Debug build panics due to `debug_assert_eq!("\t".width(), 0);` assertion

[styris-ame]

(1) When compiling a debug build and running a comparison with it, the mentioned assertion causes a panic:
left: 1
right: 0

I tested this on both Windows and macOS.

The code comment for that assertion states:

.width() on tabs returns 0, whereas we want to model them as tab_width spaces.

However this appears to somehow no longer be the case, at least for me?

(2) Irrelevant

(3) Latest commit

[Wilfred]

Could you provide a full repro? How are you running difftastic, and could you share an example file?

Whilst I generally develop on linux, all the tests are run on GitHub actions are passing on all platforms, and Rust tests are run in debug mode by default. I've not see this assertion fail.