ref: Add no-class-field-initializers eslint rule (#8700)

Adding a lint rule (see
#5316) to enforce
initializing of fields in constructor, to reduce bundle size of
transpiled code (and streamline this a bit overall).

Closes #5316

Author: mydea

packages/angular/src/errorhandler.ts

@@ -83,9 +83,11 @@ class SentryErrorHandler implements AngularErrorHandler {
   protected readonly _options: ErrorHandlerOptions;
 
   /* indicates if we already registered our the afterSendEvent handler */
-  private _registeredAfterSendEventHandler = false;
+  private _registeredAfterSendEventHandler;
 
   public constructor(@Inject('errorHandlerOptions') options?: ErrorHandlerOptions) {
+    this._registeredAfterSendEventHandler = false;
+
     this._options = {
       logErrors: true,
       ...options,

packages/angular/src/tracing.ts

@@ -145,11 +145,14 @@ export class TraceService implements OnDestroy {
     }),
   );
 
-  private _routingSpan: Span | null = null;
+  private _routingSpan: Span | null;
 
-  private _subscription: Subscription = new Subscription();
+  private _subscription: Subscription;
 
   public constructor(private readonly _router: Router) {
+    this._routingSpan = null;
+    this._subscription = new Subscription();
+
     this._subscription.add(this.navStart$.subscribe());
     this._subscription.add(this.resEnd$.subscribe());
     this._subscription.add(this.navEnd$.subscribe());

packages/browser/src/integrations/breadcrumbs.ts

@@ -56,7 +56,7 @@ export class Breadcrumbs implements Integration {
   /**
    * @inheritDoc
    */
-  public name: string = Breadcrumbs.id;
+  public name: string;
 
   /**
    * Options of the breadcrumbs integration.
@@ -68,6 +68,7 @@ export class Breadcrumbs implements Integration {
    * @inheritDoc
    */
   public constructor(options?: Partial<BreadcrumbsOptions>) {
+    this.name = Breadcrumbs.id;
     this.options = {
       console: true,
       dom: true,

packages/browser/src/integrations/dedupe.ts

@@ -11,13 +11,17 @@ export class Dedupe implements Integration {
   /**
    * @inheritDoc
    */
-  public name: string = Dedupe.id;
+  public name: string;
 
   /**
    * @inheritDoc
    */
   private _previousEvent?: Event;
 
+  public constructor() {
+    this.name = Dedupe.id;
+  }
+
   /**
    * @inheritDoc
    */

packages/browser/src/integrations/globalhandlers.ts

@@ -30,7 +30,7 @@ export class GlobalHandlers implements Integration {
   /**
    * @inheritDoc
    */
-  public name: string = GlobalHandlers.id;
+  public name: string;
 
   /** JSDoc */
   private readonly _options: GlobalHandlersIntegrations;
@@ -39,18 +39,21 @@ export class GlobalHandlers implements Integration {
    * Stores references functions to installing handlers. Will set to undefined
    * after they have been run so that they are not used twice.
    */
-  private _installFunc: Record<GlobalHandlersIntegrationsOptionKeys, (() => void) | undefined> = {
-    onerror: _installGlobalOnErrorHandler,
-    onunhandledrejection: _installGlobalOnUnhandledRejectionHandler,
-  };
+  private _installFunc: Record<GlobalHandlersIntegrationsOptionKeys, (() => void) | undefined>;
 
   /** JSDoc */
   public constructor(options?: GlobalHandlersIntegrations) {
+    this.name = GlobalHandlers.id;
     this._options = {
       onerror: true,
       onunhandledrejection: true,
       ...options,
     };
+
+    this._installFunc = {
+      onerror: _installGlobalOnErrorHandler,
+      onunhandledrejection: _installGlobalOnUnhandledRejectionHandler,
+    };
   }
   /**
    * @inheritDoc

packages/browser/src/integrations/httpcontext.ts

@@ -13,7 +13,11 @@ export class HttpContext implements Integration {
   /**
    * @inheritDoc
    */
-  public name: string = HttpContext.id;
+  public name: string;
+
+  public constructor() {
+    this.name = HttpContext.id;
+  }
 
   /**
    * @inheritDoc

packages/browser/src/integrations/linkederrors.ts

@@ -21,7 +21,7 @@ export class LinkedErrors implements Integration {
   /**
    * @inheritDoc
    */
-  public readonly name: string = LinkedErrors.id;
+  public readonly name: string;
 
   /**
    * @inheritDoc
@@ -37,6 +37,7 @@ export class LinkedErrors implements Integration {
    * @inheritDoc
    */
   public constructor(options: Partial<LinkedErrorsOptions> = {}) {
+    this.name = LinkedErrors.id;
     this._key = options.key || DEFAULT_KEY;
     this._limit = options.limit || DEFAULT_LIMIT;
   }

packages/browser/src/integrations/trycatch.ts

@@ -56,7 +56,7 @@ export class TryCatch implements Integration {
   /**
    * @inheritDoc
    */
-  public name: string = TryCatch.id;
+  public name: string;
 
   /** JSDoc */
   private readonly _options: TryCatchOptions;
@@ -65,6 +65,7 @@ export class TryCatch implements Integration {
    * @inheritDoc
    */
   public constructor(options?: Partial<TryCatchOptions>) {
+    this.name = TryCatch.id;
     this._options = {
       XMLHttpRequest: true,
       eventTarget: true,

packages/browser/src/profiling/integration.ts

@@ -22,8 +22,15 @@ import {
  * @experimental
  */
 export class BrowserProfilingIntegration implements Integration {
-  public readonly name: string = 'BrowserProfilingIntegration';
-  public getCurrentHub?: () => Hub = undefined;
+  public static id: string = 'BrowserProfilingIntegration';
+
+  public readonly name: string;
+
+  public getCurrentHub?: () => Hub;
+
+  public constructor() {
+    this.name = BrowserProfilingIntegration.id;
+  }
 
   /**
    * @inheritDoc

packages/core/src/baseclient.ts

@@ -93,19 +93,19 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
   protected readonly _transport?: Transport;
 
   /** Array of set up integrations. */
-  protected _integrations: IntegrationIndex = {};
+  protected _integrations: IntegrationIndex;
 
   /** Indicates whether this client's integrations have been set up. */
-  protected _integrationsInitialized: boolean = false;
+  protected _integrationsInitialized: boolean;
 
   /** Number of calls being processed */
-  protected _numProcessing: number = 0;
+  protected _numProcessing: number;
 
   /** Holds flushable  */
-  private _outcomes: { [key: string]: number } = {};
+  private _outcomes: { [key: string]: number };
 
   // eslint-disable-next-line @typescript-eslint/ban-types
-  private _hooks: Record<string, Function[]> = {};
+  private _hooks: Record<string, Function[]>;
 
   /**
    * Initializes this client instance.
@@ -114,6 +114,11 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
    */
   protected constructor(options: O) {
     this._options = options;
+    this._integrations = {};
+    this._integrationsInitialized = false;
+    this._numProcessing = 0;
+    this._outcomes = {};
+    this._hooks = {};
 
     if (options.dsn) {
       this._dsn = makeDsn(options.dsn);