feat(chat): right-click menus everywhere in the chat, and deleting your own message

Rail: a room — open, mark as read, mute / unmute notifications (per browser,
the unread count still shows), copy name, group settings, leave; the pet and
+ — chat with the pet, new chat, mark all chats as read. A message — copy
text, reply (quotes it into the box), message the sender privately (group),
delete your own (asks first). A file — open in a new tab, download, copy file
name. A group member — message privately, copy name, remove (the creator).

DELETE /api/chat/rooms/:id/messages/:messageId deletes the caller's OWN text
message and its files (403 for anyone else, an admin included) and tells the
members with a chat_deleted frame (exactAudience).

server/__tests__/chat.test.js

@@ -3,7 +3,8 @@
  * @description Chat between users (server/lib/chat.js, server/routes/chat.js):
  * a direct chat is one per pair, a group's creator alone changes it, only a
  * room's members read it — an admin included —, unread counts and read marks,
- * files served only to members under a sandbox CSP, local mode refused, and
+ * files served only to members under a sandbox CSP, a message deleted only by
+ * its author, local mode refused, and
  * every chat frame reaches exactly the users in its `to` (scope.exactAudience).
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
@@ -151,6 +152,22 @@ describe("chat", () => {
     );
   });
 
+  it("lets only the author delete a message, its files too", async () => {
+    const fd = new FormData();
+    fd.append("body", "xoá tôi");
+    fd.append("files", new Blob(["x"], { type: "text/plain" }), "a.txt");
+    const m = (await call(2, "POST", `/rooms/${group}/messages`, fd)).body.message;
+    assert.equal((await call(3, "DELETE", `/rooms/${group}/messages/${m.id}`)).status, 403);
+    assert.equal((await call(1, "DELETE", `/rooms/${group}/messages/${m.id}`)).status, 404);
+    assert.equal((await call(2, "DELETE", `/rooms/${group}/messages/${m.id}`)).status, 200);
+    const left = (await call(2, "GET", `/rooms/${group}/messages`)).body.messages;
+    assert.ok(!left.some((x) => x.id === m.id));
+    assert.equal((await call(2, "GET", `/rooms/${group}/files/${m.files[0].id}`)).status, 404);
+    // A system line is nobody's to delete.
+    const sys = left.find((x) => x.kind === "system");
+    assert.equal((await call(2, "DELETE", `/rooms/${group}/messages/${sys.id}`)).status, 403);
+  });
+
   it("refuses an empty message", async () => {
     assert.equal((await call(2, "POST", `/rooms/${dm}/messages`, { body: "  " })).status, 400);
   });

server/lib/chat.js

@@ -5,7 +5,7 @@
  * per pair of users) or a group anyone may start and name. Only a room's
  * MEMBERS read or write it — an admin or analyst included, and there is no
  * route that lists another user's rooms. A group's creator adds, removes and
- * renames; any member may leave. A message is text (≤ 8000 chars) and up to
+ * renames; any member may leave; anyone deletes their own messages (only). A message is text (≤ 8000 chars) and up to
  * `MAX_FILES` files of ≤ `MAX_FILE_BYTES` each, stored once under
  * `<data dir>/chat/<room id>/<random id>` — a name the server makes, never one
  * from the request — and served back only to the room's members (the route
@@ -349,6 +349,31 @@ function markRead(me, roomId, upTo) {
   return { lastReadId: Math.max(n, 0) };
 }
 
+/**
+ * `me` deletes their OWN text message (and its files) — never anyone else's,
+ * an admin included. Answers who to tell (every member).
+ */
+function removeMessage(me, roomId, messageId) {
+  const room = roomFor(me, roomId);
+  const id = Number(messageId);
+  const m = Number.isSafeInteger(id)
+    ? sql("SELECT * FROM chat_messages WHERE id = ? AND room_id = ?").get(id, room.id)
+    : null;
+  if (!m) throw err("ENOTFOUND", "no such message", 404);
+  if (m.user_id !== me || m.kind !== "text")
+    throw err("EFORBIDDEN", "only your own messages can be deleted", 403);
+  const files = sql("SELECT id FROM chat_files WHERE message_id = ?").all(id);
+  db().transaction(() => {
+    sql("DELETE FROM chat_messages WHERE id = ?").run(id);
+    const last = sql("SELECT MAX(created_at) AS at FROM chat_messages WHERE room_id = ?").get(
+      room.id
+    );
+    sql("UPDATE chat_rooms SET last_message_at = ? WHERE id = ?").run(last.at ?? null, room.id);
+  })();
+  for (const f of files) fs.rmSync(path.join(fileDir(room.id), f.id), { force: true });
+  return { notify: memberIds(room.id) };
+}
+
 /** A file of a room `me` is in: `{path, name, type, inline}`. */
 function file(me, roomId, fileId) {
   const room = roomFor(me, roomId);
@@ -372,6 +397,7 @@ module.exports = {
   messages,
   post,
   markRead,
+  removeMessage,
   file,
   roomFor,
   shapeRoom,

server/lib/scope.js

@@ -347,7 +347,7 @@ function exactAudience(type, data) {
   const d = data && typeof data === "object" ? data : {};
   // Chat (server/lib/chat.js): only the room's members, whatever their role —
   // an admin reads no one else's chat. No list = nobody.
-  if (type === "chat_message" || type === "chat_room") {
+  if (type === "chat_message" || type === "chat_room" || type === "chat_deleted") {
     return new Set(Array.isArray(d.to) ? d.to : []);
   }
   if (type === "cc_config_changed" && d.ownerId != null) return new Set([d.ownerId]);

server/openapi-extra/chat.js

@@ -239,6 +239,25 @@ const paths = {
       },
     },
   },
+  "/api/chat/rooms/{id}/messages/{messageId}": {
+    delete: {
+      tags: ["Chat"],
+      summary: "Delete your own message",
+      description:
+        "Only the message's author (`403 EFORBIDDEN`, an admin included); its files go with it. Broadcasts `chat_deleted` to the members.",
+      parameters: [
+        idParam,
+        { name: "messageId", in: "path", required: true, schema: { type: "integer" } },
+      ],
+      responses: {
+        200: {
+          description: "Deleted",
+          ...json({ type: "object", properties: { ok: { type: "boolean" } } }),
+        },
+        ...fail([403, 404]),
+      },
+    },
+  },
   "/api/chat/rooms/{id}/read": {
     post: {
       tags: ["Chat"],

server/routes/chat.js

@@ -6,7 +6,7 @@
  * multipart `POST`), read marks and a room's files. Everything acts on the
  * CALLER's own rooms (`server/lib/chat.js`): a room they are not in is 404,
  * whatever their role. Local mode has one person and no chat (`400 ELOCALMODE`).
- * Each change is broadcast as `chat_message` / `chat_room` to exactly the
+ * Each change is broadcast as `chat_message` / `chat_room` / `chat_deleted` to exactly the
  * users concerned (`to`, `scope.exactAudience`).
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
@@ -139,6 +139,17 @@ router.post("/rooms/:id/messages", sameOriginGuard, upload, (req, res) =>
   })(req, res)
 );
 
+router.delete(
+  "/rooms/:id/messages/:messageId",
+  sameOriginGuard,
+  handle((me, req, res) => {
+    const { notify } = chat.removeMessage(me, req.params.id, req.params.messageId);
+    const roomId = Number(req.params.id);
+    tell("chat_deleted", { roomId, messageId: Number(req.params.messageId) }, notify);
+    res.json({ ok: true });
+  })
+);
+
 router.post(
   "/rooms/:id/read",
   sameOriginGuard,