Resolver function signature in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a resolver function in GraphQL?

A resolver function is a function that tells GraphQL how to fetch or compute the data for a specific field in a query.

beginner

What are the four standard parameters of a GraphQL resolver function?

The four standard parameters are: <br>1. parent (or root) - the result from the parent resolver.<br>2. args - an object containing the arguments passed to the field.<br>3. context - shared data available to all resolvers, like authentication info.<br>4. info - information about the execution state of the query.

beginner

Show a simple resolver function signature in JavaScript for a field named 'user'.

function user(parent, args, context, info) {<br>  // code to fetch user data<br>}

intermediate

Why is the 'context' parameter important in a resolver function?

The 'context' parameter holds shared information like user authentication, database connections, or loaders. It helps resolvers access common resources without passing them explicitly each time.

advanced

What does the 'info' parameter provide in a resolver function?

The 'info' parameter provides details about the execution state of the query, including the field name, path, and the GraphQL schema. It is useful for advanced features like query analysis or optimization.

Which parameter in a resolver function contains the arguments passed in the GraphQL query?

A parent

B context

C info

D args

The 'args' parameter contains the arguments passed to the field in the GraphQL query.

What is the first parameter of a resolver function usually called?

A parent

B context

C args

D info

The first parameter is called 'parent' or 'root' and contains the result from the parent resolver.

Which resolver parameter is commonly used to share authentication data?

A context

B args

C parent

D info

The 'context' parameter is used to share data like authentication info across resolvers.

What does the 'info' parameter NOT provide?

A Field name being resolved

B Arguments passed to the field

C Query execution state

D GraphQL schema details

Arguments are provided in the 'args' parameter, not in 'info'.

Which of these is a valid resolver function signature?

A function resolver(args, parent, context, info)

B function resolver(info, context, args, parent)

C function resolver(parent, args, context, info)

D function resolver(context, args, parent, info)

The correct order is (parent, args, context, info).

Describe the four parameters of a GraphQL resolver function and their roles.

Think about what data each parameter carries and why it is useful.

Explain why the 'context' parameter is useful when writing resolver functions.

Consider what information multiple resolvers might need access to.