example.ts

import { schema } from '~/graphql/index';
import { Context, createGraphQLContext } from '~/graphql/builder';
import {
	getGraphQLParameters,
	processRequest,
	renderGraphiQL,
	shouldRenderGraphiQL,
} from 'graphql-helix';
import { NextApiHandler } from 'next';
import { ExecutionResult, GraphQLError } from 'graphql';
import { IncomingHttpHeaders } from 'http';
import { resolveSession } from '~/utils/sessions';

const handler: NextApiHandler = async (req, res) => {
	const session = await resolveSession({ req, res });

	try {
		const request: GraphQLRequest = {
			headers: req.headers,
			method: req.method ?? 'GET',
			query: req.query,
			body: req.body,
		};

		if (shouldRenderGraphiQL(request)) {
			res.setHeader('Content-Type', 'text/html');
			res.send(
				renderGraphiQL({
					endpoint: '/api/graphql',
					headers: JSON.stringify({
						'X-CSRF-Trick': 'Charity',
					}),
				}),
			);
		} else {
			const { operationName, query, variables } = getGraphQLParameters(request);

			const result = await processRequest<Context>({
				operationName,
				query,
				variables,
				request,
				schema,
				contextFactory: () => createGraphQLContext(req, res, session),
			});

			if (result.type !== 'RESPONSE') {
				throw new Error(`Unsupported response type: "${result.type}"`);
			}

			result.headers.forEach(({ name, value }) => res.setHeader(name, value));
			res.status(result.status);
			res.json(formatResult(result.payload));
		}
	} catch (err) {
		res.status(500);
		res.end(String(err));
	}
};

export default handler;