fix(tracing-internal): Fix case when lrp keys offset is 0

packages/tracing-internal/src/node/integrations/express.ts

@@ -413,10 +413,9 @@ export const extractOriginalRoute = (
   regexp?: Layer['regexp'],
   keys?: Layer['keys'],
 ): string | undefined => {
-  if (!path || !regexp || !keys || Object.keys(keys).length === 0 || !keys[0]?.offset) {
+  if (!path || !regexp || !keys || Object.keys(keys).length === 0 || keys[0]?.offset === undefined ||  keys[0]?.offset === null) {
     return undefined;
   }
-
   const orderedKeys = keys.sort((a, b) => a.offset - b.offset);
 
   // add d flag for getting indices from regexp result

packages/tracing-internal/test/node/express.test.ts

@@ -87,13 +87,20 @@ if (major >= 16) {
       expect(extractOriginalRoute(path, regex, [key])).toBeUndefined();
     });
 
-    it('should return the original route path when valid inputs are provided', () => {
+    it('should return the original route path when valid inputs are provided first static value then dynamic', () => {
       const path = '/router/123';
       const regex = /^\/router\/(\d+)$/;
       const keys = [{ name: 'pathParam', offset: 8, optional: false }];
       expect(extractOriginalRoute(path, regex, keys)).toBe('/router/:pathParam');
     });
 
+    it('should return the original route path when valid inputs are provided first dynamic value then static', () => {
+      const path = '/123/router';
+      const regex = /^(?:\/([^/]+?))\/router\/?(?=\/|$)/i;
+      const keys = [{ name: 'pathParam', offset: 0, optional: false }];
+      expect(extractOriginalRoute(path, regex, keys)).toBe('/:pathParam/router');
+    });
+
     it('should handle multiple parameters in the route', () => {
       const path = '/user/42/profile/username';
       const regex = /^\/user\/(\d+)\/profile\/(\w+)$/;