PY-45368 Fixed completing 'None' in type annotations

GitOrigin-RevId: fc7e7ff0a03ce41373bac2eedbf3e8b7aaa2ce4d

python/python-psi-impl/src/com/jetbrains/python/codeInsight/completion/PyKeywordCompletionContributor.java

@@ -323,6 +323,9 @@ public class PyKeywordCompletionContributor extends CompletionContributor implem
   private static final PsiElementPattern.Capture<PsiElement> IN_ELSE_BODY_OF_TRY =
     psiElement().inside(psiElement(PyStatementList.class).inside(psiElement(PyElsePart.class).inside(PyTryExceptStatement.class)));
 
+  private static final PsiElementPattern.Capture<PsiElement> IN_ANNOTATION =
+    psiElement().inside(psiElement(PyAnnotation.class));
+
   private static final PsiElementPattern.Capture<PsiElement> AFTER_IF = afterStatement(psiElement(PyIfStatement.class).withLastChild(
     psiElement(PyIfPart.class)));
   private static final PsiElementPattern.Capture<PsiElement> AFTER_TRY = afterStatement(psiElement(PyTryExceptStatement.class));
@@ -644,6 +647,11 @@ public class PyKeywordCompletionContributor extends CompletionContributor implem
              .and(PY35)
              .afterLeaf(psiElement().withElementType(PyTokenTypes.IDENTIFIER).withText(PyNames.ASYNC)),
            new PyKeywordCompletionProvider(PyNames.DEF, PyNames.WITH, PyNames.FOR));
+    extend(CompletionType.BASIC,
+           psiElement()
+             .withLanguage(PythonLanguage.getInstance())
+             .and(IN_ANNOTATION),
+           new PyKeywordCompletionProvider(TailType.NONE, PyNames.NONE));
   }
 
   private void addAs() {

python/testData/keywordCompletion/noneInParameterAnnotation.after.py

@@ -0,0 +1,5 @@
+from typing import Union
+
+
+def foo(x: Union[int, None]):
+    pass

python/testData/keywordCompletion/noneInParameterAnnotation.py

@@ -0,0 +1,5 @@
+from typing import Union
+
+
+def foo(x: Union[int, Non<caret>]):
+    pass

python/testData/keywordCompletion/noneInReturnAnnotation.after.py

@@ -0,0 +1 @@
+def foo() -> None

python/testData/keywordCompletion/noneInReturnAnnotation.py

@@ -0,0 +1 @@
+def foo() -> Non<caret>

python/testSrc/com/jetbrains/python/PythonKeywordCompletionTest.java

@@ -248,4 +248,14 @@ public class PythonKeywordCompletionTest extends PyTestCase {
   public void testNoForAndYieldInCommentContext() {
     assertDoesntContain(doTestByTestName(), "for", "yield");
   }
+
+  // PY-45368
+  public void testNoneInParameterAnnotation() {
+    doTest();
+  }
+
+  // PY-45368
+  public void testNoneInReturnAnnotation() {
+    doTest();
+  }
 }