fix(dynamic-sampling): Do not freeze DSC if no Sentry values are present

dynamic_sampling_context.go

@@ -33,7 +33,8 @@ func DynamicSamplingContextFromHeader(header []byte) (DynamicSamplingContext, er
 
 	return DynamicSamplingContext{
 		Entries: entries,
-		Frozen:  true,
+		// If there's at least one Sentry value, we consider the DSC frozen
+		Frozen: len(entries) > 0,
 	}, nil
 }
 

dynamic_sampling_context_test.go

@@ -8,16 +8,27 @@ import (
 
 func TestDynamicSamplingContextFromHeader(t *testing.T) {
 	tests := []struct {
-		input []byte
-		want  DynamicSamplingContext
+		input  []byte
+		want   DynamicSamplingContext
+		errMsg string
 	}{
+		// Empty baggage header
 		{
 			input: []byte(""),
 			want: DynamicSamplingContext{
-				Frozen:  true,
+				Frozen:  false,
 				Entries: map[string]string{},
 			},
 		},
+		// Third-party baggage
+		{
+			input: []byte("other-vendor-key1=value1;value2, other-vendor-key2=value3"),
+			want: DynamicSamplingContext{
+				Frozen:  false,
+				Entries: map[string]string{},
+			},
+		},
+		// Sentry-only baggage
 		{
 			input: []byte("sentry-trace_id=d49d9bf66f13450b81f65bc51cf49c03,sentry-public_key=public,sentry-sample_rate=1"),
 			want: DynamicSamplingContext{
@@ -29,6 +40,7 @@ func TestDynamicSamplingContextFromHeader(t *testing.T) {
 				},
 			},
 		},
+		// Mixed baggage
 		{
 			input: []byte("sentry-trace_id=d49d9bf66f13450b81f65bc51cf49c03,sentry-public_key=public,sentry-sample_rate=1,foo=bar;foo;bar;bar=baz"),
 			want: DynamicSamplingContext{
@@ -40,14 +52,22 @@ func TestDynamicSamplingContextFromHeader(t *testing.T) {
 				},
 			},
 		},
+		// Invalid baggage value
+		{
+			input: []byte(","),
+			want: DynamicSamplingContext{
+				Frozen: false,
+			},
+			errMsg: "invalid baggage list-member: \"\"",
+		},
 	}
 
 	for _, tc := range tests {
 		got, err := DynamicSamplingContextFromHeader(tc.input)
+		assertEqual(t, got, tc.want, "Context mismatch")
 		if err != nil {
-			t.Fatal(err)
+			assertEqual(t, err.Error(), tc.errMsg, "Error mismatch")
 		}
-		assertEqual(t, got, tc.want)
 	}
 }