Update heartbeat goroutine to call ExtendLease on active tasks

internal/timeutil/timeutil_test.go

@@ -0,0 +1,48 @@
+// Copyright 2022 Kentaro Hibino. All rights reserved.
+// Use of this source code is governed by a MIT license
+// that can be found in the LICENSE file.
+
+package timeutil
+
+import (
+	"testing"
+	"time"
+)
+
+func TestSimulatedClock(t *testing.T) {
+	now := time.Now()
+
+	tests := []struct {
+		desc      string
+		initTime  time.Time
+		advanceBy time.Duration
+		wantTime  time.Time
+	}{
+		{
+			desc:      "advance time forward",
+			initTime:  now,
+			advanceBy: 30 * time.Second,
+			wantTime:  now.Add(30 * time.Second),
+		},
+		{
+			desc:      "advance time backward",
+			initTime:  now,
+			advanceBy: -10 * time.Second,
+			wantTime:  now.Add(-10 * time.Second),
+		},
+	}
+
+	for _, tc := range tests {
+		c := NewSimulatedClock(tc.initTime)
+
+		if c.Now() != tc.initTime {
+			t.Errorf("%s: Before Advance; SimulatedClock.Now() = %v, want %v", tc.desc, c.Now(), tc.initTime)
+		}
+
+		c.AdvanceTime(tc.advanceBy)
+
+		if c.Now() != tc.wantTime {
+			t.Errorf("%s: After Advance; SimulatedClock.Now() = %v, want %v", tc.desc, c.Now(), tc.wantTime)
+		}
+	}
+}