Rollback

Whenever the Task itself failed or its subtasks have failed, rollback will revert anything that needs to be reverted by that uncompleted action. Rollback will only execute if the task itself has been marked as failed and can be defined as the rollback property of a task.

Since when you return a new Listr as a subtask list, it is not the easiest, and most convenient to do something on failure, and each subtask should be handled separately. But this can still be used for singular tasks where some action needs to be reverted if the task does not complete.

v3.3.0 #257

Example

You can find the related examples here.

Usage

For Subtask

import { delay, Listr } from 'listr2'

const tasks = new Listr(
  [
    {
      title: 'Something with rollback.',
      task: (_, task): Listr =>
        task.newListr(
          [
            {
              title: 'This task will fail.',
              task: async (): Promise<void> => {
                await delay(2000)
                throw new Error('This task failed after 2 seconds.')
              }
            },
            {
              title: 'This task will execute.',
              task: (_, task): void => {
                task.title = 'I will change my title if this executes.'
              }
            }
          ],
          { exitOnError: true }
        ),
      rollback: async (_, task): Promise<void> => {
        task.title = 'I am trying to rollback stuff, previous action failed.'

        await delay(1000)

        task.title = 'Doing something other than this.'

        await delay(1000)

        task.title = 'Some actions required rollback stuff.'
      }
    }
  ],
  {
    concurrent: false,
    exitOnError: true
  }
)

await tasks.run()

Options

Rollback, when it fails by default, throws an exception and stops the execution of the upcoming tasks. But this can be overwritten by { exitAfterRollback: false } option. This is the main Listr option that acts independently of exitOnError since failing the rollback might have worse consequences.

Renderer

DefaultRenderer

When rollback is activated the default renderer will change the spinner color to bright red, if the rollback successfully concludes then it will be a redback arrow, else it would be like a normal error where it will show the error from the rollback action itself.