usm: tests: http2: Fix a bug in debug output of a test (#21469)

* usm: tests: http2: Fix a bug in debug output of a test

The PR fixes a bug in the test debug log (when the test fails)
Also, the PR moves out from the test, the generation of expected results for the tests

* Update monitor_test.go

pkg/network/usm/monitor_test.go

@@ -664,24 +664,30 @@ func (s *USMHTTP2Suite) TestHTTP2ManyDifferentPaths() {
 	}
 }
 
-func (s *USMHTTP2Suite) TestSimpleHTTP2() {
-	t := s.T()
-	cfg := networkconfig.New()
-	cfg.EnableHTTP2Monitoring = true
-
-	startH2CServer(t)
-
+func getExpectedOutcomeForPathWithRepeatedChars() map[http.Key]captureRange {
 	expected := make(map[http.Key]captureRange)
-	// currently we have a bug with paths which are not Huffman encoded, therefore, we are skipping them by starting from `/aaa` (i := 3).
+	// The path `/a` and `/aa` are not being encoded with Huffman, and that's an edge case for our http2 monitoring for the moment,
+	// thus we're starting with `/aaa` and above.
 	for i := 3; i < 100; i++ {
 		expected[http.Key{
-			Path:   http.Path{Content: http.Interner.GetString(fmt.Sprintf("/%s", strings.Repeat("a", i)))},
+			Path: http.Path{
+				Content: http.Interner.GetString(fmt.Sprintf("/%s", strings.Repeat("a", i))),
+			},
 			Method: http.MethodPost,
 		}] = captureRange{
 			lower: 1,
 			upper: 1,
 		}
 	}
+	return expected
+}
+
+func (s *USMHTTP2Suite) TestSimpleHTTP2() {
+	t := s.T()
+	cfg := networkconfig.New()
+	cfg.EnableHTTP2Monitoring = true
+
+	startH2CServer(t)
 
 	tests := []struct {
 		name              string
@@ -746,7 +752,7 @@ func (s *USMHTTP2Suite) TestSimpleHTTP2() {
 					req.Body.Close()
 				}
 			},
-			expectedEndpoints: expected,
+			expectedEndpoints: getExpectedOutcomeForPathWithRepeatedChars(),
 		},
 	}
 	for _, tt := range tests {
@@ -800,7 +806,7 @@ func (s *USMHTTP2Suite) TestSimpleHTTP2() {
 					return true
 				}, time.Second*5, time.Millisecond*100, "%v != %v", res, tt.expectedEndpoints)
 				if t.Failed() {
-					for key := range expected {
+					for key := range tt.expectedEndpoints {
 						if _, ok := res[key]; !ok {
 							t.Logf("key: %v was not found in res", key.Path.Content.Get())
 						}