gh-7: Add unit tests for pure configuration helpers.

tests/test_config.py

@@ -0,0 +1,203 @@
+import pytest
+
+from manage.config import (
+    _expand_vars,
+    config_append,
+    config_bool,
+    config_dict_merge,
+    config_split,
+    config_split_append,
+)
+
+
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    [
+        (None, False),
+        ("", False),
+        ("true", True),
+        (0, False),
+        ("TRUE", True),
+        ("True", True),
+        ("yes", True),
+        ("1", True),
+        ("false", False),
+        ("no", False),
+        ("0", False),
+        ("yellow", True),
+        ("%PYTHON_MANAGER_CONFIRM%", False),
+        (True, True),
+        (42, True),
+        (["x"], True),
+    ],
+    ids=[
+        "none",
+        "str_empty",
+        "str_true_lower",
+        "int_zero",
+        "str_true_upper",
+        "str_true_title",
+        "str_yes",
+        "str_one",
+        "str_false",
+        "str_no",
+        "str_zero",
+        "str_yellow",
+        "str_environment_variable",
+        "bool_true",
+        "int_positive",
+        "list_nonempty",
+    ],
+)
+def test_config_bool(value, expected):
+    assert config_bool(value) is expected
+
+
+def test_config_bool_any_t_prefixed_string_is_true():
+    assert config_bool("tomato") is True
+
+
+@pytest.mark.parametrize(
+    ("value", "variables", "expected"),
+    [
+        ("%FOO%", {"FOO": "bar"}, "bar"),
+        (
+            "%LocalAppData%\\Python",
+            {"LocalAppData": "C:\\Temp"},
+            "C:\\Temp\\Python",
+        ),
+        ("./bundled/fallback-index.json", {}, "./bundled/fallback-index.json"),
+        ("%A%%B%", {"A": "x", "B": "y"}, "xy"),
+        (
+            "%LocalAppData%\\Python\\_cache",
+            {"LocalAppData": "C:\\Temp"},
+            "C:\\Temp\\Python\\_cache",
+        ),
+        ("%FOO%/bar", {"FOO": "x"}, "x/bar"),
+    ],
+    ids=[
+        "var_only",
+        "var_with_separator",
+        "no_vars",
+        "adjacent_vars",
+        "nested_path",
+        "forward_slash",
+    ],
+)
+def test_expand_vars(value, variables, expected):
+    assert _expand_vars(value, variables) == expected
+
+
+def test_expand_vars_removes_missing_variable_and_leading_separator():
+    actual = _expand_vars("%MISSING%\\Python", {})
+
+    assert actual == "Python"
+
+
+def test_expand_vars_removes_empty_variable_and_leading_separator():
+    actual = _expand_vars("%EMPTY%\\Python", {"EMPTY": ""})
+
+    assert actual == "Python"
+
+
+@pytest.mark.parametrize(
+    ("existing", "value", "expected"),
+    [
+        (None, "a", ["a"]),
+        ("a", "b", ["a", "b"]),
+        (["a"], "b", ["a", "b"]),
+    ],
+    ids=[
+        "none",
+        "scalar",
+        "list",
+    ],
+)
+def test_config_append(existing, value, expected):
+    assert config_append(existing, value) == expected
+
+
+def test_config_append_does_not_mutate_existing_list():
+    existing = ["a"]
+
+    actual = config_append(existing, "b")
+
+    assert actual == ["a", "b"]
+    assert existing == ["a"]
+    assert actual is not existing
+
+
+@pytest.mark.parametrize(
+    ("existing", "new", "expected"),
+    [
+        ({"a": 1}, {"b": 2}, {"a": 1, "b": 2}),
+        ({"a": 1}, {"a": 2}, {"a": 2}),
+    ],
+    ids=[
+        "distinct_keys",
+        "new_value_overwrites",
+    ],
+)
+def test_config_dict_merge(existing, new, expected):
+    assert config_dict_merge(existing, new) == expected
+
+
+def test_config_dict_merge_does_not_mutate_inputs():
+    existing = {"a": 1}
+    new = {"b": 2}
+
+    actual = config_dict_merge(existing, new)
+
+    assert actual == {"a": 1, "b": 2}
+    assert existing == {"a": 1}
+    assert new == {"b": 2}
+    assert actual is not existing
+    assert actual is not new
+
+
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    [
+        ("", [""]),
+        ("a,b", ["a", "b"]),
+        ("a,,b", ["a", "", "b"]),
+        ("C:\\tools", ["C", "\\tools"]),
+        ("a;b:c|d+e", ["a", "b", "c", "d", "e"]),
+    ],
+    ids=[
+        "empty",
+        "comma",
+        "consecutive_delimiters",
+        "windows_path",
+        "all_delimiters",
+    ],
+)
+def test_config_split(value, expected):
+    assert config_split(value) == expected
+
+
+@pytest.mark.parametrize(
+    ("existing", "value", "expected"),
+    [
+        (None, "a,b", [["a", "b"]]),
+        ("existing", "a,b", ["existing", ["a", "b"]]),
+        (["existing"], "a,b", ["existing", ["a", "b"]]),
+    ],
+    ids=[
+        "none",
+        "scalar",
+        "list",
+    ],
+)
+def test_config_split_append(existing, value, expected):
+    assert config_split_append(existing, value) == expected
+
+
+def test_config_split_append_does_not_mutate_existing_list():
+    existing = ["first"]
+
+    actual = config_split_append(existing, "second,third")
+
+    assert actual == ["first", ["second", "third"]]
+    assert existing == ["first"]
+    assert actual is not existing