pkg/testutil: add RandSource helper

The code to send rand source is dublicated in several packages.
Move it to testutil package.

1 files changed, 24 insertions, 0 deletions

diff --git a/pkg/testutil/testutil.go b/pkg/testutil/testutil.go
new file mode 100644
index 000000000..9a8de26bd
--- /dev/null
+++ b/pkg/testutil/testutil.go
@@ -0,0 +1,24 @@
+// Copyright 2022 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package testutil
+
+import (
+	"math/rand"
+	"os"
+	"strconv"
+	"testing"
+	"time"
+)
+
+func RandSource(t *testing.T) rand.Source {
+	seed := time.Now().UnixNano()
+	if fixed := os.Getenv("SYZ_SEED"); fixed != "" {
+		seed, _ = strconv.ParseInt(fixed, 0, 64)
+	}
+	if os.Getenv("CI") != "" {
+		seed = 0 // required for deterministic coverage reports
+	}
+	t.Logf("seed=%v", seed)
+	return rand.NewSource(seed)
+}