Make templateExportDefault default to true #352
Description
I don't think making removing export defaults the out-of-box behavior is the right way to go. In gjs files where there are no imports or other code, I think omitting the export default does make sense so it looks like "just HTML":
<template>
Hello world
</template>That's nice and clean! However, if there is other code in the file, especially other exports, I think it's confusing:
import { State } from '../utils/state.js';
export function createStateForComponent(data) {
return new State(data, 'component1');
}
<template>
{{@state.output}}
</template>Now we have a mix of standard ES module syntax and...weird magic where there's no default export but somehow there is, and readers of the file just have to know that <template> tags are special-cased.
Moreover, it's pretty common (at least for me) to implement "private" components in gjs/gts files, e.g.
const Message = <template>
<div>
<span class="bold">{{@label}}:</span>
{{@text}}
</div>
</template>
<template>
{{#each @messages as |msg|}}
<Message @label={{msg.label}} @text={{msg.text}} />
{{/each}}
</template>So now readers have to know that <template> tags that are assigned to variables don't get exported, but the ones that aren't become the default export. Oh, and if you realize that you need a component class wrapping your template you have to add the export default. Oh, and if you have two "bare" <template> tags in a single file, it's an error even though it's not really evident why.
One of my favorite things about template tags is that template-only components become "regular values" like anything else that can be assigned to variables, passed to functions, etc etc. Once users adopt that mental model, I think it really starts unlocking the potential of low-overhead component composition, code organization, etc that template tags provide. So I really think that for consistency, clarity, and learning, our default happy-path should be that they follow ES module semantics as well and don't represent an exception.
If folks agree that this makes sense, I'm happy to open a PR.