test(core): add unit tests for untested core modules

Adds 113 tests covering:
- abc: RegistryABC (concrete implementation + edge cases)
- environment: Environment get/set, EnvironmentEnum
- pipes: BoolPipe, IPAddressPipe (incl. roundtrip + error cases)
- time: Cron (next(), intervals, invalid expression)
- utils: Cache (TTL, expiry, cleanup), get_value (incl. bug
  documentation: cast result not returned for string->typed values),
  JSONProcessor (nested objects, enums, defaults)
- property: classproperty (class access, instance access, subclass)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

test/core/utils/cache_test.py

@@ -0,0 +1,125 @@
+import time
+import pytest
+from cpl.core.utils.cache import Cache
+
+
+def test_set_and_get():
+    cache = Cache()
+    cache.set("key1", "value1")
+    assert cache.get("key1") == "value1"
+    cache.stop()
+
+
+def test_get_missing_key_returns_none():
+    cache = Cache()
+    assert cache.get("nonexistent") is None
+    cache.stop()
+
+
+def test_has_existing_key():
+    cache = Cache()
+    cache.set("key", "val")
+    assert cache.has("key") is True
+    cache.stop()
+
+
+def test_has_missing_key():
+    cache = Cache()
+    assert cache.has("missing") is False
+    cache.stop()
+
+
+def test_delete():
+    cache = Cache()
+    cache.set("key", "val")
+    cache.delete("key")
+    assert cache.get("key") is None
+    assert cache.has("key") is False
+    cache.stop()
+
+
+def test_clear():
+    cache = Cache()
+    cache.set("a", 1)
+    cache.set("b", 2)
+    cache.clear()
+    assert cache.get("a") is None
+    assert cache.get("b") is None
+    cache.stop()
+
+
+def test_get_all():
+    cache = Cache()
+    cache.set("x", 10)
+    cache.set("y", 20)
+    values = cache.get_all()
+    assert set(values) == {10, 20}
+    cache.stop()
+
+
+def test_get_all_empty():
+    cache = Cache()
+    assert cache.get_all() == []
+    cache.stop()
+
+
+def test_ttl_expiry():
+    cache = Cache()
+    cache.set("temp", "data", ttl=1)
+    assert cache.get("temp") == "data"
+    time.sleep(1.1)
+    assert cache.get("temp") is None
+    cache.stop()
+
+
+def test_has_after_ttl_expiry():
+    cache = Cache()
+    cache.set("temp", "data", ttl=1)
+    time.sleep(1.1)
+    assert cache.has("temp") is False
+    cache.stop()
+
+
+def test_default_ttl():
+    cache = Cache(default_ttl=1)
+    cache.set("key", "value")
+    assert cache.get("key") == "value"
+    time.sleep(1.1)
+    assert cache.get("key") is None
+    cache.stop()
+
+
+def test_per_key_ttl_overrides_default():
+    cache = Cache(default_ttl=60)
+    cache.set("short", "val", ttl=1)
+    time.sleep(1.1)
+    assert cache.get("short") is None
+    cache.stop()
+
+
+def test_get_all_excludes_expired():
+    cache = Cache()
+    cache.set("permanent", "keep")
+    cache.set("temporary", "gone", ttl=1)
+    time.sleep(1.1)
+    values = cache.get_all()
+    assert "keep" in values
+    assert "gone" not in values
+    cache.stop()
+
+
+def test_overwrite_key():
+    cache = Cache()
+    cache.set("key", "old")
+    cache.set("key", "new")
+    assert cache.get("key") == "new"
+    cache.stop()
+
+
+def test_cleanup_removes_expired():
+    cache = Cache(cleanup_interval=9999)
+    cache.set("exp", "x", ttl=1)
+    time.sleep(1.1)
+    cache.cleanup()
+    assert cache.get("exp") is None
+    cache.stop()

test/core/utils/get_value_test.py

@@ -0,0 +1,64 @@
+import pytest
+from typing import List
+from cpl.core.utils.get_value import get_value
+
+
+def test_get_existing_str():
+    assert get_value({"key": "hello"}, "key", str) == "hello"
+
+
+def test_get_existing_int_already_typed():
+    # Value already has the correct type -> returned directly
+    assert get_value({"count": 42}, "count", int) == 42
+
+
+def test_get_existing_float_already_typed():
+    # Value already has the correct type -> returned directly
+    assert get_value({"pi": 3.14}, "pi", float) == 3.14
+
+
+# NOTE: get_value calls cast() internally but does NOT return the cast result
+# (the return value is lost). String "42" -> int returns None instead of 42.
+# This is a known bug in get_value.
+def test_get_str_to_int_returns_none_bug():
+    result = get_value({"count": "42"}, "count", int)
+    assert result is None  # Bug: should be 42
+
+
+def test_get_missing_key_returns_none():
+    assert get_value({}, "missing", str) is None
+
+
+def test_get_missing_key_returns_default():
+    assert get_value({}, "missing", str, "fallback") == "fallback"
+
+
+def test_get_value_already_correct_type():
+    assert get_value({"x": 5}, "x", int) == 5
+
+
+def test_get_list_already_correct_type():
+    result = get_value({"items": [1, 2, 3]}, "items", List[int])
+    assert result == [1, 2, 3]
+
+
+def test_get_list_of_str_already_correct_type():
+    result = get_value({"tags": ["a", "b"]}, "tags", List[str])
+    assert result == ["a", "b"]
+
+
+def test_get_bool_already_typed():
+    # Value is already bool -> returned directly
+    assert get_value({"flag": True}, "flag", bool) is True
+    assert get_value({"flag": False}, "flag", bool) is False
+
+
+# NOTE: Same bug – string "true" -> bool returns None
+def test_get_bool_from_str_returns_none_bug():
+    result = get_value({"flag": "true"}, "flag", bool)
+    assert result is None  # Bug: should be True
+
+
+def test_cast_failure_returns_default():
+    result = get_value({"val": "not_a_number"}, "val", int, -1)
+    assert result == -1

test/core/utils/json_processor_test.py

@@ -0,0 +1,68 @@
+import pytest
+from enum import Enum
+from cpl.core.utils.json_processor import JSONProcessor
+
+
+class Color(Enum):
+    RED = "RED"
+    GREEN = "GREEN"
+
+
+class Point:
+    def __init__(self, x: int, y: int):
+        self.x = x
+        self.y = y
+
+
+class Named:
+    def __init__(self, name: str, value: int = 0):
+        self.name = name
+        self.value = value
+
+
+class Nested:
+    def __init__(self, point: Point, label: str):
+        self.point = point
+        self.label = label
+
+
+class WithEnum:
+    def __init__(self, color: Color):
+        self.color = color
+
+
+def test_simple_object():
+    obj = JSONProcessor.process(Point, {"X": 3, "Y": 7})
+    assert obj.x == 3
+    assert obj.y == 7
+
+
+def test_camel_case_keys():
+    obj = JSONProcessor.process(Named, {"Name": "Alice", "Value": 42})
+    assert obj.name == "Alice"
+    assert obj.value == 42
+
+
+def test_default_value_used():
+    obj = JSONProcessor.process(Named, {"Name": "Bob"})
+    assert obj.name == "Bob"
+    assert obj.value == 0
+
+
+def test_none_for_missing_required():
+    obj = JSONProcessor.process(Named, {})
+    assert obj.name is None
+
+
+def test_nested_object():
+    data = {"Point": {"X": 1, "Y": 2}, "Label": "origin"}
+    obj = JSONProcessor.process(Nested, data)
+    assert isinstance(obj.point, Point)
+    assert obj.point.x == 1
+    assert obj.point.y == 2
+    assert obj.label == "origin"
+
+
+def test_enum_value():
+    obj = JSONProcessor.process(WithEnum, {"Color": "RED"})
+    assert obj.color == Color.RED