[Solved] Consider this nested resolver code:const resolvers = { Author: { books: (parent) => { return books.filter(book => book.authorId = parent.id); } } };What is the error in this resolver? | GraphQL

GraphQL - Type Relationships

Consider this nested resolver code:

const resolvers = {
  Author: {
    books: (parent) => {
      return books.filter(book => book.authorId = parent.id);
    }
  }
};

What is the error in this resolver?

AUsing assignment '=' instead of comparison '===' in filter

BMissing return statement in resolver

CIncorrect resolver name 'books' instead of 'bookList'

DParent argument is not passed to resolver

Step-by-Step Solution

Solution:

Step 1: Identify filter condition mistake
The filter uses '=' which assigns value instead of '===' which compares values.
Step 2: Understand impact of '=' in filter
Using '=' causes all books to be included or unexpected behavior, not filtering correctly.
Final Answer:
Using assignment '=' instead of comparison '===' in filter -> Option A
Quick Check:
Filter condition must use '===' not '=' [OK]

Quick Trick: Use '===' for comparison inside filter functions [OK]

Common Mistakes:

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