Skip to main content

Hypothesis strategies for GraphQL queries and mutations

Project description


Build Coverage Version Python versions Chat License

Hypothesis strategies for GraphQL operations. Allows you to generate arbitrary GraphQL queries for the given schema. It starts with simple examples and iteratively goes to more complex ones.

For web API testing, Schemathesis provides a higher-level wrapper and can detect internal server errors.


hypothesis_graphql exposes the from_schema function, which takes a GraphQL schema and returns a Hypothesis strategy for defined queries and mutations:

from hypothesis import given
from hypothesis_graphql import from_schema

SCHEMA = """
type Book {
  title: String
  author: Author

type Author {
  name: String
  books: [Book]

type Query {
  getBooks: [Book]
  getAuthors: [Author]

type Mutation {
  addBook(title: String!, author: String!): Book!
  addAuthor(name: String!): Author!

def test_graphql(query):
    # Will generate samples like these:
    # {
    #   getBooks {
    #     title
    #   }
    # }
    # mutation {
    #   addBook(title: "H4Z\u7869", author: "\u00d2"){
    #     title
    #   }
    # }

It is also possible to generate queries or mutations separately with hypothesis_graphql.queries and hypothesis_graphql.mutations.


To restrict the set of fields in generated operations use the fields argument:

@given(from_schema(SCHEMA, fields=["getAuthors"]))
def test_graphql(query):
    # Only `getAuthors` will be generated

It is also possible to generate custom scalars. For example, Date:

from hypothesis import strategies as st, given
from hypothesis_graphql import from_schema, nodes

SCHEMA = """
scalar Date

type Query {
  getByDate(created: Date!): Int

            # Standard scalars work out of the box, for custom ones you need
            # to pass custom strategies that generate proper AST nodes
            "Date": st.dates().map(nodes.String)
def test_graphql(query):
    # Example:
    #  { getByDate(created: "2000-01-01") }

The hypothesis_graphql.nodes module includes a few helpers to generate various node types:

  • String -> graphql.StringValueNode
  • Float -> graphql.FloatValueNode
  • Int -> graphql.IntValueNode
  • Object -> graphql.ObjectValueNode
  • List -> graphql.ListValueNode
  • Boolean -> graphql.BooleanValueNode
  • Enum -> graphql.EnumValueNode
  • Null -> graphql.NullValueNode (a constant, not a function)

They exist because classes like graphql.StringValueNode can't be directly used in map calls due to kwarg-only arguments.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

hypothesis-graphql-0.9.0.tar.gz (13.2 kB view hashes)

Uploaded Source

Built Distribution

hypothesis_graphql-0.9.0-py3-none-any.whl (15.2 kB view hashes)

Uploaded Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page