fix deprecation wrapper & tests

pytorch_lightning/utilities/deprecation.py

@@ -38,33 +38,36 @@ def deprecated(target: Callable, ver_deprecate: str = "", ver_remove: str = "")
     """
     Decorate a function or class ``__init__`` with warning message
      and pass all arguments directly to the target class/method.
-     """
+    """
 
-    def inner_function(func):
+    def inner_function(base):
 
-        @wraps(func)
+        @wraps(base)
         def wrapped_fn(*args, **kwargs):
             is_class = inspect.isclass(target)
             target_func = target.__init__ if is_class else target
             # warn user only once in lifetime
-            if not getattr(inner_function, 'warned', False):
+            if not getattr(wrapped_fn, 'warned', False):
                 target_str = f'{target.__module__}.{target.__name__}'
-                func_name = func.__qualname__.split('.')[-2] if is_class else func.__name__
+                base_name = base.__qualname__.split('.')[-2] if is_class else base.__name__
                 rank_zero_warn(
-                    f"The `{func_name}` was deprecated since v{ver_deprecate} in favor of `{target_str}`."
+                    f"The `{base_name}` was deprecated since v{ver_deprecate} in favor of `{target_str}`."
                     f" It will be removed in v{ver_remove}.", DeprecationWarning
                 )
-                inner_function.warned = True
+                wrapped_fn.warned = True
 
             if args:  # in case any args passed move them to kwargs
                 # parse only the argument names
-                cls_arg_names = [arg[0] for arg in get_func_arguments_and_types(func)]
+                arg_names = [arg[0] for arg in get_func_arguments_and_types(base)]
                 # convert args to kwargs
-                kwargs.update({k: v for k, v in zip(cls_arg_names, args)})
+                kwargs.update({k: v for k, v in zip(arg_names, args)})
+            # fill by base defaults
+            base_defaults = {arg[0]: arg[2] for arg in get_func_arguments_and_types(base) if arg[2] != inspect._empty}
+            kwargs = dict(list(base_defaults.items()) + list(kwargs.items()))
 
             target_args = [arg[0] for arg in get_func_arguments_and_types(target_func)]
             assert all(arg in target_args for arg in kwargs), \
-                "Failed mapping, arguments missing in target func: %s" % [arg not in target_args for arg in kwargs]
+                "Failed mapping, arguments missing in target base: %s" % [arg not in target_args for arg in kwargs]
             # all args were already moved to kwargs
             return target_func(**kwargs)
 

tests/utilities/test_deprecation.py

@@ -4,34 +4,91 @@
 from tests.helpers.utils import no_warning_call
 
 
-def my_sum(a, b=3):
+def my_sum(a=0, b=3):
+    return a + b
+
+
+def my2_sum(a, b):
     return a + b
 
 
 @deprecated(target=my_sum, ver_deprecate="0.1", ver_remove="0.5")
-def dep_sum(a, b):
+def dep_sum(a, b=5):
     pass
 
 
-@deprecated(target=my_sum, ver_deprecate="0.1", ver_remove="0.5")
+@deprecated(target=my2_sum, ver_deprecate="0.1", ver_remove="0.5")
 def dep2_sum(a, b):
     pass
 
 
+@deprecated(target=my2_sum, ver_deprecate="0.1", ver_remove="0.5")
+def dep3_sum(a, b=4):
+    pass
+
+
 def test_deprecated_func():
     with pytest.deprecated_call(
         match='The `dep_sum` was deprecated since v0.1 in favor of `tests.utilities.test_deprecation.my_sum`.'
         ' It will be removed in v0.5.'
     ):
-        assert dep_sum(2, b=5) == 7
+        assert dep_sum(2) == 7
 
     # check that the warning is raised only once per function
     with no_warning_call(DeprecationWarning):
-        assert dep_sum(2, b=5) == 7
+        assert dep_sum(3) == 8
 
     # and does not affect other functions
     with pytest.deprecated_call(
-        match='The `dep2_sum` was deprecated since v0.1 in favor of `tests.utilities.test_deprecation.my_sum`.'
+        match='The `dep3_sum` was deprecated since v0.1 in favor of `tests.utilities.test_deprecation.my2_sum`.'
+        ' It will be removed in v0.5.'
+    ):
+        assert dep3_sum(2, 1) == 3
+
+
+def test_deprecated_func_incomplete():
+
+    # missing required argument
+    with pytest.raises(TypeError, match="missing 1 required positional argument: 'b'"):
+        dep2_sum(2)
+
+    # check that the warning is raised only once per function
+    with no_warning_call(DeprecationWarning):
+        assert dep2_sum(2, 1) == 3
+
+    # reset the warning
+    dep2_sum.warned = False
+    # does not affect other functions
+    with pytest.deprecated_call(
+        match='The `dep2_sum` was deprecated since v0.1 in favor of `tests.utilities.test_deprecation.my2_sum`.'
         ' It will be removed in v0.5.'
     ):
-        assert dep2_sum(2) == 5
+        assert dep2_sum(b=2, a=1) == 3
+
+
+class NewCls:
+
+    def __init__(self, c, d="abc"):
+        self.my_c = c
+        self.my_d = d
+
+
+class PastCls:
+
+    @deprecated(target=NewCls, ver_deprecate="0.2", ver_remove="0.4")
+    def __init__(self, c, d="efg"):
+        pass
+
+
+def test_deprecated_class():
+    with pytest.deprecated_call(
+        match='The `PastCls` was deprecated since v0.2 in favor of `tests.utilities.test_deprecation.NewCls`.'
+        ' It will be removed in v0.4.'
+    ):
+        past = PastCls(2)
+    assert past.my_c == 2
+    assert past.my_d == "efg"
+
+    # check that the warning is raised only once per function
+    with no_warning_call(DeprecationWarning):
+        assert PastCls(c=2, d="")