lnwallet+lntest: add test for pagination

Here we add unit test to cover getting exactly how many
transactions we requested for, and first and last index
offsets are returned correctly.

lntest/mock/walletcontroller.go

@@ -187,9 +187,10 @@ func (w *WalletController) ListUnspentWitness(int32, int32,
 
 // ListTransactionDetails currently returns dummy values.
 func (w *WalletController) ListTransactionDetails(int32, int32,
-	string, uint, int) ([]*lnwallet.TransactionDetail, error) {
+	string, uint, int) ([]*lnwallet.TransactionDetail,
+	uint64, uint64, error) {
 
-	return nil, nil
+	return nil, 0, 0, nil
 }
 
 // LeaseOutput returns the current time and a nil error.

lnwallet/mock.go

@@ -197,9 +197,9 @@ func (w *mockWalletController) ListUnspentWitness(int32, int32,
 
 // ListTransactionDetails currently returns dummy values.
 func (w *mockWalletController) ListTransactionDetails(int32, int32,
-	string) ([]*TransactionDetail, error) {
+	string, uint, int) ([]*TransactionDetail, uint64, uint64, error) {
 
-	return nil, nil
+	return nil, 0, 0, nil
 }
 
 // LeaseOutput returns the current time and a nil error.

lnwallet/test/test_interface.go

@@ -199,7 +199,7 @@ func assertTxInWallet(t *testing.T, w *lnwallet.LightningWallet,
 	// We'll fetch all of our transaction and go through each one until
 	// finding the expected transaction with its expected confirmation
 	// status.
-	txs, err := w.ListTransactionDetails(
+	txs, _, _, err := w.ListTransactionDetails(
 		0, btcwallet.UnconfirmedHeight, "", 0, 1000,
 	)
 	require.NoError(t, err, "unable to retrieve transactions")
@@ -1103,7 +1103,7 @@ func testListTransactionDetails(miner *rpctest.Harness,
 	// should be confirmed.
 	err = waitForWalletSync(miner, alice)
 	require.NoError(t, err, "Couldn't sync Alice's wallet")
-	txDetails, err := alice.ListTransactionDetails(
+	txDetails, _, _, err := alice.ListTransactionDetails(
 		startHeight, chainTip, "", 0, 1000,
 	)
 	require.NoError(t, err, "unable to fetch tx details")
@@ -1215,7 +1215,7 @@ func testListTransactionDetails(miner *rpctest.Harness,
 	// unconfirmed transactions. The transaction above should be included
 	// with a confirmation height of 0, indicating that it has not been
 	// mined yet.
-	txDetails, err = alice.ListTransactionDetails(
+	txDetails, _, _, err = alice.ListTransactionDetails(
 		chainTip, btcwallet.UnconfirmedHeight, "", 0, 1000,
 	)
 	require.NoError(t, err, "unable to fetch tx details")
@@ -1268,7 +1268,7 @@ func testListTransactionDetails(miner *rpctest.Harness,
 	// transactions from the last block.
 	err = waitForWalletSync(miner, alice)
 	require.NoError(t, err, "Couldn't sync Alice's wallet")
-	txDetails, err = alice.ListTransactionDetails(
+	txDetails, _, _, err = alice.ListTransactionDetails(
 		chainTip, chainTip, "", 0, 1000,
 	)
 	require.NoError(t, err, "unable to fetch tx details")
@@ -1311,13 +1311,64 @@ func testListTransactionDetails(miner *rpctest.Harness,
 
 	// Query for transactions only in the latest block. We do not expect
 	// any transactions to be returned.
-	txDetails, err = alice.ListTransactionDetails(
+	txDetails, _, _, err = alice.ListTransactionDetails(
 		chainTip, chainTip, "", 0, 1000,
 	)
 	require.NoError(t, err, "unexpected error")
 	if len(txDetails) != 0 {
 		t.Fatalf("expected 0 transactions, got: %v", len(txDetails))
 	}
+
+	// Next we try to query for only 5 transactions.
+	var (
+		firstIdx, lastIdx uint64
+	)
+	txDetails, firstIdx, lastIdx, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 0, 5,
+	)
+	require.NoError(t, err, "unexpected error")
+	require.Len(t, txDetails, 5)
+	require.EqualValues(t, 1, firstIdx)
+	require.EqualValues(t, 5, lastIdx)
+
+	// Query for transactions, setting max_transactions to zero. We expect
+	// no transactions to be returned.
+	txDetails, _, _, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 0, 0,
+	)
+	require.NoError(t, err, "unexpected error")
+	require.Len(t, txDetails, 0)
+
+	// Query for transactions, more than we have in the wallet (10). We
+	// expect less transactions to be returned.
+	txDetails, _, _, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 0, 1000,
+	)
+	require.NoError(t, err, "unexpected error")
+	require.Less(t, len(txDetails), 1000)
+
+	// Query for transactions, using a -1 as the max_transactions.
+	// We expect to get the whole (10) transactions.
+	txDetails, _, _, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 0, -1,
+	)
+	require.NoError(t, err, "unexpected error")
+	require.Len(t, txDetails, 10)
+
+	// Query for transactions where the offset is greater than the number
+	// of transactions available. We expect no transactions to be returned.
+	txDetails, _, _, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 10, 10,
+	)
+	require.NoError(t, err, "unexpected error")
+	require.Len(t, txDetails, 0)
+
+	// Query for transactions, using a negative value less than -1 as the
+	// max_transactions. We expect to get an error.
+	_, _, _, err = alice.ListTransactionDetails(
+		startHeight, chainTip, "", 0, -10,
+	)
+	require.Error(t, err, "unexpected error")
 }
 
 func testTransactionSubscriptions(miner *rpctest.Harness,