Transpilation issue with this remaining in function args

[Techn1x]

I have a GTS file like the following;

function someFunction(this: SomeContext, data: Row[]) {
  const filter = this.filter
  return data.map(...)
}

class extends Component<Signature> {
  get something() {
    someFunction.call(this.args.someOtherContext, this.rows)
  }

  <template>
    {{#each this.something as |row|}}
      ...
    {{/each}}
  </template>
}

It's a contrived example, but the point is there's the someFunction function in the GTS file that has this: SomeContext intended to be a type hint, to be transpiled away.

When debugging the code in browser, I can see that it is present as a real arg.

(I also checked the source without sourcemaps, and can see this1 is still present in the args)

This means the actual named argument data becomes undefined in the function.

Some findings;

• This was not an issue in the original TS file - it was only once the file was converted to GTS
• The application does not have ember-cli-typescript installed - but installing it makes no difference to the output.

[backspace]

I’m seeing this too in this PR to update to 4.1.1. We have tests that use an extended this, they are unable to access the QUnit assert as it is undefined.

It shows up in tests as a failed call to a custom assertion.

[NullVoxPopuli]

Have you also updated:

• ember-cli-babel (at least 8.2)
• babel-plugin-ember-template-compilation (should be at least 2.2.5 in your lockfile)
• @embroider/compat (at least updated in the last couple weeks)
• @emmroider/core (same)
• ember-auto-import

?

V4 of ember-template-imports requires newer babel transpilation settings, provided by the above packages (embroider not required if you aren't using it, fwiw)

[backspace]

Thanks, should these be mentioned here? I do see it here.

I updated each of these in a series of commits (babel-plugin-ember-template-compilation seemed to need to happen with the Embroider updates) and sadly the problem remained.

However I looked for other tests that used a custom test context because I was sure we had them in .gts files and found that they were using a different style:

  test<TestContextWithSave>('can create new card-instance file in local realm with card type from same realm', async function (assert) {

I changed the tests to follow that pattern and the problem went away. (Some tests are still failing but seemingly not due to this problem.) Maybe this is more of a workaround than a true fix, but it’s worth trying?

[ef4]

This bug is covered by embroider-build/content-tag#71

[NullVoxPopuli]

should be fixed now