Clean up the code a bit

Author: Joachim Seminck

lib/rules/prop-types.js

@@ -710,6 +710,14 @@ module.exports = {
       });
     }
 
+    /**
+     * Marks all props found inside ObjectTypeAnnotaiton as declared.
+     * 
+     * Modifies the declaredProperties object
+     * @param {ASTNode} propTypes 
+     * @param {Object} declaredPropTypes 
+     * @returns {Boolean} True if propTypes should be ignored (e.g. when a type can't be resolved, when it is imported)
+     */
     function declarePropTypesForObjectTypeAnnotation(propTypes, declaredPropTypes) {
       let ignorePropsValidation = false;
 
@@ -734,33 +742,31 @@ module.exports = {
      * @returns {Boolean} True if propTypes should be ignored (e.g. when a type can't be resolved, when it is imported)
      */
     function declarePropTypesForIntersectionTypeAnnotation(propTypes, declaredPropTypes) {
-      let ignorePropsValidation = false;
+      return propTypes.types.reduce((ignorePropsValidation, annotation) => {
+        // If we already decided to skip props validation then we don't have to continue processing anything else
+        if (ignorePropsValidation) {
+          return ignorePropsValidation;
+        }
 
-      propTypes.types.forEach(annotation => {
         if (annotation.type === 'ObjectTypeAnnotation') {
           ignorePropsValidation = declarePropTypesForObjectTypeAnnotation(annotation, declaredPropTypes);
         } else {
           const typeNode = typeScope(annotation.id.name);
+
           if (!typeNode) {
             ignorePropsValidation = true;
-            return;
-          }
-
-          if (typeNode.type === 'IntersectionTypeAnnotation') {
+          } else if (typeNode.type === 'IntersectionTypeAnnotation') {
             ignorePropsValidation = declarePropTypesForIntersectionTypeAnnotation(typeNode, declaredPropTypes);
           } else {
-            iterateProperties(typeNode.properties, (key, value) => {
-              if (!value) {
-                ignorePropsValidation = true;
-                return;
-              }
-              declaredPropTypes[key] = buildTypeAnnotationDeclarationTypes(value);
-            });
+            ignorePropsValidation = declarePropTypesForObjectTypeAnnotation(typeNode, declaredPropTypes);
           }
         }
-      });
 
-      return ignorePropsValidation;
+        // Return early if we have to ignore props validation. No point to continue processing.
+        if (ignorePropsValidation) {
+          return ignorePropsValidation;
+        }
+      }, false);
     }
 
     /**