Prefinem/lambdify

const event = (originalEvent = {}, body = {}, overrides = {}) => ({
  ...originalEvent,
  ...overrides,
  body: JSON.stringify(body),
  headers: {
    ...originalEvent.headers,
    ...overrides.headers,
  },
  pathParameters: {
    ...originalEvent.pathParameters,
    ...overrides.pathParameters,
  },
  queryStringParameters: {
    ...originalEvent.queryStringParameters,
    ...overrides.queryStringParameters,
  },
  requestContext: {
    ...originalEvent.requestContext,
    ...overrides.requestContext,
    identity: {
      ...(originalEvent.requestContext ? originalEvent.requestContext.identity : {}),
      ...(overrides.requestContext ? overrides.requestContext.identity : {}),
    },
  },
});

module.exports = event;