fix: add prefer-readonly rule (#5122)

.eslintrc.js

@@ -270,6 +270,7 @@ const config = {
           },
         ],
         '@typescript-eslint/no-misused-promises': ['error'],
+        '@typescript-eslint/prefer-readonly': 'error',
         'i/no-extraneous-dependencies': ['error'],
         'react-hooks/exhaustive-deps': [
           'warn',

packages/backend/server/src/middleware/exception-logger.ts

@@ -14,7 +14,7 @@ const TrivialExceptions = [NotFoundException];
 
 @Catch()
 export class ExceptionLogger implements ExceptionFilter {
-  private logger = new Logger('ExceptionLogger');
+  private readonly logger = new Logger('ExceptionLogger');
 
   catch(exception: Error, host: ArgumentsHost) {
     // with useGlobalFilters, the context is always HTTP

packages/backend/server/src/modules/auth/guard.ts

@@ -53,8 +53,8 @@ class AuthGuard implements CanActivate {
   constructor(
     @Inject(NextAuthOptionsProvide)
     private readonly nextAuthOptions: NextAuthOptions,
-    private auth: AuthService,
-    private prisma: PrismaService,
+    private readonly auth: AuthService,
+    private readonly prisma: PrismaService,
     private readonly reflector: Reflector
   ) {}
 

packages/backend/server/src/modules/auth/service.ts

@@ -28,9 +28,9 @@ export const getUtcTimestamp = () => Math.floor(Date.now() / 1000);
 @Injectable()
 export class AuthService {
   constructor(
-    private config: Config,
-    private prisma: PrismaService,
-    private mailer: MailService
+    private readonly config: Config,
+    private readonly prisma: PrismaService,
+    private readonly mailer: MailService
   ) {}
 
   sign(user: UserClaim) {

packages/backend/server/src/modules/doc/manager.ts

@@ -60,9 +60,9 @@ const MAX_SEQ_NUM = 0x3fffffff; // u31
  */
 @Injectable()
 export class DocManager implements OnModuleInit, OnModuleDestroy {
-  private logger = new Logger(DocManager.name);
+  private readonly logger = new Logger(DocManager.name);
   private job: NodeJS.Timeout | null = null;
-  private seqMap = new Map<string, number>();
+  private readonly seqMap = new Map<string, number>();
   private busy = false;
 
   constructor(

packages/backend/server/src/utils/doc.ts

@@ -16,7 +16,7 @@ export class DocID {
   raw: string;
   workspace: string;
   variant: DocVariant;
-  private sub: string | null;
+  private readonly sub: string | null;
 
   static parse(raw: string): DocID | null {
     try {

packages/common/debug/src/index.ts

@@ -24,7 +24,7 @@ if (typeof window !== 'undefined') {
 }
 
 export class DebugLogger {
-  private _debug: debug.Debugger;
+  private readonly _debug: debug.Debugger;
 
   constructor(namespace: string) {
     this._debug = debug(namespace);

packages/common/env/src/ua-helper.ts

@@ -1,7 +1,7 @@
 import { assertExists } from '@blocksuite/global/utils';
 
 export class UaHelper {
-  private uaMap;
+  private readonly uaMap;
   public isLinux = false;
   public isMacOs = false;
   public isSafari = false;

packages/common/infra/src/type.ts

@@ -45,8 +45,8 @@ export abstract class HandlerManager<
   Handlers extends Record<string, PrimitiveHandlers>,
 > {
   static instance: HandlerManager<string, Record<string, PrimitiveHandlers>>;
-  private _app: App<Namespace, Handlers>;
-  private _namespace: Namespace;
+  private readonly _app: App<Namespace, Handlers>;
+  private readonly _namespace: Namespace;
   private _handlers: Handlers;
 
   constructor() {

packages/frontend/component/src/components/page-list/filter/logical/matcher.ts

@@ -4,9 +4,11 @@ import { typesystem } from './typesystem';
 type MatcherData<Data, Type extends TType = TType> = { type: Type; data: Data };
 
 export class Matcher<Data, Type extends TType = TType> {
-  private list: MatcherData<Data, Type>[] = [];
+  private readonly list: MatcherData<Data, Type>[] = [];
 
-  constructor(private _match?: (type: Type, target: TType) => boolean) {}
+  constructor(
+    private readonly _match?: (type: Type, target: TType) => boolean
+  ) {}
 
   register(type: Type, data: Data) {
     this.list.push({ type, data });

packages/frontend/component/src/components/page-list/filter/logical/typesystem.ts

@@ -92,8 +92,8 @@ export type ValueOfData<T extends DataDefine> = T extends DataDefine<infer R>
 
 export class DataDefine<Data extends DataTypeShape = Record<string, unknown>> {
   constructor(
-    private config: DataDefineConfig<Data>,
-    private dataMap: Map<string, DataDefine>
+    private readonly config: DataDefineConfig<Data>,
+    private readonly dataMap: Map<string, DataDefine>
   ) {}
 
   create(data?: Data): TDataType<Data> {

packages/frontend/core/src/utils/user-setting.ts

@@ -5,8 +5,8 @@ import type { Map as YMap } from 'yjs';
 import { Doc as YDoc } from 'yjs';
 export class UserSetting {
   constructor(
-    private workspace: Workspace,
-    private userId: string
+    private readonly workspace: Workspace,
+    private readonly userId: string
   ) {}
 
   get setting(): YDoc {

packages/frontend/core/src/utils/workspace-setting.ts

@@ -13,7 +13,7 @@ const COLLECTIONS_TRASH_KEY = 'collections_trash';
 const SETTING_KEY = 'setting';
 
 export class WorkspaceSetting {
-  constructor(private workspace: Workspace) {}
+  constructor(private readonly workspace: Workspace) {}
 
   get doc() {
     return this.workspace.doc;

packages/frontend/electron/src/main/helper-process.ts

@@ -33,7 +33,7 @@ function pickAndBind<T extends object, U extends keyof T>(
 
 class HelperProcessManager {
   ready: Promise<void>;
-  #process: UtilityProcess;
+  readonly #process: UtilityProcess;
 
   // a rpc server for the main process -> helper process
   rpc?: _AsyncVersionOf<HelperToMain>;

packages/frontend/electron/src/main/updater/custom-github-provider.ts

@@ -29,7 +29,7 @@ const hrefRegExp = /\/tag\/([^/]+)$/;
 export class CustomGitHubProvider extends BaseGitHubProvider<GithubUpdateInfo> {
   constructor(
     options: CustomPublishOptions,
-    private updater: AppUpdater,
+    private readonly updater: AppUpdater,
     runtimeOptions: ProviderRuntimeOptions
   ) {
     super(options as unknown as GithubOptions, 'github.com', runtimeOptions);

packages/frontend/electron/src/shared/utils.ts

@@ -22,7 +22,7 @@ interface MessagePortLike {
 }
 
 export class MessageEventChannel implements EventBasedChannel {
-  constructor(private worker: MessagePortLike) {}
+  constructor(private readonly worker: MessagePortLike) {}
 
   on(listener: (data: unknown) => void) {
     const f = (data: unknown) => {

packages/frontend/graphql/src/utils.ts

@@ -54,7 +54,7 @@ export class TraceReporter {
 
   private spansCache = new Array<TraceSpan>();
   private reportIntervalId: number | undefined | NodeJS.Timeout;
-  private reportInterval = 60_000;
+  private readonly reportInterval = 60_000;
 
   private static instance: TraceReporter;
 
@@ -175,7 +175,7 @@ export class TraceReporter {
     };
   }
 
-  private initTraceReport = () => {
+  private readonly initTraceReport = () => {
     if (!this.reportIntervalId && TraceReporter.shouldReportTrace) {
       if (typeof window !== 'undefined') {
         this.reportIntervalId = window.setInterval(
@@ -191,7 +191,7 @@ export class TraceReporter {
     }
   };
 
-  private reportHandler = () => {
+  private readonly reportHandler = () => {
     if (this.spansCache.length <= 0) {
       clearInterval(this.reportIntervalId);
       this.reportIntervalId = undefined;

packages/frontend/workspace/src/blob/engine.ts

@@ -5,8 +5,8 @@ const logger = new DebugLogger('affine:blob-engine');
 
 export class BlobEngine {
   constructor(
-    private local: BlobStorage,
-    private remotes: BlobStorage[]
+    private readonly local: BlobStorage,
+    private readonly remotes: BlobStorage[]
   ) {}
 
   get storages() {

packages/frontend/workspace/src/providers/storage/affine/batch-sync-sender.ts

@@ -15,12 +15,12 @@ interface SyncUpdateSender {
  *   - retryable, allow retry when previous sync request failed but with retry flag been set to true
  */
 export class BatchSyncSender {
-  private buffered: Uint8Array[] = [];
+  private readonly buffered: Uint8Array[] = [];
   private job: Promise<void> | null = null;
   private started = true;
 
   constructor(
-    private guid: string,
+    private readonly guid: string,
     private readonly rawSender: SyncUpdateSender
   ) {}
 

packages/frontend/workspace/src/providers/sync/engine.ts

@@ -63,9 +63,9 @@ export class SyncEngine {
   private abort = new AbortController();
 
   constructor(
-    private rootDoc: Doc,
-    private local: Storage,
-    private remotes: Storage[]
+    private readonly rootDoc: Doc,
+    private readonly local: Storage,
+    private readonly remotes: Storage[]
   ) {
     this._status = {
       step: SyncEngineStep.Stopped,

packages/frontend/workspace/src/providers/sync/peer.ts

@@ -69,8 +69,8 @@ export class SyncPeer {
   logger = new DebugLogger('affine:sync-peer:' + this.name);
 
   constructor(
-    private rootDoc: Doc,
-    private storage: Storage
+    private readonly rootDoc: Doc,
+    private readonly storage: Storage
   ) {
     this.logger.debug('peer start');
 
@@ -150,7 +150,7 @@ export class SyncPeer {
     }
   }
 
-  private state: {
+  private readonly state: {
     connectedDocs: Map<string, Doc>;
     pushUpdatesQueue: AsyncQueue<{
       docId: string;