Don't try (and fail) to show replies for redacted events

src/utils/Reply.ts

@@ -18,13 +18,14 @@ import { IContent, MatrixEvent } from "matrix-js-sdk/src/models/event";
 import sanitizeHtml from "sanitize-html";
 import escapeHtml from "escape-html";
 import { THREAD_RELATION_TYPE } from "matrix-js-sdk/src/models/thread";
+import { MsgType } from "matrix-js-sdk/src/@types/event";
 
 import { PERMITTED_URL_SCHEMES } from "../HtmlUtils";
 import { makeUserPermalink, RoomPermalinkCreator } from "./permalinks/Permalinks";
 import { RecursivePartial } from "../@types/common";
 import SettingsStore from "../settings/SettingsStore";
 
-export function getParentEventId(ev: MatrixEvent): string | undefined {
+export function getParentEventId(ev?: MatrixEvent): string | undefined {
     if (!ev || ev.isRedacted()) return;
     if (ev.replyEventId) {
         return ev.replyEventId;
@@ -70,7 +71,7 @@ export function getNestedReplyText(
 ): { body: string, html: string } | null {
     if (!ev) return null;
 
-    let { body, formatted_body: html } = ev.getContent();
+    let { body, formatted_body: html, msgtype } = ev.getContent();
     if (getParentEventId(ev)) {
         if (body) body = stripPlainReply(body);
     }
@@ -94,9 +95,9 @@ export function getNestedReplyText(
     const mxid = ev.getSender();
 
     // This fallback contains text that is explicitly EN.
-    switch (ev.getContent().msgtype) {
-        case 'm.text':
-        case 'm.notice': {
+    switch (msgtype) {
+        case MsgType.Text:
+        case MsgType.Notice: {
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> <a href="${userLink}">${mxid}</a>`
                 + `<br>${html}</blockquote></mx-reply>`;
             const lines = body.trim().split('\n');
@@ -106,27 +107,27 @@ export function getNestedReplyText(
             }
             break;
         }
-        case 'm.image':
+        case MsgType.Image:
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> <a href="${userLink}">${mxid}</a>`
                 + `<br>sent an image.</blockquote></mx-reply>`;
             body = `> <${mxid}> sent an image.\n\n`;
             break;
-        case 'm.video':
+        case MsgType.Video:
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> <a href="${userLink}">${mxid}</a>`
                 + `<br>sent a video.</blockquote></mx-reply>`;
             body = `> <${mxid}> sent a video.\n\n`;
             break;
-        case 'm.audio':
+        case MsgType.Audio:
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> <a href="${userLink}">${mxid}</a>`
                 + `<br>sent an audio file.</blockquote></mx-reply>`;
             body = `> <${mxid}> sent an audio file.\n\n`;
             break;
-        case 'm.file':
+        case MsgType.File:
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> <a href="${userLink}">${mxid}</a>`
                 + `<br>sent a file.</blockquote></mx-reply>`;
             body = `> <${mxid}> sent a file.\n\n`;
             break;
-        case 'm.emote': {
+        case MsgType.Emote: {
             html = `<mx-reply><blockquote><a href="${evLink}">In reply to</a> * `
                 + `<a href="${userLink}">${mxid}</a><br>${html}</blockquote></mx-reply>`;
             const lines = body.trim().split('\n');
@@ -173,6 +174,10 @@ export function makeReplyMixIn(ev?: MatrixEvent): RecursivePartial<IContent> {
 }
 
 export function shouldDisplayReply(event: MatrixEvent): boolean {
+    if (event.isRedacted()) {
+        return false;
+    }
+
     const inReplyTo = event.getWireContent()?.["m.relates_to"]?.["m.in_reply_to"];
     if (!inReplyTo) {
         return false;

test/Reply-test.ts

@@ -0,0 +1,148 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import './skinned-sdk';
+import {
+    getNestedReplyText,
+    getParentEventId,
+    shouldDisplayReply,
+    stripHTMLReply,
+    stripPlainReply,
+} from "../src/utils/Reply";
+import { mkEvent } from "./test-utils";
+import { RoomPermalinkCreator } from "../src/utils/permalinks/Permalinks";
+
+// don't litter test console with logs
+jest.mock("matrix-js-sdk/src/logger");
+
+describe("Reply", () => {
+    describe("getParentEventId", () => {
+        it("returns undefined if given a falsey value", async () => {
+            expect(getParentEventId()).toBeUndefined();
+        });
+        it("returns undefined if given a redacted event", async () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {},
+            });
+            event.makeRedacted(event);
+
+            expect(getParentEventId(event)).toBeUndefined();
+        });
+        it("returns undefined if the given event is not a reply", async () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {},
+            });
+
+            expect(getParentEventId(event)).toBeUndefined();
+        });
+        it("returns id of the event being replied to", async () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {
+                    "m.relates_to": {
+                        "m.in_reply_to": {
+                            "event_id": "$event1",
+                        },
+                    },
+                },
+            });
+
+            expect(getParentEventId(event)).toBe("$event1");
+        });
+    });
+
+    describe("stripPlainReply", () => {
+        it("Removes leading quotes until the first blank line", () => {
+            expect(stripPlainReply(`
+> This is part
+> of the quote
+
+But this is not
+            `.trim())).toBe("But this is not");
+        });
+    });
+
+    describe("stripHTMLReply", () => {
+        it("Removes <mx-reply> from the input", () => {
+            expect(stripHTMLReply(`
+                <mx-reply>
+                    This is part
+                    of the quote
+                </mx-reply>
+                But this is not
+            `).trim()).toBe("But this is not");
+        });
+    });
+
+    describe("getNestedReplyText", () => {
+        it("Returns valid reply fallback text for m.text msgtypes", () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {
+                    body: "body",
+                    msgtype: "m.text",
+                },
+            });
+
+            expect(getNestedReplyText(event, {
+                forEvent(eventId: string): string {
+                    return "$$permalink$$";
+                },
+            } as RoomPermalinkCreator)).toMatchSnapshot();
+        });
+    });
+
+    describe("shouldDisplayReply", () => {
+        it("Returns false for redacted events", () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {},
+            });
+            event.makeRedacted(event);
+
+            expect(shouldDisplayReply(event)).toBe(false);
+        });
+
+        it("Returns false for non-reply events", () => {
+            const event = mkEvent({
+                event: true,
+                type: "m.room.message",
+                user: "@user1:server",
+                room: "!room1:server",
+                content: {},
+            });
+
+            expect(shouldDisplayReply(event)).toBe(false);
+        });
+    });
+});

test/__snapshots__/Reply-test.ts.snap

@@ -0,0 +1,10 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Reply getNestedReplyText Returns valid reply fallback text for m.text msgtypes 1`] = `
+Object {
+  "body": "> <@user1:server> body
+
+",
+  "html": "<mx-reply><blockquote><a href=\\"$$permalink$$\\">In reply to</a> <a href=\\"https://matrix.to/#/@user1:server\\">@user1:server</a><br>body</blockquote></mx-reply>",
+}
+`;