Add orm_deprecated function and related tests

Author: insspb

flask_mongoengine/decorators.py

@@ -1,5 +1,7 @@
+"""Collection of project wide decorators."""
 import functools
 import logging
+import warnings
 
 try:
     import wtforms  # noqa
@@ -23,3 +25,25 @@ def wrapped(*args, **kwargs):
         return func(*args, **kwargs)
 
     return wrapped
+
+
+def orm_deprecated(func):
+    """Warning about usage of deprecated functions, that will be removed in the future."""
+
+    @functools.wraps(func)
+    def wrapped(*args, **kwargs):
+        # TODO: Insert URL
+        warnings.warn(
+            (
+                f"ORM module and function '{func.__name__}' are deprecated and will be "
+                "removed in version 3.0.0. Please switch to form generation from full "
+                "model nesting. Support and bugfixes are not available for stalled code. "
+                "Please read: "
+            ),
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
+        return func(*args, **kwargs)
+
+    return wrapped

tests/test_decorators.py

@@ -0,0 +1,17 @@
+"""Tests for project wide decorators."""
+from flask_mongoengine.decorators import orm_deprecated
+
+
+def test__orm_deprecated(recwarn):
+    @orm_deprecated
+    def func(a, b):
+        """Function example."""
+        return a + b
+
+    assert func(1, 1) == 2
+    assert str(recwarn.list[0].message) == (
+        "ORM module and function 'func' are deprecated and will be removed in version 3.0.0. "
+        "Please switch to form generation from full model nesting. "
+        "Support and bugfixes are not available for stalled code. "
+        "Please read: "
+    )