Update inspection for Final variables without assigned values (PEP 591) (PY-34945)

Raise a warning about explicit type argument only in stubs or on class level
In other scopes raise a warning about necessity to initialize such values

GitOrigin-RevId: 97759220d67b174b54d4ff90186b4109a5256354

python/src/com/jetbrains/python/inspections/PyFinalInspection.kt

@@ -5,6 +5,7 @@ import com.intellij.codeInspection.LocalInspectionToolSession
 import com.intellij.codeInspection.ProblemsHolder
 import com.intellij.psi.PsiElementVisitor
 import com.intellij.psi.impl.source.resolve.FileContextUtil
+import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil
 import com.jetbrains.python.codeInsight.functionTypeComments.psi.PyParameterTypeList
 import com.jetbrains.python.codeInsight.typing.PyTypingTypeProvider
 import com.jetbrains.python.codeInsight.typing.PyTypingTypeProvider.getFunctionTypeAnnotation
@@ -80,8 +81,17 @@ class PyFinalInspection : PyInspection() {
       super.visitPyTargetExpression(node)
 
       if (!node.hasAssignedValue()) {
-        node.annotation?.value.takeIf(this::resolvesToFinal).let {
-          registerProblem(it, "If assigned value is omitted, there should be an explicit type argument to 'Final'")
+        node.annotation?.value?.let {
+          if (PyiUtil.isInsideStub(node) || ScopeUtil.getScopeOwner(node) is PyClass) {
+            if (resolvesToFinal(it)) {
+              registerProblem(it, "If assigned value is omitted, there should be an explicit type argument to 'Final'")
+            }
+          }
+          else {
+            if (resolvesToFinal(if (it is PySubscriptionExpression) it.operand else it)) {
+              registerProblem(node, "'Final' name should be initialized with a value")
+            }
+          }
         }
       }
     }

python/testData/inspections/PyFinalInspection/omittedAssignedValueInStubOnClassLevel.pyi

@@ -0,0 +1,13 @@
+from typing_extensions import Final
+
+class A:
+    a: <warning descr="If assigned value is omitted, there should be an explicit type argument to 'Final'">Final</warning>
+    b: Final[int]
+    c: int
+
+MY_FINAL = Final
+MY_FINAL_INT = Final[int]
+
+class B:
+    с: <warning descr="If assigned value is omitted, there should be an explicit type argument to 'Final'">MY_FINAL</warning>
+    d: MY_FINAL_INT

python/testData/inspections/PyFinalInspection/omittedAssignedValueInStubOnModuleLevel.pyi

@@ -0,0 +1,7 @@
+from typing_extensions import Final
+
+a: Final[int]
+b: <warning descr="If assigned value is omitted, there should be an explicit type argument to 'Final'">Final</warning>
+b = "10"
+c: Final[str] = "10"
+d: int

python/testSrc/com/jetbrains/python/inspections/PyFinalInspectionTest.java

@@ -69,22 +69,66 @@ public class PyFinalInspectionTest extends PyInspectionTestCase {
   }
 
   // PY-34945
-  public void testOmittedAssignedValue() {
+  public void testOmittedAssignedValueOnModuleLevel() {
     runWithLanguageLevel(
       LanguageLevel.PYTHON36,
       () -> doTestByText("from typing_extensions import Final\n" +
                          "\n" +
-                         "a: <warning descr=\"If assigned value is omitted, there should be an explicit type argument to 'Final'\">Final</warning>\n" +
-                         "b: Final[int]\n" +
+                         "<warning descr=\"'Final' name should be initialized with a value\">a</warning>: Final[int]\n" +
+                         "<warning descr=\"'Final' name should be initialized with a value\">b</warning>: Final\n" +
+                         "b = \"10\"\n" +
+                         "c: Final[str] = \"10\"\n" +
+                         "d: int\n")
+    );
+  }
+
+  // PY-34945
+  public void testOmittedAssignedValueOnClassLevel() {
+    runWithLanguageLevel(
+      LanguageLevel.PYTHON36,
+      () -> doTestByText("from typing_extensions import Final\n" +
+                         "\n" +
+                         "class A:\n" +
+                         "    a: <warning descr=\"If assigned value is omitted, there should be an explicit type argument to 'Final'\">Final</warning>\n" +
+                         "    b: Final[int]\n" +
+                         "    c: int\n" +
                          "\n" +
                          "MY_FINAL = Final\n" +
                          "MY_FINAL_INT = Final[int]\n" +
                          "\n" +
-                         "с: <warning descr=\"If assigned value is omitted, there should be an explicit type argument to 'Final'\">MY_FINAL</warning>\n" +
-                         "в: MY_FINAL_INT")
+                         "class B:\n" +
+                         "    с: <warning descr=\"If assigned value is omitted, there should be an explicit type argument to 'Final'\">MY_FINAL</warning>\n" +
+                         "    d: MY_FINAL_INT")
     );
   }
 
+  // PY-34945
+  public void testOmittedAssignedValueOnFunctionLevel() {
+    runWithLanguageLevel(
+      LanguageLevel.PYTHON36,
+      () -> doTestByText("from typing_extensions import Final\n" +
+                         "\n" +
+                         "def foo(self):\n" +
+                         "    <warning descr=\"'Final' name should be initialized with a value\">a</warning>: Final[int]\n" +
+                         "    <warning descr=\"'Final' name should be initialized with a value\">b</warning>: Final\n" +
+                         "    c: Final[str] = \"10\"\n")
+    );
+  }
+
+  // PY-34945
+  public void testOmittedAssignedValueInStubOnModuleLevel() {
+    final PsiFile currentFile = myFixture.configureByFile(getTestFilePath() + "i");
+    configureInspection();
+    assertSdkRootsNotParsed(currentFile);
+  }
+
+  // PY-34945
+  public void testOmittedAssignedValueInStubOnClassLevel() {
+    final PsiFile currentFile = myFixture.configureByFile(getTestFilePath() + "i");
+    configureInspection();
+    assertSdkRootsNotParsed(currentFile);
+  }
+
   // PY-34945
   public void testOverloadedFinalMethod() {
     runWithLanguageLevel(