Escaping non-special characters in strings, template literals, and regular expressions doesn\'t have any effect
Source: https://eslint.org/d
Some linting rules are meant to make your code perfect.
You can escape characters if you want to, but sometimes it doesn't have any effect. If you still do that, you just put a meaningless character in your code, confusing other programmers and wasting 1 byte. Your code escapes the underscore character with \_
sequence, whereas \
doesn't do anything in that sequence.
This lint rule tells you about that. It's not the end of the world, but using that lint rule, you wanted to know.
If the escape character isn't doing anything useful, what is it doing there?
Perhaps the writer of the code wanted a literal backslash character. The error draws attention to it so they can replace \
with \\
.
Perhaps they thought the next character needed escaping. This educates them otherwise.
Perhaps it is just a typo.
Since there is no good reason to have the \
there, there can only be bad reasons. Some are more seriously bad than others, but the linter will draw attention to them.