@thi.ng/rstream/trace.js

Reactive streams & subscription primitives for constructing dataflow graphs / pipelines

const trace = (prefix) => ({
  next(x) {
    prefix ? console.log(prefix, x) : console.log(x);
  },
  done() {
    prefix ? console.log(prefix, "done") : console.log("done");
  },
  error(e) {
    prefix ? console.log(prefix, "error", e) : console.log("error", e);
    return false;
  }
});
export {
  trace
};