oclif hook prompt test

[jspruance]

I'm having a hard time writing a unit test for a prompt inside an oclif hook. Is there any additional documentation or samples for this library that would cover this scenario? Thanks!

See:
https://stackoverflow.com/questions/56797392/oclif-prompt-testing

[AlbertoMata]

I have found a way to test multiple calls to ux.prompt, no extra libraries needed aside from the default @oclif/core (which is actually an extension of fancy-test):

Let's suppose we have a single-command-cli Hello, then our src/index.ts file would look like this:

import {Command, Flags, ux} from '@oclif/core'

export default class Hello extends Command {
  static description = 'describe the command here'

  static examples = [
    `$ myplugin hello
hello world from ./src/hello.ts!
`,
  ]

  static flags = {
    help: Flags.help({char: 'h'}),
    // add --version flag to show CLI version
    version: Flags.version({char: 'v'}),
  }

  interactive = async () => {
    const object = {
      email: '',
      name: '',
      phone: '',
    }

    const name = await ux.prompt('What is your name?')
    const email = await ux.prompt('What is your email?')
    const phone = await ux.prompt('What is your phone number?')

    object.name = name
    object.email = email
    object.phone = phone

    return object
  }

  async run(): Promise<void> {
    const object = await this.interactive()

    console.log(`Hello ${object.name}!`)
    console.log(`Your email is ${object.email}`)
    console.log(`Your phone number is ${object.phone}`)
  }
}

Our test/index.test.tes file will look like this:

import {ux} from '@oclif/core'
import {expect, test} from '@oclif/test'

import Hello from '../src/index'

const promptStub = (stub) => {
  stub.onFirstCall().resolves('John Doe') // Alias for stub.onCall(0).resolves('John Doe')
  stub.onSecondCall().resolves('[email protected]') // Alias for stub.onCall(1).resolves('[email protected]') 
  stub.onThirdCall().resolves('123-456-7890') // Alias for stub.onCall(2).resolves('123-456-7890')
  return stub
}

describe('basic usage', () => {
  test
    .stdout({print: true})
    .stub(ux, 'prompt', promptStub)
    .do(() => Hello.run([]))
    .it('runs hello', (ctx) => {
      expect(ctx.stdout).to.contain('Hello John Doe!')
      expect(ctx.stdout).to.contain('Your email is [email protected]')
      expect(ctx.stdout).to.contain('Your phone number is 123-456-7890')
    })
})

We need understand that stub is part of the Sinon.JS library, and that we can use some of the stub features in our oclif tests. Data types are specially important if we are using TypeScript.

In addition, to test multiple-command-cli's just replace .do(() => Hello.run([])) with the regular .command() calls.