Error "@computed can only be used on accessors or fields..." using task decorator with modifiers

[davideferre]

Writing code like explained in the tutorial "Version 3: Preventing Concurrency (with Tasks)" throws an exception:

Error: Assertion Failed: @computed can only be used on accessors or fields, attempted to use it with seriesAddTask but that was a method. Try converting it to a getter (e.g. get seriesAddTask() {})

My code is:

import { task } from 'ember-concurrency';
....
@task({ drop: true })
    *seriesAddTask() {
        ....
    }

I'm using ember-concurrency 2.0.3.

Writing it in this other way works fine:

@(task(function* () {
    ....
}).drop()) seriesAddTask;

[maxfierke]

It sounds like you're maybe on an Ember version lower than 3.10? You may need to do this instead:

@task({ drop: true })
seriesAddTask = function*() {
   // ...
}

[davideferre]

It sounds like you're maybe on an Ember version lower than 3.10? You may need to do this instead:

@task({ drop: true })
seriesAddTask = function*() {
   // ...
}

No, I'm on ember 3.25...

[maxfierke]

No, I'm on ember 3.25...

@task only uses computed for Ember versions below 3.10 or on ember-concurrency 1.x. My next guess is that something else in your app is probably loading an earlier version of ember-concurrency, and not ember-concurrency 2.x. yarn why ember-concurrency is a good way to find out what other versions of ember-concurrency might be present, if you're using Yarn.

[davideferre]

I'm using npm but you have found the problem!

├── ember-concurrency@2.0.3 └─┬ ember-google-maps@3.3.0 └── ember-concurrency@1.3.0

There's a way to solve the problem without uninstalling ember-google-maps?

[maxfierke]

With yarn, you can force it with resolutions. Not sure if there's an npm equivalent? Otherwise, you may need to contact the upstream author to relax the dependency range or have them push a new version with v2 support.

[davideferre]

With yarn, you can force it with resolutions. Not sure if there's an npm equivalent? Otherwise, you may need to contact the upstream author to relax the dependency range or have them push a new version with v2 support.

Ok, thank you so much!