Mailspring/spec-nylas/tasks/task-spec.coffee
Ben Gotow 343bb3163b feat(offline-mode, undo-redo): Tasks handle network errors better and retry, undo/redo based on tasks
Summary:
This diff does a couple things:

- Undo redo with a new undo/redo store that maintains it's own queue of undo/redo tasks. This queue is separate from the TaskQueue because not all tasks should be considered for undo history! Right now just the AddRemoveTagsTask is undoable.

- NylasAPI.makeRequest now returns a promise which resolves with the result or rejects with an error. For things that still need them, there's still `success` and `error` callbacks. I also added `started:(req) ->` which allows you to get the underlying request.

- Aborting a NylasAPI request now makes it call it's error callback / promise reject.

- You can now run code after perform local has completed using this syntax:

```
    task = new AddRemoveTagsTask(focused, ['archive'], ['inbox'])
    task.waitForPerformLocal().then ->
      Actions.setFocus(collection: 'thread', item: nextFocus)
      Actions.setCursorPosition(collection: 'thread', item: nextKeyboard)
    Actions.queueTask(task)
```

- In specs, you can now use `advanceClock` to get through a Promise.then/catch/finally. Turns out it was using something low level and not using setTimeout(0).

- The TaskQueue uses promises better and defers a lot of the complexity around queueState for performLocal/performRemote to a task subclass called APITask. APITask implements "perform" and breaks it into "performLocal" and "performRemote".

- All tasks either resolve or reject. They're always removed from the queue, unless they resolve with Task.Status.Retry, which means they internally did a .catch (err) => Promise.resolve(Task.Status.Retry) and they want to be run again later.

- API tasks retry until they succeed or receive a NylasAPI.PermanentErrorCode (400,404,500), in which case they revert and finish.

- The AddRemoveTags Task can now take more than one thread! This is super cool because you can undo/redo a bulk action and also because we'll probably have a bulk tag modification API endpoint soon.

Getting undo / redo working revealed that the thread versioning system we built isn't working because the server was incrementing things by more than 1 at a time. Now we count the number of unresolved "optimistic" changes we've made to a given model, and only accept the server's version of it once the number of optimistic changes is back at zero.

Known Issues:

- AddRemoveTagsTasks aren't dependent on each other, so if you (undo/redo x lots) and then come back online, all the tasks try to add / remove all the tags at the same time. To fix this we can either allow the tasks to be merged together into a minimal set or make them block on each other.

- When Offline, you still get errors in the console for GET requests. Need to catch these and display an offline status bar.

- The metadata tasks haven't been updated yet to the new API. Wanted to get it reviewed first!

Test Plan: All the tests still pass!

Reviewers: evan

Reviewed By: evan

Differential Revision: https://phab.nylas.com/D1694
2015-07-07 13:38:53 -04:00

128 lines
4.4 KiB
CoffeeScript

Actions = require '../../src/flux/actions'
TaskQueue = require '../../src/flux/stores/task-queue'
Task = require '../../src/flux/tasks/task'
{APIError,
OfflineError,
TimeoutError} = require '../../src/flux/errors'
noop = ->
describe "Task", ->
describe "initial state", ->
it "should set up queue state with additional information about local/remote", ->
task = new Task()
expect(task.queueState).toEqual({ isProcessing : false, localError : null, localComplete : false, remoteError : null, remoteAttempts : 0, remoteComplete : false })
describe "runLocal", ->
beforeEach ->
class APITestTask extends Task
performLocal: -> Promise.resolve()
performRemote: -> Promise.resolve(Task.Status.Finished)
@task = new APITestTask()
describe "when performLocal is not complete", ->
it "should run performLocal", ->
spyOn(@task, 'performLocal').andCallThrough()
@task.runLocal()
expect(@task.performLocal).toHaveBeenCalled()
describe "when performLocal rejects", ->
beforeEach ->
spyOn(@task, 'performLocal').andCallFake =>
Promise.reject(new Error("Oh no!"))
it "should save the error to the queueState", ->
@task.runLocal().catch(noop)
advanceClock()
expect(@task.performLocal).toHaveBeenCalled()
expect(@task.queueState.localComplete).toBe(false)
expect(@task.queueState.localError.message).toBe("Oh no!")
it "should reject with the error", ->
rejection = null
runs ->
@task.runLocal().catch (err) ->
rejection = err
waitsFor ->
rejection
runs ->
expect(rejection.message).toBe("Oh no!")
describe "when performLocal resolves", ->
beforeEach ->
spyOn(@task, 'performLocal').andCallFake -> Promise.resolve('Hooray')
it "should save that performLocal is complete", ->
@task.runLocal()
advanceClock()
expect(@task.queueState.localComplete).toBe(true)
it "should save that there was no performLocal error", ->
@task.runLocal()
advanceClock()
expect(@task.queueState.localError).toBe(null)
describe "runRemote", ->
beforeEach ->
@task.queueState.localComplete = true
it "should run performRemote", ->
spyOn(@task, 'performRemote').andCallThrough()
@task.runRemote()
advanceClock()
expect(@task.performRemote).toHaveBeenCalled()
describe "when performRemote resolves", ->
beforeEach ->
spyOn(@task, 'performRemote').andCallFake ->
Promise.resolve(Task.Status.Finished)
it "should save that performRemote is complete with no errors", ->
@task.runRemote()
advanceClock()
expect(@task.performRemote).toHaveBeenCalled()
expect(@task.queueState.remoteError).toBe(null)
expect(@task.queueState.remoteComplete).toBe(true)
it "should only allow the performRemote method to return a Task.Status", ->
result = null
err = null
class OKTask extends Task
performRemote: -> Promise.resolve(Task.Status.Retry)
@ok = new OKTask()
@ok.queueState.localComplete = true
@ok.runRemote().then (r) -> result = r
advanceClock()
expect(result).toBe(Task.Status.Retry)
class BadTask extends Task
performRemote: -> Promise.resolve('lalal')
@bad = new BadTask()
@bad.queueState.localComplete = true
@bad.runRemote().catch (e) -> err = e
advanceClock()
expect(err.message).toBe('performRemote returned lalal, which is not a Task.Status')
describe "when performRemote rejects", ->
beforeEach ->
@error = new APIError("Oh no!")
spyOn(@task, 'performRemote').andCallFake => Promise.reject(@error)
it "should save the error to the queueState", ->
@task.runRemote().catch(noop)
advanceClock()
expect(@task.queueState.remoteError).toBe(@error)
it "should increment the number of attempts", ->
runs ->
@task.runRemote().catch(noop)
waitsFor ->
@task.queueState.remoteAttempts == 1
runs ->
@task.runRemote().catch(noop)
waitsFor ->
@task.queueState.remoteAttempts == 2