sqlite3: Support 'size' keyword argument in Cursor::fetchmany

Author: ever0de

Lib/test/test_sqlite3/test_dbapi.py

@@ -1069,8 +1069,6 @@ def test_fetchmany(self):
         res = self.cu.fetchmany(100)
         self.assertEqual(res, [])
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_fetchmany_kw_arg(self):
         """Checks if fetchmany works with keyword arguments"""
         self.cu.execute("select name from test")

stdlib/src/sqlite.rs

@@ -1684,14 +1684,40 @@ mod _sqlite {
         #[pymethod]
         fn fetchmany(
             zelf: &Py<Self>,
-            max_rows: OptionalArg<c_int>,
+            mut args: FuncArgs,
             vm: &VirtualMachine,
         ) -> PyResult<Vec<PyObjectRef>> {
-            let max_rows = max_rows.unwrap_or_else(|| zelf.arraysize.load(Ordering::Relaxed));
+            let size_posarg = args.take_positional();
+            let size_kwarg = args.take_keyword("size");
+
+            if !args.args.is_empty() {
+                return Err(vm.new_type_error(format!(
+                    "fetchmany() takes from 0 to 1 positional arguments but {} were given",
+                    args.args.len() + 1
+                )));
+            }
+
+            if let Some((name_str, _)) = args.kwargs.into_iter().next() {
+                return Err(vm.new_type_error(format!(
+                    "fetchmany() got an unexpected keyword argument {name_str}",
+                )));
+            }
+
+            let max_rows: c_int = match (size_posarg, size_kwarg) {
+                (Some(pos), None) => pos.try_into_value(vm)?,
+                (None, Some(kw)) => kw.try_into_value(vm)?,
+                (None, None) => zelf.arraysize.load(Ordering::Relaxed),
+                (Some(_), Some(_)) => {
+                    return Err(vm.new_type_error(
+                        "fetchmany() got multiple values for argument 'size'".to_owned(),
+                    ));
+                }
+            };
+
             let mut list = vec![];
             while let PyIterReturn::Return(row) = Self::next(zelf, vm)? {
                 list.push(row);
-                if list.len() as c_int >= max_rows {
+                if max_rows > 0 && list.len() as c_int >= max_rows {
                     break;
                 }
             }