detect extension-less CoffeeScript scripts

[eventualbuddha]

The decaffeinate-examples fork of hubot still has bin/hubot as CoffeeScript because bulk-decaffeinate doesn't find it. We could pretty easily look in all extension-less files (maybe that are executable?) and look for a shebang line like this: #!/usr/bin/env coffee.

[alangpierce]

👍 I've got a few of those in my codebase as well, and they all have no extension and #!/usr/bin/env coffee at the top. Another possible option is to just have a list of additional files to process in bulk-decaffeinate.config.js.

One difficulty here is what to do with the git history. Currently the code assumes that all files end in .coffee and I think it assumes that the .coffee and .js files can exist at the same time, and it makes the rename operation its own commit.

Also, I guess it would make sense to modify the shebang line to run node instead? Also maybe we'd need to use babel-register, but I'd also like to avoid making those kinds of assumptions, I think.

This could also be done in more of a one-off way for each case, like renaming the file to .coffee beforehand, then renaming the .js file back and changing the shebang line afterward. For decaffeinate-examples, this could be done with a patch before and a patch after.

[eventualbuddha]

decaffeinate already patches it to replace coffee with node, though you're right that sometimes you'll need babel-register.

[alangpierce]

Ah, neat, I hadn't seen that.