feat: add voting route

src/api/routes/channels/#channel_id/polls/#poll_id/answers/@me.ts

@@ -0,0 +1,72 @@
+/*
+  Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
+  Copyright (C) 2026 Spacebar and Spacebar Contributors
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU Affero General Public License as published
+  by the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { Request, Response, Router } from "express";
+import { route } from "@spacebar/api/util/handlers/route";
+import { PollAnswerCount, PollUserAnswersSchema } from "@spacebar/schemas";
+import { Message } from "#database";
+import { DiscordApiErrors, ErrorList, FieldError, makeObjectErrorContent } from "#util";
+
+const router: Router = Router({ mergeParams: true });
+
+router.put("/", route({ requestBody: "PollUserAnswersSchema", permission: "VIEW_CHANNEL" }), async (req: Request, res: Response) => {
+    const payload = req.body as PollUserAnswersSchema;
+    const { poll_id } = req.params as { [key: string]: string };
+
+    const message = await Message.findOne({ where: { id: poll_id } });
+
+    if (!message || !message.poll || !message.poll.results) {
+        throw DiscordApiErrors.UNKNOWN_MESSAGE;
+    }
+
+    if (new Date() > new Date(message.poll.expiry)) {
+        throw DiscordApiErrors.POLL_EXPIRED;
+    }
+
+    if (!message.poll.allow_multiselect && payload.answer_ids.length > 1) {
+        const errors: ErrorList = {};
+        errors["answer_ids"] = makeObjectErrorContent("CANNOT_ADD_MULTIPLE_POLL_ANSWERS", "Multiple votes are not allowed for this poll.");
+        throw new FieldError(50035, "Invalid form body", errors);
+    }
+
+    const allAnswerCounts = message.poll.results.answer_counts as unknown as (Omit<PollAnswerCount, "me_voted"> & { voters: string[] })[];
+
+    for (const answer_id of payload.answer_ids) {
+        let answerCount = allAnswerCounts.find((a) => a.id === answer_id);
+
+        if (!answerCount) {
+            allAnswerCounts.push({ id: answer_id, count: 0, voters: [] });
+            answerCount = allAnswerCounts.find((a) => a.id === answer_id)!;
+        }
+
+        if (!answerCount.voters.includes(req.user_id)) {
+            answerCount.voters.push(req.user_id);
+            answerCount.count = answerCount.voters.length;
+        }
+    }
+
+    for (const answerCount of allAnswerCounts.filter((a) => !payload.answer_ids.includes(a.id))) {
+        answerCount.voters = answerCount.voters.filter((voter) => voter != req.user_id);
+        answerCount.count = answerCount.voters.length;
+    }
+
+    await message.save();
+    res.send();
+});
+
+export default router;

src/schemas/api/messages/Polls.ts

@@ -46,3 +46,7 @@ export interface PollAnswerCount {
     count: number;
     me_voted: boolean;
 }
+
+export interface PollUserAnswersSchema {
+    answer_ids: string[];
+}

src/util/util/Constants.ts

@@ -659,6 +659,8 @@ export const DiscordApiErrors = {
     STICKER_ANIMATION_DURATION_MAXIMUM: new ApiError("Sticker animation duration exceeds maximum of {} seconds", 170007, undefined, ["5"]),
     AUTOMODERATOR_BLOCK: new ApiError("Message was blocked by automatic moderation", 200000),
     BULK_BAN_FAILED: new ApiError("Failed to ban users", 500000),
+    POLL_VOTING_BLOCKED: new ApiError("Poll voting blocked", 520000),
+    POLL_EXPIRED: new ApiError("Poll expired", 520001),
 
     //Other errors
     UNKNOWN_VOICE_STATE: new ApiError("Unknown Voice State", 10065, 404),