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`import {readFile} from 'fs/promises';` ESM syntax fails trying to import from a file

See original GitHub issue

Describe the bug A page component that imports promisified fs methods like this

<script context="module">
    import {readFile} from 'fs/promises';
</script>

…fails with the error Failed to resolve import "fs/promises" from "index.svelte". Does the file exist?:

Stacktrace

500
Failed to resolve import "fs/promises" from "index.svelte". Does the file exist?

Error: Failed to resolve import "fs/promises" from "index.svelte". Does the file exist?
    at formatError (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:44070:46)
    at TransformContext.error (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:44066:19)
    at normalizeUrl (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:68952:26)
    at async TransformContext.transform (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:69080:57)
    at async Object.transform (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:44268:30)
    at async transformRequest (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:58540:29)
    at async instantiateModule (/app/server/node_modules/vite/dist/node/chunks/dep-e9a16784.js:68145:10)

Information about your SvelteKit Installation:

Diagnostics

The output of npx envinfo --system --npmPackages svelte,@sveltejs/kit,@sveltejs/adapter-node,@sveltejs/adapter-static,@sveltejs/adapter-begin,@sveltejs/adapter-netlify,@sveltejs/adapter-vercel vite --binaries --browsers

  System:
    OS: Linux 5.10 Alpine Linux
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 2.36 GB / 7.77 GB
    Container: Yes
    Shell: 1.31.1 - /bin/ash
  Binaries:
    Node: 14.17.0 - /usr/local/bin/node
    Yarn: 1.22.5 - /usr/local/bin/yarn
    npm: 6.14.13 - /usr/local/bin/npm
  npmPackages:
    @sveltejs/adapter-node: next => 1.0.0-next.24
    @sveltejs/kit: ^1.0.0-next.115 => 1.0.0-next.115
    svelte: ^3.38.2 => 3.38.2

Severity I can work around this like so:

<script context="module">
    import {promises as fsPromises} from 'fs';
    const {readFile} = fsPromises;
</script>

Issue Analytics

State:
Created 2 years ago
Reactions:6
Comments:10 (7 by maintainers)

Top GitHub Comments

2reactions

mdynnlcommented, Jun 18, 2021

A repro-repo is probably not necessary. Just a fresh svelte-kit + node v16.3.0 and an endpoint with import fs from 'fs/promises'; console.log(fs) is enough. But for the sake of repro. Here’s the repro-repo => https://github.com/mdynnl/svelte-kit-issue-1689

1reaction

raythurnevoidcommented, Jul 23, 2021

I’m quite sure this is an issue caused by the fact that Vite uses this package to determine built-in node modules: https://github.com/sindresorhus/builtin-modules I’ve opened two issues about this: https://github.com/sindresorhus/builtin-modules/issues/12, https://github.com/vitejs/vite/issues/4037

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