feat(custom-routes): expose query params on request object

src/index.ts

@@ -68,6 +68,7 @@ export {
   RequestVerificationOptions,
 } from './receivers/HTTPModuleFunctions';
 export type { HTTPReceiverOptions } from './receivers/HTTPReceiver';
+export type { ParamsIncomingMessage, QueryDictionary } from './receivers/ParamsIncomingMessage';
 export { HTTPResponseAck } from './receivers/HTTPResponseAck';
 export {
   defaultProcessEventErrorHandler,

src/receivers/HTTPReceiver.ts

@@ -31,7 +31,7 @@ import type { BufferedIncomingMessage } from './BufferedIncomingMessage';
 import { buildReceiverRoutes, type CustomRoute, type ReceiverRoutes } from './custom-routes';
 import * as httpFunc from './HTTPModuleFunctions';
 import { HTTPResponseAck } from './HTTPResponseAck';
-import type { ParamsIncomingMessage } from './ParamsIncomingMessage';
+import type { ParamsIncomingMessage, QueryDictionary } from './ParamsIncomingMessage';
 import { verifyRedirectOpts } from './verify-redirect-opts';
 
 // Option keys for tls.createServer() and tls.createSecureContext(), exclusive of those for http.createServer()
@@ -413,7 +413,9 @@ export default class HTTPReceiver implements Receiver {
       const pathMatch = matchRegex(path);
       if (pathMatch && this.routes[route][method] !== undefined) {
         const params = pathMatch.params as ParamsDictionary;
-        const message: ParamsIncomingMessage = Object.assign(req, { params });
+        const parsedUrl = new URL(req.url as string, 'http://localhost');
+        const query = parseSearchParams(parsedUrl.searchParams);
+        const message: ParamsIncomingMessage = Object.assign(req, { params, query });
         return this.routes[route][method](message, res);
       }
     }
@@ -567,3 +569,12 @@ export default class HTTPReceiver implements Receiver {
     }
   }
 }
+
+function parseSearchParams(searchParams: URLSearchParams): QueryDictionary {
+  const query: QueryDictionary = {};
+  for (const key of searchParams.keys()) {
+    const values = searchParams.getAll(key);
+    query[key] = values.length === 1 ? values[0] : values;
+  }
+  return query;
+}

src/receivers/ParamsIncomingMessage.ts

@@ -1,6 +1,8 @@
 import type { IncomingMessage } from 'node:http';
 import type { ParamsDictionary } from 'express-serve-static-core';
 
+export type QueryDictionary = Record<string, string | string[] | undefined>;
+
 export interface ParamsIncomingMessage extends IncomingMessage {
   /**
    * **Only valid for requests with path parameters.**
@@ -10,4 +12,11 @@ export interface ParamsIncomingMessage extends IncomingMessage {
    * then `request.params` will be `{ id: '123' }`.
    */
   params?: ParamsDictionary;
+
+  /**
+   * The query parameters of the request. For example, if the request URL is
+   * `/greetings?name=you&tags=a&tags=b`, then `request.query` will be
+   * `{ name: 'you', tags: ['a', 'b'] }`.
+   */
+  query?: QueryDictionary;
 }

src/receivers/SocketModeReceiver.ts

@@ -17,7 +17,7 @@ import type { CodedError } from '../errors';
 import type { Receiver, ReceiverEvent } from '../types';
 import type { StringIndexed } from '../types/utilities';
 import { buildReceiverRoutes, type ReceiverRoutes } from './custom-routes';
-import type { ParamsIncomingMessage } from './ParamsIncomingMessage';
+import type { ParamsIncomingMessage, QueryDictionary } from './ParamsIncomingMessage';
 import {
   defaultProcessEventErrorHandler,
   type SocketModeReceiverProcessEventErrorHandlerArgs,
@@ -209,15 +209,17 @@ export default class SocketModeReceiver implements Receiver {
         if (customRoutes.length && req.url) {
           // NOTE: the domain and scheme are irrelevant here.
           // The URL object is only used to safely obtain the path to match
-          const { pathname: path } = new URL(req.url as string, 'http://localhost');
+          const parsedUrl = new URL(req.url as string, 'http://localhost');
+          const { pathname: path } = parsedUrl;
           const routes = Object.keys(this.routes);
           for (let i = 0; i < routes.length; i += 1) {
             const route = routes[i];
             const matchRegex = match(route, { decode: decodeURIComponent });
             const pathMatch = matchRegex(path);
             if (pathMatch && this.routes[route][method] !== undefined) {
               const params = pathMatch.params as ParamsDictionary;
-              const message: ParamsIncomingMessage = Object.assign(req, { params });
+              const query = parseSearchParams(parsedUrl.searchParams);
+              const message: ParamsIncomingMessage = Object.assign(req, { params, query });
               this.routes[route][method](message, res);
               return;
             }
@@ -291,3 +293,12 @@ export default class SocketModeReceiver implements Receiver {
     });
   }
 }
+
+function parseSearchParams(searchParams: URLSearchParams): QueryDictionary {
+  const query: QueryDictionary = {};
+  for (const key of searchParams.keys()) {
+    const values = searchParams.getAll(key);
+    query[key] = values.length === 1 ? values[0] : values;
+  }
+  return query;
+}