useNewTransformation Feedback Thread

We introduced a new transformation which powers the Svelte intellisense under the hood. The goal is to get rid of a tsx-style transformation and simplify transformations along the way.

Advantages for users:

• no messing with projects who use JSX for some other reason and then have conflicting JSX definitions (#1256, #1149)
• better type inference in some cases, for example around svelte:component

Internal advantages:

• TS control flow easier to keep flowing
• overall easier transformations of Svelte specific syntax like await, each etc.

You can try out the new transformation using

• “Svelte for VS Code” version 105.11.1 and setting svelte.plugin.svelte.useNewTransformation to true
• svelte-check version 2.4.0 with the --use-new-transformation flag.

Please provide feedback in here about any improvements or regressions.

[dummdidumm]

Thanks @ignatiusmb, @rgossiaux and @kevin-legion for the feedback!

• The “is this a valid component” check should be better now, fixing the case @ignatiusmb mentioned and also hopefully makes it more clear that the error reported by @rgossiaux and @kevin-legion are actually usage errors - you need to pass a component constructor type, not the instance type (component: new ({target: any, props: any}) => YourComponent or component: typeof YourComponent instead of component: YourComponent)
• The #each bug should be fixed

[dummdidumm]

Thanks @sw-yx and @ignatiusmb ! Both issues are hopefully fixed with the latest version.