./node_modules/esbuild/lib/main.d.ts Module parse failed - when building my package in a Next.js 14 app

[empz]

I'm new to library development so bear with me.

I've built a simple library meant to be used in Node >20 environments.

package.json

{
	"name": "my-package-name",
	"description": "My description",
	"version": "0.1.0-beta.2",
	"files": [
		"dist/**"
	],
	"main": "dist/index.js",
	"module": "dist/index.mjs",
	"types": "dist/index.d.ts",
	"type": "module",
	"scripts": {
		"build": "tsup",
		"test": "vitest",
		"version": "npm run build"
	},
	"dependencies": {
		"@aws-sdk/client-s3": "^3.686.0",
		"adm-zip": "^0.5.16",
		"ky": "^1.7.2",
		"zod": "^3.23.8"
	},
	"devDependencies": {
		"@biomejs/biome": "1.9.4",
		"@remotion/bundler": "^4.0.200",
		"@types/adm-zip": "^0.5.6",
		"@types/react": "^18.3.12",
		"@types/react-dom": "^18.3.1",
		"msw": "^2.6.1",
		"tsup": "^8.3.5",
		"typescript": "5.5.4",
		"vitest": "^2.1.4"
	},
	"peerDependencies": {
		"@remotion/bundler": "^4.0.200"
	},
	"engines": {
		"node": ">=20.0.0"
	}
}

tsconfig.json

{
  "compilerOptions": {
    // Enable latest features
    "lib": [
      "ES2023"
    ],
    "target": "ES2022",
    "module": "node16",
    "moduleDetection": "force",
    "jsx": "react-jsx",
    "allowJs": true,
    "outDir": "./dist",
    // Bundler mode
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    "noEmit": true,
    // Best practices
    "strict": true,
    "skipLibCheck": true,
    "noFallthroughCasesInSwitch": true,
    // Some stricter flags (disabled by default)
    "noUnusedLocals": false,
    "noUnusedParameters": false,
    "noPropertyAccessFromIndexSignature": false
  },
  "exclude": [
    "node_modules",
    "dist"
  ],
}

tsup.config.ts

import { defineConfig } from "tsup";

export default defineConfig({
  entry: ["src/index.ts"],
  format: ["cjs", "esm"], // Build for commonJS and ESmodules
  dts: true, // Generate declaration file (.d.ts)
  target: "",
  splitting: false,
  sourcemap: false,
  clean: true,
});

Running build generates 4 files in the dist/ directory:

index.cjs
index.d.cts
index.d.ts
index.js

I publish the package to npm and import it in a Next.js 14 project with Typescript.

When I try to build the Next.js project, I get the following error:

Failed to compile.

./node_modules/esbuild/lib/main.d.ts
Module parse failed: Unexpected token (1:7)
File was processed with these loaders:
 * ./node_modules/next/dist/build/webpack/loaders/next-flight-loader/index.js
 * ./node_modules/next/dist/build/webpack/loaders/next-swc-loader.js
You may need an additional loader to handle the result of these loaders.
> export type Platform = 'browser' | 'node' | 'neutral'
| export type Format = 'iife' | 'cjs' | 'esm'
| export type Loader = 'base64' | 'binary' | 'copy' | 'css' | 'dataurl' | 'default' | 'empty' | 'file' | 'js' | 'json' | 'jsx' | 'text' | 'ts' | 'tsx'

Import trace for requested module:
./node_modules/esbuild/lib/main.d.ts
./node_modules/esbuild/lib/ sync ^.*\/.*$
./node_modules/esbuild/lib/main.js
./node_modules/@remotion/bundler/dist/index.js
./node_modules/my-package-name/dist/index.js
./app/api/v4/lambda/render/route.ts

./node_modules/@remotion/bundler/dist/esbuild-loader/index.js
Self-reference dependency has unused export name: This should not happen

Import trace for requested module:
./node_modules/@remotion/bundler/dist/esbuild-loader/index.js
./node_modules/@remotion/bundler/dist/webpack-config.js
./node_modules/@remotion/bundler/dist/index.js
./node_modules/my-package-name/dist/index.js
./app/api/render/route.ts

./node_modules/@remotion/bundler/dist/fast-refresh/runtime.js
Self-reference dependency has unused export name: This should not happen

Import trace for requested module:
./node_modules/@remotion/bundler/dist/fast-refresh/runtime.js
./node_modules/@remotion/bundler/dist/webpack-config.js
./node_modules/@remotion/bundler/dist/index.js
./node_modules/my-package-name/dist/index.js
./app/api/render/route.ts


> Build failed because of webpack errors

The @remotion/bundler package itself is a peer dependency of my library. Not sure if that's related to the issue in question.

Any ideas?

[empz]

Nothing to do with tsup.