$ nettime -f json https://www.github.com
$ nettime --http2 -C 3 -A https://www.google.com
`

Programmatic usage

Make sure that you use [Node.js] >= 14.8. Install the nettime package locally and get time duration of waiting for the response and downloading the content of a sample web page:

`bash
npm install --save nettime
`

`js
const { nettime, getDuration } = require('nettime')
nettime('https://www.google.com')
.then(result => {
if (result.statusCode === 200) {
let timings = result.timings
let waiting = getDuration([0, 0], timings.firstByte)
let downloading = getDuration(timings.firstByte, timings.contentTransfer)
console.log('Waiting for the response:', nettime.getMilliseconds(waiting) + 'ms')
console.log('Downloading the content:', nettime.getMilliseconds(downloading) + 'ms')
}
})
.catch(error => console.error(error))
`

The main module exports a function which makes a HTTP/S request and returns a [Promise] to the result object. The function carries properties nettime, getDuration, getMilliseconds and isRedirect, so that the export can be consumed as an object with several static functions too:

`js
const nettime = require('nettime')
const { nettime, getDuration } = require('nettime')
`

The input argument is a string with a URL to make the request with, or an object with multiple properties.

The input object can contain:

* url: string with a URL to make the request with.
* credentials: object with username and password string properties to be used for formatting of the Basic Authentication HTTP header.
* data: string or Buffer to send to the server using the HTTP verb POST and the content type application/x-www-form-urlencoded by default.
* failOnOutputFileError: boolean for preventing the request timing operation from failing, if writing to the output file failed. If set to false, the error will be printed on the standard output and the process exit code will be set to 2. It is in effect only if outputFile is specified. The default is true.
* headers: object with header names as string keys and header values as string values.
* httpVersion: string with the protocol version ('1.0', '1.1' or '2.0') to be sent to the server. (Node.js HTTP support is hard-coded for 1.1. There can be a difference between 1.0 and 1.1 on the server side only. Node.js supports HTTP/2 in the version 8.4.0 or newer with the --expose-http2 command-lime option and in the version 8.8.1 or newer out-of-the-box. Alternatively, you can install a "http2" module as a polyfill.)
* followRedirects: boolean to continue making requests, if the original response contained a redirecting HTTP status code
* includeHeaders: boolean for including property headers (Object) with response headers in the promised result object. If outputFile is specified, the headers are written to the beginning of the output file too.
* method: HTTP verb to use in the HTTP request; GET is the default, unless -i or -d options are not set.
* outputFile: file path to write the received data to.
* rejectUnauthorized: boolean to refuse finishing the HTTPS request, is set to true (the default), if validation of the web site certificate fails; setting it to false makes the request ignore certificate errors.
* returnResponse: boolean for including property response (Buffer) with the received data in the promised result object.
* requestCount: integer for making multiple requests instead of one.
* requestDelay: integer to introduce a delay (in milliseconds ) between each two requests. The default is 100.
* timeout: intere to set the maximum time (in milliseconds) a single request should take before aborting it.

The result object contains:

* httpVersion: HTTP version, which the server responsed with (string).
* statusCode: [HTTP status code] of the response (integer).
* statusMessage: HTTP status message for the status code (string).
* timings: object with timing properties from various stages of the request. Timing is an array with two integers - seconds and nanoseconds passed since the request has been made, as returned by [process.hrtime].
* headers: an optional object with the response headers, if enabled by the option includeHeaders.
* url: an optional string with the requested URL, if the option followRedirects was set to true.

`js
{
"httpVersion": '1.1',
"statusCode": 200,
"statusMessage": "OK",
"timings": {
"socketOpen": [ 0, 13260126 ],
"dnsLookup": [ 0, 13747391 ], // Optional, if hostname was specified
"tcpConnection": [ 0, 152135165 ],
"tlsHandshake": [ 0, 433219351 ], // Optional, if HTTPS protocol was used
"firstByte": [ 1, 888887072 ],
"contentTransfer": [ 1, 891221207 ],
"socketClose": [ 1, 893156380 ]
}
}
`

If the option requestCount is greater than 1, the result objects will be returned in an array of the same length as the requestCount value.
If the option followRedirects us set to true, the result objects will be returned in an array of the length depending on the presence and count of redirecting responses.

Note: The time-unit parameter affects not only the "text" output format of the command line script, but also the "json" one. If set to "ms", timing values will be printed in milliseconds. If set to "s+ns", timings will be printed as arrays in [process.hrtime]'s format. Calling the nettime function programmatically will always return the timings as arrays in [process.hrtime]'s format.

$3

The following functions are exposed as named exports from the nettime/lib/timings module to help dealing with [process.hrtime]'s timing format and timings from multiple requests:

* getDuration(start, end): computes the difference between two timings. Expects two arrays in [process.hrtime]'s format and returns the result as an array in the same [process.hrtime]'s format.
* getMilliseconds(timing): converts the timing to milliseconds. Expects an array in [process.hrtime]'s format and returns the result as an integer.
* computeAverageDurations(multipleTimings): computes average durations from an array of event timings. The array is supposed to contain objects with the same keys as the timings object from the nettime response. The returned object will contain the same keys pointing to event durations in [process.hrtime]'s format.
* createTimingsFromDurations(timings, startTime): reconstructs event timings from event durations. The timings object is supposed to contain the same keys as the timings object from the nettime response, but pointing to event durations in [process.hrtime]'s format. The returned object will contain the same keys, but pointing to event times in [process.hrtime]'s format. The startTime parameter can shoft the event times. The default is no shift - [0, 0].
* isRedirect(statusCode): checks if the HTTP status code means a redirect. Returns true if it is, otherwise false.

These methods can be required separately too:

`js
const { isRedirect } = require('nettime')
const {
getDuration, getMilliseconds,
computeAverageDurations, createTimingsFromDurations
} = require('nettime/lib/timings')
`

Methods getDuration, getMilliseconds and isRedirect are accessible also as static methods of the nettime function exported from the main nettime` module.

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.

License

Copyright (c) 2017-2022 Ferdinand Prantl

Licensed under the MIT license.

[time]: https://en.wikipedia.org/wiki/Time_(Unix)
[Node.js]: http://nodejs.org/
[Promise]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise
[HTTP status code]: https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
[process.hrtime]: https://nodejs.org/api/process.html#process_process_hrtime_time
[curl]: https://curl.haxx.se/