Programmable interface to `clinic doctor`
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Latest commit 21fe9db Nov 12, 2018


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Programmable interface to clinic doctor. Learn more about clinic:


Supported node versions

  • Node.js 10.0.0 and above
  • Node.js 9.4.0 and above
  • Node.js 8.10.0 and above

Node.js 8.9.4 also works, however you have to listen to SIGINT and shutdown the process nicely.


const ClinicDoctor = require('@nearform/doctor')
const doctor = new ClinicDoctor()

doctor.collect(['node', './path-to-script.js'], function (err, filepath) {
  if (err) throw err

  doctor.visualize(filepath, filepath + '.html', function (err) {
    if (err) throw err

You can find examples in node-clinic-doctor-examples


const ClinicDoctor = require('@nearform/doctor')
const doctor = new ClinicDoctor()

new ClinicDoctor([settings])

  • settings <Object>
    • sampleInterval <number> Time between each sample in milliseconds. Default: 10
    • detectPort <boolean> Default: false
    • path [<string>][] The folder where the collected data is stored. Default: '.'
    • debug <boolean> If set to true, the generated html will not be minified. Default: false

doctor.collect(args, callback)

Starts a process by using:

const { spawn } = require('child_process')
spawn(args[0], ['-r', 'sampler.js'].concat(args.slice(1)))

The injected sampler will produce a file in the current working directory, with the process PID in its filename. The filepath relative to the current working directory will be the value in the callback.

stdout, stderr, and stdin will be relayed to the calling process. As will the SIGINT event.

doctor.visualize(dataFilename, outputFilename, callback)

Will consume the datafile specified by dataFilename, this datafile will be produced by the sampler using doctor.collect.

doctor.visualize will then output a standalone HTML file to outputFilename. When completed the callback will be called with no extra arguments, except a possible error.


GPL 3.0