Resolver params

When you pass a function as the handler config, it becomes a resolver. It receives a single argument with everything you need to read the incoming request and shape the outgoing response. Destructure only the fields you use.

graphql.query('GetUsers', ({ entities }) => ({
  data: { users: [] }
}));

request

The parsed incoming HTTP request — query, body, params, headers, and method. For most GraphQL scenarios, prefer entities.variables over request.body since variables are already parsed for you.

graphql.query('GetUsers', ({ request }) => ({
  data: { locale: request.query.locale }
}));

entities

The request entities resolved for the matched handler — variables, headers, cookies, and queries.

graphql.query('GetUsers', ({ entities }) => ({
  data: {
    users: [{ id: 1, role: entities.variables?.role }]
  }
}));

setStatusCode

Sets the HTTP status code of the response.

graphql.query('GetUsers', ({ setStatusCode }) => {
  setStatusCode(403);
  return { errors: [{ message: 'Forbidden' }] };
});

setDelay

Holds the response for a number of milliseconds. Returns a promise, so you can await it.

graphql.query('GetUsers', async ({ setDelay }) => {
  await setDelay(1000);
  return { data: { users: [] } };
});

setHeader

Sets a response header.

graphql.query('GetUsers', ({ setHeader }) => {
  setHeader('x-powered-by', 'mock-config-server');
  return { data: { users: [] } };
});

appendHeader

Appends a value to an existing response header.

graphql.query('GetUsers', ({ appendHeader }) => {
  appendHeader('vary', 'accept-encoding');
  return { data: { users: [] } };
});

getRequestHeader

Reads a single incoming request header.

graphql.query('GetUsers', ({ getRequestHeader }) => {
  const token = getRequestHeader('authorization');
  return { data: { token } };
});

getRequestHeaders

Reads all incoming request headers.

graphql.query('GetUsers', ({ getRequestHeaders }) => {
  const headers = getRequestHeaders();
  return { data: { headers } };
});

getResponseHeader

Reads a single response header that was already set.

graphql.query('GetUsers', ({ setHeader, getResponseHeader }) => {
  setHeader('x-powered-by', 'mock-config-server');
  return { data: { poweredBy: getResponseHeader('x-powered-by') } };
});

getResponseHeaders

Reads all response headers that were already set.

graphql.query('GetUsers', ({ getResponseHeaders }) => {
  const headers = getResponseHeaders();
  return { data: { headers } };
});

getCookie

Reads a request cookie.

graphql.query('GetProfile', ({ getCookie }) => {
  const session = getCookie('session');
  return { data: { session } };
});

setCookie

Sets a response cookie.

graphql.mutation('Login', ({ setCookie }) => {
  setCookie('auth', 'token', { httpOnly: true });
  return { data: { ok: true } };
});

clearCookie

Removes a response cookie.

graphql.mutation('Logout', ({ clearCookie }) => {
  clearCookie('auth');
  return { data: { ok: true } };
});

broadcast

Sends a response to all connected clients.

graphql.mutation('CreateUser', ({ broadcast }) => {
  broadcast({ event: 'user:created' });
  return { data: { ok: true } };
});

Stops handling in the current resolver and passes control to the next matching handler.

graphql.query('GetUsers', ({ entities, next }) => {
  if (!entities.variables?.role) return next();
  return { data: { users: [] } };
});

The params described on this page apply to graphql.query and graphql.mutation handlers only. Subscriptions run over WebSocket and have a different set of params — next, complete, setDelay, variables, and socket. See Subscriptions for the full details.

Resolver params

On this page