Solve ts related double setComponentTemplate

[NullVoxPopuli]

Depends on: #1126
(Only because my reproduction repos cover both TS and template-only)

Reproduction repo: https://github.com/NullVoxPopuli/ember-addon-v2-typescript-demo/

This PR aims to solve the problem discovered here: #1099
Where prior to the changes in this PR, component output for TS files (using rollup-plugin-ts) included two setComponentTemplate calls, such as:

❯ cat dist/components/demo/index.js
import { setComponentTemplate } from '@ember/component';
import { hbs } from 'ember-cli-htmlbars';
import { __decorate } from 'tslib';
import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';

var TEMPLATE = setComponentTemplate(TEMPLATE, hbs`Hello there!

<out>{{this.active}}</out>

<button {{on 'click' this.flip}}>
  flip
</button>
`);

class Demo extends Component {
  constructor(...args) {
    super(...args);
    this.active = false;

    this.flip = () => this.active = !this.active;
  }

}

__decorate([tracked], Demo.prototype, "active", void 0);

setComponentTemplate(TEMPLATE, Demo);

export { Demo as default };
//# sourceMappingURL=index.js.map

The line that has:

var TEMPLATE = setComponentTemplate(TEMPLATE, hbs`Hello there!

erroneously has setComponentTemplate doing a self-reference, which wouldn't cause a an error during app boot, but would cause additional boot time for apps (the less to do during boot the bett)

[SergeAstapov]

@NullVoxPopuli am I missing something or looks like this does not actually solve the problem with double setComponentTemplate call?

[NullVoxPopuli]

Correct. The diff is goofy becauso the upsteam PR that handles template only components hass't been merged

[NullVoxPopuli]

It looks like the latest changes to how co-located templates and template-only components are handled fixed this! yay!

There is another issue I ran in to at runtime about ember-cli-htmlbars not being found -- so I'm going to start with other PR with a failing test for that (if I can get a reproduction figured out)