asyncio: Tulip issue 173: Enhance repr(Handle) and repr(Task)

repr(Handle) is shorter for function: "foo" instead of "<function foo at
0x...>". It now also includes the source of the callback, filename and line
number where it was defined, if available.

repr(Task) now also includes the current position in the code, filename and
line number, if available. If the coroutine (generator) is done, the line
number is omitted and "done" is added.

3 files changed, 45 insertions, 2 deletions

diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index 4a9a9a3885..de161df65f 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -8,9 +8,29 @@ __all__ = ['AbstractEventLoopPolicy',
            'get_child_watcher', 'set_child_watcher',
            ]
 
+import functools
+import inspect
 import subprocess
 import threading
 import socket
+import sys
+
+
+_PY34 = sys.version_info >= (3, 4)
+
+def _get_function_source(func):
+    if _PY34:
+        func = inspect.unwrap(func)
+    elif hasattr(func, '__wrapped__'):
+        func = func.__wrapped__
+    if inspect.isfunction(func):
+        code = func.__code__
+        return (code.co_filename, code.co_firstlineno)
+    if isinstance(func, functools.partial):
+        return _get_function_source(func.func)
+    if _PY34 and isinstance(func, functools.partialmethod):
+        return _get_function_source(func.func)
+    return None
 
 
 class Handle:
@@ -26,7 +46,15 @@ class Handle:
         self._cancelled = False
 
     def __repr__(self):
-        res = 'Handle({}, {})'.format(self._callback, self._args)
+        cb_repr = getattr(self._callback, '__qualname__', None)
+        if not cb_repr:
+            cb_repr = str(self._callback)
+
+        source = _get_function_source(self._callback)
+        if source:
+            cb_repr += ' at %s:%s' % source
+
+        res = 'Handle({}, {})'.format(cb_repr, self._args)
         if self._cancelled:
             res += '<cancelled>'
         return res
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 8b8fb82ed2..e6fd3d380b 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -188,7 +188,15 @@ class Task(futures.Future):
         i = res.find('<')
         if i < 0:
             i = len(res)
-        res = res[:i] + '(<{}>)'.format(self._coro.__name__) + res[i:]
+        text = self._coro.__name__
+        coro = self._coro
+        if inspect.isgenerator(coro):
+            filename = coro.gi_code.co_filename
+            if coro.gi_frame is not None:
+                text += ' at %s:%s' % (filename, coro.gi_frame.f_lineno)
+            else:
+                text += ' done at %s' % filename
+        res = res[:i] + '(<{}>)'.format(text) + res[i:]
         return res
 
     def get_stack(self, *, limit=None):
diff --git a/Lib/asyncio/test_utils.py b/Lib/asyncio/test_utils.py
index 9c3656ac2b..1062bae132 100644
--- a/Lib/asyncio/test_utils.py
+++ b/Lib/asyncio/test_utils.py
@@ -372,3 +372,10 @@ class MockPattern(str):
     """
     def __eq__(self, other):
         return bool(re.search(str(self), other, re.S))
+
+
+def get_function_source(func):
+    source = events._get_function_source(func)
+    if source is None:
+        raise ValueError("unable to get the source of %r" % (func,))
+    return source