Add unit tests for `SpendableInputs::LimitToAmount`

src/Makefile.gtest.include

@@ -59,6 +59,7 @@ zcash_gtest_SOURCES += \
 	gtest/test_zip32.cpp
 if ENABLE_WALLET
 zcash_gtest_SOURCES += \
+	wallet/gtest/test_note_selection.cpp \
 	wallet/gtest/test_orchard_wallet.cpp \
 	wallet/gtest/test_paymentdisclosure.cpp \
 	wallet/gtest/test_wallet.cpp

src/wallet/gtest/test_note_selection.cpp

@@ -0,0 +1,246 @@
+#include <gtest/gtest.h>
+
+#include "primitives/transaction.h"
+#include "wallet/wallet.h"
+#include "zcash/Note.hpp"
+#include "zcash/address/sapling.hpp"
+#include "zcash/address/sprout.hpp"
+
+CWalletTx FakeWalletTx()
+{
+    CMutableTransaction mtx;
+    mtx.vout.resize(1);
+    mtx.vout[0].nValue = 1;
+    return CWalletTx(nullptr, mtx);
+}
+
+SpendableInputs FakeSpendableInputs(
+    CAmount saplingValue,
+    CAmount sproutValue,
+    CAmount transparentValue = 0,
+    const CWalletTx* wtx = nullptr)
+{
+    SpendableInputs inputs;
+
+    while (saplingValue > 0) {
+        SaplingOutPoint op;
+        libzcash::SaplingPaymentAddress address;
+        libzcash::SaplingNote note(address, 1, libzcash::Zip212Enabled::AfterZip212);
+        inputs.saplingNoteEntries.push_back(SaplingNoteEntry{
+            op, address, note, {}, 100});
+        saplingValue -= 1;
+    }
+
+    while (sproutValue > 0) {
+        JSOutPoint jsop;
+        libzcash::SproutPaymentAddress address;
+        libzcash::SproutNote note(uint256(), 1, uint256(), uint256());
+        inputs.sproutNoteEntries.push_back(SproutNoteEntry{
+            jsop, address, note, {}, 100});
+        sproutValue -= 1;
+    }
+
+    while (transparentValue > 0) {
+        COutput utxo(wtx, 0, 100, true);
+        inputs.utxos.push_back(utxo);
+        transparentValue -= wtx->vout[0].nValue;
+    }
+
+    return inputs;
+}
+
+TEST(NoteSelectionTest, SelectsSproutBeforeTransparent)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sprout and transparent pools.
+    auto inputs = FakeSpendableInputs(0, 10, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sprout notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 5 zatoshis.
+    inputs.LimitToAmount(5, 1);
+    EXPECT_EQ(inputs.Total(), 5);
+
+    // We only have Sprout notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 5);
+    EXPECT_EQ(inputs.utxos.size(), 0);
+}
+
+TEST(NoteSelectionTest, SelectsSproutThenTransparent)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sprout and transparent pools.
+    auto inputs = FakeSpendableInputs(0, 10, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sprout notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 14 zatoshis.
+    inputs.LimitToAmount(14, 1);
+    EXPECT_EQ(inputs.Total(), 14);
+
+    // We have all Sprout notes and some transparent notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 4);
+}
+
+TEST(NoteSelectionTest, SelectsSproutBeforeSapling)
+{
+    // Create a set of inputs from Sapling and Sprout.
+    auto inputs = FakeSpendableInputs(10, 10);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sapling and Sprout notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 0);
+
+    // Limit to 7 zatoshis.
+    inputs.LimitToAmount(7, 1);
+    EXPECT_EQ(inputs.Total(), 7);
+
+    // We only have Sprout notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 7);
+    EXPECT_EQ(inputs.utxos.size(), 0);
+}
+
+TEST(NoteSelectionTest, SelectsSproutThenSapling)
+{
+    // Create a set of inputs from Sapling and Sprout.
+    auto inputs = FakeSpendableInputs(10, 10);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sapling and Sprout notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 0);
+
+    // Limit to 16 zatoshis.
+    inputs.LimitToAmount(16, 1);
+    EXPECT_EQ(inputs.Total(), 16);
+
+    // We have all Sprout notes and some Sapling notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 6);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 0);
+}
+
+TEST(NoteSelectionTest, SelectsTransparentBeforeSapling)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sapling and transparent pools.
+    auto inputs = FakeSpendableInputs(10, 0, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sapling notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 8 zatoshis.
+    inputs.LimitToAmount(8, 1);
+    EXPECT_EQ(inputs.Total(), 8);
+
+    // We only have UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.utxos.size(), 8);
+}
+
+TEST(NoteSelectionTest, SelectsTransparentThenSapling)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sapling and transparent pools.
+    auto inputs = FakeSpendableInputs(10, 0, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 20);
+
+    // We have Sapling notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 13 zatoshis.
+    inputs.LimitToAmount(13, 1);
+    EXPECT_EQ(inputs.Total(), 13);
+
+    // We have all UTXOs and some Sapling notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 3);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+}
+
+TEST(NoteSelectionTest, SelectsSproutAndTransparentBeforeSapling)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sapling and transparent pools.
+    auto inputs = FakeSpendableInputs(10, 10, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 30);
+
+    // We have Sapling notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 12 zatoshis.
+    inputs.LimitToAmount(12, 1);
+    EXPECT_EQ(inputs.Total(), 12);
+
+    // We have all UTXOs and some Sapling notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 0);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 2);
+}
+
+TEST(NoteSelectionTest, SelectsSproutAndTransparentThenSapling)
+{
+    auto wtx = FakeWalletTx();
+
+    // Create a set of inputs from Sapling and transparent pools.
+    auto inputs = FakeSpendableInputs(10, 10, 10, &wtx);
+    EXPECT_EQ(inputs.Total(), 30);
+
+    // We have Sapling notes and UTXOs.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+
+    // Limit to 24 zatoshis.
+    inputs.LimitToAmount(24, 1);
+    EXPECT_EQ(inputs.Total(), 24);
+
+    // We have all UTXOs and Sprout notes, and some Sapling notes.
+    EXPECT_EQ(inputs.orchardNoteMetadata.size(), 0);
+    EXPECT_EQ(inputs.saplingNoteEntries.size(), 4);
+    EXPECT_EQ(inputs.sproutNoteEntries.size(), 10);
+    EXPECT_EQ(inputs.utxos.size(), 10);
+}