Documentation and symbolic constants for dispatcher actions (#31278)

* Remove unreachable code

`view_last_screen` is never used.

* Remove unused action `user_activity_started`

Nothing listens to this, so it's pointless.

* Symbolic constant for `Action.UserActivity`

* Define symbolic constants for more `Action`s

Constants for some actions that are emitted by `Lifecycle`

src/BasePlatform.ts

@@ -88,7 +88,7 @@ export default abstract class BasePlatform {
 
     protected onAction(payload: ActionPayload): void {
         switch (payload.action) {
-            case "on_client_not_viable":
+            case Action.ClientNotViable:
             case Action.OnLoggedOut:
                 this.setNotificationCount(0);
                 break;

src/Lifecycle.ts

@@ -1001,7 +1001,7 @@ export function softLogout(): void {
     // Ensure that we dispatch a view change **before** stopping the client so
     // so that React components unmount first. This avoids React soft crashes
     // that can occur when components try to use a null client.
-    dis.dispatch({ action: "on_client_not_viable" }); // generic version of on_logged_out
+    dis.dispatch({ action: Action.ClientNotViable }); // generic version of on_logged_out
     stopMatrixClient(/*unsetClient=*/ false);
 
     // DO NOT CALL LOGOUT. A soft logout preserves data, logout does not.
@@ -1034,7 +1034,7 @@ async function startMatrixClient(
     // to add listeners for the 'sync' event so otherwise we'd have
     // a race condition (and we need to dispatch synchronously for this
     // to work).
-    dis.dispatch({ action: "will_start_client" }, true);
+    dis.dispatch({ action: Action.WillStartClient }, true);
 
     // reset things first just in case
     SdkContextClass.instance.typingStore.reset();
@@ -1080,7 +1080,7 @@ async function startMatrixClient(
 
     // dispatch that we finished starting up to wire up any other bits
     // of the matrix client that cannot be set prior to starting up.
-    dis.dispatch({ action: "client_started" });
+    dis.dispatch({ action: Action.ClientStarted });
 
     if (isSoftLogout()) {
         softLogout();

src/Presence.ts

@@ -15,6 +15,7 @@ import { MatrixClientPeg } from "./MatrixClientPeg";
 import dis from "./dispatcher/dispatcher";
 import Timer from "./utils/Timer";
 import { type ActionPayload } from "./dispatcher/payloads";
+import { Action } from "./dispatcher/actions.ts";
 
 // Time in ms after that a user is considered as unavailable/away
 const UNAVAILABLE_TIME_MS = 3 * 60 * 1000; // 3 mins
@@ -61,7 +62,7 @@ class Presence {
     }
 
     private onAction = (payload: ActionPayload): void => {
-        if (payload.action === "user_activity") {
+        if (payload.action === Action.UserActivity) {
             this.setState(SetPresence.Online);
             this.unavailableTimer?.restart();
         }

src/UserActivity.ts

@@ -8,6 +8,7 @@ Please see LICENSE files in the repository root for full details.
 
 import dis from "./dispatcher/dispatcher";
 import Timer from "./utils/Timer";
+import { Action } from "./dispatcher/actions.ts";
 
 // important these are larger than the timeouts of timers
 // used with UserActivity.timeWhileActive*,
@@ -190,11 +191,9 @@ export default class UserActivity {
             this.lastScreenY = event.screenY;
         }
 
-        dis.dispatch({ action: "user_activity" });
+        dis.dispatch({ action: Action.UserActivity });
         if (!this.activeNowTimeout.isRunning()) {
             this.activeNowTimeout.start();
-            dis.dispatch({ action: "user_activity_start" });
-
             UserActivity.runTimersUntilTimeout(this.attachedActiveNowTimers, this.activeNowTimeout);
         } else {
             this.activeNowTimeout.restart();

src/components/structures/EmbeddedPage.tsx

@@ -18,6 +18,7 @@ import { MatrixClientPeg } from "../../MatrixClientPeg";
 import MatrixClientContext from "../../contexts/MatrixClientContext";
 import AutoHideScrollbar from "./AutoHideScrollbar";
 import { type ActionPayload } from "../../dispatcher/payloads";
+import { Action } from "../../dispatcher/actions.ts";
 
 interface IProps {
     // URL to request embedded page content from
@@ -109,7 +110,7 @@ export default class EmbeddedPage extends React.PureComponent<IProps, IState> {
 
     private onAction = (payload: ActionPayload): void => {
         // HACK: Workaround for the context's MatrixClient not being set up at render time.
-        if (payload.action === "client_started") {
+        if (payload.action === Action.ClientStarted) {
             this.forceUpdate();
         }
     };

src/components/structures/MatrixChat.tsx

@@ -812,13 +812,6 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                 }
                 break;
             }
-            case "view_last_screen":
-                // This function does what we want, despite the name. The idea is that it shows
-                // the last room we were looking at or some reasonable default/guess. We don't
-                // have to worry about email invites or similar being re-triggered because the
-                // function will have cleared that state and not execute that path.
-                this.showScreenAfterLogin();
-                break;
             case "hide_left_panel":
                 this.setState(
                     {
@@ -856,13 +849,13 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                     this.onLoggedIn();
                 }
                 break;
-            case "on_client_not_viable":
+            case Action.ClientNotViable:
                 this.onSoftLogout();
                 break;
             case Action.OnLoggedOut:
                 this.onLoggedOut();
                 break;
-            case "will_start_client":
+            case Action.WillStartClient:
                 this.setState({ ready: false }, () => {
                     // if the client is about to start, we are, by definition, not ready.
                     // Set ready to false now, then it'll be set to true when the sync
@@ -870,7 +863,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                     this.onWillStartClient();
                 });
                 break;
-            case "client_started":
+            case Action.ClientStarted:
                 // No need to make this handler async to wait for the result of this
                 this.onClientStarted().catch((e) => {
                     logger.error("Exception in onClientStarted", e);

src/dispatcher/actions.ts

@@ -316,16 +316,39 @@ export enum Action {
      */
     ShowRoomTopic = "show_room_topic",
 
+    /**
+     * Fired when the client is no longer viable to use: specifically, that we have been "soft-logged out".
+     */
+    ClientNotViable = "client_not_viable",
+
     /**
      * Fired when the client was logged out. No additional payload information required.
      */
     OnLoggedOut = "on_logged_out",
 
     /**
-     * Fired when the client was logged in. No additional payload information required.
+     * Fired when the client was logged in, or has otherwise been set up with authentication data (e.g., by loading the
+     * access token from local storage). Note that this does not necessarily mean that a login action has happened,
+     * just that authentication creds have been set up.
+     *
+     * No additional payload information required.
      */
     OnLoggedIn = "on_logged_in",
 
+    /**
+     * Fired when the client is about to be started, shortly after {@link OnLoggedIn}.
+     *
+     * No additional payload information required.
+     */
+    WillStartClient = "will_start_client",
+
+    /**
+     * Fired when the client has started, shortly after {@link WillStartClient}.
+     *
+     * No additional payload information required.
+     */
+    ClientStarted = "client_started",
+
     /**
      * Overwrites the existing login with fresh session credentials. Use with a OverwriteLoginPayload.
      */
@@ -380,4 +403,10 @@ export enum Action {
      * Open the create room dialog
      */
     CreateRoom = "view_create_room",
+
+    /**
+     * The `UserActivity` tracker determined that there was some activity from the user (typically a mouse movement
+     * or keyboard event).
+     */
+    UserActivity = "user_activity",
 }

src/stores/LifecycleStore.ts

@@ -69,7 +69,7 @@ class LifecycleStore extends AsyncStore<IState> {
                 dis.dispatch(deferredAction);
                 break;
             }
-            case "on_client_not_viable":
+            case Action.ClientNotViable:
             case Action.OnLoggedOut:
                 this.reset();
                 break;

src/stores/ReadyWatchingStore.ts

@@ -77,7 +77,7 @@ export abstract class ReadyWatchingStore extends EventEmitter implements IDestro
                 this.matrixClient = payload.matrixClient;
                 await this.onReady();
             }
-        } else if (payload.action === "on_client_not_viable" || payload.action === Action.OnLoggedOut) {
+        } else if (payload.action === Action.ClientNotViable || payload.action === Action.OnLoggedOut) {
             if (this.matrixClient) {
                 await this.onNotReady();
                 this.matrixClient = undefined;

src/stores/RoomViewStore.tsx

@@ -285,7 +285,7 @@ export class RoomViewStore extends EventEmitter {
 
                 break;
             }
-            case "on_client_not_viable":
+            case Action.ClientNotViable:
             case Action.OnLoggedOut:
                 this.reset();
                 break;

src/vector/platform/ElectronPlatform.tsx

@@ -218,7 +218,7 @@ export default class ElectronPlatform extends BasePlatform {
             this.electron.send("app_onAction", payload);
         }
 
-        if (payload.action === "client_started") {
+        if (payload.action === Action.ClientStarted) {
             this.clientStartedPromiseWithResolvers.resolve();
         }
     }

src/vector/platform/WebPlatform.ts

@@ -53,7 +53,7 @@ export default class WebPlatform extends BasePlatform {
         super.onAction(payload);
 
         switch (payload.action) {
-            case "client_started":
+            case Action.ClientStarted:
                 // Defer drawing the toast until the client is started as the lifecycle methods reset the ToastStore right before
                 this.registerServiceWorkerPromise.catch(this.handleServiceWorkerRegistrationError);
                 break;

test/unit-tests/components/structures/MatrixChat-test.tsx

@@ -547,11 +547,11 @@ describe("<MatrixChat />", () => {
                 getComponent({ realQueryParams });
 
                 defaultDispatcher.dispatch({
-                    action: "will_start_client",
+                    action: Action.WillStartClient,
                 });
                 // client successfully started
                 await waitFor(() =>
-                    expect(defaultDispatcher.dispatch).toHaveBeenCalledWith({ action: "client_started" }),
+                    expect(defaultDispatcher.dispatch).toHaveBeenCalledWith({ action: Action.ClientStarted }),
                 );
 
                 // set up keys screen is rendered
@@ -1172,10 +1172,10 @@ describe("<MatrixChat />", () => {
                     getComponent({ realQueryParams });
 
                     defaultDispatcher.dispatch({
-                        action: "will_start_client",
+                        action: Action.WillStartClient,
                     });
                     await waitFor(() =>
-                        expect(defaultDispatcher.dispatch).toHaveBeenCalledWith({ action: "client_started" }),
+                        expect(defaultDispatcher.dispatch).toHaveBeenCalledWith({ action: Action.ClientStarted }),
                     );
 
                     // Then we are not allowed in - we are being asked to verify
@@ -1568,7 +1568,7 @@ describe("<MatrixChat />", () => {
             it("should continue to post login setup when no session is found in local storage", async () => {
                 getComponent({ realQueryParams });
                 defaultDispatcher.dispatch({
-                    action: "will_start_client",
+                    action: Action.WillStartClient,
                 });
 
                 // set up keys screen is rendered
@@ -1828,7 +1828,7 @@ describe("<MatrixChat />", () => {
 
             getComponent({});
             defaultDispatcher.dispatch({
-                action: "will_start_client",
+                action: Action.WillStartClient,
             });
             await flushPromises();
             mockClient.emit(CryptoEvent.KeyBackupFailed, "error code");
@@ -1851,7 +1851,7 @@ describe("<MatrixChat />", () => {
 
             getComponent({});
             defaultDispatcher.dispatch({
-                action: "will_start_client",
+                action: Action.WillStartClient,
             });
             await flushPromises();
             mockClient.emit(CryptoEvent.KeyBackupFailed, "error code");

test/unit-tests/stores/WidgetLayoutStore-test.ts

@@ -14,6 +14,7 @@ import { Container, WidgetLayoutStore } from "../../../src/stores/widgets/Widget
 import { stubClient } from "../../test-utils";
 import defaultDispatcher from "../../../src/dispatcher/dispatcher";
 import SettingsStore from "../../../src/settings/SettingsStore";
+import { Action } from "../../../src/dispatcher/actions.ts";
 
 // setup test env values
 const roomId = "!room:server";
@@ -196,12 +197,7 @@ describe("WidgetLayoutStore", () => {
 
     it("should clear the layout if the client is not viable", () => {
         store.recalculateRoom(mockRoom);
-        defaultDispatcher.dispatch(
-            {
-                action: "on_client_not_viable",
-            },
-            true,
-        );
+        defaultDispatcher.dispatch({ action: Action.ClientNotViable }, true);
 
         expect(store.getContainerWidgets(mockRoom, Container.Top)).toEqual([]);
         expect(store.getContainerWidgets(mockRoom, Container.Center)).toEqual([]);

test/unit-tests/vector/platform/ElectronPlatform-test.ts

@@ -132,7 +132,7 @@ describe("ElectronPlatform", () => {
         new ElectronPlatform();
         dispatcher.dispatch(
             {
-                action: "client_started",
+                action: Action.ClientStarted,
             },
             true,
         );

test/unit-tests/vector/platform/WebPlatform-test.ts

@@ -15,6 +15,7 @@ import { setupLanguageMock } from "../../../setup/setupLanguage";
 import ToastStore from "../../../../src/stores/ToastStore.ts";
 import defaultDispatcher from "../../../../src/dispatcher/dispatcher.ts";
 import { emitPromise } from "../../../test-utils";
+import { Action } from "../../../../src/dispatcher/actions.ts";
 
 fetchMock.config.overwriteRoutes = true;
 
@@ -49,7 +50,7 @@ describe("WebPlatform", () => {
             };
             new WebPlatform();
 
-            defaultDispatcher.dispatch({ action: "client_started" });
+            defaultDispatcher.dispatch({ action: Action.ClientStarted });
             await emitPromise(ToastStore.sharedInstance(), "update");
             const toasts = ToastStore.sharedInstance().getToasts();
             expect(toasts).toHaveLength(1);