contrib/check-commit

revset: delay showing parse error for the revset alias until it is referred

Before this patch, a problematic revset alias aborts execution
immediately, even if it isn't referred in the specified revset.

If old "hg" may be used too (for example, bisecting Mercurial itself),
it is also difficult to write alias definitions using features newly
introduced by newer "hg" into configuration files, because such alias
definitions cause unexpected abortion at parsing revset aliases with
old "hg".

This patch delays showing parse error for the revset alias until it is
actually referred at runtime.

This patch detects referring problematic aliases in "_expandaliases"
by examination of "revsetalias.error", which is initialized with the
error message only when parsing fails.

For usability, this patch also warns about problematic aliases, even
if they aren't referred at runtime. This should help users to know
potential problems in their alias definitions earlier.

#!/usr/bin/env python
#
# Copyright 2014 Matt Mackall <[e-mail]>
#
# A tool/hook to run basic sanity checks on commits/patches for
# submission to Mercurial. Install by adding the following to your
# .hg/hgrc:
#
# [hooks]
# pretxncommit = contrib/check-commit
#
# The hook can be temporarily bypassed with:
#
# $ BYPASS= hg commit
#
# See also: http://mercurial.selenic.com/wiki/ContributingChanges

import re, sys, os

errors = [
    (r"[(]bc[)]", "(BC) needs to be uppercase"),
    (r"[(]issue \d\d\d", "no space allowed between issue and number"),
    (r"[(]bug", "use (issueDDDD) instead of bug"),
    (r"^# User [^@\n]+$", "username is not an email address"),
    (r"^# .*\n(?!merge with )[^#]\S+[^:] ",
     "summary line doesn't start with 'topic: '"),
    (r"^# .*\n[A-Z][a-z]\S+", "don't capitalize summary lines"),
    (r"^# .*\n.*\.\s+$", "don't add trailing period on summary line"),
    (r"^# .*\n.{78,}", "summary line too long"),
    (r"^\+\n \n", "adds double empty line"),
    (r"\+\s+def [a-z]+_[a-z]", "adds a function with foo_bar naming"),
]

node = os.environ.get("HG_NODE")

if node:
    commit = os.popen("hg export %s" % node).read()
else:
    commit = sys.stdin.read()

exitcode = 0
for exp, msg in errors:
    m = re.search(exp, commit, re.MULTILINE)
    if m:
        pos = 0
        for n, l in enumerate(commit.splitlines(True)):
            pos += len(l)
            if pos >= m.end():
                print "%d: %s" % (n, msg)
                print " %s" % l[:-1]
                if "BYPASS" not in os.environ:
                    exitcode = 1
                break

sys.exit(exitcode)