contrib/check-commit

import-checker: make imported_modules yield absolute dotted_name_of_path

This patch makes `imported_modules()` always yield absolute
`dotted_name_of_path()`-ed name by strict detection with
`fromlocal()`.

This change improves circular detection in some points:

  - locally defined modules, of which name collides against one of
    standard library, can be examined correctly

    For example, circular import related to `commands` is overlooked
    before this patch.

  - names not useful for circular detection are ignored

    Names below are also yielded before this patch:

      - module names of standard library (= not locally defined one)
      - non-module names (e.g. `node.nullid` of `from node import nullid`)

    These redundant names decrease performance of circular detection.

    For example, with files at 1ef96a3b8b89, average loops per file in
    `checkmod()` is reduced from 165 to 109.

  - `__init__` can be handled correctly in `checkmod()`

    For example, current implementation has problems below:

      - `from xxx import yyy` doesn't recognize `xxx.__init__` as imported

      - `xxx.__init__` imported via `import xxx` is treated as `xxx`,
        and circular detection is aborted, because `key` of such
        module name is not `xxx` but `xxx.__init__`

  - it is easy to enhance for `from . import xxx` style or so (in the
    future)

    Module name detection in `imported_modules()` can use information
    in `ast.ImportFrom` fully.

It is assumed that all locally defined modules are correctly specified
to `import-checker.py` at once.

Strictly speaking, when `from foo.bar.baz import module1` imports
`foo.bar.baz.module1` module, current `imported_modules()` yields only
`foo.bar.baz.__init__`, even though also `foo.__init__` and
`foo.bar.__init__` should be yielded to detect circular import
exactly.

But this limitation is reasonable one for improvement in this patch,
because current `__init__` files in Mercurial seems to be implemented
carefully.

#!/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(\d|\s)", "use (issueDDDD) instead of bug"),
    (r"^# User [^@\n]+$", "username is not an email address"),
    (r"^# .*\n(?!merge with )[^#]\S+[^:] ",
     "summary line doesn't start with 'topic: '"),
    (r"^# .*\n[A-Z][a-z]\S+", "don't capitalize summary lines"),
    (r"^# .*\n[^\n]*: *[A-Z][a-z]\S+", "don't capitalize summary lines"),
    (r"^# .*\n.*\.\s+$", "don't add trailing period on summary line"),
    (r"^# .*\n.{78,}", "summary line too long (limit is 78)"),
    (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)