From 952919a5c04784cb93439ba3523cdb0cb8204281 Mon Sep 17 00:00:00 2001
From: Semyon Proshev <Semyon.Proshev@jetbrains.com>
Date: Wed, 25 Apr 2018 14:40:00 +0300
Subject: [PATCH] Error about assignments to frozen attrs and its fields
 removal (PY-26354)

---
 .../inspections/PyDataclassInspection.kt      |  7 +--
 .../mutatingFrozenAttrs.py                    | 49 +++++++++++++++++++
 .../PyDataclassInspectionTest.java            |  5 ++
 3 files changed, 56 insertions(+), 5 deletions(-)
 create mode 100644 python/testData/inspections/PyDataclassInspection/mutatingFrozenAttrs.py

diff --git a/python/src/com/jetbrains/python/inspections/PyDataclassInspection.kt b/python/src/com/jetbrains/python/inspections/PyDataclassInspection.kt
index db5d5262d88a..57eca0b4e0b4 100644
--- a/python/src/com/jetbrains/python/inspections/PyDataclassInspection.kt
+++ b/python/src/com/jetbrains/python/inspections/PyDataclassInspection.kt
@@ -9,10 +9,7 @@ import com.intellij.codeInspection.ProblemsHolder
 import com.intellij.psi.PsiElementVisitor
 import com.intellij.util.containers.ContainerUtil
 import com.jetbrains.python.PyNames
-import com.jetbrains.python.codeInsight.stdlib.DATACLASSES_INITVAR_TYPE
-import com.jetbrains.python.codeInsight.stdlib.DUNDER_POST_INIT
-import com.jetbrains.python.codeInsight.stdlib.PyDataclassParameters
-import com.jetbrains.python.codeInsight.stdlib.parseStdDataclassParameters
+import com.jetbrains.python.codeInsight.stdlib.*
 import com.jetbrains.python.codeInsight.typing.PyTypingTypeProvider
 import com.jetbrains.python.psi.*
 import com.jetbrains.python.psi.impl.PyCallExpressionHelper
@@ -167,7 +164,7 @@ class PyDataclassInspection : PyInspection() {
 
     private fun checkMutatingFrozenAttribute(expression: PyQualifiedExpression) {
       val cls = getInstancePyClass(expression.qualifier) ?: return
-      if (parseStdDataclassParameters(cls, myTypeEvalContext)?.frozen == true) {
+      if (parseDataclassParameters(cls, myTypeEvalContext)?.frozen == true) {
         registerProblem(expression, "'${cls.name}' object attribute '${expression.name}' is read-only", ProblemHighlightType.GENERIC_ERROR)
       }
     }
diff --git a/python/testData/inspections/PyDataclassInspection/mutatingFrozenAttrs.py b/python/testData/inspections/PyDataclassInspection/mutatingFrozenAttrs.py
new file mode 100644
index 000000000000..c8e54b717543
--- /dev/null
+++ b/python/testData/inspections/PyDataclassInspection/mutatingFrozenAttrs.py
@@ -0,0 +1,49 @@
+import attr
+
+
+@attr.s(auto_attribs=True)
+class B1:
+    x: int
+    y: str
+    z: float = 0.0
+
+B1.x = 5
+b1 = B1(1, "2")
+b1.x = 2
+b1.y = "3"
+b1.z = 1.0
+del b1.x
+del b1.y
+del b1.z
+
+
+@attr.s(frozen=False, auto_attribs=True)
+class B2:
+    x: int
+    y: str
+    z: float = 0.0
+
+B2.x = 5
+b2 = B2(1, "2")
+b2.x = 2
+b2.y = "3"
+b2.z = 1.0
+del b2.x
+del b2.y
+del b2.z
+
+
+@attr.s(frozen=True, auto_attribs=True)
+class B3:
+    x: int
+    y: str
+    z: float = 0.0
+
+B3.x = 5
+b3 = B3(1, "2")
+<error descr="'B3' object attribute 'x' is read-only">b3.x</error> = 2
+<error descr="'B3' object attribute 'y' is read-only">b3.y</error> = "3"
+<error descr="'B3' object attribute 'z' is read-only">b3.z</error> = 1.0
+del <error descr="'B3' object attribute 'x' is read-only">b3.x</error>
+del <error descr="'B3' object attribute 'y' is read-only">b3.y</error>
+del <error descr="'B3' object attribute 'z' is read-only">b3.z</error>
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/inspections/PyDataclassInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/PyDataclassInspectionTest.java
index 4f27c688815e..60f811db6ad1 100644
--- a/python/testSrc/com/jetbrains/python/inspections/PyDataclassInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/PyDataclassInspectionTest.java
@@ -16,6 +16,11 @@ public class PyDataclassInspectionTest extends PyInspectionTestCase {
     doTest();
   }
 
+  // PY-26354
+  public void testMutatingFrozenAttrs() {
+    doTest();
+  }
+
   // PY-27398
   public void testOrderAndNotEq() {
     doTest();