Fix usage of propTypes with an external object (fixes #9)

Author: yannickcr

docs/rules/prop-types.md

@@ -42,4 +42,12 @@ var Hello = React.createClass({
     return <div>Hello {this.props.name}</div>;
   }
 });
+
+// Referencing an external object disable the rule for the component
+var Hello = React.createClass({
+  propTypes: myPropTypes,
+  render: function() {
+    return <div>Hello {this.props.name}</div>;
+  }
+});
 ```

lib/rules/prop-types.js

@@ -12,6 +12,7 @@ module.exports = function(context) {
 
   var declaredPropTypes = [];
   var usedPropTypes = [];
+  var ignorePropsValidation = false;
 
   function isComponentDefinition(node) {
     return (
@@ -48,6 +49,11 @@ module.exports = function(context) {
         if (keyName !== 'propTypes') {
           return;
         }
+        if (property.value.type !== 'ObjectExpression') {
+          ignorePropsValidation = true;
+          return;
+        }
+
         for (var i = 0, j = property.value.properties.length; i < j; i++) {
           declaredPropTypes.push(property.value.properties[i].key.name);
         }
@@ -60,14 +66,16 @@ module.exports = function(context) {
         return;
       }
 
-      for (var i = 0, j = usedPropTypes.length; i < j; i++) {
-        if (declaredPropTypes.indexOf(usedPropTypes[i]) === -1 && usedPropTypes[i] !== 'children') {
-          context.report(node, '\'' + usedPropTypes[i] + '\' is missing in props validation');
+      for (var i = 0, j = usedPropTypes.length; !ignorePropsValidation && i < j; i++) {
+        if (declaredPropTypes.indexOf(usedPropTypes[i]) !== -1 || usedPropTypes[i] === 'children') {
+          continue;
         }
+        context.report(node, '\'' + usedPropTypes[i] + '\' is missing in props validation');
       }
 
       declaredPropTypes.length = 0;
       usedPropTypes.length = 0;
+      ignorePropsValidation = false;
     }
   };
 

tests/lib/rules/prop-types.js

@@ -76,6 +76,17 @@ eslintTester.addRuleTest('lib/rules/prop-types', {
             ecmaFeatures: {
               jsx: true
             }
+        }, {
+            code: '\
+              var Hello = React.createClass({\
+                propTypes: externalPropTypes,\
+                render: function() {\
+                  return <div>Hello {this.props.name}</div>;\
+                }\
+              });',
+            ecmaFeatures: {
+              jsx: true
+            }
         }
     ],