Package org.mockserver.graphql

Class GraphQLResponseSynthesizer

java.lang.Object
org.mockserver.graphql.GraphQLResponseSynthesizer
public class GraphQLResponseSynthesizer extends Object
Synthesizes schema-valid GraphQL responses for a matched query, given a registered GraphQL schema. This is the GraphQL analogue of the OpenAPI ExampleBuilder: it walks the requested selection set against the schema's type system and emits a JSON {"data": {...}} envelope with deterministic, type-correct placeholder values — no hand-authored response JSON required.

Supported schema input:

  • SDL text, e.g. "type Query { hello: String }"
  • An introspection JSON result — either the full {"data": {"__schema": ...}} envelope or the bare {"__schema": ...} object

Synthesis rules mirror GraphQL execution semantics:

  • only requested fields (the selection set) appear in the response
  • scalars produce deterministic placeholders (String, Int, Float, Boolean, ID and common custom scalars)
  • enums produce their first declared value
  • list types produce a single-element array
  • object types recurse into their sub-selection
  • non-null wrappers are unwrapped; nullable fields with no sub-selection on an object type yield null (only scalars/enums/lists are auto-populated as leaves)
  • inline fragments and named fragment spreads are flattened into the selection

Instances are immutable and thread-safe once constructed.

  • Constructor Details

    • GraphQLResponseSynthesizer

      public GraphQLResponseSynthesizer(String schemaDefinition)
      Build a synthesizer from a GraphQL schema definition.
      Parameters:
      schemaDefinition - SDL text or an introspection JSON result
      Throws:
      GraphQLSchemaException - if the schema cannot be parsed

  • Method Details

    • synthesizeResponse

      public String synthesizeResponse(String requestBody)
      Synthesize a schema-valid response for the supplied GraphQL request body.
      Parameters:
      requestBody - the raw request body — either a JSON-wrapped GraphQL-over-HTTP body ({"query": "..."}) or a raw GraphQL document
      Returns:
      a JSON string of the form {"data": {...}}
      Throws:
      GraphQLSchemaException - if the query cannot be parsed against the schema