stack: add Snapshot.IsRace()

Cleaner than inspecting manually the first goroutine.

Author: maruel

internal/main.go

@@ -129,7 +129,7 @@ func processInner(out io.Writer, p *Palette, s stack.Similarity, pf pathFormat,
 	log.Printf("GOPATH=%s", c.RemoteGOPATHs)
 	needsEnv := len(c.Goroutines) == 1 && showBanner()
 	// Bucketing should only be done if no data race was detected.
-	if c.Goroutines[0].RaceAddr == 0 {
+	if !c.IsRace() {
 		a := c.Aggregate(s)
 		if html == "" {
 			return writeBucketsToConsole(out, p, a, pf, needsEnv, filter, match)

stack/context.go

@@ -207,6 +207,15 @@ func ScanSnapshot(in io.Reader, prefix io.Writer, opts *Opts) (*Snapshot, []byte
 	return nil, suffix, err
 }
 
+// IsRace returns true if a race detector stack trace was found.
+//
+// Otherwise, it is a normal goroutines snapshot.
+//
+// When a race condition was detected, it is preferable to not call Aggregate().
+func (s *Snapshot) IsRace() bool {
+	return s.Goroutines[0].RaceAddr != 0
+}
+
 func (s *Snapshot) guessPaths() bool {
 	b := s.findRoots() == 0
 	for _, r := range s.Goroutines {

stack/context_test.go

@@ -1344,6 +1344,9 @@ func TestGomoduleComplex(t *testing.T) {
 	if s == nil {
 		t.Fatal("expected snapshot")
 	}
+	if s.IsRace() {
+		t.Fatal("unexpected race")
+	}
 	compareString(t, "panic: 42\n\n", prefix.String())
 	compareString(t, "", string(suffix))
 	wantGOROOT := ""

stack/html_test.go

@@ -245,6 +245,9 @@ func TestSnapshot_ToHTML(t *testing.T) {
 	if s.Goroutines[0].RaceAddr == 0 {
 		t.Fatal("expected a race")
 	}
+	if !s.IsRace() {
+		t.Fatal("expected a race")
+	}
 	if err := s.ToHTML(ioutil.Discard, ""); err != nil {
 		t.Fatal(err)
 	}