[QUEST] Glimmer

[jgwhite]

Objective

We want to get Prettier’s support for Ember templates up to the point where it is complete and maintainable enough to be officially released.

This quest issue was created to track the outstanding work required to meet this objective and to help volunteers coordinate to get the work done.

Contributing

The easiest way to contribute is to try Prettier’s Ember template support out in your apps and report any unwanted, incomplete, or otherwise wonky behaviour as a comment on this issue so it can be added to the quest. To do this:

$ yarn add -D prettier
$ yarn prettier '**/*.hbs' --parser glimmer

Or

$ npm i --save-dev prettier
$ npm run prettier '**/*.hbs' --parser glimmer

Then check the changes and look for stuff that makes you frown!

When you’re ready to contribute some code, identify an unowned item on the list below and leave a comment stating that you intend to work on it. We’ll tag the item with your handle. Once you have a PR that we can reference, leave another comment so we can link the item to the PR.

If you decide for whatever reason that you no longer wish to pursue the work, leave another comment and we’ll remove your handle from it. This is absolutely fine and you shouldn’t feel any regret if things don’t pan out.

Tasks

Check bugs on Prettier labeled with "lang:handlebars".

Why does this quest issue live on a fork of prettier/prettier?

We’re trying it out as an experiment so we can easily add administrators on this issue.

[rwjblue]

RE: the entity escaping, we really need to avoid the escaping all together (see prettier#4533 (comment) for more details)

[GavinJoyce]

I'm working on fixing the HTML entities here: prettier#6234

[tchak]

@jgwhite if you add me to this fork it will be easier for me to copy the source markdown to the upstream issue

[GavinJoyce]

Perhaps it would be better to just have a single quest issue? Perhaps we should just use this one as we can have multiple editors? We could link to this issue from prettier#4908

@jgwhite perhaps you could give me edit access to this issue too?

[tchak]

I just linked the main issue to this one

[dcyriller]

I've opened a PR to fix a bug: prettier is a bit eager regarding whitespaces between text and helpers prettier#6239

// Input
{{#component propA}}
    for {{propB}}  do {{propC}} f
{{/component}}

// Output (Prettier stable)
{{#component propA}}
  for{{propB}}do{{propC}}f
{{/component}}

// Output (Prettier the PR)
{{#component propA}}
  for {{propB}}  do {{propC}} f
{{/component}}

@GavinJoyce I hope it won't conflict with what your current work 😅

[Alonski]

@dcyriller Do you rely on this whitespace? I personally would like a more verbose way to specify significant whitespace. Maybe I'm wrong 😅

[jgwhite]

@dcyriller added to the tracking info description. Nice one!

Personally I’d like Prettier to behave like this:

Before:

<p>Hello   {{name}}   happy   {{age}}    birthday!</p>

<pre>
  Name: {{name}}
  Age:  {{age}}
</pre>

After:

<p>Hello {{name}} happy {{age}} birthday!</p>

<pre>
  Name: {{name}}
  Age:  {{age}}
</pre>

i.e. don’t mess with whitespace instead <pre> tags.

Edit:

Though it now occurs to me that there’d be no way for Prettier to know about components like:

<CodeBlock @format="plain">
  Name: {{name}}
  Age:  {{age}}
</CodeBlock>

[GavinJoyce]

Though it now occurs to me that there’d be no way for Prettier to know about components like:

I think we'll need to add support for {{!-- prettier-ignore --}}:

{{!-- prettier-ignore --}}
<CodeBlock @format="plain">
  Name: {{name}}
  Age:  {{age}}
</CodeBlock>

[dcyriller]

Reading your comments I understand we should have:

// Input
{{#component propA}}
    for {{propB}}  do {{propC}} f
{{/component}}

// Output (Prettier stable)
{{#component propA}}
  for{{propB}}do{{propC}}f
{{/component}}

// Output (Prettier the PR)
{{#component propA}}
  for {{propB}} do {{propC}} f
{{/component}}

I'll update my PR tomorrow to reflect that!

Also, we should implement {{!-- prettier-ignore --}} for handlebars (most probably in an other PR).

Thank you for your feedbacks!

EDIT: just saw that you opened a new PR two hours before mine @GavinJoyce 😬. So, I'll close it for now. Once yours is merged, I'll be able to rebase and open mine (if still necessary).

[GavinJoyce]

@dcyriller please feel free to land anything you like, I'm going to switch focus this weekend and try an experiment to rebuild prettier's glimmer printer from first principles. I doubt that it will come to anything, but I think it will be useful in learning prettier's internals.

[jgwhite]

@GavinJoyce I sense a future emberconf talk in the making…

@GavinJoyce I'm in the peanut gallery here, but I'm curious if there is any overlap with @rwjblue 's ember-template-recast. If anything another implementation to compare.