Input validation patterns in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is input validation in GraphQL?

Input validation in GraphQL means checking the data sent by users to make sure it is correct and safe before using it in the system.

beginner

Why is input validation important in GraphQL APIs?

It helps prevent errors and security problems by making sure only valid and expected data is accepted.

intermediate

Name a common pattern to validate inputs in GraphQL schemas.

Using custom scalar types or input types with specific fields and constraints to check data format and values.

intermediate

How can you validate an email input in GraphQL?

Create a custom scalar type for email that checks the string matches an email pattern before accepting it.

intermediate

What role do resolver functions play in input validation?

Resolvers can add extra checks on inputs before processing, ensuring data meets business rules beyond schema validation.

What is the first step in input validation in GraphQL?

A Design UI forms

B Define input types with constraints

C Create database tables

D Write resolver functions

Defining input types with constraints helps GraphQL check inputs automatically.

Which GraphQL feature helps enforce input formats like email or date?

A Directives

B Fragments

C Subscriptions

D Custom scalar types

Custom scalar types allow defining specific validation rules for inputs like email or date.

Where can you add extra input validation beyond schema checks?

A In resolver functions

B In the database only

C In the client UI only

D In GraphQL queries

Resolvers can perform additional validation before processing data.

What happens if input validation fails in GraphQL?

A The query returns an error

B The query runs anyway

C The server crashes

D The input is ignored silently

GraphQL returns an error when input validation fails to prevent bad data.

Which is NOT a good practice for input validation in GraphQL?

A Validate inputs in schema and resolvers

B Use custom scalars for special formats

C Trust all client inputs without checks

D Return clear error messages on invalid input

Trusting client inputs without validation is unsafe and not recommended.

Explain how input validation works in GraphQL and why it is important.

Think about how GraphQL schema helps check data.

Describe two ways to implement input validation in a GraphQL API.

Consider schema design and resolver roles.