Support template-only-glimmer-components optional feature

[karellm]

I was playing with Ember 3.1 and saw a move from innerHTML to outerHTML (see here). From my quick tests, it doesn't seem to play nice with ember-css-modules.

[karellm]

Discard this, I had a problem with my configuration.

[dfreeman]

@karellm It actually wouldn't surprise me at all if ECM doesn't work with that feature turned on (or, more likely, if it interferes with that feature because of this logic).

If it is a problem, I'm not positive we'll be able to fix it until module unification lands, but I'll keep an eye on things. Please let me know if you run into any issues!

[karellm]

@dfreeman Thanks for taking the time to check this. local-class still works ok for me. At first I was using class which doesn't work. I will keep experimenting with this and definitely reopen this if I find blocking things.

[mswanson]

It appears this bug should be reopened. I just did some testing with a basic Ember 3.1-beta.5 app. Removing the application template wrapper appears to work just fine, but template-only components silently fail and the wrapper div is still present in the DOM (see screenshot)

I am using the latest 3.1 beta versions of ember and ember-cli

ember-cli: 3.1.0-beta.1
node: 9.5.0
os: darwin x64

Steps to reproduce

1. Installed the latest ember-cli beta yarn global upgrade ember-cli#3.1.0-beta.1
2. ember install @ember/optional-features
3. ember feature:disable application-template-wrapper
4. ember feature:enable template-only-glimmer-components
5. ember g component my-component
6. deleted app/components/my-component.js

[dfreeman]

Yep, that's the issue I was expecting to see—thanks for confirming @mswanson!

The short version is that ECM relies on having a component class defined, so it does the equivalent of creating a component.js for you in order to make the local styles work. And that, clearly, gets in the way of the template-only-glimmer-components feature 🙂

I'll reopen this, but I may not have a chance to investigate what the options are in the near future. If anyone's interested in taking a look, though, I'm happy to point you toward what I do know!

[mswanson]

@dfreeman I can try to take a look. I am expecting my first kid in the next few weeks so i'm not gonna be sleeping anyway! 😄

[dfreeman]

@mswanson Sorry, I totally lost track of this issue — I hope parenthood is treating you well! If you do find yourself with some spare time at some point, feel free to ping me here or in Slack and I can talk you through what I know.