src/build.js
function resolveOutputTarget(customPath, filename) {
    const realPath = path.resolve('.', customPath);

    const getPath = tryCatch(
        realPath => fs.lstatSync(realPath).isDirectory()
            ? path.join(realPath, filename)
            : realPath,
        identity);

    return getPath(realPath);
}
function resolveOutputTarget(customPath, filename) {
    const realPath = path.resolve('.', customPath);

    const getPath = tryCatch(
        realPath => fs.lstatSync(realPath).isDirectory()
            ? path.join(realPath, filename)
            : realPath,
        identity);

    return getPath(realPath);
}
function resolveOutputTarget ( customPath , filename ) { const realPath = path . resolve ( '.' , customPath ) ; const getPath = tryCatch ( realPath => fs . lstatSync ( realPath ) . isDirectory ( ) ? path . join ( realPath , filename ) : realPath , identity ) ; return getPath ( realPath ) ; }
Taking account the -o parameter can be used to specify the output directory,
let's deal with it

@param {String} customPath
@param {String} filename
@return {String}
Taking account the - o parameter can be used to specify the output directory let s deal with it