Rustfmt fails to format code with a long string inside struct

[sterliakov]

This terrible input (reduced from some larger struct with 2 levels of nesting) is left as-is.

fn test_fetch_existing_receipt() {
    let expected =
    Event {
                            topics: 1,
                            data: Bytes::copy_from_slice(&b"vtho-usd\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x84\x17\x19\x1a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0e\x7f\x8eJ"[..])
                        };
}

Applies to both current nightly and stable:

$ cargo fmt -- -V
rustfmt 1.6.0-stable (a28077b 2023-12-04)
$ cargo +nightly fmt -- -V
rustfmt 1.7.0-nightly (3f28fe1 2023-12-18)

I wanted to just split a struct copied from terminal output, but ended up doing it manually:(

[ytmimi]

Thanks for reaching out.

Originally I thought this was a duplicate of #4992 #4800. Both of those issues are fixed when using version=Two.
Unfortunately the call to Bytes::copy_from_slice is what makes this a different issues. Because the string literal is way longer than the default of max_width rustfmt fails to format Bytes::copy_from_slice, which prevents rustfmt from formatting the Event struct.

I think your best option here is to refactor your code:

Option 3:

input

fn test_fetch_existing_receipt() {
    let data = Bytes::copy_from_slice(&b"vtho-usd\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x84\x17\x19\x1a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0e\x7f\x8eJ"[..]);
    let expected = 
    Event {
                            topics: 1,
                            data
                        };
}

Output

fn test_fetch_existing_receipt() {
    let data = Bytes::copy_from_slice(&b"vtho-usd\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x84\x17\x19\x1a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0e\x7f\x8eJ"[..]);
    let expected = Event { topics: 1, data };
}