From 4e1bcc0020834f06801a6987043e085658e72bd7 Mon Sep 17 00:00:00 2001
From: Yannick Croissant <yannick.croissant@gmail.com>
Date: Sun, 21 Feb 2016 21:07:42 +0000
Subject: [PATCH] Fix used props detection in components for which we are not
 confident (fixes #420)

---
 lib/util/Components.js        | 26 ++++++++++++++++++++++++--
 tests/lib/rules/prop-types.js | 10 ++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lib/util/Components.js b/lib/util/Components.js
index b0e190a67c..ee2e051824 100644
--- a/lib/util/Components.js
+++ b/lib/util/Components.js
@@ -77,11 +77,33 @@ Components.prototype.set = function(node, props) {
  */
 Components.prototype.list = function() {
   var list = {};
+  var usedPropTypes = {};
+  // Find props used in components for which we are not confident
   for (var i in this._list) {
-    if (!this._list.hasOwnProperty(i) || this._list[i].confidence < 2) {
+    if (!this._list.hasOwnProperty(i) || this._list[i].confidence >= 2) {
       continue;
     }
-    list[i] = this._list[i];
+    var component;
+    var node;
+    node = this._list[i].node;
+    while (!component && node.parent) {
+      node = node.parent;
+      component = this.get(node);
+    }
+    if (component) {
+      usedPropTypes[this._getId(component.node)] = this._list[i].usedPropTypes;
+    }
+  }
+  // Assign used props in not confident components to the parent component
+  for (var j in this._list) {
+    if (!this._list.hasOwnProperty(j) || this._list[j].confidence < 2) {
+      continue;
+    }
+    var id = this._getId(this._list[j].node);
+    list[j] = this._list[j];
+    if (usedPropTypes[id]) {
+      list[j].usedPropTypes = (list[j].usedPropTypes || []).concat(usedPropTypes[id]);
+    }
   }
   return list;
 };
diff --git a/tests/lib/rules/prop-types.js b/tests/lib/rules/prop-types.js
index 8d9c2cfc9c..263948eab9 100644
--- a/tests/lib/rules/prop-types.js
+++ b/tests/lib/rules/prop-types.js
@@ -1937,6 +1937,16 @@ ruleTester.run('prop-types', rule, {
       errors: [{
         message: '\'names\' is missing in props validation'
       }]
+    }, {
+      code: [
+        'const MyComponent = props => (',
+        '  <div onClick={() => props.toggle()}></div>',
+        ')'
+      ].join('\n'),
+      parserOptions: parserOptions,
+      errors: [{
+        message: '\'toggle\' is missing in props validation'
+      }]
     }
   ]
 });