test: cover lowercase compatibility method returns

tests/test_validate_typecheck_diagnostics.py

@@ -80,6 +80,12 @@ class ValidateTypecheckDiagnosticsTests(unittest.TestCase):
     def test_includes_compatibility_method_return_success_fixture(self):
         self.assertIn("tests/typecheck_method_compat_return_good.claro", MODULE.EXPECTED_OK)
 
+    def test_includes_lowercase_compatibility_method_return_success_fixture(self):
+        self.assertIn(
+            "tests/typecheck_method_compat_lowercase_return_good.claro",
+            MODULE.EXPECTED_OK,
+        )
+
     def test_includes_compatibility_missing_method_argument_fixture(self):
         self.assertIn(
             "tests/typecheck_method_call_missing_unchecked_arg_bad.claro",
@@ -95,6 +101,10 @@ class ValidateTypecheckDiagnosticsTests(unittest.TestCase):
         )
         self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
         self.assertIn("tests/typecheck_method_call_bad.claro", result.stdout)
+        self.assertIn(
+            '"tests/typecheck_method_compat_lowercase_return_good.claro"',
+            (ROOT / "src" / "claro.c").read_text(),
+        )
 
 
 if __name__ == "__main__":

tests/typecheck_method_compat_lowercase_return_good.claro

@@ -0,0 +1,9 @@
+CLASS Player
+    TEACH score TAKES amount returns NUMBER
+        CHECK TYPE amount IS NUMBER
+        RETURN amount
+    LEARNED
+END
+
+NEW Player player
+CALL player.score WITH 4