gRPC reflection doesn't work for one endpoint handling multiple services

[mr-nagashima]

Issue workflow progress

Progress of the issue based on the Contributor Workflow

• [x] 1. The issue provides a reproduction available on Github, Stackblitz or CodeSandbox

Make sure to fork this template and run yarn generate in the terminal.

Please make sure Mesh package versions under package.json matches yours.

• [ ] 2. A failing test has been provided
• [ ] 3. A local solution has been provided
• [ ] 4. A pull request is pending review

---

Describe the bug

The backend's gRPC API provides nine services.

I wrote the .meshrc.yaml below.

.meshrc.yaml

sources:
  - name: Backend
    handler:
      grpc:
        endpoint: backend:3000

And when I started GraphQL Mesh in dev mode, I got an error at the end.

$ mesh dev
    :
Mesh - Server 💡 Starting GraphQL Mesh...
Mesh - Server 💡 Serving GraphQL Mesh: http://0.0.0.0:4000
Mesh - Backend 🐛 Getting stored root and decoded descriptor set objects
Mesh - Backend 🐛 Building Roots
Mesh - Backend 🐛 Using the reflection
Mesh - Backend 🐛 Creating gRPC Reflection Client
Mesh - Backend 🐛 Resolving root of Service: greet.v1.GreetService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: cancellation.v1.CancellationService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: supplier.v1.SupplierService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: depot.v1.DepotService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: warehouse.v1.WarehouseService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: office.v1.OfficeService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: company.v1.CompanyService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: plan.v1.PlanService from the reflection response
Mesh - Backend 🐛 Resolving root of Service: room.v1.RoomService from the reflection response
    :
Mesh - Backend 🐛 Building the schema structure based on the root object
Mesh - Backend - Root0 🐛 Visiting .nested[greet]
    :
Mesh - Backend 🐛 Building the schema structure based on the root object
Mesh - Backend - Root8 🐛 Visiting .nested[google]
    :
Mesh - Backend 🐛 Building the final GraphQL Schema
Mesh - Backend - Root8 🐛 Creating service client for package definition
Mesh - Backend 💥 Failed to generate the schema for the source "Backend"
Invalid value used as weak map key
Mesh HTTP 💥 Error: Schemas couldn't be generated successfully. Check for the logs by running Mesh.
    at getMesh (/app/node_modules/@graphql-mesh/runtime/cjs/get-mesh.js:124:15)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)

I think that the reflection has been loaded, the above error occurs at the very end. What does "Invalid value used as weak map key" indicate?

I would appreciate it if you could tell me the solution.

To Reproduce Steps to reproduce the behavior:

Expected behavior

Start normally

Environment:

• OS: macOS 14.4.1
• @graphql-mesh/...:
• NodeJS: 20

Additional context

[mbrowne]

Caused by https://github.com/ardatan/graphql-mesh/issues/6424. The bug was introduced by https://github.com/ardatan/graphql-mesh/pull/5420 (this used to work fine before that).

[ardatan]

An isolated, minimal reproduction would be good for us in order to debug so that we can try to fix it after.

[mbrowne]

Hi @ardatan , @Francismb created a reproduction here earlier: https://github.com/ardatan/graphql-mesh/issues/5438#issuecomment-1590313857

And I had created this reproduction originally: https://github.com/mbrowne/graphql-mesh-bug-repro/tree/grpc-source-issue

There's also a lot of info in https://github.com/ardatan/graphql-mesh/issues/5438 that you might find helpful for debugging.

[mbrowne]

Actually I took a closer look at https://github.com/Francismb/graphql-mesh-issue and it doesn't reproduce the issue for me because it apparently depends on a gRPC server not included in that repo. Here are updated/fixed instructions on how to more simply reproduce the issue using my branch:

git clone git@github.com:mbrowne/graphql-mesh-bug-repro.git --single-branch --branch grpc-source-issue
yarn
yarn start

[ardatan]

Thanks for the reproduction! Fixed by https://github.com/ardatan/graphql-mesh/pull/7807

[mbrowne]

@ardatan Thanks! I'll take a closer look at this later. I still think there is a bug in @graphql-tools/stitch, but if your fix makes gRPC work properly without needing to fix that bug then that's awesome! :-)