test: add KeyValueAction unit tests

tests/unit/byteb4rb1e/utils/argparse/test_actions.py

@@ -0,0 +1,52 @@
+"""Tests for custom argparse actions."""
+
+from argparse import ArgumentParser
+
+import pytest
+
+from byteb4rb1e.utils.argparse.actions import KeyValueAction
+
+
+def _parse(*args):
+    parser = ArgumentParser()
+    parser.add_argument("--config", action=KeyValueAction, default={}, metavar="KEY=VALUE")
+    return parser.parse_args(list(args))
+
+
+class TestKeyValueAction:
+
+    def test_single_pair(self):
+        args = _parse("--config", "key=value")
+        assert args.config == {"key": "value"}
+
+    def test_multiple_pairs(self):
+        args = _parse("--config", "a=1", "--config", "b=2")
+        assert args.config == {"a": "1", "b": "2"}
+
+    def test_dotted_key(self):
+        args = _parse("--config", "provider.base_url=http://localhost")
+        assert args.config == {"provider.base_url": "http://localhost"}
+
+    def test_value_with_equals(self):
+        args = _parse("--config", "url=http://host?a=1&b=2")
+        assert args.config == {"url": "http://host?a=1&b=2"}
+
+    def test_empty_value(self):
+        args = _parse("--config", "key=")
+        assert args.config == {"key": ""}
+
+    def test_strips_whitespace(self):
+        args = _parse("--config", " key = value ")
+        assert args.config == {"key": "value"}
+
+    def test_overwrites_duplicate_key(self):
+        args = _parse("--config", "key=first", "--config", "key=second")
+        assert args.config == {"key": "second"}
+
+    def test_default_empty_dict(self):
+        args = _parse()
+        assert args.config == {}
+
+    def test_no_equals_raises(self):
+        with pytest.raises(SystemExit):
+            _parse("--config", "no_equals_here")