Infer correct type for docstrings (PY-35885)

GitOrigin-RevId: 2994a2e312611b038c72ec18abb2cd96880213e9

python/python-psi-impl/src/com/jetbrains/python/psi/impl/PyStringLiteralExpressionImpl.java

@@ -165,6 +165,9 @@ public class PyStringLiteralExpressionImpl extends PyElementImpl implements PySt
         // f-strings can't have "b" prefix so they are always unicode
         return builtinCache.getUnicodeType(languageLevel);
       }
+      else if (firstNode.getElementType() == PyTokenTypes.DOCSTRING) {
+        return builtinCache.getStrType();
+      }
 
       if (file != null) {
         final IElementType type = PythonHighlightingLexer.convertStringType(firstNode.getElementType(),

python/testSrc/com/jetbrains/python/Py3TypeTest.java

@@ -1133,6 +1133,15 @@ public class Py3TypeTest extends PyTestCase {
            "expr = f'foo'");
   }
 
+  // PY-35885
+  public void testFunctionDunderDoc() {
+    doTest("str",
+           "def example():\n" +
+           "    \"\"\"Example Docstring\"\"\"\n" +
+           "    return 0\n" +
+           "expr = example.__doc__");
+  }
+
   private void doTest(final String expectedType, final String text) {
     myFixture.configureByText(PythonFileType.INSTANCE, text);
     final PyExpression expr = myFixture.findElementByText("expr", PyExpression.class);

python/testSrc/com/jetbrains/python/PyTypeTest.java

@@ -3768,6 +3768,15 @@ public class PyTypeTest extends PyTestCase {
     );
   }
 
+  // PY-35885
+  public void testFunctionDunderDoc() {
+    doTest("str",
+           "def example():\n" +
+           "    \"\"\"Example Docstring\"\"\"\n" +
+           "    return 0\n" +
+           "expr = example.__doc__");
+  }
+
   private static List<TypeEvalContext> getTypeEvalContexts(@NotNull PyExpression element) {
     return ImmutableList.of(TypeEvalContext.codeAnalysis(element.getProject(), element.getContainingFile()).withTracing(),
                             TypeEvalContext.userInitiated(element.getProject(), element.getContainingFile()).withTracing());