Typescript preset does nothing in current REPL beta

[simonbuchan]

Bug Report

Current Behavior

The typescript preset in the repl since 7.0.0-beta.48 doesn't enable any plugins, leading to syntax errors on any typescript syntax.

Input Code

• Working on beta.47
• Broken on beta.48

Note the UI shows a version behind due to #6174 - is something still holding up #7039?

Searching for and enabling (the second?) syntax-typescript allows parsing again, so it's something about the preset, not the plugins being broken or something.

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[loganfsmyth]

This is pending babel/website#1666 because the filename is currently hard-coded to "repl", so the presets doesn't see it as a .ts file.

[loganfsmyth]

This was a change from https://github.com/babel/babel/pull/7955/files#diff-a31d321b4911bbbc31e1d19a726637c6R30 so that Babel differentiates .js, .ts, and .tsx.

[simonbuchan]

Alternative fix is to provide allExtensions: true in the preset (and presumably isTSX: true if react is provided, though I assume that just also enables syntax-jsx?)

#7955 seems a little odd to force this, since you could use overrides for the same behavior (though, obviously for more work)

[loganfsmyth]

We could, but the more we do stuff like that, the more the REPL diverges from what users would actually see in their own project, which I'd rather avoid.

What specifically makes that PR seem odd?

[simonbuchan]

Right, that makes sense, though the UX about switching to typescript seems like it would be tricky to get feeling right.

Sorry, probably "surprising" is a better term? I just didn't expect plugins to have the power to apply presets per file, so it seems a little magic coming from babel 6. From the tsc side, it makes perfect sense, and means it's much easier to migrate and set up.

[loganfsmyth]

Sorry, probably "surprising" is a better term?

Fair!

I just didn't expect plugins to have the power to apply presets per file

Yeah, it's all relatively new, but where we're ending up is that presets are allowed to set configuration like that, but plugins don't have nearly as much access to that kind of thing.

[ghost]

@loganfsmyth
Are you talking about https://babeljs.io/repl ? I really have no clue how to enable typescript support there

[danez]

Closing as this is website related and there is already discussion in the linked PR.

[JLHwung]

It is now fixed.