Refactor reaction removals and add tests

d2m/converters/remove-reaction.js

@@ -0,0 +1,88 @@
+// @ts-check
+
+const Ty = require("../../types")
+const DiscordTypes = require("discord-api-types/v10")
+
+const passthrough = require("../../passthrough")
+const {discord, sync, select} = passthrough
+/** @type {import("../../m2d/converters/utils")} */
+const utils = sync.require("../../m2d/converters/utils")
+
+/**
+ * @typedef ReactionRemoveRequest
+ * @prop {string} eventID
+ * @prop {string | null} mxid
+ * @prop {BigInt} [hash]
+ */
+
+/**
+ * @param {DiscordTypes.GatewayMessageReactionRemoveDispatchData} data
+ * @param {Ty.Pagination<Ty.Event.Outer<Ty.Event.M_Reaction>>} relations
+ * @param {string} key
+ */
+function removeReaction(data, relations, key) {
+	/** @type {ReactionRemoveRequest[]} */
+	const removals = []
+
+	const wantToRemoveMatrixReaction = data.user_id === discord.application.id
+	for (const event of relations.chunk) {
+		const eventID = event.event_id
+		if (event.content["m.relates_to"].key === key) {
+			const lookingAtMatrixReaction = !utils.eventSenderIsFromDiscord(event.sender)
+			if (lookingAtMatrixReaction && wantToRemoveMatrixReaction) {
+				// We are removing a Matrix user's reaction, so we need to redact from the correct user ID (not @_ooye_matrix_bridge).
+				// Even though the bridge bot only reacted once on Discord-side, multiple Matrix users may have
+				// reacted on Matrix-side. Semantically, we want to remove the reaction from EVERY Matrix user.
+				// Also need to clean up the database.
+				const hash = utils.getEventIDHash(event.event_id)
+				removals.push({eventID, mxid: null, hash})
+			}
+			if (!lookingAtMatrixReaction && !wantToRemoveMatrixReaction) {
+				// We are removing a Discord user's reaction, so we just make the sim user remove it.
+				const mxid = select("sim", "mxid", {user_id: data.user_id}).pluck().get()
+				if (mxid === event.sender) {
+					removals.push({eventID, mxid})
+				}
+			}
+		}
+	}
+
+	return removals
+}
+
+/**
+ * @param {DiscordTypes.GatewayMessageReactionRemoveEmojiDispatchData} data
+ * @param {Ty.Pagination<Ty.Event.Outer<Ty.Event.M_Reaction>>} relations
+ * @param {string} key
+ */
+function removeEmojiReaction(data, relations, key) {
+	/** @type {ReactionRemoveRequest[]} */
+	const removals = []
+
+	for (const event of relations.chunk) {
+		const eventID = event.event_id
+		if (event.content["m.relates_to"].key === key) {
+			const mxid = utils.eventSenderIsFromDiscord(event.sender) ? event.sender : null
+			removals.push({eventID, mxid})
+		}
+	}
+
+	return removals
+}
+
+/**
+ * @param {DiscordTypes.GatewayMessageReactionRemoveAllDispatchData} data
+ * @param {Ty.Pagination<Ty.Event.Outer<Ty.Event.M_Reaction>>} relations
+ * @returns {ReactionRemoveRequest[]}
+ */
+function removeAllReactions(data, relations) {
+	return relations.chunk.map(event => {
+		const eventID = event.event_id
+		const mxid = utils.eventSenderIsFromDiscord(event.sender) ? event.sender : null
+		return {eventID, mxid}
+	})
+}
+
+module.exports.removeReaction = removeReaction
+module.exports.removeEmojiReaction = removeEmojiReaction
+module.exports.removeAllReactions = removeAllReactions