Postman-to-k6

Converts a Postman collection to a k6 script.

The postman-to-k6 converter utilizes your Postman collection and converts all the Postman requests, including tests, variables, ... to K6 scripts that can be executed by K6 to run performance tests.

This project is a friendly fork of the original grafana/postman-to-k6 converter, actively maintained and open for new contributions.

Feel free to contribute or pass any suggestion to improve postman-to-k6.

Content

• Features
• Installation
  • Local Installation (recommended)
  • Global Installation
• Usage
• Video introduction
• Options
  • Iterations
  • Environment Variables
  • Global Variables
  • CSV Data File
  • JSON Data File
  • K6 Param Options File
  • K6 Handle Summary as JSON
  • K6 Request tag
  • Separate
  • Skip Pre
  • Skip Post
  • CLI options file
• Examples
• Testing
• Unsupported Features
• Other similar tools
• Credits

Features

• Pre-request scripts.
• Test scripts.
• Variables (at all scopes + dynamic).
• Data files.
• Authentication methods (except Hawk).
• File uploads (experimental).
• postman.* interface (exceptions below).
• pm.* interface (exceptions below).
• Support for Postman Dynamic Variables & ReplaceIn function.
• Global variables exposed by Postman: globals environment data iteration.
• xml2Json conversion.
• All Postman Schema versions.

Installation

Local Installation (recommended)

While possible to install globally, we recommend that you, if possible, add the converter to the node_modules of your test project using:

$ npm install -D @apideck/postman-to-k6

or using yarn...

$ yarn add @apideck/postman-to-k6

Note that this will require you to run the converter with npx @apideck/postman-to-k6 your-postman-file or, if you are using an older versions of npm, ./node_modules/.bin/postman-to-k6 your-postman-file.

Global Installation

$ npm install -g @apideck/postman-to-k6

Usage

To convert an exported collection to a k6 script:

$ postman-to-k6 collection.json -o k6-script.js

Then run the script in k6, as usual, using:

$ k6 run k6-script.js

Video Introduction

Together with Nicole van der Hoeven & Paul Balogh from the K6 team, we talked about "postman-to-k6" in the K6 Office Hours podcast. We talked about how to convert a Postman collection to a k6 load test, the advantages of Postman, and the benefits of reusing automation testing scripts for performance.

Watch it on Youtube >> https://www.youtube.com/watch?v=Be66Db4wHLA

Topics covered:

• Use cases for k6
• Quick tour of Postman
• Why Postman is not designed for load testing
• Demo of postman-to-k6
• How to use Portman to generate tests from an OpenAPI spec

Options

Iterations

Configures how many times the script will be executed before completion.

Example:

$ postman-to-k6 collection.json --iterations 25 -o k6-script.js

Environment Variables

Provide environment variables from a JSON file.

Example:

$ postman-to-k6 collection.json --environment environment.json -o k6-script.js

Global Variables

Provide global variables from a JSON file.

$ postman-to-k6 collection.json --global globals.json -o k6-script.js

CSV Data File

Provide a data file in the CSV format.

$ postman-to-k6 collection.json --csv data.csv -o k6-script.js

JSON Data File

Pass in a data file in the JSON format.

$ postman-to-k6 collection.json --json data.json -o k6-script.js

K6 Param Options File

Pass K6 parameter options as a file in JSON format.

$ postman-to-k6 collection.json --k6-params k6-params.json -o k6-script.js

K6 Handle Summary as JSON

Output the K6 summary as a file in JSON format. This will add the K6 handleSummary(data) to the generated script, providing the functionality that K6 will store the summary output as JSON file locally.

$ postman-to-k6 collection.json --k6-handle-summary-json summary-report.json -o k6-script.js

K6 Request tag

Generate K6 request name tags based on available naming strategies:

• none: no automatic generated tags | default
• request: uses the request name as tag (example "Show all accounts")
• folder-request: uses Postman folder name and the request name (example: "Accounts - Show all accounts")

Example for request strategy

$ postman-to-k6 collection.json --k6-request-tagging=request -o k6-script.js

Example for folder-request strategy

$ postman-to-k6 collection.json --k6-request-tagging=folder-request -o k6-script.js

Separate

Split requests into separate files, for easier rearrangement of the logic.

$ postman-to-k6 collection.json --separate -o k6-script.js

$ postman-to-k6 collection.json -s -o k6-script.js

Skip Pre

Skips any pre-request scripts during conversion

$ postman-to-k6 collection.json --skip-pre -o k6-script.js

Skip Post

Skips any post-request scripts during conversion

$ postman-to-k6 collection.json --skip-pre -o k6-script.js

CLI options file

Manage all the CLI options in a separate configuration file and pass them along to the postman-to-k6 command. To make the CLI usage easier, especially in CI/CD implementations.

All the available CLI options can be used in the config file. By passing the CLI options as parameters, you can overwrite the defined CLI options defined in the file.

$ postman-to-k6 collection.json --cli-options-file cli-config.json

Example of JSON CLI config file

{
    "output": "k6-script.js",
    "k6-params": "config/k6-params.json",
    "environment": "config/envs/team.env.json",
    "separate": true
}

Examples

A collection of Postman examples are located under example. To run one of the examples, just run it as you would any other command:

$ postman-to-k6 example/v2/echo.json -o k6-script.js

Testing

Run the test suite:

$ npm run test-jest

npm run test-jest includes a native-Jest guard for tests/** (fails on AVA-style APIs or mock-require).

Run the default test entrypoint:

$ npm run test-all

Run coverage and generate a combined summary/trend artifact:

$ npm run coverage-all

npm run coverage-jest-regression enforces a Jest coverage regression gate against scripts/coverage/jest-coverage-baseline.json with a max drop of 0.30% for lines/statements/functions/branches.

Jest-native testing rules for tests/**:

• Use native Jest assertions (expect(...)) only.
• Do not import AVA (import test from 'ava') in tests/**.
• Do not use AVA-specific APIs (test.serial, t.is, t.deepEqual, t.throws, etc.).
• Do not use mock-require in tests/**; use the shared Jest shim harness in tests/helpers/shimHarness.js.

The guard command is:

$ npm run test-jest-native-guard

Unsupported Features

• Sending requests from scripts using pm.sendRequest.
• Controlling request execution order using postman.setNextRequest.
• Cookie properties, like hostOnly, session, and storeId.
• Postman methods:
  • pm.response.reason
  • pm.response.to.have.status(reason)
  • pm.response.to.not.have.status(reason)
  • pm.request.auth
• The Hawk authentication method.
• Deprecated xmlToJson method.
• Request IDs are changed. Postman doesn't provide them in the export, so we have to generate new ones.

Resources

A collection of blog posts and resources about postman-to-k6

• k6 Office Hours #43 Podcast by Grafana/K6 & Tim Haselaars (maintainer of postman-to-k6)
• Load testing your API with Postman by Mostafa Moradian from Grafana
• Unlocking the Power of Spec-Driven API Development by Tim Haselaars
• API load testing: A beginner's guide by Grafana/K6
• Charge your APIs Volume 6: Perfecting Your APIOps - Harnessing the Power of k6 for API Testing by Daniel Kocot from Codecentric
• Load Testing with Postman and Grafana K6 by Lukman Patel
• Shift left performance test by converting Postman API script to K6 and integrate it with bitbucket by sukma ragil
• Hacker News
• Transformando testes de API com Postman em testes de performance com K6 by Marlo Henrique
• Converting Postman Collection to K6 Script
• Using Postman with k6 by RiaNaik
• Postman to K6 Automating Performance Testing with Auto Script Generation by Huzaifa Asif
• Postman to k6 in under 5 minutes / YouTube by loan Solderea

Other similar tools

• jmeter-to-k6: Convert JMeter JMX files to k6 JS.

Credits

Special thanks to the K6 team from Grafana for open-sourcing & growing the converter and contributing it to the community. Thanks to bookmoons for creating this tool. Also, thanks to borjacampina for creating the original incarnation of the tool.