[Solved] This resolver code throws an error:const resolvers = { User: { posts: (parent) => { return parent.posts.map(p => p.title); } } };What is the most likely cause? | GraphQL

GraphQL - Type Relationships

This resolver code throws an error:

const resolvers = {
  User: {
    posts: (parent) => {
      return parent.posts.map(p => p.title);
    }
  }
};

What is the most likely cause?

ASyntax error in map function

Bparent.posts is undefined or null

CMissing return statement

DGraphQL query missing posts field

Step-by-Step Solution

Solution:

Step 1: Analyze posts resolver code
It calls parent.posts.map, assuming parent.posts is an array.
Step 2: Identify cause of error
If parent.posts is undefined or null, calling map causes runtime error.
Final Answer:
parent.posts is undefined or null -> Option B
Quick Check:
Undefined array causes map error [OK]

Quick Trick: Check if parent.posts exists before mapping [OK]

Common Mistakes:

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