template: add predecessors template
Add a 'predecessors' template that returns the list of all closest known
predecessors for a changectx. The elements of the list are row changectx node id
formatted by default as short nodes.
The "closest predecessors" are the first locally known revisions encountered
while, walking predecessors markers. For example:
1) If a (A, (B)) markers exists and both A and B are locally known A is a
closest predecessors of B.
2) If a (A, (B)) and (B, (C)) markers exists and only A and C are known
locally, A will be the closest precursors of C.
This logic respect repository filtering. So hidden revision will be skipped by
this logic unless --hidden is specified. Since we only display the visible
predecessors, this template will not display anything in most case. It makes a
good candidate for inclusion in the default log output.
I added a new test-file for testing the precursors in various scenarios. This
test file will also be used for the successors template.
A new "obsutil" module has been added to start gathering utility function
outside of the large obsolete.py module.
from __future__ import absolute_import
import silenttestrunner
import unittest
from mercurial import util
class contextmanager(object):
def __init__(self, name, trace):
self.name = name
self.entered = False
self.exited = False
self.trace = trace
def __enter__(self):
self.entered = True
self.trace(('enter', self.name))
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.exited = exc_type, exc_val, exc_tb
self.trace(('exit', self.name))
def __repr__(self):
return '<ctx %r>' % self.name
class ctxerror(Exception):
pass
class raise_on_enter(contextmanager):
def __enter__(self):
self.trace(('raise', self.name))
raise ctxerror(self.name)
class raise_on_exit(contextmanager):
def __exit__(self, exc_type, exc_val, exc_tb):
self.trace(('raise', self.name))
raise ctxerror(self.name)
def ctxmgr(name, trace):
return lambda: contextmanager(name, trace)
class test_ctxmanager(unittest.TestCase):
def test_basics(self):
trace = []
addtrace = trace.append
with util.ctxmanager(ctxmgr('a', addtrace), ctxmgr('b', addtrace)) as c:
a, b = c.enter()
c.atexit(addtrace, ('atexit', 'x'))
c.atexit(addtrace, ('atexit', 'y'))
self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'),
('atexit', 'y'), ('atexit', 'x'),
('exit', 'b'), ('exit', 'a')])
def test_raise_on_enter(self):
trace = []
addtrace = trace.append
with self.assertRaises(ctxerror):
with util.ctxmanager(ctxmgr('a', addtrace),
lambda: raise_on_enter('b', addtrace)) as c:
c.enter()
addtrace('unreachable')
self.assertEqual(trace, [('enter', 'a'), ('raise', 'b'), ('exit', 'a')])
def test_raise_on_exit(self):
trace = []
addtrace = trace.append
with self.assertRaises(ctxerror):
with util.ctxmanager(ctxmgr('a', addtrace),
lambda: raise_on_exit('b', addtrace)) as c:
c.enter()
addtrace('running')
self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), 'running',
('raise', 'b'), ('exit', 'a')])
if __name__ == '__main__':
silenttestrunner.main(__name__)