[Solved] A developer writes this resolver:function getItem(root, args) { return items.filter(i => i.category === args.category); }But the query:{ getItem(category:... What is the most likely cause? | GraphQL

GraphQL - Resolvers

A developer writes this resolver:

function getItem(root, args) { return items.filter(i => i.category === args.category); }

But the query:

{ getItem(category: "books") { name } }

returns an error. What is the most likely cause?

AThe resolver returns an array but the schema expects a single object

BThe argument name is misspelled in the query

CThe filter function is used incorrectly

DThe query is missing required arguments

Step-by-Step Solution

Solution:

Step 1: Understand resolver return type
The resolver returns an array from filter.
Step 2: Check schema expectation
If the schema expects a single object but resolver returns array, GraphQL throws an error.
Final Answer:
The resolver returns an array but the schema expects a single object -> Option A
Quick Check:
Return type must match schema type [OK]

Quick Trick: Return type must match schema: array vs object [OK]

Common Mistakes:

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