progress-logger-js

Node.js module for logging progress information and statistics about long-lasting activities

Usage

Installation:

npm install progress-logger-js --save

usage:

const ProgressLogger = require("progress-logger-js").ProgressLogger;

usage with TypeScript:

import {ProgressLogger} from "progress-logger-js"

Consider the following fake long-lasting process:

let progress = new ProgressLogger();

for (var i = 0; i < 100; i++){
  progress.increment()
  await sleep(200);
}

progress.end()

Output will be:

Processing started at 2016-11-16T00:24:49.317Z
Processing ... 26 (5.2/sec)
Processing ... 51 (5.0/sec)
Processing ... 76 (5.0/sec)
Processing completed (100) in 20.0 seconds (5.0/sec)

You can also customize some options:

let progress = new ProgressLogger({
  label: "my-label",
  logInterval: 2000,
  count: 100
});

In this case output will be:

my-label started at 2016-11-16T00:20:37.382Z
my-label ... 11.00% (11 of 100, 5.5/sec)
my-label ... 21.00% (21 of 100, 5.0/sec)
my-label ... 31.00% (31 of 100, 5.0/sec)
my-label ... 41.00% (41 of 100, 5.0/sec)
my-label ... 51.00% (51 of 100, 5.0/sec)
my-label ... 61.00% (61 of 100, 5.0/sec)
my-label ... 71.00% (71 of 100, 5.0/sec)
my-label ... 81.00% (81 of 100, 5.0/sec)
my-label ... 91.00% (91 of 100, 5.0/sec)
my-label ... 100.00% (100 of 100, 5.0/sec)
my-label completed (100) in 20.0 seconds (5.0/sec)

Statistics

Some more statistics are also available using progressLogger.stats method:

{ label: 'my-label',
  start: 2016-11-16T00:24:49.317Z,
  end: 2016-11-16T00:25:09.359Z,
  elapsed: 20042,
  avg: 200.42,
  rate: 4.98,
  count: 100,
  success: 1,
  errors : [] }

NOTE: avg is simply calculated using elapsed/count, if you are running steps in parallel this metric is not correct.

Handling promises

To handle the progress increment of a Promise just use progressLogger.incrementPromise method:

progress.incrementPromise(yourPromise);

This will automatically catch errors.

Handling errors

To log errors you can use:

progress.increment(err);

or passing a Promise:

progress.incrementPromise(yourPromise);