Is there a stable way to tell Rustfmt to skip an entire file

Question

The official way to get Rustfmt to skip an item is #[rustfmt::skip], however I want it to skip an entire file. I tried this:

#![rustfmt::skip]

However you get this error

error[E0658]: non-builtin inner attributes are unstable

Here is the issue for that error.

Is there a workaround for this? Solutions I am not interested in:

• Use unstable Rust
• Tell Rustfmt not to process the file using something external to the file (rustfmt.toml for example)

Answer 1

Currently Rustfmt traverses the mod tree itself so you can put the attribute on the file that declared the module you want to ignore.

#[rustfmt::skip]
mod dont_format_this_file;

Then dont_format_this_file.rs will be skipped.

However, Rustfmt 2 changed its behaviour so that it doesn't traverse the mod tree, so you have to specify dont_format_this_file.rs directly. In that case it seems likely that it will find the mod dont_format_this_file; declaration so this may not work when Rustfmt 2 is released.

Answer 2

To skip an entire file you can add this to the top of the file:

#![cfg_attr(rustfmt, rustfmt_skip)]

This attribute is outlined in the tips section of the rustfmt nightly docs. It just worked in my case but I'm unsure if thats because I'm using nightly or something.