TypeScript: sapper dev crashes on syntax errors

[plashenkov]

As @benmccann noted in his comment #760 (comment) it's better to report TypeScript-related bugs as a new issues, so...

I've found that when using TypeScript with Sapper, sapper dev crashes when some mistakes/errors appear in source files.
It works correctly in JS mode.

Here is the example: https://take.ms/i9Ntm
(this example is taken from this template: https://github.com/babichjacob/sapper-typescript-graphql-template)

[nikibreg]

I think that's generally the expected behaviour of TypeScript.

[plashenkov]

It's okay for TypeScript transpiler to "crash" on syntax errors. As well as ES* transpiler. But dev server shouldn't crash when you do some accidental mistakes. It's developer unfriendly. You just type something incorrect, then your IDE or editor autosaves this, and dev server crashes, and you have to manually restart it. That's not OK.

[benmccann]

Thanks for taking the time to file this and providing a way to reproduce. I took a look at this and it also happens with https://github.com/sveltejs/template after running node scripts/setupTypeScript.js, so this is a bug with @rollup/plugin-typescript because it doesn't happen with rollup-plugin-typescript2

[benmccann]

I've done ahead and filed an issue over in the plugin repo: rollup/plugins#542

[plashenkov]

Great, thank you!