Error about assignments to frozen attrs and its fields removal (PY-26354)

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>