Error Handling

Handle GraphQL errors gracefully in your application.

Error Structure

{
  "data": null,
  "errors": [
    {
      "message": "Field 'nonexistent_field' not found in type 'atoms'",
      "extensions": {
        "path": "$.selectionSet.atoms.selectionSet.nonexistent_field",
        "code": "validation-failed"
      }
    }
  ]
}

Error Types

• validation-failed: Query syntax or schema validation error
• constraint-violation: Database constraint violated
• unexpected: Internal server error

Best Practice

import { GraphQLClient, ClientError } from 'graphql-request'

try {
  const data = await client.request(query, variables)
  console.log('Success:', data)
} catch (error) {
  if (error instanceof ClientError) {
    console.error('GraphQL errors:', error.response.errors)
    console.error('Status:', error.response.status)
  } else {
    console.error('Network error:', error)
  }
}

Tips

1. Check errors array: GraphQL can return partial data with errors
2. Log error details: Include query and variables for debugging
3. Show user-friendly messages: Don't expose internal errors
4. Implement retry logic: For network failures