How to Mock a GraphQL Query Type in Python

Create a lightweight mock of a GraphQL Query type to simulate repository lookups without a server.

Easy Python 3.9+ Aug 9, 2026 API design & gRPC 14 views 0 copies

graphql mock resolver api

Python code

18 lines

Python 3.9+

import json

class Query:
    def __init__(self):
        self.starred_repos = [
            {"id": 1, "name": "graphql", "owner": "graphql"}
        ]

    def repository(self, name):
        if name == "graphql":
            return {"id": 1, "name": "graphql", "stargazerCount": 85000}
        return None


if __name__ == "__main__":
    query = Query()
    result = query.repository("graphql")
    print(json.dumps(result, indent=2))

Output

stdout

{
  "id": 1,
  "name": "graphql",
  "stargazerCount": 85000
}

How it works

This code defines a Query class that mimics the root resolver of a GraphQL schema. The repository method acts as a resolver returning a dict-shaped object when the queried name matches, otherwise returning None to simulate a null response. Using a Python class for the schema allows you to test resolver logic or build a simple mock server without heavyweight dependencies. The json.dumps call formats the result nicely when run as a script for quick verification.

Common mistakes

Returning the wrong key names compared to the GraphQL schema contract
Forgetting to handle the None case when the requested resource doesn't exist
Hardcoding data instead of using a small dataset or fixture for more realistic tests

Variations

Use dataclasses to define the response objects for stronger typing
Wrap the mock in a callable handler for use with a WSGI mock server library

Real-world use cases

Unit-testing resolver logic before wiring up a real GraphQL server
Providing a local stub for frontend development against a not-yet-built API
Simulating schema behavior in integration tests that don't need a network call

How to Mock a GraphQL Query Type in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

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Python code

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How it works

Common mistakes

Variations

Real-world use cases

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