Snapshot testing queries in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is snapshot testing in the context of GraphQL queries?

Snapshot testing is a way to save the output of a GraphQL query and compare future query results against this saved snapshot to detect unexpected changes.

beginner

Why is snapshot testing useful for GraphQL queries?

It helps catch changes in query results early, ensuring that updates to the backend or schema do not break the expected data structure or content.

intermediate

How do you create a snapshot test for a GraphQL query?

You run the query once, save the result as a snapshot file, and then in future tests, compare the query result to this saved snapshot automatically.

intermediate

What happens if a GraphQL query result changes and does not match the snapshot?

The test fails, alerting you that the query output has changed. You can then review if the change is expected and update the snapshot or fix the issue.

beginner

Name a common tool or library used for snapshot testing GraphQL queries.

Jest is a popular testing framework that supports snapshot testing, including for GraphQL query results.

What does snapshot testing primarily compare in GraphQL?

A The query result to a saved snapshot

B The query syntax to a template

C The query execution time

D The number of fields in the query

Snapshot testing compares the actual query result to a previously saved snapshot to detect changes.

If a snapshot test fails, what should you do first?

A Review the changes to see if they are expected

B Delete the snapshot file

C Ignore the failure

D Rewrite the query

You should review the changes to confirm if they are intentional before updating the snapshot or fixing issues.

Which testing framework is commonly used for snapshot testing GraphQL queries?

A Mocha

B Chai

C Jest

D Cypress

Jest supports snapshot testing natively and is widely used with GraphQL.

Snapshot testing helps to detect what kind of changes in GraphQL queries?

A Changes in query execution speed

B Changes in server hardware

C Changes in query syntax errors

D Changes in query result structure or data

Snapshot testing detects changes in the structure or content of the query result.

When is a snapshot created during testing?

A Before running any queries

B After running the query for the first time

C Only when tests fail

D After every test run

The snapshot is created after the first successful query run to save the expected output.

Explain how snapshot testing works for GraphQL queries and why it is helpful.

Think about saving and comparing query results over time.

Describe the steps you take when a snapshot test for a GraphQL query fails.

Consider how to handle differences between current and saved results.