Ignoring EditorConfig on stdin is probably a bad idea

[rassie]

It's a common use-case for editors (e.g. Emacs) to use stdin, stdout and stderr as an interface to linters and formatters. Usually, the formatter is executed in the project directory so that even though there is no path information, an .editorconfig can be found. Would be great if stdin+editorconfig combination would be supported.

[mvdan]

Interesting, I hadn't thought about this scenario at all. Thanks for bringing it up.

If one wants to use shfmt on standard input with no EditorConfig, they can always rely on a formatting flag to turn off the feature, like -i=0. I mainly did this to reduce the amount of backwards incompatible changes in v3, but I think this change is probably worth it, and would make the EditorConfig logic a bit simpler.

[lassik]

• Supporting editorconfig with stdin is an excellent idea.

• However, it should not be done by default. When people call a program to filter some data from stdin to stdout, they are not generally aware which directory they are running that program from. It can lead to surprising problems if the working directory matters in this case.

• If cmd/shfmt: EditorConfig support in stdin doesn't support filenames #577 is implemented, stdin formatting should use .editorconfig if and only if the stdin filename flag is given.

[mvdan]

@lassik you're very right that I didn't consider filenames in my patch above. I'll write a longer reply to your new issue, since this one is closed.