From e3735015e4bd808f2b755b439e94280dd7e1e188 Mon Sep 17 00:00:00 2001
From: Semyon Proshev <Semyon.Proshev@jetbrains.com>
Date: Tue, 8 May 2018 19:11:28 +0300
Subject: [PATCH] Fix return type for dataclass callable type (PY-28442)

---
 .../codeInsight/stdlib/PyDataclassTypeProvider.kt     |  2 +-
 .../PyTypeCheckerInspection/DataclassClsCallType/a.py | 11 +++++++++++
 .../DataclassClsCallType/dataclasses.py               |  3 +++
 .../inspections/Py3TypeCheckerInspectionTest.java     |  5 +++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/a.py
 create mode 100644 python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/dataclasses.py

diff --git a/python/src/com/jetbrains/python/codeInsight/stdlib/PyDataclassTypeProvider.kt b/python/src/com/jetbrains/python/codeInsight/stdlib/PyDataclassTypeProvider.kt
index 51e73040d670..05781d3be64b 100644
--- a/python/src/com/jetbrains/python/codeInsight/stdlib/PyDataclassTypeProvider.kt
+++ b/python/src/com/jetbrains/python/codeInsight/stdlib/PyDataclassTypeProvider.kt
@@ -108,7 +108,7 @@ class PyDataclassTypeProvider : PyTypeProviderBase() {
       .mapNotNull { fieldToParameter(cls, it, dataclassParameters.type, ellipsis, context) }
       .toList()
 
-    return PyCallableTypeImpl(parameters, context.getType(cls))
+    return PyCallableTypeImpl(parameters, context.getType(cls)?.let { if (it is PyInstantiableType<*>) it.toInstance() else it })
   }
 
   private fun fieldToParameter(cls: PyClass,
diff --git a/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/a.py b/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/a.py
new file mode 100644
index 000000000000..b1e7f8012bd7
--- /dev/null
+++ b/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/a.py
@@ -0,0 +1,11 @@
+from dataclasses import dataclass
+
+
+@dataclass
+class Point:
+    x: int
+    y: int
+
+    @classmethod
+    def from_str(cls, string: str) -> 'Point':
+        return cls(1, 2)
\ No newline at end of file
diff --git a/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/dataclasses.py b/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/dataclasses.py
new file mode 100644
index 000000000000..68675bfddc1b
--- /dev/null
+++ b/python/testData/inspections/PyTypeCheckerInspection/DataclassClsCallType/dataclasses.py
@@ -0,0 +1,3 @@
+def dataclass(_cls=None, *, init=True, repr=True, eq=True, order=False,
+              unsafe_hash=False, frozen=False):
+    pass
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java
index fcd49d94b122..881db67ca55b 100644
--- a/python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java
@@ -297,6 +297,11 @@ public class Py3TypeCheckerInspectionTest extends PyInspectionTestCase {
     runWithLanguageLevel(LanguageLevel.PYTHON37, () -> super.doMultiFileTest());
   }
 
+  // PY-28442
+  public void testDataclassClsCallType() {
+    runWithLanguageLevel(LanguageLevel.PYTHON37, () -> super.doMultiFileTest());
+  }
+
   // PY-26354
   public void testInitializingAttrs() {
     doTestByText("import attr\n" +