Typescript plugin behaves differently depending on whether the `include` option is a string or a regular expression about plugins HOT 1 OPEN

Actually, it seems to come from @rollup/pluginutils itself:

There, the createFilter method behaves differently depending on the type of the pattern: if it is a regular expression, it is used as-is; if it is a string, a regular expression is created from it and the current working directory, hence preventing plugins to handle files located outside of the working directory.

Is this a deliberate move or a bug? If it is a deliberate move, what is the rational?

For information, it forces plugin developers to transform the passed options to regular expressions to make sure that their plugin works in every situation, for example my own TypeScript plugin:

options.include = options.include || /\.(cts|mts|ts|tsx)$/;
    
if (typeof options.include === "string") {
    options.include = [options.include];
}
  
if (Array.isArray(options.include)) {
    options.include = options.include.map((include) => {
        if (typeof include === "string") {
            return new RegExp(include);
        }
        
        return include;
    });
}

from plugins.