Re: How to simulate a real checkout to test a new smudge filter?

[john smith <wempwer@gmail.com>]

On 9/6/16, Torsten Bögershausen <tboegi@web.de> wrote:
> On 06.09.16 19:47, john smith wrote:
>> I am looking for a way to force smudge filter to run by simulating a
>> real life checkout. Let's say I just created a new branch and did not
>> modify any files but want to test my new smudge filter. According to
>> some answers such as
>> https://stackoverflow.com/questions/22909620/git-smudge-clean-filter-between-branches
>> and
>> https://stackoverflow.com/questions/21652242/git-re-checkout-files-after-creating-smudge-filter
>> it should be possible by running:
>>
>> git checkout HEAD --
>>
>> but in doesn't work with git 2.9.0. Method suggested in accepted
>> answer here
>> https://stackoverflow.com/questions/17223527/how-do-i-force-git-to-checkout-the-master-branch-and-remove-carriage-returns-aft
>> works but I don't like because it seems fragile. Is there a safe way
>> to do what I want to do in Git still today?
>>
> It depends what you mean with "safe way".

I want to store all my dotfiles in a single repoitory.  The problem is
that that some specific pieces of these files are different on
different machines.  I have a special .conf file that is different on
every branch and contains machine-specific definitions of some
variables such as EMAIL or SMTP server.  In my smudge filter I call a
script which parses .conf file and replace all template variable
definitions saved in the given file with correct definitions.  For
example in my ~/.bashrc I have this on all branches:

export EMAIL="@EMAIL@"

and in my .conf file on `home' branch

EMAIL=home@address.com

and on `work' branch:

EMAIL=work@address.com

And in .gitattributes on both branches:

bash/.bashrc     filter=make-usable

I also have single `master' branch that only contains template
dotfiles and no .conf.  When setting up a new machine I could just
create a new branch off master branch and add a new .conf.

In turn, clean filter replace all correct definitions in the given
dotfiles back into template definitions.

I'd prefer smudge/clean filters instead of `make' scripts etc. to
convert template dotfiles into something usable and back because
filters:

1. could be run automatically

2. do not modify files as shown by `git show HEAD:<file>' and
therefore no files are reported as modified by git status and also
there are not conflicts when merging master into work/home branch.

I have problems because with point 1 because apparently smudge filter
is not run automatically every time when branch is changed if files
listed in .gitattributes do not change. As the last resort I could
force smudge/clean filter to run just to keep advantage specified in
point 2.

-- 
<wempwer@gmail.com>