[TypeScript] Module resolution doesn't work in rollup.config.ts when using modern project settings

[jdharrisnz]

• Rollup Plugin Name: @rollup/plugin-typescript
• Rollup Plugin Version: 11.1.6
• Rollup Version: 4.9.4
• Operating System (or Browser): macOS
• Node Version: 21.5.0
• Link to reproduction: https://replit.com/@jdharrisnz/rollup-plugin-repro-typescript-import

Expected Behavior

Compile as usual. Use npm run bug in my repl to see what happens.

Actual Behavior

Produces errors when compiling:

npx rollup --config rollup.config.ts --configPlugin typescript
loaded rollup.config.ts with warnings
(!) Plugin typescript: @rollup/plugin-typescript TS2349: This expression is not callable.
  Type 'typeof import("/home/runner/rollup-plugin-repro-typescript-import/node_modules/@rollup/plugin-typescript/types/index")' has no call signatures.

Additional Information

Key ingredients are:

• "type": "module" in package.json
• "moduleResolution": "NodeNext" or "Node16" in tsconfig.json
• A rollup config file written in ESM format and TypeScript

The workaround is to use a JavaScript config file, so this is really the smallest of inconveniences, but it's something to fix nonetheless.

[07akioni]

Same issue encountered.

[thisisanto]

Alternatively

// @ts-expect-error see https://github.com/rollup/plugins/issues/1662
commonjs(),

Which again isn't nice, but allows you to keep using a TS config file.

[Arnesfield]

Might be off-topic, but here is another workaround to keep the typings:

// rollup.config.ts
import _eslint from '@rollup/plugin-eslint';
import _typescript from '@rollup/plugin-typescript';

// NOTE: remove once import errors are fixed for their respective packages
const eslint = _eslint as unknown as typeof _eslint.default;
const typescript = _typescript as unknown as typeof _typescript.default;

// ...
export default {
  // ...
  plugins: [eslint(), typescript()]
};

[Silic0nS0ldier]

This issue sounds like microsoft/TypeScript#58890

The cause appears to be related to how TypeScript classifies imports. microsoft/TypeScript#58890 (comment) concluded that if the .d.ts file is in a CJS scope, the import will be treated CJS.

In the case of @rollup/plugin-commonjs the types live at types/index.d.ts which is outside the ESM scope (dist/es/).

This issue is fixable, but it will mean duplicating .d.ts in the published package.

EDIT: This also affects @rollup/plugin-json, and likely any other plugin in this collection that uses default exports.

[cowwoc]

@Arnesfield's workaround failed for me with the following error:

@rollup/plugin-typescript TS2339: Property 'default' does not exist on type '(options?: RollupCommonJSOptions | undefined) => Plugin<any>'.

I had to specify the type explicitly for it to work. In the case of rollupCommonJs the options (RollupCommonJSOptions) are not exported, so you can map them to unknown instead:

import _rollupCommonJs from "@rollup/plugin-commonjs";
import _rollupTypescript, {type RollupTypescriptOptions} from "@rollup/plugin-typescript";

const rollupCommonJs = _rollupCommonJs as unknown as (options?: unknown) => Plugin;
const rollupTypescript = _rollupTypescript as unknown as (options?: RollupTypescriptOptions) => Plugin;

I hope this helps.

[Mister-Hope]

Interested to find out that no one pick this, I believe at least some of the maintainer should leave a message guiding us a expected solution to fix this.

For me, I would prefer to add type: module in package.json directly, this can still remain these packages to be a valid cjs/esm dual packages.

[brandongit2]

@Silic0nS0ldier Your answer is almost correct, but there is a singular solution to this problem.

package.json:

{
    "name": "@rollup/plugin-typescript",
    "exports": {
        "import": {
            "types": "./types/index.d.mts",
            "default": "./dist/es/index.js"
        },
        "require": {
            "types": "./types/index.d.ts",
            "default": "./dist/cjs/index.js"
        }
    }
}

This would require creating a new index.d.mts declaration file, which I believe (but need to confirm) can just be a symlink to the existing index.d.ts file.

---

Update: It looks like there's already a PR open which does exactly this: #1782

Just need to wait for a test fix and a merge!

[stale]

Hey folks. This issue hasn't received any traction for 60 days, so we're going to close this for housekeeping. If this is still an ongoing issue, please do consider contributing a Pull Request to resolve it. Further discussion is always welcome even with the issue closed. If anything actionable is posted in the comments, we'll consider reopening it. ⓘ

[Mister-Hope]

.

[stale]

Hey folks. This issue hasn't received any traction for 60 days, so we're going to close this for housekeeping. If this is still an ongoing issue, please do consider contributing a Pull Request to resolve it. Further discussion is always welcome even with the issue closed. If anything actionable is posted in the comments, we'll consider reopening it. ⓘ

[AverageHelper]

apparently #1782 is meant to help with this? @Stale please consider reopening...