add suggested tests

Author: lobsterkatie

packages/tracing/test/hub.test.ts

@@ -178,6 +178,24 @@ describe('Hub', () => {
         expect(tracesSampler).toHaveBeenCalled();
       });
 
+      it('should set sampled = false if tracesSampler returns 0', () => {
+        const tracesSampler = jest.fn().mockReturnValue(0);
+        const hub = new Hub(new BrowserClient({ tracesSampler }));
+        const transaction = hub.startTransaction({ name: 'dogpark' });
+
+        expect(tracesSampler).toHaveBeenCalled();
+        expect(transaction.sampled).toBe(false);
+      });
+
+      it('should set sampled = true if tracesSampler returns 1', () => {
+        const tracesSampler = jest.fn().mockReturnValue(1);
+        const hub = new Hub(new BrowserClient({ tracesSampler }));
+        const transaction = hub.startTransaction({ name: 'dogpark' });
+
+        expect(tracesSampler).toHaveBeenCalled();
+        expect(transaction.sampled).toBe(true);
+      });
+
       it('should prefer tracesSampler to tracesSampleRate', () => {
         // make the two options do opposite things to prove precedence
         const tracesSampler = jest.fn().mockReturnValue(true);