fastify parse request

Author: enisdenjo

src/use/fastify.ts

@@ -2,8 +2,11 @@ import type { FastifyRequest, FastifyReply, RouteHandler } from 'fastify';
 import {
   createHandler as createRawHandler,
   HandlerOptions as RawHandlerOptions,
+  Request as RawRequest,
+  parseRequestParams as rawParseRequestParams,
   OperationContext,
 } from '../handler';
+import { RequestParams } from '../common';
 
 /**
  * The context in the request for the handler.
@@ -13,6 +16,62 @@ import {
 export interface RequestContext {
   reply: FastifyReply;
 }
+/**
+ * The GraphQL over HTTP spec compliant request parser for an incoming GraphQL request.
+ *
+ * If the HTTP request _is not_ a [well-formatted GraphQL over HTTP request](https://graphql.github.io/graphql-over-http/draft/#sec-Request), the function will respond
+ * on the `Response` argument and return `null`.
+ *
+ * If the HTTP request _is_ a [well-formatted GraphQL over HTTP request](https://graphql.github.io/graphql-over-http/draft/#sec-Request), but is invalid or malformed,
+ * the function will throw an error and it is up to the user to handle and respond as they see fit.
+ *
+ * ```js
+ * import Fastify from 'fastify'; // yarn add fastify
+ * import { parseRequestParams } from 'graphql-http/lib/use/fastify';
+ *
+ * const fastify = Fastify();
+ * fastify.all('/graphql', async (req, reply) => {
+ *   try {
+ *     const maybeParams = await parseRequestParams(req, reply);
+ *     if (!maybeParams) {
+ *       // not a well-formatted GraphQL over HTTP request,
+ *       // parser responded and there's nothing else to do
+ *       return;
+ *     }
+ *
+ *     // well-formatted GraphQL over HTTP request,
+ *     // with valid parameters
+ *     reply.status(200).send(JSON.stringify(maybeParams, null, '  '));
+ *   } catch (err) {
+ *     // well-formatted GraphQL over HTTP request,
+ *     // but with invalid parameters
+ *     reply.status(400).send(err.message);
+ *   }
+ * });
+ *
+ * fastify.listen({ port: 4000 });
+ * console.log('Listening to port 4000');
+ * ```
+ *
+ * @category Server/fastify
+ */
+export async function parseRequestParams(
+  req: FastifyRequest,
+  reply: FastifyReply,
+): Promise<RequestParams | null> {
+  const rawReq = toRequest(req, reply);
+  const paramsOrRes = await rawParseRequestParams(rawReq);
+  if (!('query' in paramsOrRes)) {
+    const [body, init] = paramsOrRes;
+    reply
+      .status(init.status)
+      .headers(init.headers || {})
+      // "or undefined" because `null` will be JSON stringified
+      .send(body || undefined);
+    return null;
+  }
+  return paramsOrRes;
+}
 
 /**
  * Handler options when using the fastify adapter.
@@ -46,15 +105,7 @@ export function createHandler<Context extends OperationContext = undefined>(
   const handle = createRawHandler(options);
   return async function requestListener(req, reply) {
     try {
-      const [body, init] = await handle({
-        url: req.url,
-        method: req.method,
-        headers: req.headers,
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        body: req.body as any,
-        raw: req,
-        context: { reply },
-      });
+      const [body, init] = await handle(toRequest(req, reply));
       reply
         .status(init.status)
         .headers(init.headers || {})
@@ -72,3 +123,18 @@ export function createHandler<Context extends OperationContext = undefined>(
     }
   };
 }
+
+function toRequest(
+  req: FastifyRequest,
+  reply: FastifyReply,
+): RawRequest<FastifyRequest, RequestContext> {
+  return {
+    url: req.url,
+    method: req.method,
+    headers: req.headers,
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    body: req.body as any,
+    raw: req,
+    context: { reply },
+  };
+}