Refactor

db/pg/leader_internal_test.go

@@ -0,0 +1,41 @@
+package pg
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// The lease logic is pure time arithmetic, so it is unit-tested here without a database; the
+// external leader tests cover the loop end to end.
+
+func TestLeader_Lease_HoldoffMeansNoLeaderRatherThanTwo(t *testing.T) {
+	// Freshly acquired lock: belief must wait out the hold-off
+	l := &Leader{renewInterval: 20 * time.Second} // Lease duration 1m, hold-off 2m
+	l.acquiredAt = time.Now()
+	l.renewedAt = l.acquiredAt
+	require.False(t, l.IsLeader())
+	// Once the hold-off has passed (and verification is fresh), belief begins
+	l.acquiredAt = time.Now().Add(-3 * time.Minute)
+	l.renewedAt = time.Now()
+	require.True(t, l.IsLeader())
+}
+
+func TestLeader_Lease_ExpiredLeaseRevokesLeadership(t *testing.T) {
+	// A leader that cannot renew its lease (wedged process, long GC pause) must stop
+	// believing once the lease expires, even though the lock may still be held
+	l := &Leader{renewInterval: 20 * time.Second} // Lease duration 1m, hold-off 2m
+	l.acquiredAt = time.Now().Add(-time.Hour)
+	l.renewedAt = time.Now().Add(-2 * time.Minute) // Lease expired
+	require.False(t, l.IsLeader())
+	l.renewedAt = time.Now() // Fresh renewal restores belief
+	require.True(t, l.IsLeader())
+}
+
+func TestLeader_Lease_ReleasedIsNeverLeader(t *testing.T) {
+	// release() zeroes renewedAt, which fails the lease check no matter how old the tenure
+	l := &Leader{renewInterval: 20 * time.Second} // Lease duration 1m, hold-off 2m
+	l.acquiredAt = time.Now().Add(-time.Hour)
+	require.False(t, l.IsLeader())
+}