Fix cron

.editorconfig

@@ -11,5 +11,6 @@ indent_style = space
 indent_size = 4
 tab_width = 4
 
-[*.{yml,yaml}]
+[*.{yml,yaml,md}]
 indent_size = 2
+tab_width = 2

.github/workflows/e2e.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: ["main"]
   schedule:
-    - cron: '*/30 * * * *'
+    - cron: '0 * * * *'
 
 concurrency:
   group: e2e-tests

docs/.prettierrc

@@ -1,7 +1,7 @@
 {
     "printWidth": 120,
     "tabWidth": 4,
-    "useTabs": true,
+    "useTabs": false,
     "semi": false,
     "singleQuote": false,
     "trailingComma": "none",

docs/architecture/data-flow.md

@@ -125,7 +125,7 @@ sequenceDiagram
 ```
 ┌─────────┐
 │ Client  │
-└────┬────┘
+└───┬─-───┘
     │ 1. Detect file change
     │
     ├─► 2. Read file content
@@ -142,7 +142,7 @@ sequenceDiagram
     ▼
 ┌─────────┐
 │ Server  │
-└────┬────┘
+└───┬────-┘
     │ 4. Validate message
     │
     ├─► 5. Check permissions
@@ -163,7 +163,7 @@ sequenceDiagram
 ```
 ┌─────────┐
 │ Server  │
-└────┬────┘
+└───┬─-───┘
     │ 1. File updated by another client
     │
     ├─► 2. Broadcast notification
@@ -176,7 +176,7 @@ sequenceDiagram
     ▼
 ┌─────────┐
 │ Client  │
-└────┬────┘
+└───┬─-───┘
     │ 3. Receive notification
     │
     ├─► 4. Request file download
@@ -189,7 +189,7 @@ sequenceDiagram
     ▼
 ┌─────────┐
 │ Server  │
-└────┬────┘
+└───┬─=───┘
     │ 5. Retrieve from database
     │
     └─► 6. Send file content
@@ -203,7 +203,7 @@ sequenceDiagram
           ▼
     ┌─────────┐
     │ Client  │
-     └────┬────┘
+    └───-─┬───┘
           │ 7. Write to filesystem
           │
           └─► 8. Update local metadata

frontend/eslint.config.mjs

@@ -55,6 +55,25 @@ export default [
                     message: "Use replaceAll instead of replace to replace all occurrences of a substring."
                 }
             ],
+            "no-restricted-syntax": [
+                "error",
+                {
+                    selector: "CallExpression[callee.property.name='splice'][arguments.length=2][arguments.1.type='Literal'][arguments.1.value=1]",
+                    message: "Use `removeFromArray(array, item)` instead of manually using indexOf + splice(index, 1). Import from 'sync-client/src/utils/remove-from-array'."
+                },
+                {
+                    selector: "CallExpression[callee.property.name='filter'] > ArrowFunctionExpression[body.type='BinaryExpression'][body.operator='!==']",
+                    message: "Use `removeFromArray(array, item)` instead of filter(x => x !== item) for better performance. Import from 'sync-client/src/utils/remove-from-array'."
+                },
+                {
+                    selector: "CallExpression[callee.property.name='filter'] > ArrowFunctionExpression > BlockStatement > ReturnStatement > BinaryExpression[operator='!==']",
+                    message: "Use `removeFromArray(array, item)` instead of filter(x => { return x !== item }) for better performance. Import from 'sync-client/src/utils/remove-from-array'."
+                },
+                {
+                    selector: "CallExpression[callee.property.name='filter'] > FunctionExpression[body.type='BlockStatement'] > BlockStatement > ReturnStatement > BinaryExpression[operator='!==']",
+                    message: "Use `removeFromArray(array, item)` instead of filter(function(x) { return x !== item }) for better performance. Import from 'sync-client/src/utils/remove-from-array'."
+                }
+            ],
             "unused-imports/no-unused-vars": [
                 "warn",
                 {

frontend/local-client-cli/package.json

@@ -9,10 +9,11 @@
     "scripts": {
         "dev": "webpack watch --mode development",
         "build": "webpack --mode production",
-		"test": "tsx --test src/args.test.ts src/node-filesystem.test.ts"
+        "test": "tsx --test 'src/**/*.test.ts'"
     },
     "dependencies": {
-		"commander": "^14.0.2"
+        "commander": "^14.0.2",
+        "watcher": "^2.3.1"
     },
     "devDependencies": {
         "@types/node": "^24.8.1",

frontend/local-client-cli/src/cli.ts

@@ -39,6 +39,10 @@ async function main(): Promise<void> {
     const args = parseArgs(process.argv);
     const absolutePath = path.resolve(args.localPath);
 
+    if (!fsSync.existsSync(absolutePath)) {
+        fsSync.mkdirSync(absolutePath, { recursive: true });
+    }
+
     try {
         const stats = await fs.stat(absolutePath);
         if (!stats.isDirectory()) {
@@ -153,7 +157,7 @@ async function main(): Promise<void> {
     }
 
     // Add colored log formatter with level filtering
-	client.logger.addOnMessageListener((logLine) => {
+    client.logger.onLogEmitted.add((logLine) => {
         // Only show messages at or above the configured log level
         if (LOG_LEVEL_ORDER[logLine.level] >= LOG_LEVEL_ORDER[args.logLevel]) {
             console.log(formatLogLine(logLine));
@@ -164,14 +168,14 @@ async function main(): Promise<void> {
 
     const fileWatcher = new FileWatcher(absolutePath, client);
 
-	client.addWebSocketStatusChangeListener(() => {
+    client.onWebSocketStatusChanged.add(() => {
         const isConnected = client.isWebSocketConnected;
         client.logger.info(
             `WebSocket status changed: ${isConnected ? "connected" : "disconnected"}`
         );
     });
 
-	client.addRemainingSyncOperationsListener((remaining) => {
+    client.onRemainingOperationsCountChanged.add((remaining) => {
         if (remaining === 0) {
             client.logger.info("All sync operations completed");
         } else {

frontend/local-client-cli/src/file-watcher.ts

@@ -1,9 +1,9 @@
-import * as fs from "fs";
+import Watcher from "watcher";
 import * as path from "path";
 import type { SyncClient, RelativePath } from "sync-client";
 
 export class FileWatcher {
-	private watcher: fs.FSWatcher | undefined;
+    private watcher: Watcher | undefined;
     private isRunning = false;
 
     public constructor(
@@ -18,25 +18,31 @@ export class FileWatcher {
 
         this.isRunning = true;
 
-		this.watcher = fs.watch(
+        this.watcher = new Watcher(this.basePath, {
-			this.basePath,
+            recursive: true,
-			{ recursive: true },
+            renameDetection: true,
-			(eventType, filename) => {
+            renameTimeout: 125,
-				if (filename === null || filename.length === 0) {
+            ignoreInitial: true
-					return;
+        });
-				}
 
-				// Convert to forward slashes for consistency
+        this.watcher.on("add", (filePath: string) => {
-				const relativePath = this.toUnixPath(filename);
+            this.handleCreate(this.toRelativePath(filePath));
+        });
 
-				if (eventType === "rename") {
+        this.watcher.on("change", (filePath: string) => {
-					this.handleRenameOrDelete(relativePath);
+            this.handleChange(this.toRelativePath(filePath));
-				} else {
+        });
-					// Must be "change" event
+
-					this.handleChange(relativePath);
+        this.watcher.on("unlink", (filePath: string) => {
-				}
+            this.handleDelete(this.toRelativePath(filePath));
-			}
+        });
+
+        this.watcher.on("rename", (oldPath: string, newPath: string) => {
+            this.handleRename(
+                this.toRelativePath(oldPath),
+                this.toRelativePath(newPath)
             );
+        });
 
         this.client.logger.info("File watcher started");
     }
@@ -50,44 +56,53 @@ export class FileWatcher {
         this.client.logger.info("File watcher stopped");
     }
 
+    private handleCreate(relativePath: RelativePath): void {
+        this.client
+            .syncLocallyCreatedFile(relativePath)
+            .catch((err: unknown) => {
+                this.client.logger.error(
+                    `Failed to sync created file ${relativePath}: ${this.formatError(err)}`
+                );
+            });
+    }
+
     private handleChange(relativePath: RelativePath): void {
         this.client
             .syncLocallyUpdatedFile({ relativePath })
             .catch((err: unknown) => {
                 this.client.logger.error(
-					`Failed to sync updated file ${relativePath}: ${err instanceof Error ? err.message : String(err)}`
+                    `Failed to sync updated file ${relativePath}: ${this.formatError(err)}`
                 );
             });
     }
 
-	private handleRenameOrDelete(relativePath: RelativePath): void {
+    private handleDelete(relativePath: RelativePath): void {
-		const fullPath = path.join(this.basePath, relativePath);
-
-		fs.access(fullPath, fs.constants.F_OK, (accessError) => {
-			if (accessError) {
         this.client
             .syncLocallyDeletedFile(relativePath)
-					.catch((deleteErr: unknown) => {
+            .catch((err: unknown) => {
                 this.client.logger.error(
-							`Failed to sync deleted file ${relativePath}: ${deleteErr instanceof Error ? deleteErr.message : String(deleteErr)}`
+                    `Failed to sync deleted file ${relativePath}: ${this.formatError(err)}`
                 );
             });
-			} else {
-				fs.stat(fullPath, (statErr, stats) => {
-					if (statErr !== null || !stats.isFile()) {
-						return;
     }
 
+    private handleRename(oldPath: RelativePath, newPath: RelativePath): void {
+        this.client.logger.info(`File renamed: ${oldPath} -> ${newPath}`);
         this.client
-						.syncLocallyCreatedFile(relativePath)
+            .syncLocallyUpdatedFile({
-						.catch((createErr: unknown) => {
+                oldPath,
+                relativePath: newPath
+            })
+            .catch((err: unknown) => {
                 this.client.logger.error(
-								`Failed to sync created file ${relativePath}: ${createErr instanceof Error ? createErr.message : String(createErr)}`
+                    `Failed to sync renamed file ${oldPath} -> ${newPath}: ${this.formatError(err)}`
                 );
             });
-				});
     }
-		});
+
+    private toRelativePath(absolutePath: string): RelativePath {
+        const relative = path.relative(this.basePath, absolutePath);
+        return this.toUnixPath(relative);
     }
 
     /**
@@ -99,4 +114,8 @@ export class FileWatcher {
         }
         return nativePath;
     }
+
+    private formatError(err: unknown): string {
+        return err instanceof Error ? err.message : String(err);
+    }
 }

frontend/local-client-cli/tsconfig.json

@@ -18,5 +18,7 @@
         "declarationMap": true,
         "sourceMap": true
     },
-    "exclude": ["dist"]
+    "exclude": [
+        "dist"
+    ]
 }

frontend/obsidian-plugin/.hotreload

@@ -0,0 +1 @@
+

frontend/obsidian-plugin/README.md

@@ -85,8 +85,3 @@ If you have multiple URLs, you can also do:
 ## API Documentation
 
 See https://github.com/obsidianmd/obsidian-api
-
-
-
-
-

frontend/obsidian-plugin/src/vault-link-plugin.ts

@@ -136,10 +136,7 @@ export default class VaultLinkPlugin extends Plugin {
             ...(IS_DEBUG_BUILD
                 ? {
                     fetch: debugging.slowFetchFactory(1),
-						webSocket: debugging.slowWebSocketFactory(
+                    webSocket: debugging.slowWebSocketFactory(1, new Logger())
-							1,
-							new Logger()
-						)
                 }
                 : {})
         });
@@ -174,7 +171,7 @@ export default class VaultLinkPlugin extends Plugin {
 
         this.registerEditorExtension([remoteCursorsTheme, remoteCursorsPlugin]);
 
-		client.addRemoteCursorsUpdateListener((cursors) => {
+        client.onRemoteCursorsUpdated.add((cursors) => {
             RemoteCursorsPluginValue.setCursors(cursors, this.app);
             renderCursorsInFileExplorer(cursors, this.app);
         });

frontend/obsidian-plugin/src/views/history/history-view.ts

@@ -24,7 +24,7 @@ export class HistoryView extends ItemView {
         super(leaf);
         this.icon = HistoryView.ICON;
 
-		this.client.addSyncHistoryUpdateListener(async () =>
+        this.client.onSyncHistoryUpdated.add(async () =>
             this.updateView().catch((error: unknown) => {
                 this.client.logger.error(
                     `Failed to update history view: ${error}`

frontend/obsidian-plugin/src/views/logs/logs-view.ts

@@ -21,7 +21,7 @@ export class LogsView extends ItemView {
     ) {
         super(leaf);
         this.icon = LogsView.ICON;
-		this.client.logger.addOnMessageListener(() => {
+        this.client.logger.onLogEmitted.add(() => {
             this.updateView();
         });
     }

frontend/obsidian-plugin/src/views/settings/settings-tab.ts

@@ -41,8 +41,7 @@ export class SyncSettingsTab extends PluginSettingTab {
         this.editedToken = this.syncClient.getSettings().token;
         this.editedVaultName = this.syncClient.getSettings().vaultName;
 
-		this.syncClient.addOnSettingsChangeListener(
+        this.syncClient.onSettingsChanged.add((newSettings, oldSettings) => {
-			(newSettings, oldSettings) => {
             let hasChanged = false;
 
             if (newSettings.remoteUri !== oldSettings.remoteUri) {
@@ -63,8 +62,7 @@ export class SyncSettingsTab extends PluginSettingTab {
             if (hasChanged) {
                 this.display();
             }
-			}
+        });
-		);
     }
 
     private get isApplyingChanges(): boolean {

frontend/obsidian-plugin/src/views/status-bar/status-bar.ts

@@ -14,19 +14,19 @@ export class StatusBar {
         private readonly syncClient: SyncClient
     ) {
         this.statusBarItem = plugin.addStatusBarItem();
-		this.syncClient.addSyncHistoryUpdateListener((status) => {
+        this.syncClient.onSyncHistoryUpdated.add((status) => {
             this.lastHistoryStats = status;
             this.updateStatus();
         });
 
-		this.syncClient.addRemainingSyncOperationsListener(
+        this.syncClient.onRemainingOperationsCountChanged.add(
             (remainingOperations) => {
                 this.lastRemaining = remainingOperations;
                 this.updateStatus();
             }
         );
 
-		this.syncClient.addOnSettingsChangeListener(() => {
+        this.syncClient.onSettingsChanged.add(() => {
             this.updateStatus();
         });
     }

frontend/obsidian-plugin/src/views/status-description/status-description.ts

@@ -5,34 +5,35 @@ import type {
     NetworkConnectionStatus,
     SyncClient
 } from "sync-client";
+import { utils } from "sync-client";
 
 export class StatusDescription {
     private lastHistoryStats: HistoryStats | undefined;
     private lastRemaining: number | undefined;
     private lastConnectionState: NetworkConnectionStatus | undefined;
 
-	private statusChangeListeners: (() => unknown)[] = [];
+    private readonly statusChangeListeners: (() => unknown)[] = [];
 
     public constructor(private readonly syncClient: SyncClient) {
         void this.updateConnectionState();
 
-		syncClient.addSyncHistoryUpdateListener((status) => {
+        syncClient.onSyncHistoryUpdated.add((status) => {
             this.lastHistoryStats = status;
             this.updateDescription();
         });
 
-		this.syncClient.addRemainingSyncOperationsListener(
+        this.syncClient.onRemainingOperationsCountChanged.add(
             (remainingOperations) => {
                 this.lastRemaining = remainingOperations;
                 this.updateDescription();
             }
         );
 
-		this.syncClient.addWebSocketStatusChangeListener(async () =>
+        this.syncClient.onWebSocketStatusChanged.add(async () =>
             this.updateConnectionState()
         );
 
-		this.syncClient.addOnSettingsChangeListener(async () =>
+        this.syncClient.onSettingsChanged.add(async () =>
             this.updateConnectionState()
         );
     }
@@ -46,9 +47,7 @@ export class StatusDescription {
         this.statusChangeListeners.push(listener);
     }
     public removeStatusChangeListener(listener: () => unknown): void {
-		this.statusChangeListeners = this.statusChangeListeners.filter(
+        utils.removeFromArray(this.statusChangeListeners, listener);
-			(l) => l !== listener
-		);
     }
 
     public renderStatusDescription(container: HTMLElement): void {

frontend/package.json

@@ -10,7 +10,7 @@
     "prettier": {
         "trailingComma": "none",
         "tabWidth": 4,
-		"useTabs": true,
+        "useTabs": false,
         "endOfLine": "lf"
     },
     "scripts": {
@@ -22,6 +22,7 @@
     },
     "devDependencies": {
         "concurrently": "^9.2.1",
+        "eclint": "^2.8.1",
         "eslint": "9.38.0",
         "eslint-plugin-unused-imports": "^4.1.4",
         "npm-check-updates": "^19.1.1",

frontend/sync-client/package.json

@@ -10,7 +10,7 @@
     "scripts": {
         "dev": "webpack watch --mode development",
         "build": "webpack --mode production",
-        "test": "tsx --test src/**/*.test.ts"
+        "test": "tsx --test 'src/**/*.test.ts'"
     },
     "devDependencies": {
         "byte-base64": "^1.1.0",

frontend/sync-client/src/index.ts

@@ -5,6 +5,7 @@ import { slowWebSocketFactory } from "./utils/debugging/slow-web-socket-factory"
 import { getRandomColor } from "./utils/get-random-color";
 import { lineAndColumnToPosition } from "./utils/line-and-column-to-position";
 import { positionToLineAndColumn } from "./utils/position-to-line-and-column";
+import { removeFromArray } from "./utils/remove-from-array";
 
 export {
     SyncType,
@@ -43,5 +44,6 @@ export const utils = {
     getRandomColor,
     positionToLineAndColumn,
     lineAndColumnToPosition,
-	awaitAll
+    awaitAll,
+    removeFromArray
 };

frontend/sync-client/src/persistence/database.ts

@@ -2,6 +2,7 @@ import type { Logger } from "../tracing/logger";
 import { EMPTY_HASH } from "../utils/hash";
 import { CoveredValues } from "../utils/data-structures/min-covered";
 import { awaitAll } from "../utils/await-all";
+import { removeFromArray } from "../utils/remove-from-array";
 
 export type VaultUpdateId = number;
 export type DocumentId = string;
@@ -93,6 +94,7 @@ export class Database {
     public get resolvedDocuments(): DocumentRecord[] {
         const paths = new Map<string, DocumentRecord[]>();
         this.documents
+            // eslint-disable-next-line no-restricted-syntax -- Type narrowing, not removing a specific item
             .filter(({ metadata }) => metadata !== undefined)
             .forEach((record) =>
                 paths.set(record.relativePath, [
@@ -151,12 +153,12 @@ export class Database {
             return;
         }
 
-		entry.updates = entry.updates.filter((update) => update !== promise);
+        removeFromArray(entry.updates, promise);
         // No need to save as Promises don't get serialized
     }
 
     public removeDocument(find: DocumentRecord): void {
-		this.documents = this.documents.filter((document) => document !== find);
+        removeFromArray(this.documents, find);
         this.saveInTheBackground();
     }
 

frontend/sync-client/src/persistence/settings.ts

@@ -1,6 +1,6 @@
 import type { Logger } from "../tracing/logger";
-import { awaitAll } from "../utils/await-all";
 import { Lock } from "../utils/data-structures/locks";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 export interface SyncSettings {
     remoteUri: string;
@@ -33,14 +33,13 @@ export const DEFAULT_SETTINGS: SyncSettings = {
 };
 
 export class Settings {
+    public readonly onSettingsChanged = new EventListeners<
+        (newSettings: SyncSettings, oldSettings: SyncSettings) => unknown
+    >();
+
     private settings: SyncSettings;
     private readonly lock: Lock = new Lock();
 
-	private readonly onSettingsChangeHandlers: ((
-		newSettings: SyncSettings,
-		oldSettings: SyncSettings
-	) => unknown)[] = [];
-
     public constructor(
         private readonly logger: Logger,
         initialState: Partial<SyncSettings> | undefined,
@@ -60,21 +59,6 @@ export class Settings {
         return this.settings;
     }
 
-	public addOnSettingsChangeListener(
-		listener: (settings: SyncSettings, oldSettings: SyncSettings) => unknown
-	): void {
-		this.onSettingsChangeHandlers.push(listener);
-	}
-
-	public removeOnSettingsChangeListener(
-		listener: (settings: SyncSettings, oldSettings: SyncSettings) => unknown
-	): void {
-		const index = this.onSettingsChangeHandlers.indexOf(listener);
-		if (index !== -1) {
-			this.onSettingsChangeHandlers.splice(index, 1);
-		}
-	}
-
     public async setSetting<T extends keyof SyncSettings>(
         key: T,
         value: SyncSettings[T]
@@ -95,14 +79,9 @@ export class Settings {
                 ...value
             };
 
-			await awaitAll(
+            await this.onSettingsChanged.triggerAsync(
-				this.onSettingsChangeHandlers
+                this.settings,
-					.map((handler) => {
+                oldSettings
-						return handler(this.settings, oldSettings);
-					})
-					.filter((result): result is Promise<unknown> => {
-						return result instanceof Promise;
-					})
             );
 
             await this.save();

frontend/sync-client/src/services/websocket-manager.test.ts

@@ -122,7 +122,7 @@ describe("WebSocketManager", () => {
             MockWebSocket as unknown as typeof WebSocket
         );
 
-		manager.addRemoteVaultUpdateListener(async () => {
+        manager.onRemoteVaultUpdateReceived.add(async () => {
             await new Promise((resolve) => setTimeout(resolve, 10));
         });
         manager.start();
@@ -152,7 +152,7 @@ describe("WebSocketManager", () => {
             MockWebSocket as unknown as typeof WebSocket
         );
 
-		manager.addRemoteCursorsUpdateListener(async () => {
+        manager.onRemoteCursorsUpdateReceived.add(async () => {
             await new Promise((resolve) => setTimeout(resolve, 10));
         });
         manager.start();
@@ -227,7 +227,7 @@ describe("WebSocketManager", () => {
         );
 
         let statusChangeCount = 0;
-		manager.addWebSocketStatusChangeListener(() => {
+        manager.onWebSocketStatusChanged.add(() => {
             statusChangeCount++;
         });
 
@@ -269,7 +269,7 @@ describe("WebSocketManager", () => {
             resolveListener = resolve;
         });
 
-		manager.addRemoteVaultUpdateListener(async () => {
+        manager.onRemoteVaultUpdateReceived.add(async () => {
             await listenerPromise;
         });
 

frontend/sync-client/src/services/websocket-manager.ts

@@ -6,21 +6,23 @@ import type { CursorPositionFromClient } from "./types/CursorPositionFromClient"
 import type { ClientCursors } from "./types/ClientCursors";
 import { createPromise } from "../utils/create-promise";
 import type { WebSocketVaultUpdate } from "./types/WebSocketVaultUpdate";
-import { awaitAll } from "../utils/await-all";
 import { WEBSOCKET_DISCONNECT_TIMEOUT_IN_S } from "../consts";
+import { removeFromArray } from "../utils/remove-from-array";
+import { EventListeners } from "../utils/data-structures/event-listeners";
+import { awaitAll } from "../utils/await-all";
 
 export class WebSocketManager {
-	private readonly webSocketStatusChangeListeners: ((
+    public readonly onWebSocketStatusChanged = new EventListeners<
-		isConnected: boolean
+        (isConnected: boolean) => unknown
-	) => unknown)[] = [];
+    >();
 
-	private readonly remoteVaultUpdateListeners: ((
+    public readonly onRemoteVaultUpdateReceived = new EventListeners<
-		update: WebSocketVaultUpdate
+        (update: WebSocketVaultUpdate) => Promise<void>
-	) => Promise<void>)[] = [];
+    >();
 
-	private readonly remoteCursorsUpdateListeners: ((
+    public readonly onRemoteCursorsUpdateReceived = new EventListeners<
-		cursors: ClientCursors[]
+        (cursors: ClientCursors[]) => Promise<void>
-	) => Promise<void>)[] = [];
+    >();
 
     private isStopped = true;
     private resolveDisconnectingPromise: null | (() => unknown) = null;
@@ -59,24 +61,6 @@ export class WebSocketManager {
         );
     }
 
-	public addWebSocketStatusChangeListener(
-		listener: (isConnected: boolean) => unknown
-	): void {
-		this.webSocketStatusChangeListeners.push(listener);
-	}
-
-	public addRemoteCursorsUpdateListener(
-		listener: (cursors: ClientCursors[]) => Promise<void>
-	): void {
-		this.remoteCursorsUpdateListeners.push(listener);
-	}
-
-	public addRemoteVaultUpdateListener(
-		listener: (update: WebSocketVaultUpdate) => Promise<void>
-	): void {
-		this.remoteVaultUpdateListeners.push(listener);
-	}
-
     public start(): void {
         this.isStopped = false;
         this.initializeWebSocket();
@@ -205,9 +189,7 @@ export class WebSocketManager {
 
         this.webSocket.onopen = (): void => {
             this.logger.info("WebSocket connection opened");
-			this.webSocketStatusChangeListeners.forEach((listener) =>
+            this.onWebSocketStatusChanged.trigger(true);
-				listener(true)
-			);
         };
 
         this.webSocket.onmessage = (event): void => {
@@ -227,12 +209,10 @@ export class WebSocketManager {
                         );
                     })
                     .finally(() => {
-						const index = this.outstandingPromises.indexOf(
+                        removeFromArray(
+                            this.outstandingPromises,
                             messageHandlingPromise
                         );
-						if (index !== -1) {
-							void this.outstandingPromises.splice(index, 1); // ignore the returned promise
-						}
                     });
 
                 void this.outstandingPromises.push(messageHandlingPromise); // ignore the returned promise
@@ -247,9 +227,7 @@ export class WebSocketManager {
             this.logger.warn(
                 `WebSocket closed with code ${event.code} (${event.reason == "" ? "unknown reason" : event.reason})`
             );
-			this.webSocketStatusChangeListeners.forEach((listener) =>
+            this.onWebSocketStatusChanged.trigger(false);
-				listener(false)
-			);
 
             if (this.isStopped) {
                 this.resolveDisconnectingPromise?.();
@@ -267,15 +245,7 @@ export class WebSocketManager {
         message: WebSocketServerMessage
     ): Promise<void> {
         if (message.type === "vaultUpdate") {
-			await awaitAll(
+            await this.onRemoteVaultUpdateReceived.triggerAsync(message);
-				this.remoteVaultUpdateListeners.map(async (listener) => {
-					await listener(message).catch((error: unknown) => {
-						this.logger.error(
-							`Error in vault update listener: ${String(error)}`
-						);
-					});
-				})
-			);
 
             // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
         } else if (message.type === "cursorPositions") {
@@ -283,14 +253,8 @@ export class WebSocketManager {
                 `Received cursor positions for ${JSON.stringify(message.clients)}`
             );
 
-			await awaitAll(
+            await this.onRemoteCursorsUpdateReceived.triggerAsync(
-				this.remoteCursorsUpdateListeners.map(async (listener) => {
+                message.clients
-					await listener(message.clients).catch((error: unknown) => {
-						this.logger.error(
-							`Error in cursor positions listener: ${String(error)}`
-						);
-					});
-				})
             );
         } else {
             this.logger.warn(

frontend/sync-client/src/sync-client.ts

@@ -26,6 +26,7 @@ import { FixedSizeDocumentCache } from "./utils/data-structures/fix-sized-cache"
 import { setUpTelemetry } from "./utils/set-up-telemetry";
 import { DIFF_CACHE_SIZE_MB } from "./consts";
 import { ServerConfig } from "./services/server-config";
+import type { EventListeners } from "./utils/data-structures/event-listeners";
 
 export class SyncClient {
     private hasStartedOfflineSync = false;
@@ -62,6 +63,42 @@ export class SyncClient {
     public get isWebSocketConnected(): boolean {
         return this.webSocketManager.isWebSocketConnected;
     }
+
+    public get onSyncHistoryUpdated(): EventListeners<
+        (stats: HistoryStats) => unknown
+    > {
+        this.checkIfDestroyed("onSyncHistoryUpdated getter");
+        return this.history.onHistoryUpdated;
+    }
+
+    public get onSettingsChanged(): EventListeners<
+        (newSettings: SyncSettings, oldSettings: SyncSettings) => unknown
+    > {
+        this.checkIfDestroyed("onSettingsChanged getter");
+        return this.settings.onSettingsChanged;
+    }
+
+    public get onRemainingOperationsCountChanged(): EventListeners<
+        (remainingOperationsCount: number) => unknown
+    > {
+        this.checkIfDestroyed("onRemainingOperationsCountChanged getter");
+        return this.syncer.onRemainingOperationsCountChanged;
+    }
+
+    public get onWebSocketStatusChanged(): EventListeners<
+        (isConnected: boolean) => unknown
+    > {
+        this.checkIfDestroyed("onWebSocketStatusChanged getter");
+        return this.webSocketManager.onWebSocketStatusChanged;
+    }
+
+    public get onRemoteCursorsUpdated(): EventListeners<
+        (cursors: MaybeOutdatedClientCursors[]) => unknown
+    > {
+        this.checkIfDestroyed("onRemoteCursorsUpdated getter");
+        return this.cursorTracker.onRemoteCursorsUpdated;
+    }
+
     public static async create({
         fs,
         persistence,
@@ -122,7 +159,7 @@ export class SyncClient {
             settings.getSettings().isSyncEnabled,
             logger
         );
-		settings.addOnSettingsChangeListener((newSettings, oldSettings) => {
+        settings.onSettingsChanged.add((newSettings, oldSettings) => {
             if (oldSettings.isSyncEnabled != newSettings.isSyncEnabled) {
                 fetchController.canFetch = newSettings.isSyncEnabled;
             }
@@ -221,15 +258,13 @@ export class SyncClient {
             this.unloadTelemetry = setUpTelemetry();
         }
 
-		this.logger.addOnMessageListener((log): void => {
+        this.logger.onLogEmitted.add((log): void => {
             if (log.level === LogLevel.ERROR && Sentry.isInitialized()) {
                 Sentry.captureMessage(log.message);
             }
         });
 
-		this.settings.addOnSettingsChangeListener(
+        this.settings.onSettingsChanged.add(this.onSettingsChange.bind(this));
-			this.onSettingsChange.bind(this)
-		);
 
         if (this.settings.getSettings().isSyncEnabled) {
             this.logger.info("Starting SyncClient");
@@ -273,14 +308,6 @@ export class SyncClient {
         return this.history.entries;
     }
 
-	public addSyncHistoryUpdateListener(
-		listener: (stats: HistoryStats) => unknown
-	): void {
-		this.checkIfDestroyed("addSyncHistoryUpdateListener");
-
-		this.history.addSyncHistoryUpdateListener(listener);
-	}
-
     /**
     * Wait for the in-flight operations to finish, reset all tracking,
     * and the local database but retain the settings.
@@ -325,28 +352,6 @@ export class SyncClient {
         await this.settings.setSettings(value);
     }
 
-	public addOnSettingsChangeListener(
-		listener: (settings: SyncSettings, oldSettings: SyncSettings) => unknown
-	): void {
-		this.checkIfDestroyed("addOnSettingsChangeListener");
-
-		this.settings.addOnSettingsChangeListener(listener);
-	}
-
-	public addRemainingSyncOperationsListener(
-		listener: (remainingOperations: number) => unknown
-	): void {
-		this.checkIfDestroyed("addRemainingSyncOperationsListener");
-
-		this.syncer.addRemainingOperationsListener(listener);
-	}
-
-	public addWebSocketStatusChangeListener(listener: () => unknown): void {
-		this.checkIfDestroyed("addWebSocketStatusChangeListener");
-
-		this.webSocketManager.addWebSocketStatusChangeListener(listener);
-	}
-
     public async syncLocallyCreatedFile(
         relativePath: RelativePath
     ): Promise<void> {
@@ -412,14 +417,6 @@ export class SyncClient {
         await this.cursorTracker.sendLocalCursorsToServer(documentToCursors);
     }
 
-	public addRemoteCursorsUpdateListener(
-		listener: (cursors: MaybeOutdatedClientCursors[]) => unknown
-	): void {
-		this.checkIfDestroyed("addRemoteCursorsUpdateListener");
-
-		this.cursorTracker.addRemoteCursorsUpdateListener(listener);
-	}
-
     public async waitUntilFinished(): Promise<void> {
         this.checkIfDestroyed("waitUntilIdle");
         await this.syncer.waitUntilFinished();

frontend/sync-client/src/sync-operations/cursor-tracker.ts

@@ -9,12 +9,19 @@ import { DocumentUpToDateness } from "../types/document-up-to-dateness";
 import { hash } from "../utils/hash";
 import type { FileChangeNotifier } from "./file-change-notifier";
 import { Lock } from "../utils/data-structures/locks";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 // Cursor positions are updated separately from documents. However, a given cursor position is only
 // valid within a certain version of the document it belongs to. This class tracks previous and the latest
 // known remote cursor positions, and for each document, tries to return the latest cursor positions that are
 // not from the future.
 export class CursorTracker {
+    // The returned position may be accurate, if it matches the document version, or outdated, in which case
+    // the client has to heuristically guess it's current position based on the local edits.
+    public readonly onRemoteCursorsUpdated = new EventListeners<
+        (cursors: MaybeOutdatedClientCursors[]) => unknown
+    >();
+
     private readonly updateLock = new Lock();
 
     private knownRemoteCursors: (ClientCursors & {
@@ -31,7 +38,7 @@ export class CursorTracker {
         private readonly fileOperations: FileOperations,
         private readonly fileChangeNotifier: FileChangeNotifier
     ) {
-		this.webSocketManager.addRemoteCursorsUpdateListener(
+        this.webSocketManager.onRemoteCursorsUpdateReceived.add(
             async (clientCursors) => {
                 await this.updateLock.withLock(async () => {
                     // The latest message will contain all active clients, so we can delete the ones
@@ -58,10 +65,14 @@ export class CursorTracker {
 
                     this.knownRemoteCursors = updatedKnownRemoteCursors;
                 });
+
+                this.onRemoteCursorsUpdated.trigger(
+                    this.getRelevantAndPruneKnownClientCursors()
+                );
             }
         );
 
-		this.fileChangeNotifier.addFileChangeListener(async (relativePath) =>
+        this.fileChangeNotifier.onFileChanged.add(async (relativePath) =>
             this.updateLock.withLock(async () => {
                 for (const clientCursor of this.knownRemoteCursors) {
                     if (
@@ -144,19 +155,6 @@ export class CursorTracker {
         this.webSocketManager.updateLocalCursors({ documentsWithCursors });
     }
 
-	// The returned position may be accurate, if it matches the document version, or outdated, in which case
-	// the client has to heuristically guess it's current position based on the local edits.
-	public addRemoteCursorsUpdateListener(
-		listener: (cursors: MaybeOutdatedClientCursors[]) => unknown
-	): void {
-		// CursorTracker registers its own event listener in the constructor so it must have been called before this
-		this.webSocketManager.addRemoteCursorsUpdateListener(async () => {
-			await this.updateLock.withLock(() =>
-				listener(this.getRelevantAndPruneKnownClientCursors())
-			);
-		});
-	}
-
     public reset(): void {
         this.knownRemoteCursors = [];
         this.lastLocalCursorState = [];

frontend/sync-client/src/sync-operations/file-change-notifier.ts

@@ -1,24 +1,12 @@
 import type { RelativePath } from "../persistence/database";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 export class FileChangeNotifier {
-	private readonly listeners: ((filePath: RelativePath) => unknown)[] = [];
+    public readonly onFileChanged = new EventListeners<
-
+        (filePath: RelativePath) => unknown
-	public addFileChangeListener(
+    >();
-		listener: (filePath: RelativePath) => unknown
-	): void {
-		this.listeners.push(listener);
-	}
-
-	public removeFileChangeListener(
-		listener: (filePath: RelativePath) => unknown
-	): void {
-		const index = this.listeners.indexOf(listener);
-		if (index !== -1) {
-			this.listeners.splice(index, 1);
-		}
-	}
 
     public notifyOfFileChange(filePath: RelativePath): void {
-		this.listeners.forEach((listener) => listener(filePath));
+        this.onFileChanged.trigger(filePath);
     }
 }

frontend/sync-client/src/sync-operations/syncer.ts

@@ -21,18 +21,21 @@ import type { WebSocketVaultUpdate } from "../services/types/WebSocketVaultUpdat
 import type { WebSocketManager } from "../services/websocket-manager";
 import type { WebSocketClientMessage } from "../services/types/WebSocketClientMessage";
 import { awaitAll } from "../utils/await-all";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 export class Syncer {
+    public readonly onRemainingOperationsCountChanged = new EventListeners<
+        (remainingOperations: number) => unknown
+    >();
+
     private readonly remoteDocumentsLock: Locks<DocumentId>;
-	private readonly remainingOperationsListeners: ((
-		remainingOperations: number
-	) => unknown)[] = [];
 
     // FIFO to limit the number of concurrent sync operations
     private readonly syncQueue: PQueue;
 
     private _isFirstSyncComplete = false;
     private runningScheduleSyncForOfflineChanges: Promise<void> | undefined;
+    private previousRemainingOperationsCount = 0;
 
     public constructor(
         private readonly deviceId: string,
@@ -50,27 +53,28 @@ export class Syncer {
 
         this.remoteDocumentsLock = new Locks<DocumentId>(this.logger);
 
-		settings.addOnSettingsChangeListener((newSettings, oldSettings) => {
+        settings.onSettingsChanged.add((newSettings, oldSettings) => {
             if (newSettings.syncConcurrency !== oldSettings.syncConcurrency) {
                 this.syncQueue.concurrency = newSettings.syncConcurrency;
             }
         });
 
         this.syncQueue.on("active", () => {
-			this.remainingOperationsListeners.forEach((listener) => {
+            if (this.previousRemainingOperationsCount !== this.syncQueue.size) {
-				listener(this.syncQueue.size);
+                this.previousRemainingOperationsCount = this.syncQueue.size;
-			});
+                this.onRemainingOperationsCountChanged.trigger(
+                    this.syncQueue.size
+                );
+            }
         });
 
-		this.webSocketManager.addWebSocketStatusChangeListener(
+        this.webSocketManager.onWebSocketStatusChanged.add((isConnected) => {
-			(isConnected) => {
             if (isConnected) {
                 // The JS WebSocket API doesn't support setting headers, so we have to send the token as a message
                 this.sendHandshakeMessage();
             }
-			}
+        });
-		);
+        this.webSocketManager.onRemoteVaultUpdateReceived.add(
-		this.webSocketManager.addRemoteVaultUpdateListener(
             this.syncRemotelyUpdatedFile.bind(this)
         );
     }
@@ -79,12 +83,6 @@ export class Syncer {
         return this._isFirstSyncComplete;
     }
 
-	public addRemainingOperationsListener(
-		listener: (remainingOperations: number) => unknown
-	): void {
-		this.remainingOperationsListeners.push(listener);
-	}
-
     public async syncLocallyCreatedFile(
         relativePath: RelativePath
     ): Promise<void> {
@@ -444,11 +442,13 @@ export class Syncer {
                 );
                 if (originalFile !== undefined) {
                     // `originalFile` hasn't been deleted but it got moved instead
+                    /* eslint-disable no-restricted-syntax -- Comparing by property, not direct equality */
                     locallyPossiblyDeletedFiles =
                         locallyPossiblyDeletedFiles.filter(
                             (item) =>
                                 item.relativePath !== originalFile.relativePath
                         );
+                    /* eslint-enable no-restricted-syntax */
 
                     this.logger.debug(
                         `Document '${originalFile.relativePath}' was not found under its current path in the database but was found under a different path (${relativePath}), scheduling sync to move it`

frontend/sync-client/src/sync-operations/unrestricted-syncer.ts

@@ -52,7 +52,7 @@ export class UnrestrictedSyncer {
             this.logger
         );
 
-		this.settings.addOnSettingsChangeListener((newSettings) => {
+        this.settings.onSettingsChanged.add((newSettings) => {
             this.ignorePatterns = globsToRegexes(
                 newSettings.ignorePatterns,
                 this.logger

frontend/sync-client/src/tracing/logger.ts

@@ -1,4 +1,5 @@
 import { MAX_LOG_MESSAGE_COUNT } from "../consts";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 export enum LogLevel {
     DEBUG = "DEBUG",
@@ -23,14 +24,11 @@ export class LogLine {
 }
 
 export class Logger {
-	private readonly messages: LogLine[] = [];
+    public readonly onLogEmitted = new EventListeners<
-	private readonly onMessageListeners: ((message: LogLine) => unknown)[] = [];
+        (message: LogLine) => unknown
+    >();
 
-	public constructor(
+    private readonly messages: LogLine[] = [];
-		...onMessageListeners: ((message: LogLine) => unknown)[]
-	) {
-		this.onMessageListeners = onMessageListeners;
-	}
 
     public debug(message: string): void {
         this.pushMessage(message, LogLevel.DEBUG);
@@ -56,19 +54,6 @@ export class Logger {
         );
     }
 
-	public addOnMessageListener(listener: (message: LogLine) => unknown): void {
-		this.onMessageListeners.push(listener);
-	}
-
-	public removeOnMessageListener(
-		listener: (message: LogLine) => unknown
-	): void {
-		const index = this.onMessageListeners.indexOf(listener);
-		if (index !== -1) {
-			this.onMessageListeners.splice(index, 1);
-		}
-	}
-
     public reset(): void {
         this.messages.length = 0;
         this.debug("Logger has been reset");
@@ -82,8 +67,6 @@ export class Logger {
             this.messages.shift();
         }
 
-		this.onMessageListeners.forEach((listener) => {
+        this.onLogEmitted.trigger(logLine);
-			listener(logLine);
-		});
     }
 }

frontend/sync-client/src/tracing/sync-history.ts

@@ -4,6 +4,8 @@ import {
 } from "../consts";
 import type { RelativePath } from "../persistence/database";
 import type { Logger } from "./logger";
+import { removeFromArray } from "../utils/remove-from-array";
+import { EventListeners } from "../utils/data-structures/event-listeners";
 
 export interface SyncCreateDetails {
     type: SyncType.CREATE;
@@ -68,11 +70,11 @@ export interface HistoryStats {
 }
 
 export class SyncHistory {
-	private _entries: HistoryEntry[] = [];
+    public readonly onHistoryUpdated = new EventListeners<
+        (status: HistoryStats) => unknown
+    >();
 
-	private readonly syncHistoryUpdateListeners: ((
+    private readonly _entries: HistoryEntry[] = [];
-		status: HistoryStats
-	) => unknown)[] = [];
 
     private status: HistoryStats = {
         success: 0,
@@ -99,7 +101,7 @@ export class SyncHistory {
 
         const candidate = this.findSimilarRecentUpdateEntry(historyEntry);
         if (candidate !== undefined) {
-			this._entries = this._entries.filter((e) => e !== candidate);
+            removeFromArray(this._entries, candidate);
         }
 
         // Insert the entry at the beginning
@@ -112,31 +114,13 @@ export class SyncHistory {
         this.updateSuccessCount(historyEntry);
     }
 
-	public addSyncHistoryUpdateListener(
-		listener: (stats: HistoryStats) => unknown
-	): void {
-		this.syncHistoryUpdateListeners.push(listener);
-		listener({ ...this.status });
-	}
-
-	public removeSyncHistoryUpdateListener(
-		listener: (stats: HistoryStats) => unknown
-	): void {
-		const index = this.syncHistoryUpdateListeners.indexOf(listener);
-		if (index !== -1) {
-			this.syncHistoryUpdateListeners.splice(index, 1);
-		}
-	}
-
     public reset(): void {
         this._entries.length = 0;
         this.status = {
             success: 0,
             error: 0
         };
-		this.syncHistoryUpdateListeners.forEach((listener) => {
+        this.onHistoryUpdated.trigger(this.status);
-			listener(this.status);
-		});
     }
 
     private findSimilarRecentUpdateEntry(
@@ -178,8 +162,6 @@ export class SyncHistory {
                 break;
         }
 
-		this.syncHistoryUpdateListeners.forEach((listener) => {
+        this.onHistoryUpdated.trigger(this.status);
-			listener(this.status);
-		});
     }
 }

frontend/sync-client/src/utils/data-structures/event-listeners.test.ts

@@ -0,0 +1,150 @@
+import { describe, it } from "node:test";
+import assert from "node:assert";
+import { EventListeners } from "./event-listeners";
+
+describe("EventListeners", () => {
+    it("should add & remove listeners", () => {
+        const listeners = new EventListeners<() => void>();
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener = (): void => {};
+
+        listeners.add(listener);
+
+        assert.strictEqual(listeners.count, 1);
+
+        const removed = listeners.remove(listener);
+        assert.strictEqual(removed, true);
+        assert.strictEqual(listeners.count, 0);
+    });
+
+    it("should remove listeners using unsubscribe function", () => {
+        const listeners = new EventListeners<() => void>();
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener = (): void => {};
+
+        const unsubscribe = listeners.add(listener);
+        unsubscribe();
+
+        assert.strictEqual(listeners.count, 0);
+    });
+
+    it("should return false when removing non-existent listener", () => {
+        const listeners = new EventListeners<() => void>();
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener = (): void => {};
+
+        const removed = listeners.remove(listener);
+
+        assert.strictEqual(removed, false);
+    });
+
+    it("should handle multiple listeners", () => {
+        const listeners = new EventListeners<() => void>();
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener1 = (): void => {};
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener2 = (): void => {};
+        // eslint-disable-next-line @typescript-eslint/no-empty-function
+        const listener3 = (): void => {};
+
+        listeners.add(listener1);
+        listeners.add(listener2);
+        listeners.add(listener3);
+
+        assert.strictEqual(listeners.count, 3);
+
+        listeners.remove(listener2);
+
+        assert.strictEqual(listeners.count, 2);
+    });
+
+    it("should trigger all listeners synchronously", () => {
+        const listeners = new EventListeners<(value: string) => void>();
+        const calls: string[] = [];
+
+        listeners.add((value) => calls.push(`listener1-${value}`));
+        listeners.add((value) => calls.push(`listener2-${value}`));
+
+        listeners.trigger("test");
+
+        assert.deepStrictEqual(calls, ["listener1-test", "listener2-test"]);
+    });
+
+    it("should trigger listeners with multiple arguments", () => {
+        const listeners = new EventListeners<
+            (a: number, b: string, c: boolean) => void
+        >();
+        const calls: [number, string, boolean][] = [];
+
+        listeners.add((a, b, c) => calls.push([a, b, c]));
+        listeners.trigger(42, "hello", true);
+
+        assert.deepStrictEqual(calls, [[42, "hello", true]]);
+    });
+
+    it("should not trigger removed listeners", () => {
+        const listeners = new EventListeners<() => void>();
+        let count1 = 0;
+        let count2 = 0;
+
+        const listener1 = (): void => {
+            count1++;
+        };
+        const listener2 = (): void => {
+            count2++;
+        };
+
+        listeners.add(listener1);
+        const unsubscribe = listeners.add(listener2);
+
+        unsubscribe();
+        listeners.trigger();
+
+        assert.strictEqual(count1, 1);
+        assert.strictEqual(count2, 0);
+    });
+
+    it("should trigger all listeners and await promises", async () => {
+        const listeners = new EventListeners<
+            (value: string) => Promise<void> | void
+        >();
+        const results: string[] = [];
+
+        listeners.add(async (value) => {
+            await new Promise((resolve) => setTimeout(resolve, 10));
+            results.push(`async1-${value}`);
+        });
+
+        listeners.add((value) => {
+            results.push(`sync-${value}`);
+        });
+
+        listeners.add(async (value) => {
+            await new Promise((resolve) => setTimeout(resolve, 5));
+            results.push(`async2-${value}`);
+        });
+
+        await listeners.triggerAsync("test");
+
+        assert.ok(results.includes("async1-test"));
+        assert.ok(results.includes("sync-test"));
+        assert.ok(results.includes("async2-test"));
+        assert.strictEqual(results.length, 3);
+    });
+
+    it("should not trigger cleared listeners", () => {
+        const listeners = new EventListeners<() => void>();
+        let called = false;
+        const listener = (): void => {
+            called = true;
+        };
+
+        listeners.add(listener);
+        listeners.clear();
+
+        assert.strictEqual(listeners.count, 0);
+        listeners.trigger();
+
+        assert.strictEqual(called, false);
+    });
+});

frontend/sync-client/src/utils/data-structures/event-listeners.ts

@@ -0,0 +1,71 @@
+import { removeFromArray } from "../remove-from-array";
+import { awaitAll } from "../await-all";
+
+/**
+ * A utility class for managing event listeners with type-safe add/remove operations.
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export class EventListeners<TListener extends (...args: any[]) => any> {
+    private readonly listeners: TListener[] = [];
+
+    public get count(): number {
+        return this.listeners.length;
+    }
+
+    /**
+    * Adds a new listener to the collection.
+    *
+    * @param listener The listener callback to add
+    * @returns An unsubscribe function that removes this listener when called
+    */
+    public add(listener: TListener): () => void {
+        this.listeners.push(listener);
+        return () => this.remove(listener);
+    }
+
+    /**
+    * Removes a listener from the collection.
+    *
+    * @param listener The listener callback to remove
+    * @returns true if the listener was found and removed, false otherwise
+    */
+    public remove(listener: TListener): boolean {
+        return removeFromArray(this.listeners, listener);
+    }
+
+    /**
+    * Triggers all listeners synchronously with the provided arguments.
+    * Any returned promises are ignored. Use triggerAsync() to await them.
+    *
+    * @param args The arguments to pass to each listener
+    */
+    public trigger(...args: Parameters<TListener>): void {
+        this.listeners.forEach((listener) => {
+            listener(...args);
+        });
+    }
+
+    /**
+    * Triggers all listeners and awaits any promises they return.
+    * Synchronous listeners are called immediately, and any async listeners
+    * are awaited in parallel.
+    *
+    * @param args The arguments to pass to each listener
+    */
+    public async triggerAsync(...args: Parameters<TListener>): Promise<void> {
+        await awaitAll(
+            this.listeners
+                .map((listener) => {
+                    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+                    return listener(...args);
+                })
+                .filter((result): result is Promise<unknown> => {
+                    return result instanceof Promise;
+                })
+        );
+    }
+
+    public clear(): void {
+        this.listeners.length = 0;
+    }
+}

frontend/sync-client/src/utils/debugging/log-to-console.ts

@@ -3,7 +3,7 @@ import type { LogLine } from "../../tracing/logger";
 import { LogLevel } from "../../tracing/logger";
 
 export function logToConsole(client: SyncClient): void {
-	client.logger.addOnMessageListener((logLine: LogLine) => {
+    client.logger.onLogEmitted.add((logLine: LogLine) => {
         const formatted = `${logLine.timestamp.toISOString()} ${logLine.level} ${logLine.message}`;
 
         switch (logLine.level) {

frontend/sync-client/src/utils/globs-to-regexes.ts

@@ -2,7 +2,8 @@ import { makeRe } from "minimatch";
 import type { Logger } from "../tracing/logger";
 
 export function globsToRegexes(globs: string[], logger: Logger): RegExp[] {
-	return globs
+    return (
+        globs
             .map((pattern) => {
                 const result = makeRe(pattern, {
                     dot: true
@@ -14,5 +15,7 @@ export function globsToRegexes(globs: string[], logger: Logger): RegExp[] {
                 }
                 return result;
             })
-		.filter((pattern) => pattern !== false);
+            // eslint-disable-next-line no-restricted-syntax -- Filtering out false values, not removing a specific item
+            .filter((pattern) => pattern !== false)
+    );
 }

frontend/sync-client/src/utils/remove-from-array.ts

@@ -0,0 +1,17 @@
+/**
+ * Efficiently removes a specific item from an array by modifying it in place.
+ * This is more efficient than using `.filter(item => item !== toRemove)` as it avoids creating a new array
+ *
+ * @param array The array to modify
+ * @param item The item to remove
+ * @returns true if the item was found and removed, false otherwise
+ */
+export function removeFromArray<T>(array: T[], item: T): boolean {
+    const index = array.indexOf(item);
+    if (index !== -1) {
+        // eslint-disable-next-line no-restricted-syntax -- This is the implementation of the helper itself
+        array.splice(index, 1);
+        return true;
+    }
+    return false;
+}

frontend/test-client/package.json

@@ -8,7 +8,7 @@
     "scripts": {
         "dev": "webpack watch --mode development",
         "build": "webpack --mode production",
-		"test": "tsx --test src/**/*.test.ts"
+        "test": "tsx --test 'src/**/*.test.ts'"
     },
     "devDependencies": {
         "@types/node": "^24.8.1",

frontend/test-client/src/agent/mock-agent.ts

@@ -15,7 +15,7 @@ export class MockAgent extends MockClient {
     private readonly pendingActions: Promise<unknown>[] = [];
 
     // The renamed file finding algorithm isn't too smart so we can't both update and rename the same file
-	private doNotTouchWhileOffline: string[] = [];
+    private readonly doNotTouchWhileOffline: string[] = [];
 
     public constructor(
         initialSettings: Partial<SyncSettings>,
@@ -42,7 +42,7 @@ export class MockAgent extends MockClient {
             "Connection check failed"
         );
 
-		this.client.logger.addOnMessageListener((logLine: LogLine) => {
+        this.client.logger.onLogEmitted.add((logLine: LogLine) => {
             const state = this.client.getSettings().isSyncEnabled
                 ? "(online) "
                 : "(offline)";
@@ -54,9 +54,9 @@ export class MockAgent extends MockClient {
             );
 
             if (historyEntry) {
-				this.doNotTouchWhileOffline =
+                utils.removeFromArray(
-					this.doNotTouchWhileOffline.filter(
+                    this.doNotTouchWhileOffline,
-						(file) => file !== historyEntry[1]
+                    historyEntry[1]
                 );
             }
             switch (logLine.level) {

scripts/check.sh

@@ -2,7 +2,6 @@
 
 set -e
 
-# Parse arguments
 FIX_MODE=false
 if [[ "$1" == "--fix" ]]; then
     FIX_MODE=true
@@ -32,10 +31,18 @@ if [[ "$FIX_MODE" == true ]]; then
 else
     npm ci
 fi
+
+cd ..
+
+cd frontend
 npm run build
 npm run test
 npm run lint
 
+# Use git ls-files to only check tracked files, respecting .gitignore
+# We always run in fix mode and then check with git status
+git ls-files | xargs npx eclint fix
+
 if [[ "$FIX_MODE" == false ]] && [[ $(git status --porcelain) ]]; then
     git status --porcelain
     echo "Failing CI because the working directory is not clean after linting"

scripts/e2e.sh

@@ -109,4 +109,3 @@ while true; do
 
     sleep 0.2
 done
-

scripts/update-api-types.sh

@@ -11,5 +11,6 @@ cd -
 cp -r sync-server/bindings/* frontend/sync-client/src/services/types/
 
 cd frontend
-npm run lint || npx prettier --write sync-client/src/services/types/*.ts
+npm run lint
+git ls-files | xargs npx eclint fix
 cd -

sync-server/Cargo.lock

@@ -375,16 +375,6 @@ dependencies = [
  "clap_derive",
 ]
 
-[[package]]
-name = "clap-verbosity-flag"
-version = "3.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eeab6a5cdfc795a05538422012f20a5496f050223c91be4e5420bfd13c641fb1"
-dependencies = [
- "clap",
- "log",
-]
-
 [[package]]
 name = "clap_builder"
 version = "4.5.38"
@@ -2143,7 +2133,6 @@ dependencies = [
  "bimap",
  "chrono",
  "clap",
- "clap-verbosity-flag",
  "futures",
  "humantime-serde",
  "log",

sync-server/Cargo.toml

@@ -30,7 +30,6 @@ clap = { version = "4.5.38", features = ["derive"] }
 futures = "0.3.31"
 serde_yaml = "0.9.34"
 serde_json = "1.0.140"
-clap-verbosity-flag = "3.0.3"
 bimap = "0.6.3"
 ts-rs =  { version = "10.1", features = ["uuid-impl", "chrono-impl"] }
 base64 = "0.22.1"

sync-server/config-e2e.yml

@@ -30,3 +30,4 @@ users:
 logging:
   log_directory: logs
   log_rotation: 7days
+  log_level: info

sync-server/src/app_state/database.rs

@@ -57,6 +57,7 @@ impl Database {
 
         let mut connection_pools = std::collections::HashMap::new();
 
+        info!("Applying pending database migrations");
         let mut entries = tokio::fs::read_dir(&config.databases_directory_path).await?;
         while let Some(entry) = entries.next_entry().await? {
             if !entry.file_name().to_string_lossy().ends_with(".sqlite") {
@@ -319,7 +320,7 @@ impl Database {
                 device_id,
                 has_been_merged
             from latest_document_versions
-            where relative_path = ?
+            where relative_path = ? and is_deleted = false
             order by vault_update_id desc  -- `latest_document_versions` only contains a single latest version of each document, however,
                                             -- multiple documents can have the same `relative_path`, if they have been deleted. That's
                                             -- why we only care about the latest version of the document with the given relative path.

sync-server/src/cli/args.rs

@@ -1,7 +1,6 @@
 use std::ffi::OsString;
 
 use clap::Parser;
-use clap_verbosity_flag::{InfoLevel, Verbosity};
 
 use crate::cli::color_when::ColorWhen;
 
@@ -12,9 +11,6 @@ pub struct Args {
     #[arg(index = 1)]
     pub config_path: Option<OsString>,
 
-    #[command(flatten)]
-    pub verbose: Verbosity<InfoLevel>,
-
     #[arg(
             long,
             value_name = "WHEN",

sync-server/src/config/logging_config.rs

@@ -3,7 +3,10 @@ use std::time::Duration;
 use log::debug;
 use serde::{Deserialize, Serialize};
 
-use crate::consts::{DEFAULT_LOG_DIRECTORY, DEFAULT_LOG_ROTATION_INTERVAL};
+use crate::{
+    consts::{DEFAULT_LOG_DIRECTORY, DEFAULT_LOG_LEVEL, DEFAULT_LOG_ROTATION_INTERVAL},
+    utils::log_level::LogLevel,
+};
 
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct LoggingConfig {
@@ -12,6 +15,9 @@ pub struct LoggingConfig {
 
     #[serde(default = "default_log_rotation", with = "humantime_serde")]
     pub log_rotation: Duration,
+
+    #[serde(default = "default_log_level")]
+    pub log_level: LogLevel,
 }
 
 impl Default for LoggingConfig {
@@ -19,6 +25,7 @@ impl Default for LoggingConfig {
         Self {
             log_directory: default_log_directory(),
             log_rotation: default_log_rotation(),
+            log_level: default_log_level(),
         }
     }
 }
@@ -32,3 +39,8 @@ fn default_log_rotation() -> Duration {
     debug!("Using default log rotation: {DEFAULT_LOG_ROTATION_INTERVAL:?}");
     DEFAULT_LOG_ROTATION_INTERVAL
 }
+
+fn default_log_level() -> LogLevel {
+    debug!("Using default log level: Info");
+    DEFAULT_LOG_LEVEL
+}

sync-server/src/consts.rs

@@ -1,5 +1,7 @@
 use std::time::Duration;
 
+use crate::utils::log_level::LogLevel;
+
 pub const DEFAULT_CONFIG_PATH: &str = "config.yml";
 
 pub const DEFAULT_DATABASES_DIRECTORY_PATH: &str = "databases";
@@ -14,6 +16,7 @@ pub const DEFAULT_MAX_CLIENTS_PER_VAULT: usize = 256;
 
 pub const DEFAULT_LOG_DIRECTORY: &str = "logs";
 pub const DEFAULT_LOG_ROTATION_INTERVAL: Duration = Duration::from_secs(60 * 60 * 24); // 1 day
+pub const DEFAULT_LOG_LEVEL: LogLevel = LogLevel::Info;
 
 pub const DEFAULT_MERGEABLE_FILE_EXTENSIONS: &[&str] = &["md", "txt"];
 

sync-server/src/main.rs

@@ -60,14 +60,7 @@ fn set_up_logging(
     args: &Args,
     logging_config: &config::logging_config::LoggingConfig,
 ) -> Result<(), SyncServerError> {
-    let level_filter = match args.verbose.log_level_filter() {
+    let level_filter = logging_config.log_level.as_tracing_level();
-        // We don't want to allow disabling all logging
-        log::LevelFilter::Off | log::LevelFilter::Error => tracing::Level::ERROR,
-        log::LevelFilter::Warn => tracing::Level::WARN,
-        log::LevelFilter::Info => tracing::Level::INFO,
-        log::LevelFilter::Debug => tracing::Level::DEBUG,
-        log::LevelFilter::Trace => tracing::Level::TRACE,
-    };
 
     let env_filter = EnvFilter::builder()
         .with_default_directive(level_filter.into())
@@ -77,7 +70,7 @@ fn set_up_logging(
 
     let use_colors = args.color.use_colors();
 
-    let is_debug_mode = args.verbose.log_level_filter() >= log::LevelFilter::Debug;
+    let is_debug_mode = logging_config.log_level.is_debug_or_trace();
 
     let file_appender = RotatingFileWriter::new(
         &logging_config.log_directory,

sync-server/src/utils.rs

@@ -2,6 +2,7 @@ pub mod dedup_paths;
 pub mod find_first_available_path;
 pub mod is_binary;
 pub mod is_file_type_mergable;
+pub mod log_level;
 pub mod normalize;
 pub mod rotating_file_writer;
 pub mod sanitize_path;

sync-server/src/utils/log_level.rs

@@ -0,0 +1,27 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Deserialize, Serialize, Clone, Copy, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum LogLevel {
+    Error,
+    Warn,
+    Info,
+    Debug,
+    Trace,
+}
+
+impl LogLevel {
+    pub fn as_tracing_level(self) -> tracing::Level {
+        match self {
+            Self::Error => tracing::Level::ERROR,
+            Self::Warn => tracing::Level::WARN,
+            Self::Info => tracing::Level::INFO,
+            Self::Debug => tracing::Level::DEBUG,
+            Self::Trace => tracing::Level::TRACE,
+        }
+    }
+
+    pub fn is_debug_or_trace(self) -> bool {
+        matches!(self, Self::Debug | Self::Trace)
+    }
+}

sync-server/src/utils/rotating_file_writer.rs

@@ -173,6 +173,7 @@ mod tests {
     #[test]
     fn test_write_creates_log_file_and_directory() {
         let temp_dir = std::env::temp_dir().join("test_write_creates_log_file_and_directory");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         let mut writer =
             RotatingFileWriter::new(&temp_dir, "test", Duration::from_secs(3600)).unwrap();
@@ -195,6 +196,7 @@ mod tests {
     #[test]
     fn test_rotation_after_duration() {
         let temp_dir = std::env::temp_dir().join("test_rotation_after_duration");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         // Use a very short rotation duration
         // Note: We need to wait at least 1 second between rotations since
@@ -227,6 +229,7 @@ mod tests {
     fn test_calculate_next_rotation_time_no_existing_logs() {
         let temp_dir =
             std::env::temp_dir().join("test_calculate_next_rotation_time_no_existing_logs");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         fs::create_dir_all(&temp_dir).unwrap();
 
@@ -248,6 +251,7 @@ mod tests {
     fn test_calculate_next_rotation_time_with_existing_log() {
         let temp_dir =
             std::env::temp_dir().join("test_calculate_next_rotation_time_with_existing_log");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         fs::create_dir_all(&temp_dir).unwrap();
 
@@ -286,6 +290,7 @@ mod tests {
     #[test]
     fn test_picks_latest_log_file() {
         let temp_dir = std::env::temp_dir().join("test_picks_latest_log_file");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         fs::create_dir_all(&temp_dir).unwrap();
 
@@ -320,6 +325,7 @@ mod tests {
     #[test]
     fn test_ignores_malformed_filenames() {
         let temp_dir = std::env::temp_dir().join("test_ignores_malformed_filenames");
+        let _ = fs::remove_dir_all(&temp_dir);
 
         fs::create_dir_all(&temp_dir).unwrap();