question: how to test a cask binary?

[psibre]

Various casks provide binary stanzas to symlink some binary or script within a cask-installed app.
Would it be possible or desirable to provide some lightweight functionality to automatically test that the binary actually results in a working command?

For example, the praat cask creates a symlink

/usr/local/bin/praat -> /opt/homebrew-cask/Caskroom/praat/#{installed_version}/Praat.app/Contents/MacOS/Praat

It would be nice to automatically check when the cask is tested or installed that running praat actually does run that .../Praat.app/Contents/MacOS/Praat binary.

Because sometimes paths inside apps are changed upstream, and the symlinks would break on installing an updated cask. Or some other stuff happens upstream, and the binary itself no longer works.

Catching this sort of issue during the test builds, and guarding against it during postflight might be a good idea.

[vitorgalvao]

I don’t really see this as necessary, because it really isn’t a problem. Also, with #15603 this will only become less of an issue. That said, I also wouldn’t mind.

Lets see other opinions.

[psibre]

I've floated a simple test balloon in #18879

[vitorgalvao]

That’s not really the same thing as a test. You’re using postflight for it, mudding it’s usage. Either we make a proper test block for this, or we don’t do it at all.

[psibre]

@vitorgalvao I agree that's not what the postflight is for; it was intended as a proof of concept.

  binary 'Praat.app/Contents/MacOS/Praat', target: 'praat'

  # verify binary
  postflight do
    cmd = "praat --version"
    raise "Cannot run command `#{cmd}`" unless system cmd
  end

does provide the functionality I proposed above, though: it fails the installation if the praat command provided by the binary cannot be run.

Would it be possible to port the test block logic over from the main brew formula code?

[vitorgalvao]

Would it be possible to port the test block logic over from the main brew formula code?

Might be (especially with #14384), but we’re still not agreed on if this is desirable (waiting for more maintainers to chime in).

[psibre]

Fair enough. Thanks for linking to the integration issue -- I'll subscribe to that!

[vitorgalvao]

Seems like there isn’t much interest in this. Closing.