- convert wrap_callable() to a general purpose update_wrapper-like

function; the caller still passes in the "wrapper"
- move tests for wrap_callable() to be generic util tests
- changelog for pullreq github:204

5 files changed, 88 insertions, 73 deletions

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index e37fd1a69..e296be0e2 100644
--- a/doc/build/changelog/changelog_11.rst
+++ b/doc/build/changelog/changelog_11.rst
@@ -22,6 +22,16 @@
     :version: 1.1.0b1
 
     .. change::
+        :tags: enhancement, schema
+        :pullreq: github:204
+
+        The default generation functions passed to :class:`.Column` objects
+        are now run through "update_wrapper", or an equivalent function
+        if a callable non-function is passed, so that introspection tools
+        preserve the name and docstring of the wrapped function.  Pull
+        request courtesy hsum.
+
+    .. change::
         :tags: change, mssql
         :tickets: 3434
 
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index 0c433d16e..a88203e84 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -1981,13 +1981,13 @@ class ColumnDefault(DefaultGenerator):
         try:
             argspec = util.get_callable_argspec(fn, no_self=True)
         except TypeError:
-            return util.wrap_callable(fn)
+            return util.wrap_callable(lambda ctx: fn(), fn)
 
         defaulted = argspec[3] is not None and len(argspec[3]) or 0
         positionals = len(argspec[0]) - defaulted
 
         if positionals == 0:
-            return util.wrap_callable(fn)
+            return util.wrap_callable(lambda ctx: fn(), fn)
 
         elif positionals == 1:
             return fn
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py
index 9f259aea3..e9d4e09bc 100644
--- a/lib/sqlalchemy/util/langhelpers.py
+++ b/lib/sqlalchemy/util/langhelpers.py
@@ -1378,28 +1378,24 @@ class EnsureKWArgType(type):
         return update_wrapper(wrap, fn)
 
 
-def wrap_callable(fn):
-    """Wrap callable and set __name__, __doc__, and __module__.
+def wrap_callable(wrapper, fn):
+    """Augment functools.update_wrapper() to work with objects with
+    a ``__call__()`` method.
 
     :param fn:
       object with __call__ method
+
     """
     if hasattr(fn, '__name__'):
-        _f = update_wrapper(lambda ctx: fn(), fn)
-        _f.__doc__ = _f.__doc__ or fn.__name__
-        return _f
+        return update_wrapper(wrapper, fn)
     else:
-        _f = lambda ctx: fn()
+        _f = wrapper
         _f.__name__ = fn.__class__.__name__
         _f.__module__ = fn.__module__
 
         if hasattr(fn.__call__, '__doc__') and fn.__call__.__doc__:
-            _f.__doc__ = fn.__call__.__doc__ 
-        elif hasattr(fn.__class__, '__doc__') and fn.__class__.__doc__:
-            _f.__doc__ = fn.__class__.__doc__
+            _f.__doc__ = fn.__call__.__doc__
         elif fn.__doc__:
             _f.__doc__ = fn.__doc__
-        else:
-            _f.__doc__ = fn.__class__.__name__
 
         return _f
diff --git a/test/base/test_utils.py b/test/base/test_utils.py
index 8074de53e..c1027ec8e 100644
--- a/test/base/test_utils.py
+++ b/test/base/test_utils.py
@@ -313,6 +313,75 @@ class MemoizedAttrTest(fixtures.TestBase):
         eq_(canary.mock_calls, [mock.call.attr(), mock.call.method()])
 
 
+class WrapCallableTest(fixtures.TestBase):
+    def test_wrapping_update_wrapper_fn(self):
+        def my_fancy_default():
+            """run the fancy default"""
+            return 10
+
+        c = util.wrap_callable(lambda: my_fancy_default, my_fancy_default)
+
+        eq_(c.__name__, "my_fancy_default")
+        eq_(c.__doc__, "run the fancy default")
+
+    def test_wrapping_update_wrapper_fn_nodocstring(self):
+        def my_fancy_default():
+            return 10
+
+        c = util.wrap_callable(lambda: my_fancy_default, my_fancy_default)
+        eq_(c.__name__, "my_fancy_default")
+        eq_(c.__doc__, None)
+
+    def test_wrapping_update_wrapper_cls(self):
+        class MyFancyDefault(object):
+            """a fancy default"""
+
+            def __call__(self):
+                """run the fancy default"""
+                return 10
+
+        def_ = MyFancyDefault()
+        c = util.wrap_callable(lambda: def_(), def_)
+
+        eq_(c.__name__, "MyFancyDefault")
+        eq_(c.__doc__, "run the fancy default")
+
+    def test_wrapping_update_wrapper_cls_noclsdocstring(self):
+        class MyFancyDefault(object):
+
+            def __call__(self):
+                """run the fancy default"""
+                return 10
+
+        def_ = MyFancyDefault()
+        c = util.wrap_callable(lambda: def_(), def_)
+        eq_(c.__name__, "MyFancyDefault")
+        eq_(c.__doc__, "run the fancy default")
+
+    def test_wrapping_update_wrapper_cls_nomethdocstring(self):
+        class MyFancyDefault(object):
+            """a fancy default"""
+
+            def __call__(self):
+                return 10
+
+        def_ = MyFancyDefault()
+        c = util.wrap_callable(lambda: def_(), def_)
+        eq_(c.__name__, "MyFancyDefault")
+        eq_(c.__doc__, "a fancy default")
+
+    def test_wrapping_update_wrapper_cls_noclsdocstring_nomethdocstring(self):
+        class MyFancyDefault(object):
+
+            def __call__(self):
+                return 10
+
+        def_ = MyFancyDefault()
+        c = util.wrap_callable(lambda: def_(), def_)
+        eq_(c.__name__, "MyFancyDefault")
+        eq_(c.__doc__, None)
+
+
 class ToListTest(fixtures.TestBase):
     def test_from_string(self):
         eq_(
diff --git a/test/sql/test_defaults.py b/test/sql/test_defaults.py
index e2250e834..88679e208 100644
--- a/test/sql/test_defaults.py
+++ b/test/sql/test_defaults.py
@@ -301,66 +301,6 @@ class DefaultTest(fixtures.TestBase):
             c = sa.ColumnDefault(fn)
             c.arg("context")
 
-    def test_wrapping_update_wrapper_fn(self):
-        def my_fancy_default():
-            """run the fancy default"""
-            return 10
-
-        c = sa.ColumnDefault(my_fancy_default)
-        eq_(c.arg.__name__, "my_fancy_default")
-        eq_(c.arg.__doc__, "run the fancy default")
-
-    def test_wrapping_update_wrapper_fn_nodocstring(self):
-        def my_fancy_default():
-            return 10
-
-        c = sa.ColumnDefault(my_fancy_default)
-        eq_(c.arg.__name__, "my_fancy_default")
-        eq_(c.arg.__doc__, "my_fancy_default")
-
-    def test_wrapping_update_wrapper_cls(self):
-        class MyFancyDefault(object):
-            """a fancy default"""
-
-            def __call__(self):
-                """run the fancy default"""
-                return 10
-
-        c = sa.ColumnDefault(MyFancyDefault())
-        eq_(c.arg.__name__, "MyFancyDefault")
-        eq_(c.arg.__doc__, "run the fancy default")
-
-    def test_wrapping_update_wrapper_cls_noclassdocstring(self):
-        class MyFancyDefault(object):
-
-            def __call__(self):
-                """run the fancy default"""
-                return 10
-
-        c = sa.ColumnDefault(MyFancyDefault())
-        eq_(c.arg.__name__, "MyFancyDefault")
-        eq_(c.arg.__doc__, "run the fancy default")
-
-    def test_wrapping_update_wrapper_cls_nomethoddocstring(self):
-        class MyFancyDefault(object):
-            """a fancy default"""
-
-            def __call__(self):
-                return 10
-
-        c = sa.ColumnDefault(MyFancyDefault())
-        eq_(c.arg.__name__, "MyFancyDefault")
-        eq_(c.arg.__doc__, "a fancy default")
-
-    def test_wrapping_update_wrapper_cls_noclassdocstring_nomethoddocstring(self):
-        class MyFancyDefault(object):
-
-            def __call__(self):
-                return 10
-
-        c = sa.ColumnDefault(MyFancyDefault())
-        eq_(c.arg.__name__, "MyFancyDefault")
-        eq_(c.arg.__doc__, "MyFancyDefault")
 
     @testing.fails_on('firebird', 'Data type unknown')
     def test_standalone(self):