paymentsdb: make delete payments test db agnostic

We make the TestDeleteNonInFlight and separate all the logic out
for the duplicate payment test case. The deletion of duplicate
payments is now tested in isolation only for the kv backend.

payments/db/payment_test.go

@@ -1745,6 +1745,160 @@ func TestDeletePayments(t *testing.T) {
 	assertDBPayments(t, paymentDB, payments[2:])
 }
 
+// TestDeleteNonInFlight checks that calling DeletePayments only deletes
+// payments from the database that are not in-flight.
+func TestDeleteNonInFlight(t *testing.T) {
+	t.Parallel()
+
+	ctx := t.Context()
+
+	paymentDB, _ := NewTestDB(t)
+
+	// Create payments with different statuses: failed, success, inflight,
+	// and another success.
+	payments := []struct {
+		failed  bool
+		success bool
+	}{
+		// Payment 0: failed.
+		{failed: true, success: false},
+		// Payment 1: success.
+		{failed: false, success: true},
+		// Payment 2: inflight.
+		{failed: false, success: false},
+		// Payment 3: success.
+		{failed: false, success: true},
+	}
+
+	var numSuccess, numInflight int
+
+	for _, p := range payments {
+		preimg, err := genPreimage(t)
+		require.NoError(t, err)
+
+		rhash := sha256.Sum256(preimg[:])
+		info := genPaymentCreationInfo(t, rhash)
+		attempt, err := genAttemptWithHash(
+			t, 0, genSessionKey(t), rhash,
+		)
+		require.NoError(t, err)
+
+		// Init payment which initiates StatusInFlight.
+		err = paymentDB.InitPayment(ctx, info.PaymentIdentifier, info)
+		require.NoError(t, err, "unable to init payment")
+
+		_, err = paymentDB.RegisterAttempt(
+			ctx, info.PaymentIdentifier, attempt,
+		)
+		require.NoError(t, err, "unable to register attempt")
+
+		switch {
+		case p.failed:
+			// Fail the payment attempt.
+			htlcFailure := HTLCFailUnreadable
+			_, err := paymentDB.FailAttempt(
+				ctx, info.PaymentIdentifier, attempt.AttemptID,
+				&HTLCFailInfo{
+					Reason: htlcFailure,
+				},
+			)
+			require.NoError(t, err, "unable to fail htlc")
+
+			// Fail the payment, which should move it to Failed.
+			failReason := FailureReasonNoRoute
+			_, err = paymentDB.Fail(
+				ctx, info.PaymentIdentifier, failReason,
+			)
+			require.NoError(t, err, "unable to fail payment")
+
+			// Verify the status is indeed Failed.
+			assertDBPaymentstatus(
+				t, paymentDB, info.PaymentIdentifier,
+				StatusFailed,
+			)
+
+		case p.success:
+			// Settle the attempt.
+			_, err := paymentDB.SettleAttempt(
+				ctx, info.PaymentIdentifier, attempt.AttemptID,
+				&HTLCSettleInfo{
+					Preimage: preimg,
+				},
+			)
+			require.NoError(t, err, "unable to settle attempt")
+
+			assertDBPaymentstatus(
+				t, paymentDB, info.PaymentIdentifier,
+				StatusSucceeded,
+			)
+
+			numSuccess++
+
+		default:
+			// Leave as inflight.
+			assertDBPaymentstatus(
+				t, paymentDB, info.PaymentIdentifier,
+				StatusInFlight,
+			)
+
+			numInflight++
+		}
+	}
+
+	// Delete all failed payments.
+	numPayments, err := paymentDB.DeletePayments(ctx, true, false)
+	require.NoError(t, err)
+	require.EqualValues(t, 1, numPayments)
+
+	// This should leave the succeeded and in-flight payments.
+	resp, err := paymentDB.QueryPayments(ctx, Query{
+		IndexOffset:       0,
+		MaxPayments:       math.MaxUint64,
+		IncludeIncomplete: true,
+	})
+	require.NoError(t, err)
+
+	require.Equal(t, numSuccess+numInflight, len(resp.Payments),
+		"expected %d payments, got %d", numSuccess+numInflight,
+		len(resp.Payments))
+
+	var s, i int
+	for _, p := range resp.Payments {
+		switch p.Status {
+		case StatusSucceeded:
+			s++
+		case StatusInFlight:
+			i++
+		}
+	}
+
+	require.Equal(t, numSuccess, s,
+		"expected %d succeeded payments, got %d", numSuccess, s)
+	require.Equal(t, numInflight, i,
+		"expected %d in-flight payments, got %d", numInflight, i)
+
+	// Now delete all payments except in-flight.
+	numPayments, err = paymentDB.DeletePayments(ctx, false, false)
+	require.NoError(t, err)
+	require.EqualValues(t, 2, numPayments)
+
+	// This should leave the in-flight payment.
+	resp, err = paymentDB.QueryPayments(ctx, Query{
+		IndexOffset:       0,
+		MaxPayments:       math.MaxUint64,
+		IncludeIncomplete: true,
+	})
+	require.NoError(t, err)
+
+	require.Equal(t, numInflight, len(resp.Payments),
+		"expected %d payments, got %d", numInflight, len(resp.Payments))
+
+	for _, p := range resp.Payments {
+		require.Equal(t, StatusInFlight, p.Status,
+			"expected in-flight status, got %v", p.Status)
+	}
+}
+
 // TestSwitchDoubleSend checks the ability of payment control to
 // prevent double sending of htlc message, when message is in StatusInFlight.
 func TestSwitchDoubleSend(t *testing.T) {