feat(tracing): Allow for setting of an empty array (#5583)

Allow for users to set an empty array as `tracingOrigins` option if they do not want to attach outgoing headers to any request.

Author: AbhiPrasad

packages/tracing/src/browser/browsertracing.ts

@@ -142,7 +142,7 @@ export class BrowserTracing implements Integration {
     let tracingOrigins = defaultRequestInstrumentationOptions.tracingOrigins;
     // NOTE: Logger doesn't work in constructors, as it's initialized after integrations instances
     if (_options) {
-      if (_options.tracingOrigins && Array.isArray(_options.tracingOrigins) && _options.tracingOrigins.length !== 0) {
+      if (_options.tracingOrigins && Array.isArray(_options.tracingOrigins)) {
         tracingOrigins = _options.tracingOrigins;
       } else {
         __DEBUG_BUILD__ && (this._emitOptionsWarning = true);

packages/tracing/test/browser/browsertracing.test.ts

@@ -148,34 +148,36 @@ describe('BrowserTracing', () => {
         expect(inst.options.tracingOrigins).toEqual(defaultRequestInstrumentationOptions.tracingOrigins);
       });
 
-      it('warns and uses default tracing origins if empty array given', () => {
+      it('warns and uses default tracing origins if tracing origins are not defined', () => {
         const inst = createBrowserTracing(true, {
           routingInstrumentation: customInstrumentRouting,
-          tracingOrigins: [],
+          tracingOrigins: undefined,
         });
 
         expect(warnSpy).toHaveBeenCalledTimes(2);
         expect(inst.options.tracingOrigins).toEqual(defaultRequestInstrumentationOptions.tracingOrigins);
       });
 
-      it('warns and uses default tracing origins if tracing origins are not defined', () => {
+      it('sets tracing origins if provided and does not warn', () => {
+        const sampleTracingOrigins = ['something'];
         const inst = createBrowserTracing(true, {
           routingInstrumentation: customInstrumentRouting,
-          tracingOrigins: undefined,
+          tracingOrigins: sampleTracingOrigins,
         });
 
-        expect(warnSpy).toHaveBeenCalledTimes(2);
-        expect(inst.options.tracingOrigins).toEqual(defaultRequestInstrumentationOptions.tracingOrigins);
+        expect(warnSpy).toHaveBeenCalledTimes(0);
+        expect(inst.options.tracingOrigins).toEqual(sampleTracingOrigins);
       });
 
-      it('sets tracing origins if provided and does not warn', () => {
+      it('sets tracing origins to an empty array and does not warn', () => {
+        const sampleTracingOrigins: string[] = [];
         const inst = createBrowserTracing(true, {
           routingInstrumentation: customInstrumentRouting,
-          tracingOrigins: ['something'],
+          tracingOrigins: sampleTracingOrigins,
         });
 
         expect(warnSpy).toHaveBeenCalledTimes(0);
-        expect(inst.options.tracingOrigins).toEqual(['something']);
+        expect(inst.options.tracingOrigins).toEqual(sampleTracingOrigins);
       });
     });