Error: Unexpected token when including a file with `declare namespace` in it.

[Tobias S]

Hi microbundle team.

I'm trying to build a package, and I've needed to override some types since the types repo for the main dependency hasn't been updated.
I was on 0.14.x before, but I updated to 0.15.1 and I still get this error.

$ microbundle --jsx React.createElement --tsconfig tsconfig.build.json
Error: Unexpected token (Note that you need plugins to import files that are not JavaScript)

at /Users/user/Documents/osd-react-renderer/packages/renderer/src/types/OpenSeadragonV5.d.ts:3:8

1: /* eslint-disable max-classes-per-file */
2: 
3: declare namespace OpenSeadragon {
           ^
4:     export function isFunction(obj: unknown): boolean;

I actually had two errors in this file. The first error said:

osd-react-renderer: (babel plugin) SyntaxError: /Users/user/Documents/osd-react-renderer/packages/renderer/src/types/OpenSeadragonV5.d.ts: Missing semicolon. (3:7)
osd-react-renderer:   1 | /* eslint-disable max-classes-per-file */
osd-react-renderer:   2 |
osd-react-renderer: > 3 | declare namespace OpenSeadragon {
osd-react-renderer:     |        ^
osd-react-renderer:   4 |     export function isFunction(obj: unknown): boolean;
osd-react-renderer:   5 |
osd-react-renderer:   6 |     export function isCanvasTainted(canvas: HTMLCanvasElement): boolean;
osd-react-renderer: at undefined:3:7

This error I was able to resolve with a .babelrc.json file, but I can't see what configuration can be used to resolve the first error.

I noticed that previously we were able to build the app when we used declare module OpenSeadragonV2, but declare namespace` specifically is causing this.

Any suggestions on what configuration can resolve this issue?

Thanks

[Tobias S]

btw the TSConfig it's using looks like this:

{
  "extends": "../../tsconfig.build.json",
  "compilerOptions": {
    "incremental": true,
    "target": "ESNext",
    "module": "ESNext",
    "outDir": "./dist",
    "rootDir": "./src",
    "baseUrl": ".",
    "jsx": "react",
    "lib": ["DOM", "ESNext"],
    "composite": true,
    "declaration": true,
    "typeRoots": ["./node_modules/@types", "./src/@types", "./src/types"]
  },
  "include": ["src/**/*"],
  "references": []
}

and the extended file looks like this:

{
  "extends": "./tsconfig.base.json",
  "compilerOptions": {
    "noEmit": false,
    "noEmitOnError": true
  }
}

[Ryan Christian]

A reproduction would be helpful, are you using microbundle or microbundle-crl? This sounds like an issue the latter would cause.

[Tobias S]

We're just using microbundle. I can try to put a repro repository together if that will help.

[Ryan Christian]

A repro is always helpful and almost always necessary.

I can't reproduce so will definitely need a minimal reproduction. Babel shouldn't be running against .d.ts files at all, not quite sure how you've done that.

[Tobias S]

I tried to reproduce it in another project but it hasn't happened yet :S

[Tobias S]

What's more, I removed the babelrc file from the actual project, and it built as normal. I'll fiddle with it a bit more and see if it breaks again, and if not... false alarm 😅

[Ryan Christian]

No worries, feel free to ping if/when you do find something out.

One thing that might be worth trying is uninstalling & reinstalling microbundle into your project. Sometimes transitive deps (dependencies of dependencies) get stuck on odd & bugged versions, reinstalling tends to fix that.

[Tobias S]

It might also be that it was getting stuck on this babel issue with 0.14.x, and then by upgrading, it went away but the .babelrc file was then causing the other issue to remain. Hmm...