Troubleshooting “Attempted to add an ID already in GraphQLSegment” Warning with Relay and GraphQL Fragments

Avoiding Duplicate ID Warnings in GraphQLSegment in Relay/GraphQL

When working with Relay/GraphQL, it is not uncommon to encounter warnings related to duplicate IDs in the GraphQLSegment. This can happen when your Relay/GraphQL fragment contains two different queries that return objects of the same type and there is overlap between the result sets. Here’s how you can understand and resolve this issue.

Understanding the Warning

The warning message “Attempted to add an ID already in GraphQLSegment” indicates that the same Relay object is being referenced twice, causing the duplicate ID warning. Additionally, messages like “Attempted to add noncontiguous index to GraphQLSegment” suggest that the indexes for the GraphQLSegment are not contiguous.

Possible Causes

One possible cause of this issue is running the nodeDefinition on your type multiple times. Make sure you have not defined the globalIDField on your top-level object more than once.

let { nodeInterface, nodeField } = nodeDefinitions(
  (globalId) => {
    let { type, id } = fromGlobalId(globalId)
    console.log('NodeDefinitions (globalId), id:', id)
    console.log('NodeDefinitions (globalId), type:', type)

    if (type === 'TopLevelObject') {
      return topLevelObject
    }
    return null
  },
  (obj) => {
    if (obj instanceof TopLevelObject) {
      return topLevelObjectType
    }
    return null
  }
)
  

If you have referred to any other objects, make sure to do it correctly by following the code snippet below:

let itemType = new GraphQLObjectType({
  name: 'Item',
  fields: () => ({
    id: fromGlobalId('Item', obj => obj._id),
    // OR, not both..
    id: {
      type: new GraphQLNonNull(GraphQLID),
      resolve: (obj) => obj._id
    },
    name: { type: GraphQLString },
    url: { type: GraphQLString },
    state: { type: GraphQLString },
    likesCount: { type: GraphQLInt },
    createdAt: {
      type: GraphQLString,
      resolve: ...
    }
  }),
  interfaces: [nodeInterface]
})
  

Debugging and Resolving the Warning

If you are still experiencing the warning after checking for the above causes, it is recommended to review your code for any other potential causes. Consider the following steps:

1. Review your GraphQL queries and fragments to ensure they are not duplicating objects unintentionally.
2. Check your Relay container component and ensure it is not refetching or re-rendering the same query and fragment multiple times.
3. Inspect your GraphQL server and schema to ensure there are no inconsistencies or misconfigurations that could lead to duplicate object references.

By following these steps and thoroughly reviewing your code, you should be able to identify and resolve the duplicate ID warnings in the GraphQLSegment.

Conclusion

Duplicate ID warnings in the GraphQLSegment can be caused by various factors, such as running the nodeDefinition multiple times or unintentionally duplicating objects in your GraphQL queries and fragments. By understanding the warning messages and thoroughly reviewing your code, you can successfully debug and resolve these warnings, ensuring the smooth operation of your Relay/GraphQL application.

reference : 

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