• callback {Function} The callback function
    • Returns: {Function} The intercepted function

    This method is almost identical to [domain.bind(callback)][]. However, in addition to catching thrown errors, it will also intercept [Error][] objects sent as the first argument to the function.

    In this way, the common if (err) return callback(err); pattern can be replaced with a single error handler in a single place.

    1. const d = domain.create();
    3. function readSomeFile(filename, cb) {
    4.   fs.readFile(filename, 'utf8', d.intercept((data) => {
    5.     // Note, the first argument is never passed to the
    6.     // callback since it is assumed to be the 'Error' argument
    7.     // and thus intercepted by the domain.
    9.     // If this throws, it will also be passed to the domain
    10.     // so the error-handling logic can be moved to the 'error'
    11.     // event on the domain instead of being repeated throughout
    12.     // the program.
    13.     return cb(null, JSON.parse(data));
    14.   }));
    15. }
    17. d.on('error', (er) => {
    18.   // An error occurred somewhere. If we throw it now, it will crash the program
    19.   // with the normal line number and stack message.
    20. });