Using node ESM modules

[vonstring]

Is it possible at all to use ESM modules that use the node runtime? (e.g. tempy)

The approaches mentioned in the troubleshooting section fail in different ways, and I even tried exporting the import() function which made the entire CEP process crash.

Using import syntax with tempy, building fails with:

"promisify" is not exported by "__vite-browser-external", imported by "node_modules/tempy/index.js".
file: /Users/krhah771/code/esmtest/node_modules/tempy/index.js:5:8
3: import path from 'node:path';
4: import stream from 'node:stream';
5: import {promisify} from 'node:util';
           ^
6: import uniqueString from 'unique-string';
7: import tempDir from 'temp-dir';
error during build:
RollupError: "promisify" is not exported by "__vite-browser-external", imported by "node_modules/tempy/index.js".
    at error (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:2095:30)
    at Module.error (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13145:16)
    at Module.traceVariable (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13530:29)
    at ModuleScope.findVariable (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:12009:39)
    at Identifier.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:7921:40)
    at CallExpression.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:5716:23)
    at CallExpression.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:9458:15)
    at VariableDeclarator.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:5716:23)
    at VariableDeclaration.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:5712:28)
    at Program.bind (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:5712:28)
    at Module.bindReferences (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13141:18)
    at Graph.sortModules (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:24480:20)
    at Graph.build (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:24364:14)
    at async file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:25376:13
    at async catchUnfinishedHookActions (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:24534:20)
    at async rollupInternal (file:///Users/krhah771/code/esmtest/node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:25371:5)
    at async build (file:///Users/krhah771/code/esmtest/node_modules/vite/dist/node/chunks/dep-ca21228b.js:44664:18)
    at async CAC.<anonymous> (file:///Users/krhah771/code/esmtest/node_modules/vite/dist/node/cli.js:813:9)

Using request syntax, the panel throws up this:

Uncaught Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/krhah771/code/esmtest/dist/cep/node_modules/tempy/index.js
require() of ES modules is not supported.
require() of /Users/krhah771/code/esmtest/dist/cep/node_modules/tempy/index.js from /main/index.html 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 /Users/krhah771/code/esmtest/dist/cep/node_modules/tempy/package.json.

    at __node_internal_captureLargerStackTrace (node:internal/errors:415:5)
    at __node_internal_addCodeToName (node:internal/errors:168:9)
    at new NodeError (node:internal/errors:329:5)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1138:13)
    at Module.load (node:internal/modules/cjs/loader:995:32)
    at Function.Module._load (node:internal/modules/cjs/loader:836:14)
    at Module.require (node:internal/modules/cjs/loader:1019:19)
    at require (node:internal/modules/cjs/helpers:92:18)
    at http://localhost:3000/main/main.tsx:27:15

[justintaylor-dev]

I'm not sure that ESM Node.js modules will be compatible with Bolt since Vite will try and bundle anything using import and Node.js modules can't be bundled.

Most Node.js packages will ship with CJS bindings, but it looks like tempy does not. There may be a way to pull it off in the Vite config through resolve aliases.

I would say the easiest solution for this specific use case would be to simply use Node.js' built-in os.tempdir() function.

[vonstring]

Okay, thanks for clarifying, and for the suggetions!

[justintaylor-dev]

Sure thing, if you do find a possible solution feel free to open a PR.