Dapps E2E testing

What's an End-to-End test?

E2E - Characteristics

- isolated

- slow

- pretty expensive to maintain and write

- should give the confidence to deploy

Example

video

Oasis Direct CI

Challanges

- control app programatically

- control signer/web3 programatically

- deploy isolated infrastructure (backend / blockchain contracts)

- put system in a desired state

- CI / Nightly builds

- maintaining test suite / flaky tests

Controlling browser programmatically

Selenium Webdriver

- mature technology

- many backends (browsers, ios/android etc.)

- client / server achitecture

- chimp.js / protractor

Puppeteer (Headless Chrome Node API)

- works only with chrome

- maintained by google

- pretty popular

- allows for ~~easy~~ testing browser extensions

Cypress.io

- currently works only with chrome

- different, more robust architecture

- less flaky tests

- possible to test extensions

- cypress dashboard

Oasis Direct Cypress Dashboard (CI)

Test Example

Controlling web3 programmatically

inject dummy web3 instance just before the opening browser
load & control metamask extension
- OasisDEX/metamask-e2e
- DEMO 🦊

Infrastructure

Localnode with fixtures

More complicated setup with spawning backend

Continuous Integration speed hacks

- parallel jobs

- docker base images

- docker caching