string_lit_as_bytes should also detect "str".to_string().into_bytes()

[repi]

Lint name: string_lit_as_bytes

I tried this code:

let bytes1 = "Length".as_bytes();

let bytes2 = "Length".to_string().into_bytes();

I expected to see this happen: for the second case (bytes2) to also be detected by the lint and recommend using `b"Length" instead

Instead, this happened: only the first case for bytes1 was detected.

This came from real user code we had and manually fixed, would be nice if the lint can be extended to this case as well.

Meta

• clippy 0.0.212 (cb75ad5d 2021-02-10)
• rustc -Vv:

   rustc 1.50.0 (cb75ad5db 2021-02-10)
   binary: rustc
   commit-hash: cb75ad5db02783e8b0222fee363c5f63f7e2cf5b
   commit-date: 2021-02-10
   host: x86_64-pc-windows-msvc
   release: 1.50.0
  

[ebobrow]

I'd like to give this a try.

@rustbot claim