Recursively remove __typename properties from a GraphQL response.

strip-typename.ts

/**
 * Recursively remove __typename properties from a GraphQL response.
 *
 * @param response The GraphQL response object.
 * @return The cleaned response object.
 */
function stripTypename(response: any): any {
  if (Array.isArray(response)) {
    return response.map(stripTypename);
  }
  if (typeof response === 'object' && response !== null) {
    return Object.fromEntries(
      Object.entries(response)
        .filter(([key]) => key !== '__typename')
        .map(([key, value]) => [key, stripTypename(value)]),
    );
  }
  return response;
}

const response = {
  data: {
    __typename: 'Query',
    user: {
      __typename: 'User',
      id: '1',
      name: 'John Doe',
      posts: [
        {
          __typename: 'Post',
          id: '1',
          title: 'First post',
        },
        {
          __typename: 'Post',
          id: '2',
          title: 'Second post',
        },
      ],
    },
  },
};

console.log(stripTypename(response));