negative MPT amounts, other formatting feedback

XRPLF · Oct 19, 2024 · 73e282e · 73e282e
1 parent 8828d84
commit 73e282e
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Showing 5 changed files with 67 additions and 19 deletions.
diff --git a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/AmountType.java
@@ -24,8 +24,6 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.TextNode;
-import com.google.common.base.Preconditions;
-import com.google.common.io.BaseEncoding;
 import com.google.common.primitives.UnsignedLong;
 import org.xrpl.xrpl4j.codec.addresses.ByteUtils;
 import org.xrpl.xrpl4j.codec.addresses.UnsignedByte;
@@ -199,7 +197,7 @@ public AmountType fromJson(JsonNode value) throws JsonProcessingException {
       MptAmount amount = objectMapper.treeToValue(value, MptAmount.class);
 
       if (FluentCompareTo.is(amount.unsignedLongValue()).greaterThan(UnsignedLong.valueOf(Long.MAX_VALUE))) {
-        throw new IllegalArgumentException("Invalid MPT amount: given value requires 64 bits, only 63 allowed.");
+        throw new IllegalArgumentException("Invalid MPT amount. Maximum MPT value is (2^63 - 1)");
       }
 
       UnsignedByteArray amountBytes =  UnsignedByteArray.fromHex(
@@ -211,7 +209,8 @@ public AmountType fromJson(JsonNode value) throws JsonProcessingException {
       UnsignedByteArray issuanceIdBytes = new Hash192Type().fromJson(new TextNode(amount.mptIssuanceId())).value();
 
       // MPT Amounts always have 0110000 as its first byte.
-      UnsignedByteArray result = UnsignedByteArray.of(UnsignedByte.of(0x60));
+      int leadingByte = amount.isNegative() ? 0x20 : 0x60;
+      UnsignedByteArray result = UnsignedByteArray.of(UnsignedByte.of(leadingByte));
       result.append(amountBytes);
       result.append(issuanceIdBytes);
 
@@ -251,12 +250,14 @@ public JsonNode toJson() {
     } else if (this.isMpt()) {
       BinaryParser parser = new BinaryParser(this.toHex());
       // We know the first byte already based on this.isMpt()
-      parser.skip(1);
+      UnsignedByte leadingByte = parser.read(1).get(0);
+      boolean isNegative = !leadingByte.isNthBitSet(2);
       UnsignedLong amount = parser.readUInt64();
       UnsignedByteArray issuanceId = new Hash192Type().fromParser(parser).value();
 
+      String amountBase10 = amount.toString(10);
       MptAmount mptAmount = MptAmount.builder()
-        .value(amount.toString(10))
+        .value(isNegative ? "-" + amountBase10 : amountBase10)
         .mptIssuanceId(issuanceId.hexValue())
         .build();
 
@@ -301,13 +302,14 @@ public JsonNode toJson() {
    */
   private boolean isNative() {
     // 1st bit in 1st byte is set to 0 for native XRP, 3rd bit is also 0.
-    // 0xA0 is 1010 0000
-    return (toBytes()[0] & 0xA0) == 0;
+    byte leadingByte = toBytes()[0];
+    return (leadingByte & 0x80) == 0 && (leadingByte & 0x20) == 0;
   }
 
   private boolean isMpt() {
-    // 1st bit in 1st byte is 0, 2nd bit is 1, and 3rd bit is 1
-    return (toBytes()[0] & 0xA0) == 0x20;
+    // 1st bit in 1st byte is 0, and 3rd bit is 1
+    byte leadingByte = toBytes()[0];
+    return (leadingByte & 0x80) == 0 && (leadingByte & 0x20) != 0;
   }
 
   /**

diff --git a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/MptAmount.java b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/MptAmount.java
@@ -47,13 +47,20 @@ static ImmutableMptAmount.Builder builder() {
 
   String value();
 
+  @JsonProperty("mpt_issuance_id")
+  String mptIssuanceId();
+
+  @Value.Derived
   @JsonIgnore
+  default boolean isNegative() {
+    return value().startsWith("-");
+  }
+
   @Value.Derived
+  @JsonIgnore
   default UnsignedLong unsignedLongValue() {
-    return UnsignedLong.valueOf(value());
+    return isNegative() ?
+      UnsignedLong.valueOf(value().substring(1)) :
+      UnsignedLong.valueOf(value());
   }
-
-  @JsonProperty("mpt_issuance_id")
-  String mptIssuanceId();
-
 }
diff --git a/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java b/xrpl4j-core/src/main/java/org/xrpl/xrpl4j/codec/binary/types/SerializedType.java
@@ -31,7 +31,6 @@
 
 import java.util.Map;
 import java.util.Objects;
-import java.util.function.Function;
 import java.util.function.Supplier;
 
 /**
@@ -41,7 +40,6 @@
  */
 public abstract class SerializedType<T extends SerializedType<T>> {
 
-
   @SuppressWarnings("all")
   private static final Map<String, Supplier<SerializedType<?>>> typeMap =
     new ImmutableMap.Builder<String, Supplier<SerializedType<?>>>()

diff --git a/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/AmountTypeTest.java b/xrpl4j-core/src/test/java/org/xrpl/xrpl4j/codec/binary/types/AmountTypeTest.java
@@ -229,6 +229,15 @@ void encodeDecodeMptAmount() {
     assertThat(fromJson.toJson().toString()).isEqualTo(json);
   }
 
+  @Test
+  void encodeDecodeMptAmountNegative() {
+    String json = "{\"value\":\"-100\",\"mpt_issuance_id\":\"00002403C84A0A28E0190E208E982C352BBD5006600555CF\"}";
+    AmountType fromJson = codec.fromJson(json);
+    assertThat(fromJson.toHex())
+      .isEqualTo("20000000000000006400002403C84A0A28E0190E208E982C352BBD5006600555CF");
+    assertThat(fromJson.toJson().toString()).isEqualTo(json);
+  }
+
   @Test
   void encodeDecodeLargestAmount() {
     String json = "{\"value\":\"9223372036854775807\"," +
@@ -239,12 +248,31 @@ void encodeDecodeLargestAmount() {
     assertThat(fromJson.toJson().toString()).isEqualTo(json);
   }
 
+  @Test
+  void encodeDecodeLargestAmountNegative() {
+    String json = "{\"value\":\"-9223372036854775807\"," +
+      "\"mpt_issuance_id\":\"00002403C84A0A28E0190E208E982C352BBD5006600555CF\"}";
+    AmountType fromJson = codec.fromJson(json);
+    assertThat(fromJson.toHex())
+      .isEqualTo("207FFFFFFFFFFFFFFF00002403C84A0A28E0190E208E982C352BBD5006600555CF");
+    assertThat(fromJson.toJson().toString()).isEqualTo(json);
+  }
+
   @Test
   void encodeMptAmountWithMoreThan63BitAmountThrows() {
     UnsignedLong maxLongPlusOne = UnsignedLong.valueOf(Long.MAX_VALUE).plus(UnsignedLong.ONE);
     String json = "{\"value\":\"" + maxLongPlusOne + "\"," +
       "\"mpt_issuance_id\":\"00002403C84A0A28E0190E208E982C352BBD5006600555CF\"}";
     assertThatThrownBy(() -> codec.fromJson(json)).isInstanceOf(IllegalArgumentException.class)
-      .hasMessage("Invalid MPT amount: given value requires 64 bits, only 63 allowed.");
+      .hasMessage("Invalid MPT amount. Maximum MPT value is (2^63 - 1)");
+  }
+
+  @Test
+  void encodeMptAmountWithMoreThan63BitAmountThrowsNegative() {
+    UnsignedLong maxLongPlusOne = UnsignedLong.valueOf(Long.MAX_VALUE).plus(UnsignedLong.ONE);
+    String json = "{\"value\":\"-" + maxLongPlusOne + "\"," +
+      "\"mpt_issuance_id\":\"00002403C84A0A28E0190E208E982C352BBD5006600555CF\"}";
+    assertThatThrownBy(() -> codec.fromJson(json)).isInstanceOf(IllegalArgumentException.class)
+      .hasMessage("Invalid MPT amount. Maximum MPT value is (2^63 - 1)");
   }
 }
diff --git a/xrpl4j-core/src/test/resources/data-driven-tests.json b/xrpl4j-core/src/test/resources/data-driven-tests.json
@@ -3701,8 +3701,10 @@
         "mpt_issuance_id": "00002403C84A0A28E0190E208E982C352BBD5006600555CF",
         "value": "-1"
       },
+      "is_native": false,
       "type": "Amount",
-      "error": "Value is negative"
+      "expected_hex": "20000000000000000100002403C84A0A28E0190E208E982C352BBD5006600555CF",
+      "is_negative": false
     },
     {
       "test_json": {
@@ -3800,6 +3802,17 @@
       "expected_hex": "60000000000000000000002403C84A0A28E0190E208E982C352BBD5006600555CF",
       "is_negative": false
     },
+    {
+      "test_json": {
+        "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",
+        "value": "-0"
+      },
+      "type_id": 6,
+      "is_native": false,
+      "type": "Amount",
+      "expected_hex": "20000000000000000000002403C84A0A28E0190E208E982C352BBD5006600555CF",
+      "is_negative": false
+    },
     {
       "test_json": {
         "mpt_issuance_id":"00002403C84A0A28E0190E208E982C352BBD5006600555CF",