Merging test scripts and output demo

[Jesse Glick]

On 06/13/2010 02:11 PM, Martin Geisler wrote:
>    % hg pull
>    pulling from ssh://hg@hg.intevation.org/mercurial/crew/
>    searching for changes
>    no changes found
>
> ....
> We can even do away with the (IMO) silly sed syntax and invent a better:
>
>    % hg pull | replace 'ssh://.*' '<somewhere>'

Or even do away with the pipe. Since it is extremely common for the same command to produce slightly different output depending on date, etc., just build some syntax into 
the output to ignore some sections:

  $ hg pull
  pulling from ssh://...
  searching for changes
  no changes found
  $ hg tip
  changeset:   3:...
  tag:         tip
  user:        ...
  date:        ...
  summary:     test

Or if you needed to constrain things a bit more tightly, to avoid accidentally matching too much with the ellipsis operator (such as unexpected error messages), give 
regexps with some delimiter which otherwise occurs rarely, such as a tilde:

  $ hg pull
  pulling from ssh://~\S+~
  searching for changes
  no changes found
  $ hg tip
  changeset:   3:~[a-f0-9]{12}~
  tag:         tip
  user:        ~.+~
  date:        ~.+~
  summary:     test

This would help avoid cryptic test directives like my own (f8a86ea7521b):

[test]
  hg -q help help 2>&1 | python -c \
    "import sys; sys.stdout.write(sys.stdin.read().replace('$abspath', '.../badext.py'))"
[test.out]
  *** failed to import extension badext from .../badext.py: bit bucket overflow

which could be replaced with:

[test]
  $ hg -q help help
  *** failed to import extension badext from .../badext.py: bit bucket overflow
                                             ^^^
                                             now a metasyntactic var