Error while importing a NPM package

[onderbakirtas]

Describe the bug

Importing a module gives error, even though not using it.

Reproduction

Here is the repo link: https://github.com/onderbakirtas/bug-report

Logs

6:22:19 PM [vite] Error when evaluating SSR module C:\Users\onder\Desktop\node_apps\blog1\src\routes\index.json.js:
Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\index.js
require() of ES modules is not supported.
require() of C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\index.js from C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename index.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\package.json.

    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1080:13)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at nodeRequire (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js:73811:17)
    at ssrImport (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js:73753:20)
    at eval (C:\Users\onder\Desktop\node_apps\blog1\src\routes\index.json.js:6:37)
    at async instantiateModule (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js:73796:9)
Must use import to load ES Module: C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\index.js
require() of ES modules is not supported.
require() of C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\index.js from C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename index.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\package.json.
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)                                     s\blog1\node_modules\to-vfile\index.js
    at nodeRequire (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js:73811:17)                                                               Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js is an ES module file as
    at ssrImport (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks all .js files in that package scope as ES modules.\dep-972722fa.js:73753:20)                                                                 e "type": "module" from C:\Users\onder\Desktop\node_apps\blog1\node_modules\to-vfile\package.json.
    at eval (C:\Users\onder\Desktop\node_apps\blog1\src\routes\index.json.js:6:37)
    at async instantiateModule (C:\Users\onder\Desktop\node_apps\blog1\node_modules\vite\dist\node\chunks\dep-972722fa.js:73796:9)
Unexpected token E in JSON at position 0
SyntaxError: Unexpected token E in JSON at position 0
    at JSON.parse (<anonymous>)
    at Proxy.<anonymous> (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@svelks\dep-972722fa.js:73811:17)tejs/kit/dist/ssr.js:923:22)                                                               \dep-972722fa.js:73753:20)
    at async load (index.svelte:4:24)
    at async load_node (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@sveltest\node\chunks\dep-972722fa.js:73796:9)js/kit/dist/ssr.js:951:12)
    at async respond$1 (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@sveltejs/kit/dist/ssr.js:1235:15)
    at async render_page (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@sveltejs/kit/dist/ssr.js:923:22)tejs/kit/dist/ssr.js:1399:19)
    at async resolve (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@sveltejsjs/kit/dist/ssr.js:951:12)/kit/dist/ssr.js:1662:10)                                                                  js/kit/dist/ssr.js:1235:15)
    at async respond (file:///C:/Users/onder/Desktop/node_apps/blog1/node_modules/@sveltejstejs/kit/dist/ssr.js:1399:19)/kit/dist/ssr.js:1641:10)                                                                  /kit/dist/ssr.js:1662:10)
    at async Immediate.<anonymous> (file:///C:/Users/onder/Desktop/node_apps/blog1/node_mod/kit/dist/ssr.js:1641:10)ules/@sveltejs/kit/dist/chunks/index.js:3511:22)

System Info

System:
    OS: Windows 10 10.0.19043
    CPU: (12) x64 AMD Ryzen 5 1600 Six-Core Processor
    Memory: 8.37 GB / 15.94 GB
  Binaries:
    Node: 14.15.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.10 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 6.14.8 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1023.0), Chromium (92.0.902.84)
    Internet Explorer: 11.0.19041.906
  npmPackages:
    @sveltejs/adapter-static: ^1.0.0-next.17 => 1.0.0-next.17
    @sveltejs/kit: next => 1.0.0-next.159
    svelte: ^3.34.0 => 3.42.4

Severity

blocking all usage of SvelteKit

Additional Information

Using it like this:

import vile from 'to-vfile';

[benmccann]

it's an esm module: https://github.com/vfile/to-vfile/blob/d53c24488ca6ad1e155a04b8d918c18ebbfc3aef/package.json#L29

unfortunately vite can't handle for ssr yet, but hopefully will be fixed soon

closing as duplicate of vitejs/vite#4450

[korywka]

@benmccann please consider to update vite: vitejs/vite#5197

[benmccann]

Vite 2.7 will be released on Monday and we will update when that occurs