Example NodeJS/React Consumer - playwright (BYO Adapter)

Source Code

https://github.com/pactflow/example-bi-directional-consumer-playwright-js

badge.svg: https://github.com/pactflow/example-bi-directional-consumer-playwright-js/actions/workflows/build.yml

can--i--deploy-main_to_production-brightgreen.svg: https://testdemo.pactflow.io/pacticipants/pactflow-example-bi-directional-provider-readyapi/branches/master/latest-version/can-i-deploy/to-environment/production/badge

Overview of Example

This is an example of a React "Product" API consumer that uses playwright & API Hub for Contract Testing and GitHub Actions to generate and publish Pact consumer contracts.

It performs pre-deployment cross-compatibility checks to ensure that it is compatible with specified providers using the Bi-Directional contract capability of API Hub for Contract Testing.

See the full API Hub for Contract Testing Bi-Directional Workshop for which this can be substituted in as the "consumer".

Key points with playwright

It:

  • It a React app implementing a "Product" website created with Create React App

  • It utilises playwright to functionally test the website

  • It utilises a small helper file to cover playwright routes into pact interactions

Overview of Part of Bi-Directional Contract Testing Flow

In the following diagram, you can see how the consumer testing process works - it's the same as the current Pact process.

When we call "can-i-deploy" the cross-contract validation process kicks off on API Hub for Contract Testing, to ensure any consumer consumes a valid subset of the OAS for the provider.

PF_Flowchart_ConsumerScope_01.png

The project uses a Makefile to simulate a very simple build pipeline with two stages - test and deploy.

When you run the CI pipeline (see below for doing this), the pipeline should perform the following activities (simplified):

  • Test

    • Run tests (including the pact tests that generate the contract)

    • Publish pacts, tagging the consumer version with the name of the current branch

    • Check if we are safe to deploy to Production with can-i-deploy (ie. has the cross-contract validation has been successfully performed)

  • Deploy (only from <main|master>)

    • Deploy app to Production

    • Record the Production deployment in the Pact Broker

    PF_Flowchart_ConsumerPipeline_01.png

Compatible with Providers

This project is currently compatible with the following provider(s):

See Environment variables on how to set these up.

Pre-requisites

Software:

Environment variables

To be able to run some of the commands locally, you will need to export the following environment variables into your shell:

  • PACT_BROKER_TOKEN: a valid API token for API Hub for Contract Testing

  • PACT_BROKER_BASE_URL: a fully qualified domain name with protocol to your pact broker e.g., https://testdemo.pactflow.io

Usage

Steps

NOTE: playwright tests are located in ./playwright/integration. See below for how to start playwright test, generate consumer contract and publish contract to pactflow.

  • make install - install project dependencies

Run each step separately

  • make test_and_publish - tests the provider and publishes provider contracts to API Hub for Contract Testing

  • This will perform the following 2 calls

    • make test

    • make publish_provider_contract

  • make can_i_deploy - runs can-i-deploy to check if its safe to deploy the provider

  • make deploy - deploys the app and records deployment

or run the whole lot in one go

  • make ci - run the CI process, but locally (uses Docker by default)

Installing alternate pact CLI tools.

If you don't have docker, you can use one of the ruby tools. The standalone, doesn't require that you install Ruby on your host machine.

  • make install-pact-ruby-cli - installs the pact ruby CLI tool

  • make install-pact-ruby-standalone - installs the pact standalone CLI depending on your platform

  • make uninstall-pact-ruby-standalone - uninstalls the pact standalone CLI

Using alternate pact CLI tools.

  • PACT_TOOL=docker make ci - run the CI process, using the pact Docker CLI tool

  • PACT_TOOL=ruby_standalone make ci - run the CI process, using the pact standalone CLI tool

  • PACT_TOOL=ruby_cli make ci - run the CI process, using the pact ruby CLI tool

_How to use Playwright

  • Spin up the ui project by running npm run start

  • Run your playwright tests with npm run test

Look at one of the tests test/productByQuery.spec.js

  1. Import transformPlaywrightMatchToPact from test/playwrightSerialiser.js

  2. add transformPlaywrightMatchToPact function call into your playwright route

const { transformPlaywrightMatchToPact } = require('./playwrightSerialiser')

await page.route(productApiPath + '/products?id=2', async (route) => {
  const response = {
    status: 200,
    body: JSON.stringify(testData),
    headers: {
      'Content-Type': 'application/json'
    }
  }
  route.fulfill(response)
  const pacticipant = 'pactflow-example-bi-directional-consumer-playwright-js'
  const provider = process.env.PACT_PROVIDER || 'pactflow-example-bi-directional-provider-dredd'
  await transformPlaywrightMatchToPact(route, { pacticipant, provider })
  return
})

OS/Platform specific considerations

The makefile has been configured to run on Unix/Windows and MacOS based systems, and tested against Github Actions.

They can be run locally on Unix/Windows and MacOS, or on Windows via WSL2 or a shell with bash.

Caveats

Related topics / posts / discussions

Other examples of how to do this form of testing

  • TBC

Found an issue?

Reach out via a GitHub Issue, or reach us over in the Pact foundation Slack.

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