Git рулит

Как быстро отыскать ту ревизию кода, на которой падают тесты?

Есть команда bisect в git. Как ее применение выглядит на примере:

I learned about git bisect from this Stack Overflow poll: What are your favorite git features or tricks? I thought it was so cool that I wanted to share an example.

After upgrading from Django 1.2.3 to Django 1.3, something broke on the website I was working on. To figure out what was wrong, I used git bisect to find the Django revision that introduced the relevant change. I cloned the Django github repo and pip install -e'd it into my virtualenv. Then I used git bisect as follows:

• Start git bisect

  $ git bisect start 
  $ git bisect bad 1.3 
  $ git bisect good 1.2.3 
  Bisecting: a merge base must be tested
    [618153bd3b047529f6cfb50917c88270f30e8ea8] Fixed #10843: the textile tests now pass against the latest textile library.

  Note: 1.3 and 1.2.3 are git tags in the Django git repo. Commit SHA1 hashes can be used instead.
• Start the development server in another terminal. Load the webpage in the browser. The page loads without error.

  [04/Aug/2011 19:13:20] "GET /my/webpage/ HTTP/1.1" 200 16279

• Mark the revision good

  $ git bisect good 
  Bisecting: 774 revisions left to test after this (roughly 10 steps)
  [39591cddccffdf3b66cfaaa60b95257daa4ef8c5] Fixed #14781 - Setting "CACHE_PREFIX" should be "CACHE_KEY_PREFIX". Thanks to adamv for report and patch.

• Reload the page. This time it throws a 500 error.

  [04/Aug/2011 19:13:59] "GET /my/webpage/ HTTP/1.1" 500 118861

• Mark the revision bad

  $ git bisect bad 
  Bisecting: 387 revisions left to test after this (roughly 9 steps)
  [6630bd24f45c7967c49b90adf82c63dd7d93e6f7] Fixed #13863 -- Corrected decimal separator in Swedish format module. Thanks, Ulf Urdén.

• Reload

… и так далее ...

After marking the last commit, git bisect shows the first bad commit as 622bf3b2199e5e7015edccb00f1ab694291ca121

$ git bisect good
622bf3b2199e5e7015edccb00f1ab694291ca121 is the first bad commit
commit 622bf3b2199e5e7015edccb00f1ab694291ca121
Author: kmtracey <kmtracey>
Date:   Sat Sep 11 01:39:16 2010 +0000

    Fixed #11905: Raise an error on model form creation if a non-existent field was listed in fields. Thanks ben and copelco.
    
    
    git-svn-id: http://code.djangoproject.com/svn/django/trunk@13739 bcc190cf-cafb-0310-a4f2-bffc1f526a37

:040000 040000 87ec1601b970938b55382a5aa66db74716552c3d 2d418dfe8dd9f67fea408e022aa13838086ce33b M      django
:040000 040000 054e6f42b3b467e47f295f8fda6cdc8a7f2c054c 52ba5265ba9d6458f23c8cb4a8a9bdcdbfc1f590 M      tests</kmtracey>

Note: checking for failed unit tests instead of checking for a 500 error in the browser is another (probably better) way to test with git bisect.

Note 2: The problem with my code was that I was adding extra fields to a model formset in the wrong way. I was trying to use add_fields on a base model formset instead of creating a custom Form with the extra field and specifying it in the factory. This Stack Overflow answer solved the problem for me.

http://www.saltycrane.com/blog/2011/08/example-using-git-bisect-narrow-commit/

Отличная штука, однозначно.

original post http://vasnake.blogspot.com/2012/12/git.html