refactor: extract has and warning

checkPropTypes.js

@@ -12,7 +12,7 @@ var printWarning = function() {};
 if (process.env.NODE_ENV !== 'production') {
   var ReactPropTypesSecret = require('./lib/ReactPropTypesSecret');
   var loggedTypeFailures = {};
-  var has = Function.call.bind(Object.prototype.hasOwnProperty);
+  var has = require('./lib/has');
 
   printWarning = function(text) {
     var message = 'Warning: ' + text;

factoryWithTypeCheckers.js

@@ -11,9 +11,9 @@ var ReactIs = require('react-is');
 var assign = require('object-assign');
 
 var ReactPropTypesSecret = require('./lib/ReactPropTypesSecret');
+var has = require('./lib/has');
 var checkPropTypes = require('./checkPropTypes');
 
-var has = Function.call.bind(Object.prototype.hasOwnProperty);
 var printWarning = function() {};
 
 if (process.env.NODE_ENV !== 'production') {

lib/has.js

@@ -0,0 +1 @@
+module.exports = Function.call.bind(Object.prototype.hasOwnProperty);