no-unused-vars configuration incompatible with express middleware error handling

[JavaRip]

Express requires error handling functions to have 4 parameters, even if not all parameters are used: https://expressjs.com/en/guide/error-handling.html#writing-error-handlers

This is an issue as variables have to be defined even if not used, which fires an error in eslint.

GitHub thread discussing the issue: expressjs/generator#78

Potential Solutions

add an ignore pattern for next: expressjs/generator#78 (comment)
use an underscore in the variable name to mark it as not used: https://eslint.org/docs/rules/no-unused-vars#argsignorepattern

[jacekkopecky]

another possible solution: disable linting that issue for error handlers explicitly (as there's likely only up to one of those): expressjs/generator#78 (comment)

// eslint-disable-next-line no-unused-vars