From e79b624ec387dc5be9424400998049e84deefa9e Mon Sep 17 00:00:00 2001
From: Semyon Proshev <Semyon.Proshev@jetbrains.com>
Date: Tue, 6 Sep 2016 16:02:52 +0300
Subject: [PATCH] PY-20063 Fixed: Code introspection / autocomplete does not
 resolve types in Sets (and perhaps other collection types) when used with
 single-character iteration expressions

Add skeletons for set.__iter__
---
 python/helpers/python-skeletons/__builtin__.py      | 6 ++++++
 python/helpers/python-skeletons/builtins.py         | 6 ++++++
 python/testSrc/com/jetbrains/python/PyTypeTest.java | 8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/python/helpers/python-skeletons/__builtin__.py b/python/helpers/python-skeletons/__builtin__.py
index 69e30af36951..cd5ecda0da56 100644
--- a/python/helpers/python-skeletons/__builtin__.py
+++ b/python/helpers/python-skeletons/__builtin__.py
@@ -2349,6 +2349,12 @@ class set(object):
         """
         return False
 
+    def __iter__(self):
+        """
+        :rtype: collections.Iterator[T]
+        """
+        pass
+
 
 class frozenset(object):
     """frozenset object."""
diff --git a/python/helpers/python-skeletons/builtins.py b/python/helpers/python-skeletons/builtins.py
index 7171c52192ab..67f797586bb8 100644
--- a/python/helpers/python-skeletons/builtins.py
+++ b/python/helpers/python-skeletons/builtins.py
@@ -2039,6 +2039,12 @@ class set(object):
         """
         return False
 
+    def __iter__(self):
+        """
+        :rtype: collections.Iterator[T]
+        """
+        pass
+
 
 class frozenset(object):
     """frozenset object."""
diff --git a/python/testSrc/com/jetbrains/python/PyTypeTest.java b/python/testSrc/com/jetbrains/python/PyTypeTest.java
index d8e4f32b2d01..3c386e2e59a0 100644
--- a/python/testSrc/com/jetbrains/python/PyTypeTest.java
+++ b/python/testSrc/com/jetbrains/python/PyTypeTest.java
@@ -1102,6 +1102,14 @@ public class PyTypeTest extends PyTestCase {
            TypeEvalContext.userInitiated(expr.getProject(), expr.getContainingFile()));
   }
 
+  // PY-20063
+  public void testIteratedSetElement() {
+    doTest("int",
+           "xs = {1}\n" +
+           "for expr in xs:\n" +
+           "    print(expr)");
+  }
+
   private static List<TypeEvalContext> getTypeEvalContexts(@NotNull PyExpression element) {
     return ImmutableList.of(TypeEvalContext.codeAnalysis(element.getProject(), element.getContainingFile()).withTracing(),
                             TypeEvalContext.userInitiated(element.getProject(), element.getContainingFile()).withTracing());