graphql-code-generator: Unable to create custom document loader for glob pattern source

I am trying to write my own document loader to facilitate the usage of the @export directive from Apollo Client. I found several issues (#3939 & #2771) (even a PR #3886) that contain bits and pieces for the solution, but I figured I’d require a custom document loader because I need to filter out some variable definition requirements to prevent syntax errors.

I am now running into the issue that the custom document loader functionality provided by GraphQL Codegen (and if I followed the code trail correctly, it’s actually the custom loader functionality of @graphql-tools/load) is expecting a single Source, string or GraphQLSchema return value. This is a bit hard when I am trying to facilitate a loader for a glob pattern. This will inherently return a Source[] or string[].

Also, I literally tried to use the loadDocuments function from @graphql-tools/load (I noticed the arguments given to the loader are exactly the same as the ones loadDocuments expects.) This’ll return an Array<Source>, and even just returning a single Source I keep getting the following error:

    Error:
          Unable to find any GraphQL type definitions for the following pointers:

              - **/*.graphql

        at prepareResult (/workspace/node_modules/@graphql-tools/load/index.js:507:15)
        at loadTypedefs (/workspace/node_modules/@graphql-tools/load/index.js:473:12)
        at async loadDocuments (/workspace/node_modules/@graphql-codegen/cli/bin.js:540:31)
        at async /workspace/node_modules/@graphql-codegen/cli/bin.js:944:55
        at async Task.task (/workspace/node_modules/@graphql-codegen/cli/bin.js:789:17)

I hope I am doing it wrong, so I’d love a working example of a custom document loader for a glob pattern, but I am afraid it’s not supported by @graphql-tools/load (atleast not for a CustomLoader). If this is the case, what’s the expected path to take from here?

About this issue

Original URL
State: open
Created 3 years ago
Reactions: 7
Comments: 18 (1 by maintainers)

Most upvoted comments

It seems to me like custom loaders just got skipped over in https://github.com/ardatan/graphql-tools/pull/3157. Would it be sufficient to just change the lines here to add a check if the custom loader returned an array of sources, and if so, add all the sources to the list? Then custom loaders could function the same as the rest of the loaders (fallback loaders, if I’m reading the code correctly).

abrenneke on Oct 6, 2021

Oh. My. God! Option 2 does actually work! 🎉 🎉 🎉 I wish I could’ve got back the time I’ve spent on the workaround.

So to recap, if you’re working with globs and custom loaders:

Inside your loader, load the files from the glob, parse them, do your biz.
IMPORTANT: Merge them into a single document
Export the single merged document

Note: In my case, I was dealing with client-side queries, so I’ve joined the string definitions first with .join('\n'), and then graphql.parse’d the merged string.

@wesselvdv and @abrenneke, would this approach solve your issues too?

And @dotansimha, @ardatan, and @B2o5T, could we get this info into the docs, to help out other poor souls?

JuroOravec on Feb 13, 2022

Hi @B2o5T I’ll create it this weekend

JuroOravec on Feb 9, 2022

Could we add info from @JuroOravec’s comment to the documentation? For example to the “Custom Document Loader” section?

DawidKopys on Jun 30, 2023

@dotansimha You have any pointers for me?

wesselvdv on Sep 6, 2021