Add examples on how to test trackedFunction

[Christian Sánchez]

Hi, I have the following trackedFunction to populate a table (using ember-headless-table) and also I'm using Supabase to fetch the data, so in my "Table" component I have the following :

  request = trackedFunction(this, async () => {
    const { data, count, error } = await this.supabase.client
      .from('table')
      .select('*', { count: 'exact' })
      .range(this.start, this.end);

    return data;
  });

this.start and this.end are @tracked variables, so each time they change the function is triggered, that work as expected.

The issue I have is on a simple Integration test for this component:

await render(hbs`<TableComponent />`);

will trigger the request to Supabase, which throws an error because it need the Supabase env variables (url, key, etc).

Is there a way to prevent trackedFunction from executing the API request on the tests?

[NullVoxPopuli]

resources aren't mockable or anything like that -- their behaviors are private to their consumers, much like the router, or component rendering is a private detail. There are options though!

What I wrote before

there is not -- the thing you'd want to mock here is the supabase client -- is that a service?

if not, you'd probably want to make it one, like:

// app/services/tables.js
import Service from '@ember/service';


export default Tables extends Service {
  // methods here
  allExact(start, end) { /* ... */ }
}

This does restrict the amount of flexibility you have in your component, but it allows you to, in your test do:

const myMockData = [];
this.owner.register('service:tables', class extends {
   allExact(start, end) { 
      return myMockData;
    }
});

Supabase has enough fluent-builder-API, that I would hope for a test-mode, or some way to hook it up to MSW

using MSW is a great way to keep your data as-is, not do any services, and have as-real-as-it-gets mocking in your app

I have a demo on how to set up MSW for testing in these commits: https://github.com/NullVoxPopuli/ember-msw-development/commits/main

And in this repo: https://github.com/NullVoxPopuli/ember-data-resources/blob/main/tests/unit/find-all-test.ts#L16

[Christian Sánchez]

I see, in. my case I have a supabase service, so probably the best solution is to mock it, thanks for the suggestion!
Should I close this ticket then?

[NullVoxPopuli]

I can, no worries - glad you have a path forward!