rollup-plugin-import-fallback

A rollup/vite plugin that allows to define a import fallback.

Install

yarn add -D rollup-plugin-import-fallback

Usage with vite

In vite.config.ts

import { defineConfig } from "vite";
import importFallback from "rollup-plugin-import-fallback";

export default defineConfig({
  plugins: [
    importFallback({
      parameterName: "fallback", // Default f
    }),
  ],
});

In your code:

import import, {
  namedImport,
} from "./a-import-that-is-not-always-defined?f=./a-fallback-import";

Typescript

You must define the correct import types in your declaration file.

declare module "./a-import-that-is-not-always-defined?f=./a-fallback-import";

Bundle size

The final bundle contains only the import that is actually used, to minimise bundle size.