@graphitation/graphql-js-operation-payload-generator

graphql-js-operation-payload-generator

Generates a payload for a given GraphQL operation expressed in graphql-js AST and a GraphQL Schema.

It is API-wise a port of Relay’s MockPayloadGenerator.

import { graphql } from "@graphitation/graphql-js-tag";
import { generate } from "@graphitation/graphql-js-operation-payload-generator";
import { buildSchema } from "graphql";

const schema = buildSchema(/* ... */);

const query = graphql`
  query SomeQuery {
    user(id: "my-id") {
      ...SomeFragment
    }
  }

  fragment SomeFragment on User {
    id
    name
    profile_picture {
      uri
      width
      height
    }
  }
`;

const payload = generate(query, schema);
console.log(payload);

This will output something like the following:

{
  "data": {
    "__typename": "Query",
    "user": {
      "__typename": "User",
      "id": "<mock-id-2>",
      "name": "<mock-value-for-field-\\"name\\">",
      "profile_picture": {
        "__typename": "Image",
        "uri": "<mock-value-for-field-\\"uri\\">",
        "width": 42,
        "height": 42
      }
    }
  }
}

Schema type-checking and auto-completion

This version of the payload generator, accepts a type map typing to be used for the mock resolvers. It needs to consist of type-names as keys and the type itself as value. If using @graphql-code-generator, this type-map can be emitted by using the @graphitation/graphql-codegen-typescript-typemap-plugin plugin:

schema: http://localhost:3000/graphql
generates:
  ./src/types.ts:
    plugins:
      - typescript
      - @graphitation/graphql-codegen-typescript-typemap-plugin
    config:
      allowEnumStringTypes: true