contrib/python-hook-examples.py

rust-matchers: add `FileMatcher` implementation

Mercurial defines an `exactmatcher`, I find `FileMatcher` to be clearer, but
am not opposed to using the old name.
This change also switched the order of `assert_eq` arguments as it is clearer
that way for most people.

Differential Revision: https://phab.mercurial-scm.org/D7528

'''
Examples of useful python hooks for Mercurial.
'''
from __future__ import absolute_import
from mercurial import (
    patch,
    util,
)


def diffstat(ui, repo, **kwargs):
    '''Example usage:

    [hooks]
    commit.diffstat = python:/path/to/this/file.py:diffstat
    changegroup.diffstat = python:/path/to/this/file.py:diffstat
    '''
    if kwargs.get('parent2'):
        return
    node = kwargs['node']
    first = repo[node].p1().node()
    if 'url' in kwargs:
        last = repo.changelog.tip()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))