lib/util/path-utils.js
function getRelativePath(filepath, baseDir) {
    const absolutePath = path.isAbsolute(filepath)
        ? filepath
        : path.resolve(filepath);

    if (baseDir) {
        if (!path.isAbsolute(baseDir)) {
            throw new Error(`baseDir should be an absolute path: ${baseDir}`);
        }
        return path.relative(baseDir, absolutePath);
    }
    return absolutePath.replace(/^\//u, "");

}
function getRelativePath(filepath, baseDir) {
    const absolutePath = path.isAbsolute(filepath)
        ? filepath
        : path.resolve(filepath);

    if (baseDir) {
        if (!path.isAbsolute(baseDir)) {
            throw new Error(`baseDir should be an absolute path: ${baseDir}`);
        }
        return path.relative(baseDir, absolutePath);
    }
    return absolutePath.replace(/^\//u, "");

}
function getRelativePath ( filepath , baseDir ) { const absolutePath = path . isAbsolute ( filepath ) ? filepath : path . resolve ( filepath ) ; if ( baseDir ) { if ( ! path . isAbsolute ( baseDir ) ) { throw new Error ( ` ${ baseDir } ` ) ; } return path . relative ( baseDir , absolutePath ) ; } return absolutePath . replace ( / ^\/ / u , "" ) ; }
Converts an absolute filepath to a relative path from a given base path

For example, if the filepath is `/my/awesome/project/foo.bar`,
and the base directory is `/my/awesome/project/`,
then this function should return `foo.bar`.

path.relative() does something similar, but it requires a baseDir (`from` argument).
This function makes it optional and just removes a leading slash if the baseDir is not given.

It does not take into account symlinks (for now).

@param {string} filepath  Path to convert to relative path.  If already relative,
it will be assumed to be relative to process.cwd(),
converted to absolute, and then processed.
@param {string} [baseDir] Absolute base directory to resolve the filepath from.
If not provided, all this function will do is remove
a leading slash.
@returns {string} Relative filepath
Converts an absolute filepath to a relative path from a given base path