switch to empty string as default value

Author: Lms24

packages/browser-utils/src/metrics/browserMetrics.ts

@@ -541,10 +541,7 @@ export function _addResourceSpans(
   setResourceEntrySizeData(attributes, entry, 'decodedBodySize', 'http.decoded_response_content_length');
 
   if (entry.deliveryType != null) {
-    // Falling back to 'default' as attributes with empty string are dropped by our backend.
-    // The empty string is the default value for the deliveryType attribute, indicating that
-    // the browser actually sent a request (as opposed to retrieved the response from its cache).
-    attributes['http.response_delivery_type'] = entry.deliveryType || 'default';
+    attributes['http.response_delivery_type'] = entry.deliveryType;
   }
 
   if ('renderBlockingStatus' in entry) {

packages/browser-utils/test/browser/browserMetrics.test.ts

@@ -341,7 +341,7 @@ describe('_addResourceSpans', () => {
 
   // resource delivery types: https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/deliveryType
   // i.e. better but not yet widely supported way to check for browser cache hit
-  it.each(['cache', 'navigational-prefetch'])(
+  it.each(['cache', 'navigational-prefetch', ''])(
     'attaches delivery type ("%s") to resource spans if available',
     deliveryType => {
       const spans: Span[] = [];
@@ -364,27 +364,6 @@ describe('_addResourceSpans', () => {
       expect(spanToJSON(spans[0]!).data).toMatchObject({ 'http.response_delivery_type': deliveryType });
     },
   );
-
-  it('attaches "default" as delivery if the empty string ("") default value is set', () => {
-    const spans: Span[] = [];
-
-    getClient()?.on('spanEnd', span => {
-      spans.push(span);
-    });
-
-    const entry: ResourceEntry = {
-      initiatorType: 'css',
-      transferSize: 0,
-      encodedBodySize: 0,
-      decodedBodySize: 0,
-      deliveryType: '',
-    };
-
-    _addResourceSpans(span, entry, resourceEntryName, 100, 23, 345);
-
-    expect(spans).toHaveLength(1);
-    expect(spanToJSON(spans[0]!).data).toMatchObject({ 'http.response_delivery_type': 'default' });
-  });
 });
 
 const setGlobalLocation = (location: Location) => {