Cannot use ESM together with CJS -> cannot use "import" with graphql-express

[schrotie]

When mixing ECMA script modules (via import) and CommonJS modules in node.js (V14.5.0) then GraphQL complains that duplicate GraphQL modules cannot be used together.

One consequence of this is that it is to my knowledge impossible to use express-graphql together with import syntax. That is seemingly because "import" pulls other code than the "require" that express-graphql will use.

[isabelleingato]

Hello! New here and I'd like to look into this if that's okay. Do you happen to have a min repro example? I haven't seemed to run into this issue myself using express-graphql v0.12.0 with import syntax and requiring graphql v15.4.0 as cjs in the same project, so I want to make sure I'm understanding the question / set up.

I've seen similar errors before when mixing versions of graphql, unsure if related.

graphql-js/src/jsutils/instanceOf.ts

Line 22 in c589c3d

`Cannot use ${className} "${value}" from another module or realm.

, #491

thanks!

[schrotie]

Sorry, I don't have a min-setup and I haven't worked with graphql for quite some time now.

[yaacovCR]

We are tracking cjs/esm interaction in a new issue, #4062, closing this older one.

[yaacovCR]

To be discussed at Thursday June 25 5pm UTC meeting https://github.com/graphql/graphql-js-wg/blob/main/agendas/2025/06-Jun/25-graphql-js-wg-june-2025.md

We invite everyone to consider joining if you are able!