Struct ResponseBuilder 

pub struct ResponseBuilder<'a, 'doc, 'schema, R: RandomProvider> { /* private fields */ }

Builds a GraphQL response which matches the shape of a given executable GraphQL document.

ResponseBuilder is generic over its randomness source via the RandomProvider trait. This allows it to be used with arbitrary::Unstructured for fuzz testing, with RandProvider for standard random generation, or with any custom implementation.

Example

use apollo_smith::{ResponseBuilder, RandProvider};

let mut rng = RandProvider(rand::rng());
let response = ResponseBuilder::new(&mut rng, &doc, &schema).build()?;

Implementations

impl<'a, 'doc, 'schema, R: RandomProvider> ResponseBuilder<'a, 'doc, 'schema, R>

pub fn new( rng: &'a mut R, doc: &'doc Valid<ExecutableDocument>, schema: &'schema Valid<Schema>, ) -> Self

Create a new ResponseBuilder.

pub fn with_generator<G>(self, type_name: Name, generator: G) -> Self

where G: Generator<R> + 'static,

Register a Generator for the named GraphQL type.

When the builder is about to produce a value of this type — at the root or any nested position, including each item of a list — the generator is invoked instead of the default behavior. For object, interface, and union types, the generator receives the requested fields with fragment spreads and inline fragments already flattened and grouped by response key, and its return value is used as-is (the builder does not recurse into it). For scalar types, the fields argument is empty and the generator’s return value replaces the configured default.

pub fn with_min_list_size(self, min_size: usize) -> Self

Set the minimum number of items per list field. If unset, defaults to 0.

pub fn with_max_list_size(self, max_size: usize) -> Self

Set the maximum number of items per list field. If unset, defaults to 5.

pub fn with_null_ratio(self, numerator: u32, denominator: u32) -> Self

Set the frequency of null values for nullable fields. If unset, fields will never be null.

pub fn with_operation_name(self, operation_name: Option<&'doc str>) -> Self

Set the operation name to generate a response for. If unset, uses the anonymous operation. If the operation does not exist, returns a response with data: null.

pub fn build(self) -> Result<Value, ResponseError>

Builds a complete GraphQL response Value with a data key, matching the shape of self.doc.

pub fn build_data(&mut self) -> Result<Value, ResponseError>

Builds just the data portion of the response (without the { "data": ... } wrapper).

This is useful if you need to manipulate the response data before wrapping it into JSON.