diff --git a/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/default-auto.png b/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/default-auto.png
new file mode 100644
index 0000000000..92a5f4d367
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diff --git a/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/many-senders-auto.png b/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/many-senders-auto.png
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diff --git a/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/no-tooltip-auto.png b/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/no-tooltip-auto.png
new file mode 100644
index 0000000000..dcbe7310d6
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diff --git a/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/without-caption-auto.png b/packages/shared-components/__vis__/linux/__baselines__/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx/without-caption-auto.png
new file mode 100644
index 0000000000..e711eb4649
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diff --git a/packages/shared-components/src/index.ts b/packages/shared-components/src/index.ts
index b33af6c9ff..6ae20f6069 100644
--- a/packages/shared-components/src/index.ts
+++ b/packages/shared-components/src/index.ts
@@ -15,6 +15,7 @@ export * from "./composer/Banner";
export * from "./crypto/SasEmoji";
export * from "./event-tiles/TextualEventView";
export * from "./message-body/MediaBody";
+export * from "./message-body/ReactionsRowButtonTooltip";
export * from "./pill-input/Pill";
export * from "./pill-input/PillInput";
export * from "./room/RoomStatusBar";
diff --git a/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx
new file mode 100644
index 0000000000..ff8fa315b5
--- /dev/null
+++ b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.stories.tsx
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import React, { type JSX, type PropsWithChildren } from "react";
+
+import type { Meta, StoryFn } from "@storybook/react-vite";
+import { useMockedViewModel } from "../../viewmodel";
+import {
+ ReactionsRowButtonTooltipView,
+ type ReactionsRowButtonTooltipViewSnapshot,
+} from "./ReactionsRowButtonTooltipView";
+
+type WrapperProps = ReactionsRowButtonTooltipViewSnapshot & PropsWithChildren;
+
+const ReactionsRowButtonTooltipViewWrapper = ({ children, ...snapshotProps }: WrapperProps): JSX.Element => {
+ const vm = useMockedViewModel(snapshotProps, {});
+ return {children};
+};
+
+export default {
+ title: "MessageBody/ReactionsRowButtonTooltip",
+ component: ReactionsRowButtonTooltipViewWrapper,
+ tags: ["autodocs"],
+ argTypes: {
+ formattedSenders: { control: "text" },
+ caption: { control: "text" },
+ },
+ args: {
+ children: ,
+ },
+} as Meta;
+
+const Template: StoryFn = (args) => (
+
+);
+
+export const Default = Template.bind({});
+Default.args = {
+ formattedSenders: "Alice, Bob and Charlie",
+ caption: ":thumbsup:",
+ tooltipOpen: true,
+};
+
+export const ManySenders = Template.bind({});
+ManySenders.args = {
+ formattedSenders: "Alice, Bob, Charlie, David, Eve, Frank and 2 others",
+ caption: ":heart:",
+ children: ,
+ tooltipOpen: true,
+};
+
+export const WithoutCaption = Template.bind({});
+WithoutCaption.args = {
+ formattedSenders: "Alice and Bob",
+ caption: undefined,
+ children: ,
+ tooltipOpen: true,
+};
+
+export const NoTooltip = Template.bind({});
+NoTooltip.args = {
+ formattedSenders: undefined,
+ caption: undefined,
+ children: ,
+};
diff --git a/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.test.tsx b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.test.tsx
new file mode 100644
index 0000000000..4c48d0d789
--- /dev/null
+++ b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltip.test.tsx
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import { composeStories } from "@storybook/react-vite";
+import { render } from "@test-utils";
+import React from "react";
+import { describe, it, expect } from "vitest";
+
+import * as stories from "./ReactionsRowButtonTooltip.stories";
+
+const { Default, ManySenders } = composeStories(stories);
+
+describe("ReactionsRowButtonTooltip", () => {
+ it("renders the tooltip with formatted senders and caption", () => {
+ const { container } = render();
+ expect(container).toMatchSnapshot();
+ });
+
+ it("renders the tooltip with many senders", () => {
+ const { container } = render();
+ expect(container).toMatchSnapshot();
+ });
+});
diff --git a/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltipView.tsx b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltipView.tsx
new file mode 100644
index 0000000000..b8eb50f03c
--- /dev/null
+++ b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/ReactionsRowButtonTooltipView.tsx
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import { type PropsWithChildren, type JSX } from "react";
+import React from "react";
+import { Tooltip } from "@vector-im/compound-web";
+
+import { type ViewModel, useViewModel } from "../../viewmodel";
+
+/**
+ * Snapshot interface for the ReactionsRowButtonTooltip view.
+ */
+export interface ReactionsRowButtonTooltipViewSnapshot {
+ /**
+ * The formatted list of sender names who reacted.
+ */
+ formattedSenders?: string;
+ /**
+ * The caption to display (e.g., the shortcode of the reaction).
+ */
+ caption?: string;
+ /**
+ * Whether the tooltip should be forced open.
+ */
+ tooltipOpen?: boolean;
+}
+
+export type ReactionsRowButtonTooltipViewModel = ViewModel;
+
+interface ReactionsRowButtonTooltipViewProps {
+ /**
+ * The view model for the reactions row button tooltip.
+ */
+ vm: ReactionsRowButtonTooltipViewModel;
+ /**
+ * The children to wrap with the tooltip.
+ */
+ children?: PropsWithChildren["children"];
+}
+
+/**
+ * Type alias for the ReactionsRowButtonTooltip view model.
+ */
+export function ReactionsRowButtonTooltipView({
+ vm,
+ children,
+}: Readonly): JSX.Element {
+ const { formattedSenders, caption, tooltipOpen } = useViewModel(vm);
+
+ if (formattedSenders) {
+ return (
+
+ {children}
+
+ );
+ }
+
+ return <>{children}>;
+}
diff --git a/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/__snapshots__/ReactionsRowButtonTooltip.test.tsx.snap b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/__snapshots__/ReactionsRowButtonTooltip.test.tsx.snap
new file mode 100644
index 0000000000..4940b975dd
--- /dev/null
+++ b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/__snapshots__/ReactionsRowButtonTooltip.test.tsx.snap
@@ -0,0 +1,21 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`ReactionsRowButtonTooltip > renders the tooltip with formatted senders and caption 1`] = `
+
+
+
+`;
+
+exports[`ReactionsRowButtonTooltip > renders the tooltip with many senders 1`] = `
+
+
+
+`;
diff --git a/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/index.tsx b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/index.tsx
new file mode 100644
index 0000000000..92a8a8d611
--- /dev/null
+++ b/packages/shared-components/src/message-body/ReactionsRowButtonTooltip/index.tsx
@@ -0,0 +1,12 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+export {
+ ReactionsRowButtonTooltipView,
+ type ReactionsRowButtonTooltipViewSnapshot,
+ type ReactionsRowButtonTooltipViewModel,
+} from "./ReactionsRowButtonTooltipView";
diff --git a/src/components/views/messages/ReactionsRowButton.tsx b/src/components/views/messages/ReactionsRowButton.tsx
index 8320237b25..9147d7c1fc 100644
--- a/src/components/views/messages/ReactionsRowButton.tsx
+++ b/src/components/views/messages/ReactionsRowButton.tsx
@@ -9,12 +9,13 @@ Please see LICENSE files in the repository root for full details.
import React from "react";
import classNames from "classnames";
import { EventType, type MatrixEvent, RelationType } from "matrix-js-sdk/src/matrix";
+import { ReactionsRowButtonTooltipView } from "@element-hq/web-shared-components";
import { mediaFromMxc } from "../../../customisations/Media";
import { _t } from "../../../languageHandler";
import { formatList } from "../../../utils/FormattingUtils";
import dis from "../../../dispatcher/dispatcher";
-import ReactionsRowButtonTooltip from "./ReactionsRowButtonTooltip";
+import { ReactionsRowButtonTooltipViewModel } from "../../../viewmodels/message-body/ReactionsRowButtonTooltipViewModel";
import AccessibleButton from "../elements/AccessibleButton";
import MatrixClientContext from "../../../contexts/MatrixClientContext";
import { REACTION_SHORTCODE_KEY } from "./ReactionsRow";
@@ -40,6 +41,41 @@ export default class ReactionsRowButton extends React.PureComponent {
public static contextType = MatrixClientContext;
declare public context: React.ContextType;
+ private reactionsRowButtonTooltipViewModel: ReactionsRowButtonTooltipViewModel;
+
+ public constructor(props: IProps, context: React.ContextType) {
+ super(props, context);
+ this.reactionsRowButtonTooltipViewModel = new ReactionsRowButtonTooltipViewModel({
+ client: context,
+ mxEvent: props.mxEvent,
+ content: props.content,
+ reactionEvents: props.reactionEvents,
+ customReactionImagesEnabled: props.customReactionImagesEnabled,
+ });
+ }
+
+ public componentDidUpdate(prevProps: IProps): void {
+ if (
+ prevProps.mxEvent !== this.props.mxEvent ||
+ prevProps.content !== this.props.content ||
+ prevProps.reactionEvents !== this.props.reactionEvents ||
+ prevProps.customReactionImagesEnabled !== this.props.customReactionImagesEnabled
+ ) {
+ // View model bails out if derived snapshot hasn't changed.
+ this.reactionsRowButtonTooltipViewModel.setProps({
+ client: this.context,
+ mxEvent: this.props.mxEvent,
+ content: this.props.content,
+ reactionEvents: this.props.reactionEvents,
+ customReactionImagesEnabled: this.props.customReactionImagesEnabled,
+ });
+ }
+ }
+
+ public componentWillUnmount(): void {
+ this.reactionsRowButtonTooltipViewModel.dispose();
+ }
+
public onClick = (): void => {
const { mxEvent, myReactionEvent, content } = this.props;
if (myReactionEvent) {
@@ -110,12 +146,7 @@ export default class ReactionsRowButton extends React.PureComponent {
}
return (
-
+
{
{count}
-
+
);
}
}
diff --git a/src/components/views/messages/ReactionsRowButtonTooltip.tsx b/src/components/views/messages/ReactionsRowButtonTooltip.tsx
deleted file mode 100644
index f40002deff..0000000000
--- a/src/components/views/messages/ReactionsRowButtonTooltip.tsx
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
-Copyright 2024 New Vector Ltd.
-Copyright 2019-2021 The Matrix.org Foundation C.I.C.
-
-SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE files in the repository root for full details.
-*/
-
-import React, { type PropsWithChildren } from "react";
-import { type MatrixEvent } from "matrix-js-sdk/src/matrix";
-import { Tooltip } from "@vector-im/compound-web";
-
-import { unicodeToShortcode } from "../../../HtmlUtils";
-import { _t } from "../../../languageHandler";
-import { formatList } from "../../../utils/FormattingUtils";
-import MatrixClientContext from "../../../contexts/MatrixClientContext";
-import { REACTION_SHORTCODE_KEY } from "./ReactionsRow";
-interface IProps {
- // The event we're displaying reactions for
- mxEvent: MatrixEvent;
- // The reaction content / key / emoji
- content: string;
- // A list of Matrix reaction events for this key
- reactionEvents: MatrixEvent[];
- // Whether to render custom image reactions
- customReactionImagesEnabled?: boolean;
-}
-
-export default class ReactionsRowButtonTooltip extends React.PureComponent> {
- public static contextType = MatrixClientContext;
- declare public context: React.ContextType;
-
- public render(): React.ReactNode {
- const { content, reactionEvents, mxEvent, children } = this.props;
-
- const room = this.context.getRoom(mxEvent.getRoomId());
- if (room) {
- const senders: string[] = [];
- let customReactionName: string | undefined;
- for (const reactionEvent of reactionEvents) {
- const member = room.getMember(reactionEvent.getSender()!);
- const name = member?.name ?? reactionEvent.getSender()!;
- senders.push(name);
- customReactionName =
- (this.props.customReactionImagesEnabled &&
- REACTION_SHORTCODE_KEY.findIn(reactionEvent.getContent())) ||
- undefined;
- }
- const shortName = unicodeToShortcode(content) || customReactionName;
- const formattedSenders = formatList(senders, 6);
- const caption = shortName ? _t("timeline|reactions|tooltip_caption", { shortName }) : undefined;
-
- return (
-
- {children}
-
- );
- }
-
- return children;
- }
-}
diff --git a/src/viewmodels/message-body/ReactionsRowButtonTooltipViewModel.ts b/src/viewmodels/message-body/ReactionsRowButtonTooltipViewModel.ts
new file mode 100644
index 0000000000..baa7b77855
--- /dev/null
+++ b/src/viewmodels/message-body/ReactionsRowButtonTooltipViewModel.ts
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import { type MatrixClient, type MatrixEvent } from "matrix-js-sdk/src/matrix";
+import {
+ BaseViewModel,
+ type ReactionsRowButtonTooltipViewSnapshot,
+ type ReactionsRowButtonTooltipViewModel as ReactionsRowButtonTooltipViewModelInterface,
+} from "@element-hq/web-shared-components";
+
+import { _t } from "../../languageHandler";
+import { formatList } from "../../utils/FormattingUtils";
+import { unicodeToShortcode } from "../../HtmlUtils";
+import { REACTION_SHORTCODE_KEY } from "../../components/views/messages/ReactionsRow";
+
+export interface ReactionsRowButtonTooltipViewModelProps {
+ /**
+ * The Matrix client instance.
+ */
+ client: MatrixClient | null;
+ /**
+ * The event we're displaying reactions for.
+ */
+ mxEvent: MatrixEvent;
+ /**
+ * The reaction content / key / emoji.
+ */
+ content: string;
+ /**
+ * A list of Matrix reaction events for this key.
+ */
+ reactionEvents: MatrixEvent[];
+ /**
+ * Whether to render custom image reactions.
+ */
+ customReactionImagesEnabled?: boolean;
+}
+
+/**
+ * ViewModel for the reactions row button tooltip, providing the formatted sender list and caption.
+ */
+export class ReactionsRowButtonTooltipViewModel
+ extends BaseViewModel
+ implements ReactionsRowButtonTooltipViewModelInterface
+{
+ /**
+ * Computes the snapshot for the reactions row button tooltip.
+ * @param props - The view model properties
+ * @returns The computed snapshot with formattedSenders, caption, and children
+ */
+ private static readonly computeSnapshot = (
+ props: ReactionsRowButtonTooltipViewModelProps,
+ ): ReactionsRowButtonTooltipViewSnapshot => {
+ const { client, mxEvent, content, reactionEvents, customReactionImagesEnabled } = props;
+
+ const room = client?.getRoom(mxEvent.getRoomId());
+
+ if (room) {
+ const senders: string[] = [];
+ let customReactionName: string | undefined;
+
+ for (const reactionEvent of reactionEvents) {
+ const member = room.getMember(reactionEvent.getSender()!);
+ const name = member?.name ?? reactionEvent.getSender()!;
+ senders.push(name);
+ customReactionName =
+ (customReactionImagesEnabled && REACTION_SHORTCODE_KEY.findIn(reactionEvent.getContent())) ||
+ undefined;
+ }
+
+ const shortName = unicodeToShortcode(content) || customReactionName;
+ const formattedSenders = formatList(senders, 6);
+ const caption = shortName ? _t("timeline|reactions|tooltip_caption", { shortName }) : undefined;
+
+ return {
+ formattedSenders,
+ caption,
+ };
+ }
+
+ return {
+ formattedSenders: undefined,
+ caption: undefined,
+ };
+ };
+
+ public constructor(props: ReactionsRowButtonTooltipViewModelProps) {
+ super(props, ReactionsRowButtonTooltipViewModel.computeSnapshot(props));
+ }
+
+ /**
+ * Updates the properties of the view model and recomputes the snapshot.
+ * @param newProps - Partial properties to update
+ */
+ public setProps(newProps: Partial): void {
+ this.props = { ...this.props, ...newProps };
+ const nextSnapshot = ReactionsRowButtonTooltipViewModel.computeSnapshot(this.props);
+ const currentSnapshot = this.snapshot.current;
+
+ if (
+ nextSnapshot.formattedSenders === currentSnapshot.formattedSenders &&
+ nextSnapshot.caption === currentSnapshot.caption
+ ) {
+ return;
+ }
+
+ this.snapshot.set(nextSnapshot);
+ }
+}
diff --git a/test/unit-tests/components/views/messages/ReactionsRowButton-test.tsx b/test/unit-tests/components/views/messages/ReactionsRowButton-test.tsx
index 3b4298a61c..ef6fa3ba61 100644
--- a/test/unit-tests/components/views/messages/ReactionsRowButton-test.tsx
+++ b/test/unit-tests/components/views/messages/ReactionsRowButton-test.tsx
@@ -7,19 +7,38 @@ Please see LICENSE files in the repository root for full details.
*/
import React from "react";
-import { type IContent, MatrixEvent, Room } from "matrix-js-sdk/src/matrix";
-import { render } from "jest-matrix-react";
+import { EventType, type IContent, MatrixEvent, RelationType, Room } from "matrix-js-sdk/src/matrix";
+import { fireEvent, render } from "jest-matrix-react";
import MatrixClientContext from "../../../../../src/contexts/MatrixClientContext";
import { getMockClientWithEventEmitter } from "../../../../test-utils";
import ReactionsRowButton, { type IProps } from "../../../../../src/components/views/messages/ReactionsRowButton";
+import dis from "../../../../../src/dispatcher/dispatcher";
+import { type Media, mediaFromMxc } from "../../../../../src/customisations/Media";
+
+jest.mock("../../../../../src/dispatcher/dispatcher");
+
+jest.mock("../../../../../src/customisations/Media", () => ({
+ mediaFromMxc: jest.fn(),
+}));
+
+jest.mock("@element-hq/web-shared-components", () => {
+ const actual = jest.requireActual("@element-hq/web-shared-components");
+ return {
+ ...actual,
+ ReactionsRowButtonTooltipView: ({ children }: { children: React.ReactNode }) => <>{children}>,
+ };
+});
+
+const mockMediaFromMxc = mediaFromMxc as jest.MockedFunction;
describe("ReactionsRowButton", () => {
const userId = "@alice:server";
const roomId = "!randomcharacters:aser.ver";
const mockClient = getMockClientWithEventEmitter({
- mxcUrlToHttp: jest.fn().mockReturnValue("https://not.a.real.url"),
getRoom: jest.fn(),
+ sendEvent: jest.fn().mockResolvedValue({ event_id: "$sent_event" }),
+ redactEvent: jest.fn().mockResolvedValue({}),
});
const room = new Room(roomId, mockClient, userId);
@@ -52,6 +71,10 @@ describe("ReactionsRowButton", () => {
mockClient.getRoom.mockImplementation((roomId: string): Room | null => {
return roomId === room.roomId ? room : null;
});
+ // Default mock for mediaFromMxc
+ mockMediaFromMxc.mockReturnValue({
+ srcHttp: "https://not.a.real.url",
+ } as unknown as Media);
});
it("renders reaction row button emojis correctly", () => {
@@ -122,4 +145,402 @@ describe("ReactionsRowButton", () => {
expect(root.asFragment()).toMatchSnapshot();
});
+
+ it("calls setProps on ViewModel when props change", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender, container } = render(
+
+
+ ,
+ );
+
+ // Create new props with different values
+ const newMxEvent = new MatrixEvent({
+ room_id: roomId,
+ event_id: "$test2:example.com",
+ content: { body: "test2" },
+ });
+
+ const newReactionEvents = [
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user3:example.com",
+ content: {
+ "m.relates_to": {
+ event_id: "$user3:example.com",
+ key: "👎",
+ rel_type: "m.annotation",
+ },
+ },
+ }),
+ ];
+
+ const updatedProps: IProps = {
+ ...props,
+ mxEvent: newMxEvent,
+ content: "👎",
+ reactionEvents: newReactionEvents,
+ customReactionImagesEnabled: false,
+ };
+
+ rerender(
+
+
+ ,
+ );
+
+ // The component should have updated - verify by checking the rendered content
+ expect(container.querySelector(".mx_ReactionsRowButton_content")?.textContent).toBe("👎");
+ });
+
+ it("disposes ViewModel on unmount", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { unmount } = render(
+
+
+ ,
+ );
+
+ // Unmount should not throw
+ expect(() => unmount()).not.toThrow();
+ });
+
+ it("redacts reaction when clicking with myReactionEvent", () => {
+ const myReactionEvent = new MatrixEvent({
+ type: "m.reaction",
+ sender: userId,
+ event_id: "$my_reaction:example.com",
+ content: {
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ },
+ });
+
+ const props: IProps = {
+ ...createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ }),
+ myReactionEvent,
+ };
+
+ const root = render(
+
+
+ ,
+ );
+
+ const button = root.getByRole("button");
+ fireEvent.click(button);
+
+ expect(mockClient.redactEvent).toHaveBeenCalledWith(roomId, "$my_reaction:example.com");
+ });
+
+ it("sends reaction when clicking without myReactionEvent", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$test:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const root = render(
+
+
+ ,
+ );
+
+ const button = root.getByRole("button");
+ fireEvent.click(button);
+
+ expect(mockClient.sendEvent).toHaveBeenCalledWith(roomId, EventType.Reaction, {
+ "m.relates_to": {
+ rel_type: RelationType.Annotation,
+ event_id: "$test:example.com",
+ key: "👍",
+ },
+ });
+ expect(dis.dispatch).toHaveBeenCalledWith({ action: "message_sent" });
+ });
+
+ it("uses reactors as label when content is empty", () => {
+ const props: IProps = {
+ mxEvent: new MatrixEvent({
+ room_id: roomId,
+ event_id: "$test:example.com",
+ content: { body: "test" },
+ }),
+ content: "", // Empty content
+ count: 2,
+ reactionEvents: [
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user1:example.com",
+ content: {},
+ }),
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user2:example.com",
+ content: {},
+ }),
+ ],
+ customReactionImagesEnabled: true,
+ };
+
+ const root = render(
+
+
+ ,
+ );
+
+ // The button should still render
+ const button = root.getByRole("button");
+ expect(button).toBeInTheDocument();
+ });
+
+ it("renders custom image reaction with fallback label when no shortcode", () => {
+ const props: IProps = {
+ mxEvent: new MatrixEvent({
+ room_id: roomId,
+ event_id: "$test:example.com",
+ content: { body: "test" },
+ }),
+ content: "mxc://example.com/custom_image",
+ count: 1,
+ reactionEvents: [
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user1:example.com",
+ content: {
+ "m.relates_to": {
+ event_id: "$test:example.com",
+ key: "mxc://example.com/custom_image",
+ rel_type: "m.annotation",
+ },
+ },
+ }),
+ ],
+ customReactionImagesEnabled: true,
+ };
+
+ const root = render(
+
+
+ ,
+ );
+
+ // Should render an image element for custom reaction
+ const img = root.container.querySelector("img.mx_ReactionsRowButton_content");
+ expect(img).toBeInTheDocument();
+ expect(img).toHaveAttribute("src", "https://not.a.real.url");
+ });
+
+ it("falls back to text when mxc URL cannot be converted to HTTP", () => {
+ // Make mediaFromMxc return null srcHttp to simulate failed conversion
+ mockMediaFromMxc.mockReturnValueOnce({
+ srcHttp: null,
+ } as unknown as Media);
+
+ const props: IProps = {
+ mxEvent: new MatrixEvent({
+ room_id: roomId,
+ event_id: "$test:example.com",
+ content: { body: "test" },
+ }),
+ content: "mxc://example.com/invalid_image",
+ count: 1,
+ reactionEvents: [
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user1:example.com",
+ content: {
+ "m.relates_to": {
+ event_id: "$test:example.com",
+ key: "mxc://example.com/invalid_image",
+ rel_type: "m.annotation",
+ },
+ },
+ }),
+ ],
+ customReactionImagesEnabled: true,
+ };
+
+ const root = render(
+
+
+ ,
+ );
+
+ // Should render span (not img) when imageSrc is null
+ const span = root.container.querySelector("span.mx_ReactionsRowButton_content");
+ expect(span).toBeInTheDocument();
+ const img = root.container.querySelector("img.mx_ReactionsRowButton_content");
+ expect(img).not.toBeInTheDocument();
+ });
+
+ it("updates ViewModel when only mxEvent changes", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender } = render(
+
+
+ ,
+ );
+
+ // Only change mxEvent
+ const newMxEvent = new MatrixEvent({
+ room_id: roomId,
+ event_id: "$test2:example.com",
+ content: { body: "test2" },
+ });
+
+ expect(() =>
+ rerender(
+
+
+ ,
+ ),
+ ).not.toThrow();
+ });
+
+ it("updates ViewModel when only content changes", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender, container } = render(
+
+
+ ,
+ );
+
+ // Only change content
+ rerender(
+
+
+ ,
+ );
+
+ expect(container.querySelector(".mx_ReactionsRowButton_content")?.textContent).toBe("👎");
+ });
+
+ it("updates ViewModel when only reactionEvents changes", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender } = render(
+
+
+ ,
+ );
+
+ // Only change reactionEvents
+ const newReactionEvents = [
+ new MatrixEvent({
+ type: "m.reaction",
+ sender: "@user3:example.com",
+ content: {
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ },
+ }),
+ ];
+
+ expect(() =>
+ rerender(
+
+
+ ,
+ ),
+ ).not.toThrow();
+ });
+
+ it("updates ViewModel when only customReactionImagesEnabled changes", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender } = render(
+
+
+ ,
+ );
+
+ // Only change customReactionImagesEnabled
+ expect(() =>
+ rerender(
+
+
+ ,
+ ),
+ ).not.toThrow();
+ });
+
+ it("does not update ViewModel when props stay the same", () => {
+ const props = createProps({
+ "m.relates_to": {
+ event_id: "$user1:example.com",
+ key: "👍",
+ rel_type: "m.annotation",
+ },
+ });
+
+ const { rerender } = render(
+
+
+ ,
+ );
+
+ // Rerender with same props - setProps should not be called
+ expect(() =>
+ rerender(
+
+
+ ,
+ ),
+ ).not.toThrow();
+ });
});
diff --git a/test/viewmodels/message-body/ReactionsRowButtonTooltipViewModel-test.tsx b/test/viewmodels/message-body/ReactionsRowButtonTooltipViewModel-test.tsx
new file mode 100644
index 0000000000..a4b742b208
--- /dev/null
+++ b/test/viewmodels/message-body/ReactionsRowButtonTooltipViewModel-test.tsx
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import { type MatrixClient, type MatrixEvent, type Room, type RoomMember } from "matrix-js-sdk/src/matrix";
+
+import {
+ ReactionsRowButtonTooltipViewModel,
+ type ReactionsRowButtonTooltipViewModelProps,
+} from "../../../src/viewmodels/message-body/ReactionsRowButtonTooltipViewModel";
+import { stubClient, mkStubRoom, mkEvent } from "../../test-utils";
+import { unicodeToShortcode } from "../../../src/HtmlUtils";
+
+jest.mock("../../../src/HtmlUtils", () => ({
+ ...jest.requireActual("../../../src/HtmlUtils"),
+ unicodeToShortcode: jest.fn(),
+}));
+
+const mockedUnicodeToShortcode = jest.mocked(unicodeToShortcode);
+
+describe("ReactionsRowButtonTooltipViewModel", () => {
+ let client: MatrixClient;
+ let room: Room;
+ let mxEvent: MatrixEvent;
+
+ const createReactionEvent = (senderId: string, content?: Record): MatrixEvent => {
+ return mkEvent({
+ event: true,
+ type: "m.reaction",
+ room: room.roomId,
+ user: senderId,
+ content: {
+ "m.relates_to": { rel_type: "m.annotation", event_id: mxEvent.getId(), key: "👍" },
+ ...content,
+ },
+ });
+ };
+
+ const createProps = (
+ overrides?: Partial,
+ ): ReactionsRowButtonTooltipViewModelProps => ({
+ client,
+ mxEvent,
+ content: "👍",
+ reactionEvents: [],
+ customReactionImagesEnabled: false,
+ ...overrides,
+ });
+
+ beforeEach(() => {
+ client = stubClient();
+ room = mkStubRoom("!room:example.org", "Test Room", client);
+ jest.spyOn(client, "getRoom").mockReturnValue(room);
+
+ mxEvent = mkEvent({
+ event: true,
+ type: "m.room.message",
+ room: room.roomId,
+ user: "@sender:example.org",
+ content: { body: "Test message", msgtype: "m.text" },
+ });
+
+ mockedUnicodeToShortcode.mockImplementation((char: string) => {
+ if (char === "👍") return ":thumbsup:";
+ return "";
+ });
+ });
+
+ afterEach(() => {
+ jest.restoreAllMocks();
+ mockedUnicodeToShortcode.mockReset();
+ });
+
+ it("should return undefined snapshot when room is not found", () => {
+ jest.spyOn(client, "getRoom").mockReturnValue(null);
+
+ const vm = new ReactionsRowButtonTooltipViewModel(createProps());
+ const snapshot = vm.getSnapshot();
+
+ expect(snapshot.formattedSenders).toBeUndefined();
+ expect(snapshot.caption).toBeUndefined();
+ });
+
+ it("should return undefined snapshot when MatrixClient is unavailable", () => {
+ const vm = new ReactionsRowButtonTooltipViewModel(createProps({ client: null }));
+ const snapshot = vm.getSnapshot();
+
+ expect(snapshot.formattedSenders).toBeUndefined();
+ expect(snapshot.caption).toBeUndefined();
+ });
+
+ it("should compute formattedSenders and caption from reaction events", () => {
+ const reactionEvent = createReactionEvent("@alice:example.org");
+ jest.spyOn(room, "getMember").mockReturnValue({ name: "Alice", userId: "@alice:example.org" } as RoomMember);
+
+ const vm = new ReactionsRowButtonTooltipViewModel(createProps({ reactionEvents: [reactionEvent] }));
+ const snapshot = vm.getSnapshot();
+
+ expect(snapshot.formattedSenders).toBe("Alice");
+ expect(snapshot.caption).toContain(":thumbsup:");
+ });
+
+ it("should fall back to sender ID when member is not found", () => {
+ const reactionEvent = createReactionEvent("@unknown:example.org");
+ jest.spyOn(room, "getMember").mockReturnValue(null);
+
+ const vm = new ReactionsRowButtonTooltipViewModel(createProps({ reactionEvents: [reactionEvent] }));
+
+ expect(vm.getSnapshot().formattedSenders).toBe("@unknown:example.org");
+ });
+
+ it("should use custom reaction shortcode when customReactionImagesEnabled is true", () => {
+ mockedUnicodeToShortcode.mockReturnValue("");
+ const reactionEvent = createReactionEvent("@alice:example.org", {
+ "com.beeper.reaction.shortcode": "custom_emoji",
+ });
+ jest.spyOn(room, "getMember").mockReturnValue({ name: "Alice", userId: "@alice:example.org" } as RoomMember);
+
+ const vm = new ReactionsRowButtonTooltipViewModel(
+ createProps({
+ content: "mxc://custom/emoji",
+ reactionEvents: [reactionEvent],
+ customReactionImagesEnabled: true,
+ }),
+ );
+
+ expect(vm.getSnapshot().caption).toContain("custom_emoji");
+ });
+
+ it("should not use custom reaction shortcode when customReactionImagesEnabled is false", () => {
+ mockedUnicodeToShortcode.mockReturnValue("");
+ const reactionEvent = createReactionEvent("@alice:example.org", {
+ "com.beeper.reaction.shortcode": "custom_emoji",
+ });
+ jest.spyOn(room, "getMember").mockReturnValue({ name: "Alice", userId: "@alice:example.org" } as RoomMember);
+
+ const vm = new ReactionsRowButtonTooltipViewModel(
+ createProps({
+ content: "mxc://custom/emoji",
+ reactionEvents: [reactionEvent],
+ customReactionImagesEnabled: false,
+ }),
+ );
+
+ expect(vm.getSnapshot().caption).toBeUndefined();
+ });
+
+ it("should update snapshot and notify subscribers when setProps is called", () => {
+ const aliceReaction = createReactionEvent("@alice:example.org");
+ const bobReaction = createReactionEvent("@bob:example.org");
+
+ jest.spyOn(room, "getMember").mockImplementation((userId) => {
+ const names: Record = { "@alice:example.org": "Alice", "@bob:example.org": "Bob" };
+ return names[userId!] ? ({ name: names[userId!], userId } as RoomMember) : null;
+ });
+
+ const vm = new ReactionsRowButtonTooltipViewModel(createProps({ reactionEvents: [aliceReaction] }));
+ expect(vm.getSnapshot().formattedSenders).toBe("Alice");
+
+ const subscriber = jest.fn();
+ vm.subscribe(subscriber);
+
+ vm.setProps({ reactionEvents: [aliceReaction, bobReaction] });
+
+ expect(subscriber).toHaveBeenCalled();
+ expect(vm.getSnapshot().formattedSenders).toContain("Alice");
+ expect(vm.getSnapshot().formattedSenders).toContain("Bob");
+ });
+});