Flow Playground

Install Flow Javascript Testing Framework

How to install the Flow command-line interface (CLI)


It's possible to install Flow Javacript Testing Framework manually and automatically, using generator.

Automatic Installation (via npx)

Create new folder and move into it:

mkdir test && cd ./test

Generate complete setup via init call:

npx flow-js-testing init

Create new test suit via make call, specifying the name of the suit:

npx flow-js-testing make basic-test

Manual Installation

If, for some reason, you would want to do this manually here's what you need to do.

Create new folder and move into it:

mkdir test && cd ./test

Initiate a project in that folder with:

npm init

Then install all necessary packages by running following command:

npm install flow-js-testing jest @babel/core @babel/preset-env babel-jest @onflow/types

If your project is JavaScript based, then run the above command from the folder that contains your project's package.json file.

Jest Config

You'll need to configure Jest in order for tests to work properly. Add jest.config.js file next to package.json and populate it with:

module.exports = {
  testEnvironment: "node",
  verbose: true,
  coveragePathIgnorePatterns: ["/node_modules/"],

Babel Config

Similarly, create babel.config.json then copy and paste the following configuration:

  "presets": [
        "targets": {
          "node": "current"