Add deprecation decorators (#1683)

Author: VeckoTheGecko

parcels/tools/_helpers.py

@@ -0,0 +1,53 @@
+"""Internal helpers for Parcels."""
+
+import functools
+import warnings
+from typing import Callable
+
+PACKAGE = "Parcels"
+
+
+def deprecated(msg: str = "") -> Callable:
+    """Decorator marking a function as being deprecated
+
+    Parameters
+    ----------
+    msg : str, optional
+        Custom message to append to the deprecation warning.
+
+    Examples
+    --------
+    ```
+    @deprecated("Please use `another_function` instead")
+    def some_old_function(x, y):
+        return x + y
+
+    @deprecated()
+    def some_other_old_function(x, y):
+        return x + y
+    ```
+    """
+    if msg:
+        msg = " " + msg
+
+    def decorator(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            msg_formatted = (
+                f"`{func.__qualname__}` is deprecated and will be removed in a future release of {PACKAGE}.{msg}"
+            )
+
+            warnings.warn(msg_formatted, category=DeprecationWarning, stacklevel=2)
+            return func(*args, **kwargs)
+
+        return wrapper
+
+    return decorator
+
+
+def deprecated_made_private(func: Callable) -> Callable:
+    return deprecated(
+        "It has moved to the internal API as it is not expected to be directly used by "
+        "the end-user. If you feel that you use this code directly in your scripts, please "
+        "comment on our tracking issue at <>."  # TODO: Add tracking issue
+    )(func)

tests/tools/test_helpers.py

@@ -0,0 +1,53 @@
+import pytest
+
+from parcels.tools._helpers import deprecated, deprecated_made_private
+
+
+def test_deprecated():
+    class SomeClass:
+        @deprecated()
+        def some_method(self, x, y):
+            return x + y
+
+        @staticmethod
+        @deprecated()
+        def some_static_method(x, y):
+            return x + y
+
+        @property
+        @deprecated()
+        def some_property(self):
+            return 2
+
+    @deprecated()
+    def some_function(x, y):
+        return x + y
+
+    with pytest.warns(DeprecationWarning) as record:
+        SomeClass().some_method(1, 2)
+    assert "SomeClass.some_method" in record[0].message.args[0]
+
+    with pytest.warns(DeprecationWarning) as record:
+        SomeClass.some_static_method(1, 2)
+    assert "SomeClass.some_static_method" in record[0].message.args[0]
+
+    with pytest.warns(DeprecationWarning) as record:
+        _ = SomeClass().some_property
+    assert "SomeClass.some_property" in record[0].message.args[0]
+
+    with pytest.warns(DeprecationWarning) as record:
+        some_function(1, 2)
+    assert "some_function" in record[0].message.args[0]
+
+    with pytest.warns(DeprecationWarning) as record:
+        some_function(1, 2)
+    assert "some_function" in record[0].message.args[0]
+
+
+def test_deprecated_made_private():
+    @deprecated_made_private
+    def some_function(x, y):
+        return x + y
+
+    with pytest.warns(DeprecationWarning):
+        some_function(1, 2)