Cryptic runtime error when running hive-gateway supergraph

[ejkg]

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• 1. The issue provides a reproduction available on
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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

I'm having trouble replicating this bug in a smaller context. I've got a very cryptic error from sucrase being thrown when I run hive-gateway supergraph. This command produces a runtime error which doesn't seem to be caught by typescript - yet the errors suggest this is a typescript issue.

[2025-01-13T21:54:27.638Z] ERROR  SyntaxError [Error]: Unexpected token (10891:37)
    at unexpected (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/traverser/util.js:99:15)
    at tsParseNonArrayType (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:542:20)
    at tsParseArrayTypeOrHigher (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:546:3)
    at tsParseTypeOperatorOrHigher (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:587:5)
    at tsParseIntersectionTypeOrHigher (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:594:3)
    at tsParseUnionTypeOrHigher (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:604:3)
    at tsParseNonConditionalType (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:793:3)
    at tsParseType (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:756:3)
    at tsParseTypeArguments (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:1160:5)
    at tsParseTypeReference (/Users/ekjg/project/node_modules/.pnpm/[email protected]/node_modules/sucrase/dist/parser/plugins/typescript.js:162:5) {
  pos: 593782,
  loc: { line: 10891, column: 37 }
} 

I can "fix" the issue by omitting a particular resolver file from the gateway config. However something strange. If I comment all of the code from the file it still doesn't resolve the issue, only if I remove the reference from my additionalResolvers in gateway.config does it work

// customer-resolvers.ts
export const customResolvers: Resolvers<GraphQLContext> = {
    // ...Resolvers
}

// gateway.config.ts

import { customResolvers } from "./src/custom-resolvers.ts";

export const gatewayConfig = defineConfig({
  supergraph: "./src/supergraph/schema.graphql",
  additionalResolvers: [ 
        customResolvers,
        // ... other custom resolvers
    ],
  plugins: (gatewayContext) => {
        // ... plugins
    }
});

When I comment out custom resolvers like this:

// gateway.config.ts

import { customResolvers } from "./src/custom-resolvers.ts";

export const gatewayConfig = defineConfig({
  supergraph: "./src/supergraph/schema.graphql",
  additionalResolvers: [ 
        // customResolvers,
        // ... other custom resolvers
    ],
  plugins: (gatewayContext) => {
        // ... plugins
    }
});

The gateway builds and executes the supergraph as expected.

Just to summarize. I believe the issue has to do with custom resolvers in the hive gateway because that appears to be the trigger for causing the cryptic error.

To Reproduce Steps to reproduce the behavior:

Still working on isolating the actual issue.

Expected behavior

Mesh composes the supergraph properly, but the gateway is unable to run our custom resolvers.

Environment:

• OS: macos 15.2
• "@graphql-hive/gateway": "^1.7.8":
• NodeJS: v22.9.0

Additional context

Other relevant packages and their versions:

// dependencies
    "@graphql-hive/core": "^0.8.3",
    "@graphql-hive/envelop": "^0.33.11",
    "@graphql-hive/gateway": "^1.7.8",
    "@graphql-hive/gateway-runtime": "^1.4.7",
    "@graphql-tools/utils": "^10.6.2",

// dev dependencies
    "@graphql-codegen/add": "^5.0.3",
    "@graphql-codegen/cli": "^5.0.3",
    "@graphql-codegen/typescript": "^4.1.2",
    "@graphql-codegen/typescript-resolvers": "^4.4.1",
    "@graphql-mesh/compose-cli": "^1.3.5",
    "@graphql-mesh/types": "^0.103.11",

[ardatan]

It looks like a TypeScript parse error. @enisdenjo Do you think we can improve this error message to show which file is the issue?

[enisdenjo]

@ejkg I tried replicating the issue following your description but couldn't get it to fail. It could be something with the Resolvers and GraphQLContext from customer-resolvers.ts.

Can you please share also the imports you do in customer-resolvers.ts?

BTW, for future reference, the Hive Gateway has been moved to: https://github.com/graphql-hive/gateway.

[enisdenjo]

graphql-hive/gateway#462 now exposes file paths of syntax errors - can you please try the alpha release to find the error?

[ejkg]

Hey Dennis, thanks for the update using the new package version @graphql-hive/[email protected] I was able to get a better error that helped me locate the issue in no time.

basically I had to make this change in my composed supergraph.

// supergraph/resolver.types.ts

- SizeMetadata: ResolverTypeWrapper<@mesh@EnrichedProductAttributes>;
+ SizeMetadata: ResolverTypeWrapper<@mesh#EnrichedProductAttributes>;

This was caused by a typo in a codegen mapper that would have been really hard trace without the improved error reporting.

import type { CodegenConfig } from "@graphql-codegen/cli";

const config: CodegenConfig = {
  schema: "./src/supergraph/schema.graphql",
  generates: {
    "./src/supergraph/resolvers.types.ts": {
      config: {
        mappers: {
-          SizeMetadata: "@mesh@EnrichedProductAttributes",
+          SizeMetadata: "@mesh#EnrichedProductAttributes",
        },
      },
    },
  },
};
export default config;

Much appreciated.