Fix annotated function detection (fixes #498)

Author: yannickcr

lib/rules/prop-types.js

@@ -90,12 +90,10 @@ module.exports = Components.detect(function(context, components, utils) {
   function isAnnotatedFunctionPropsDeclaration(node) {
     if (node && node.params && node.params.length) {
       var tokens = context.getFirstTokens(node.params[0], 2);
-      if (
-        node.params[0].typeAnnotation && (
-          tokens[0].value === 'props' ||
-          (tokens[1] && tokens[1].value === 'props')
-        )
-      ) {
+      var isAnnotated = node.params[0].typeAnnotation;
+      var isDestructuredProps = node.params[0].type === 'ObjectPattern';
+      var isProps = tokens[0].value === 'props' || (tokens[1] && tokens[1].value === 'props');
+      if (isAnnotated && (isDestructuredProps || isProps)) {
         return true;
       }
     }

tests/lib/rules/prop-types.js

@@ -1172,6 +1172,16 @@ ruleTester.run('prop-types', rule, {
         '};'
       ].join('\n'),
       parser: 'babel-eslint'
+    }, {
+      code: [
+        'type Props = {',
+        '  firstname: ?string,',
+        '};',
+        'function Hello({firstname}: Props): React$Element {',
+        '  return <div>Hello {firstname}</div>;',
+        '}'
+      ].join('\n'),
+      parser: 'babel-eslint'
     }
   ],
 
@@ -2031,6 +2041,19 @@ ruleTester.run('prop-types', rule, {
       errors: [{
         message: '\'test\' is missing in props validation'
       }]
+    }, {
+      code: [
+        'type Props = {',
+        '  firstname: ?string,',
+        '};',
+        'function Hello({firstname, lastname}: Props): React$Element {',
+        '  return <div>Hello {firstname} {lastname}</div>;',
+        '}'
+      ].join('\n'),
+      parser: 'babel-eslint',
+      errors: [{
+        message: '\'lastname\' is missing in props validation'
+      }]
     }
   ]
 });