Unable to merge GraphQL type

[TheOrangePuff]

Currently trying to get GraphQL Mesh working with the latest version but keep running into the following error when running yarn mesh build:

💡 🕸️  Mesh Cleaning existing artifacts
💡 🕸️  Mesh Reading the configuration
💡 🕸️  Mesh Generating the unified schema
(node:38) ExperimentalWarning: buffer.Blob is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
💥 🕸️  Mesh Error: Unable to merge GraphQL type "AppliedCoupon": Field "couponType" already defined with a different type. Declared as "CouponType2", but you tried to override with "CouponType"
    at mergeType (/app/node_modules/@graphql-tools/merge/index.js:457:19)
    at mergeGraphQLNodes (/app/node_modules/@graphql-tools/merge/index.js:569:49)
    at mergeGraphQLTypes (/app/node_modules/@graphql-tools/merge/index.js:661:25)
    at Object.mergeTypeDefs (/app/node_modules/@graphql-tools/merge/index.js:608:22)
    at makeExecutableSchema (/app/node_modules/@graphql-tools/schema/index.js:494:38)
    at Object.mergeSchemas (/app/node_modules/@graphql-tools/schema/index.js:532:12)
    at BareMerger.getUnifiedSchema (/app/node_modules/@graphql-mesh/merger-bare/index.js:37:22)
    at Object.getMesh (/app/node_modules/@graphql-mesh/runtime/index.js:73:48)
    at async Object.handler (/app/node_modules/@graphql-mesh/cli/bin.js:1075:53)
error Command failed with exit code 1.

We are using the BigCommerce api and I believe the issue is stemming from merging the following two:

• https://developer.bigcommerce.com/api-reference/YXBpOjIzMTM0ODM-carts
• https://developer.bigcommerce.com/api-reference/YXBpOjIzMTM2Mjg-checkouts

The only thing that has changed was upgrading the package versions. The package.json has been upgraded to this:

{
    "name": "app",
    "version": "0.1.0",
    "private": true,
    "license": "UNLICENSED",
    "devDependencies": {
      "@graphql-mesh/cli": "0.68.x"
    },
    "dependencies": {
      "@graphql-mesh/cache-localforage": "0.5.x",
      "@graphql-mesh/graphql": "0.23.x",
      "@graphql-mesh/merger-bare": "0.13.x",
      "@graphql-mesh/openapi": "0.24.x",
      "@graphql-mesh/runtime": "0.34.x",
      "@graphql-mesh/transform-cache": "0.12.x",
      "graphql": "15.8.x"
    },
    "peerDependencies": {
      "graphql-tag": "^2.0.0",
      "react-native": "latest",
      "@types/node": "latest"
    }
}

It was previously working with these versions of the packages:

{
    "name": "app",
    "version": "0.1.0",
    "private": true,
    "license": "UNLICENSED",
    "devDependencies": {
      "@graphql-mesh/cli": "0.39.0"
    },
    "dependencies": {
      "eslint": "^7.32.0",
      "@graphql-mesh/cache-localforage": "0.5.16",
      "@graphql-mesh/graphql": "^0.19.0",
      "@graphql-mesh/merger-bare": "0.9.23",
      "@graphql-mesh/openapi": "0.18.14",
      "@graphql-mesh/runtime": "0.20.2",
      "@graphql-mesh/transform-cache": "0.9.14",
      "graphql": "15.4.0"
    }
}

I'm not sure what has changed between these versions to cause the typing error but would really appreciate any guidance. Happy to provide any more info that may be needed to help solve the issue.

Thanks!

[TheOrangePuff]

Managed to solve this by changing the merger from bare to stitching. In .meshrc.yml:

merger: stitching 

Then updating my package list to the following:

{
    "name": "app",
    "version": "0.1.0",
    "private": true,
    "license": "UNLICENSED",
    "devDependencies": {
      "@graphql-mesh/cli": "0.69.x"
    },
    "dependencies": {
      "@graphql-mesh/cache-localforage": "0.6.x",
      "@graphql-mesh/graphql": "0.25.x",
      "@graphql-mesh/merger-stitching": "0.15.x",
      "@graphql-mesh/openapi": "0.25.x",
      "@graphql-mesh/runtime": "0.34.x",
      "@graphql-mesh/transform-cache": "0.12.x",
      "graphql": "16.4.x"
    },
    "peerDependencies": {
      "graphql-tag": "^2.0.0",
      "react-native": "latest",
      "@types/node": "latest"
    }
}

I couldn't find any documentation on what the difference between these merger types are... but it did fix my issue 🙂