Transpiling error in Ember 4 without embroider

[BryanCrotaz]

The below only happens when not using embroider.

Line 352 of radar.js

    assert('Must provide a `estimateHeight` value to vertical-collection', estimateHeight !== null);

is being transpiled to

      (!(estimateHeight !== null) && Ember.assert('Must provide a `estimateHeight` value to vertical-collection', estimateHeight !== null));

This causes the error Ember is not defined

package.json

[BryanCrotaz]

Can reproduce with a new app:

ember new test-transpile --yarn
cd test-transpile
yarn
ember install @html-next/vertical-collection
ember g controller application
ember s

In application controller:

get items() {
  return ['a', 'b'];
}

In application template:

<VerticalCollection @items={{this.items}} as |item|>
  <div>{{item}}</div>
</VerticalCollection>

> ember --version
ember-cli: 4.8.0
node: 14.20.0
os: darwin x64

[BryanCrotaz]

Reproduction at
https://github.com/BryanCrotaz/vertical-collection-transpile-bug

[ef4]

I found the problem. vertical-collection's customized rollup-based build is not compatible with ember 4, because it uses compileModules: false here:

vertical-collection/index.js

Line 73 in f8ba113

compileModules: false,

But in ember-cli-babel, that forces you into globals mode, meaning import { assert } from '@ember/debug' gets compiled to Ember.assert(), which doesn't exist anymore starting at Ember 4. See:

https://github.com/babel/ember-cli-babel/blob/3ce768ada9202c0455f87511ab95acf667d0c97e/lib/babel-options-util.js#L94-L98

The comment there suggests you can set disableDebugTooling to true to stop this behavior.

But really vertical-collection should absolutely just delete all this custom build code.

The reason it works on Embroider is that Embroider already ships with a compatibility rule that completely ignores vertical-collection's custom build, because that build is fragile and locked into the classic ember-cli 3.x way of doing things:

https://github.com/embroider-build/embroider/blob/d31bee3c8fafdea6308b80642b5e56971cfd0caa/packages/compat/src/compat-adapters/%40html-next/vertical-collection.ts