Move Goroutines helpers to test package.

test/goroutines.go

@@ -0,0 +1,105 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2025 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package test
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"os/signal"
+	"runtime/pprof"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+var listenSignalOnce sync.Once
+
+func EnsureNoGoroutinesLeak(t *testing.T, f func(t *testing.T)) {
+	t.Helper()
+
+	ensureNoGoroutinesLeak(t, f, false)
+}
+
+func ensureNoGoroutinesLeak(t *testing.T, f func(t *testing.T), fromTest bool) (int, int) {
+	t.Helper()
+	// Make sure test is not executed with "t.Parallel()"
+	t.Setenv("PARALLEL_CHECK", "1")
+
+	// The signal package will start a goroutine the first time "signal.Notify"
+	// is called. Do so outside the function under test so the signal goroutine
+	// will not be shown as "leaking".
+	listenSignalOnce.Do(func() {
+		ch := make(chan os.Signal, 1)
+		signal.Notify(ch, os.Interrupt)
+		go func() {
+			for {
+				<-ch
+			}
+		}()
+	})
+
+	profile := pprof.Lookup("goroutine")
+	// Give time for things to settle before capturing the number of
+	// go routines
+	var before int
+	timeout := time.Now().Add(time.Second)
+	for time.Now().Before(timeout) {
+		before = profile.Count()
+		time.Sleep(10 * time.Millisecond)
+		if profile.Count() == before {
+			break
+		}
+	}
+	var prev bytes.Buffer
+	DumpGoroutines("Before:", &prev)
+
+	t.Run("leakcheck", f)
+
+	var after int
+	// Give time for things to settle before capturing the number of
+	// go routines
+	timeout = time.Now().Add(time.Second)
+	for time.Now().Before(timeout) {
+		after = profile.Count()
+		if after == before {
+			break
+		}
+	}
+
+	if after != before && !fromTest {
+		io.Copy(os.Stderr, &prev) // nolint
+		DumpGoroutines("After:", os.Stderr)
+		require.Equal(t, before, after, "Number of Go routines has changed")
+	}
+	return before, after
+}
+
+func DumpGoroutines(prefix string, w io.Writer) {
+	if prefix != "" {
+		io.WriteString(w, prefix+"\n") // nolint
+	}
+	profile := pprof.Lookup("goroutine")
+	profile.WriteTo(w, 2) // nolint
+}