convert private setup flag in BrowserTracing to closure variable

Author: lobsterkatie

packages/tracing/src/browser/browsertracing.ts

@@ -101,6 +101,8 @@ const DEFAULT_BROWSER_TRACING_OPTIONS = {
   ...defaultRequestInstrumentationOptions,
 };
 
+let emitOptionsWarning = false;
+
 /**
  * The Browser Tracing integration automatically instruments browser pageload/navigation
  * actions as transactions, and captures requests, metrics and errors as spans.
@@ -126,8 +128,6 @@ export class BrowserTracing implements Integration {
 
   private readonly _metrics: MetricsInstrumentation;
 
-  private readonly _emitOptionsWarning: boolean = false;
-
   /** Store configured idle timeout so that it can be added as a tag to transactions */
   private _configuredIdleTimeout: BrowserTracingOptions['idleTimeout'] | undefined = undefined;
 
@@ -139,7 +139,7 @@ export class BrowserTracing implements Integration {
       if (_options.tracingOrigins && Array.isArray(_options.tracingOrigins) && _options.tracingOrigins.length !== 0) {
         tracingOrigins = _options.tracingOrigins;
       } else {
-        isDebugBuild() && (this._emitOptionsWarning = true);
+        isDebugBuild() && (emitOptionsWarning = true);
       }
     }
 
@@ -159,7 +159,7 @@ export class BrowserTracing implements Integration {
   public setupOnce(_: (callback: EventProcessor) => void, getCurrentHub: () => Hub): void {
     this._getCurrentHub = getCurrentHub;
 
-    if (this._emitOptionsWarning) {
+    if (emitOptionsWarning) {
       isDebugBuild() &&
         logger.warn(
           '[Tracing] You need to define `tracingOrigins` in the options. Set an array of urls or patterns to trace.',