Merge branch 'pr204'

6 files changed, 106 insertions, 3 deletions

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index dcd43f28d..688818a2a 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, sql, mysql
         :tickets: 3216
 
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py
index e20545962..25eb68f6f 100644
--- a/lib/sqlalchemy/sql/schema.py
+++ b/lib/sqlalchemy/sql/schema.py
@@ -1987,13 +1987,14 @@ class ColumnDefault(DefaultGenerator):
         try:
             argspec = util.get_callable_argspec(fn, no_self=True)
         except TypeError:
-            return lambda ctx: 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 lambda ctx: fn()
+            return util.wrap_callable(lambda ctx: fn(), fn)
+
         elif positionals == 1:
             return fn
         else:
diff --git a/lib/sqlalchemy/util/__init__.py b/lib/sqlalchemy/util/__init__.py
index ed968f168..36a81dbce 100644
--- a/lib/sqlalchemy/util/__init__.py
+++ b/lib/sqlalchemy/util/__init__.py
@@ -36,7 +36,7 @@ from .langhelpers import iterate_attributes, class_hierarchy, \
     generic_repr, counter, PluginLoader, hybridproperty, hybridmethod, \
     safe_reraise,\
     get_callable_argspec, only_once, attrsetter, ellipses_string, \
-    warn_limited, map_bits, MemoizedSlots, EnsureKWArgType
+    warn_limited, map_bits, MemoizedSlots, EnsureKWArgType, wrap_callable
 
 from .deprecations import warn_deprecated, warn_pending_deprecation, \
     deprecated, pending_deprecation, inject_docstring_text
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py
index 743afccfd..e9d4e09bc 100644
--- a/lib/sqlalchemy/util/langhelpers.py
+++ b/lib/sqlalchemy/util/langhelpers.py
@@ -1377,3 +1377,25 @@ class EnsureKWArgType(type):
             return fn(*arg)
         return update_wrapper(wrap, fn)
 
+
+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__'):
+        return update_wrapper(wrapper, fn)
+    else:
+        _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 fn.__doc__:
+            _f.__doc__ = fn.__doc__
+
+        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 fc0b2bb80..e21b21ab2 100644
--- a/test/sql/test_defaults.py
+++ b/test/sql/test_defaults.py
@@ -301,6 +301,7 @@ class DefaultTest(fixtures.TestBase):
             c = sa.ColumnDefault(fn)
             c.arg("context")
 
+
     @testing.fails_on('firebird', 'Data type unknown')
     def test_standalone(self):
         c = testing.db.engine.contextual_connect()