#development-and-production-versions) to correctly bundle your application in development or production mode. Otherwise you’ll ship unnecessary code to your users.
 

__tests__/PropTypes-test.js → __tests__/PropTypesDevelopmentReact15.js

@@ -13,11 +13,13 @@
 
 var React;
 var PropTypes;
-var checkPropTypes;
 
 function resetWarningCache() {
   jest.resetModules();
-  checkPropTypes = require('../checkPropTypes');
+
+  React = require('react');
+  // This is how React 15 imports `prop-types`.
+  PropTypes = require('../factory')(React.isValidElement);
 }
 
 function getPropTypeWarningMessage(propTypes, object, componentName) {
@@ -27,7 +29,8 @@ function getPropTypeWarningMessage(propTypes, object, componentName) {
     console.error.calls.reset();
   }
   resetWarningCache();
-  checkPropTypes(propTypes, object, 'prop', 'testComponent');
+
+  PropTypes.checkPropTypes(propTypes, object, 'prop', 'testComponent');
   const callCount = console.error.calls.count();
   if (callCount > 1) {
     throw new Error('Too many warnings.');
@@ -103,11 +106,8 @@ function expectWarningInDevelopment(declaration, value) {
   console.error.calls.reset();
 }
 
-describe('ReactPropTypes', () => {
+describe('PropTypesDevelopmentReact15', () => {
   beforeEach(() => {
-    React = require('react');
-    PropTypes = require('../index');
-    checkPropTypes = PropTypes.checkPropTypes;
     resetWarningCache();
   });
 
@@ -120,7 +120,7 @@ describe('ReactPropTypes', () => {
         },
       };
       const props = {foo: 'foo'};
-      const returnValue = checkPropTypes(
+      const returnValue = PropTypes.checkPropTypes(
         propTypes,
         props,
         'prop',
@@ -139,7 +139,7 @@ describe('ReactPropTypes', () => {
         },
       };
       const props = {foo: 'foo'};
-      const returnValue = checkPropTypes(
+      const returnValue = PropTypes.checkPropTypes(
         propTypes,
         props,
         'prop',
@@ -839,9 +839,9 @@ describe('ReactPropTypes', () => {
 
     it('should warn if called manually in development', () => {
       spyOn(console, 'error');
-      expect(PropTypes.oneOf(['red', 'blue']), true);
-      expect(PropTypes.oneOf(['red', 'blue']), null);
-      expect(PropTypes.oneOf(['red', 'blue']), undefined);
+      expectWarningInDevelopment(PropTypes.oneOf(['red', 'blue']), true);
+      expectWarningInDevelopment(PropTypes.oneOf(['red', 'blue']), null);
+      expectWarningInDevelopment(PropTypes.oneOf(['red', 'blue']), undefined);
     });
   });