assertEquals error diff separately tokenizes \ of escaped chars in strings

[lionel-rowe]

Describe the bug

The error message of assertEquals separately tokenizes \ of escaped characters in strings, e.g \t representing a tab literal is treated as two separate tokens despite semantically being a single indivisible unit.

Steps to Reproduce

1. Run the following in repl:

   import { assertEquals } from 'jsr:@std/[email protected]'
   const first = 'a\tb'
   const second = 'a\fb'
   assertEquals(first, second)

2. Observe output, showing diff as a\[-tb]{+fb}
   

Expected behavior

Diff to show as a[-\t]{+\f}b

Environment

• OS: win11/WSL/ubuntu 22
• deno version: 2.1.1
• std version: [email protected]