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node.jsunit-testingava

Run ava test.before() just once for all tests

I would like to use test.before() to bootstrap my tests. The setup I have tried does not work:

// bootstrap.js
const test = require('ava')

test.before(t => {
  // do this exactly once for all tests
})


module.exports = { test }


// test1.js

const { test } = require('../bootstrap')

test(t => { ... {)

AVA will run the before() function before each test file. I could make a check within the before call to check if it has been called but I'd like to find a cleaner process. I have tried using the require parameter with:

"ava": {
  "require": [
    "./test/run.js"
  ]
 }

With:

// bootstrap,js
const test = require('ava')

module.exports = { test }


// run.js

const { test } = require('./bootstrap')

test.before(t => { })


// test1.js
const { test } = require('../bootstrap')

test(t => { ... {)

But that just breaks with worker.setRunner is not a function. Not sure what it expects there.

Solution

  • AVA runs each test file in its own process. test.before() should be used to set up fixtures that are used just by the process it's called in.

    It sounds like you want to do setup that is reused across your test files / processes. Ideally that's avoided since you can end up creating hard-to-detect dependencies between the execution of different tests.

    Still, if this is what you need then I'd suggest using a pretest npm script, which is run automatically when you do npm test.