stages(groups): add minimal parameter validation test

The schema will move to v2 so we need to ensure that at least some
minimal validation is done that the old and the new schema work
the same way.

stages/test/test_groups.py

@@ -0,0 +1,31 @@
+#!/usr/bin/python3
+
+import pytest
+
+from osbuild.testutil import assert_jsonschema_error_contains
+
+STAGE_NAME = "org.osbuild.groups"
+
+
+@pytest.mark.parametrize("test_data,expected_err", [
+    # bad
+    ({"groups": {"!invalid-name": {}}}, "'!invalid-name' does not match any of the regex"),
+    ({"groups": {"foo": {"gid": "x"}}}, "'x' is not of type 'number'"),
+    # good
+    ({}, ""),
+    ({"groups": {"foo": {}}}, ""),
+    ({"groups": {"foo": {"gid": 999}}}, ""),
+])
+def test_schema_validation(stage_schema, test_data, expected_err):
+    test_input = {
+        "type": STAGE_NAME,
+        "options": {},
+    }
+    test_input["options"].update(test_data)
+    res = stage_schema.validate(test_input)
+
+    if expected_err == "":
+        assert res.valid is True, f"err: {[e.as_dict() for e in res.errors]}"
+    else:
+        assert res.valid is False
+        assert_jsonschema_error_contains(res, expected_err, expected_num_errs=1)