Fix Go mistake findings and stabilize integration timing

2 files changed, 17 insertions, 5 deletions

diff --git a/internal/flags/flags_test.go b/internal/flags/flags_test.go
index 81d01ad..54c65b8 100644
--- a/internal/flags/flags_test.go
+++ b/internal/flags/flags_test.go
@@ -5,7 +5,6 @@ import (
 	"io"
 	"os"
 	"strings"
-	"sync"
 	"testing"
 	"time"
 )
@@ -16,7 +15,6 @@ func parseForTest(t *testing.T, args ...string) (Flags, error) {
 	oldCommandLine := flag.CommandLine
 	oldArgs := os.Args
 	oldSingleton := singleton
-	oldOnce := once
 	oldParseErr := parseErr
 	oldPID := pidFilter.Load()
 	oldTID := tidFilter.Load()
@@ -28,7 +26,6 @@ func parseForTest(t *testing.T, args ...string) (Flags, error) {
 	os.Args = append([]string{"ior"}, args...)
 
 	singleton = Flags{TUIExportEnable: true}
-	once = sync.Once{}
 	parseErr = nil
 	pidFilter.Store(-1)
 	tidFilter.Store(-1)
@@ -41,7 +38,6 @@ func parseForTest(t *testing.T, args ...string) (Flags, error) {
 		flag.CommandLine = oldCommandLine
 		os.Args = oldArgs
 		singleton = oldSingleton
-		once = oldOnce
 		parseErr = oldParseErr
 		pidFilter.Store(oldPID)
 		tidFilter.Store(oldTID)
diff --git a/internal/flamegraph/liveserver.go b/internal/flamegraph/liveserver.go
index 4cc5629..8ae2b82 100644
--- a/internal/flamegraph/liveserver.go
+++ b/internal/flamegraph/liveserver.go
@@ -71,16 +71,32 @@ func openBrowserURL(url, openCommand string) error {
 	waitCh := make(chan error, 1)
 	go func() { waitCh <- cmd.Wait() }()
 
+	timer := time.NewTimer(750 * time.Millisecond)
+	defer stopAndDrainTimer(timer)
+
 	select {
 	case waitErr := <-waitCh:
 		if waitErr != nil {
 			return fmt.Errorf("browser command exited early: %w", waitErr)
 		}
-	case <-time.After(750 * time.Millisecond):
+	case <-timer.C:
 	}
 	return nil
 }
 
+func stopAndDrainTimer(timer *time.Timer) {
+	if timer == nil {
+		return
+	}
+	if timer.Stop() {
+		return
+	}
+	select {
+	case <-timer.C:
+	default:
+	}
+}
+
 func notifyLiveWarning(warningCb func(string), message string) {
 	if message == "" {
 		return