fix: add MPTAmount support in Issue model

packages/ripple-binary-codec/HISTORY.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+### Fixed
+- add `MPTAmount` support in `Issue` (rippled internal type)
+
 ## 2.3.0 (2025-2-13)
 
 ### Added

packages/ripple-binary-codec/src/types/issue.ts

@@ -4,24 +4,35 @@ import { BinaryParser } from '../serdes/binary-parser'
 import { AccountID } from './account-id'
 import { Currency } from './currency'
 import { JsonObject, SerializedType } from './serialized-type'
+import { Hash192 } from './hash-192'
 
+interface XRPIssue extends JsonObject {
+  currency: string
+}
+
+interface IOUIssue extends JsonObject {
+  currency: string
+  issuer: string
+}
+interface MPTIssue extends JsonObject {
+  mpt_issuance_id: string
+}
 /**
  * Interface for JSON objects that represent amounts
  */
-interface IssueObject extends JsonObject {
-  currency: string
-  issuer?: string
-}
+type IssueObject = XRPIssue | IOUIssue | MPTIssue
 
 /**
  * Type guard for AmountObject
  */
 function isIssueObject(arg): arg is IssueObject {
   const keys = Object.keys(arg).sort()
-  if (keys.length === 1) {
-    return keys[0] === 'currency'
-  }
-  return keys.length === 2 && keys[0] === 'currency' && keys[1] === 'issuer'
+  const isXRP = keys.length === 1 && keys[0] === 'currency'
+  const isIOU =
+    keys.length === 2 && keys[0] === 'currency' && keys[1] === 'issuer'
+  const isMPT = keys.length === 1 && keys[0] === 'mpt_issuance_id'
+
+  return isXRP || isIOU || isMPT
 }
 
 /**
@@ -39,20 +50,34 @@ class Issue extends SerializedType {
    *
    * @param value An Amount, object representing an IOU, or a string
    *     representing an integer amount
-   * @returns An Amount object
+   * @returns An Issue object
    */
   static from<T extends Issue | IssueObject>(value: T): Issue {
     if (value instanceof Issue) {
       return value
     }
 
     if (isIssueObject(value)) {
-      const currency = Currency.from(value.currency).toBytes()
-      if (value.issuer == null) {
+      if (value.currency) {
+        const currency = Currency.from(value.currency.toString()).toBytes()
+
+        //IOU case
+        if (value.issuer) {
+          const issuer = AccountID.from(value.issuer.toString()).toBytes()
+          return new Issue(concat([currency, issuer]))
+        }
+
+        //XRP case
         return new Issue(currency)
       }
-      const issuer = AccountID.from(value.issuer).toBytes()
-      return new Issue(concat([currency, issuer]))
+
+      // MPT case
+      if (value.mpt_issuance_id) {
+        const mptIssuanceIdBytes = Hash192.from(
+          value.mpt_issuance_id.toString(),
+        ).toBytes()
+        return new Issue(mptIssuanceIdBytes)
+      }
     }
 
     throw new Error('Invalid type to construct an Amount')
@@ -62,9 +87,16 @@ class Issue extends SerializedType {
    * Read an amount from a BinaryParser
    *
    * @param parser BinaryParser to read the Amount from
-   * @returns An Amount object
+   * @param hint The number of bytes to consume from the parser.
+   * For an MPT amount, pass 24 (the fixed length for Hash192).
+   *
+   * @returns An Issue object
    */
-  static fromParser(parser: BinaryParser): Issue {
+  static fromParser(parser: BinaryParser, hint?: number): Issue {
+    if (hint === Hash192.width) {
+      const mptBytes = parser.read(Hash192.width)
+      return new Issue(mptBytes)
+    }
     const currency = parser.read(20)
     if (new Currency(currency).toJSON() === 'XRP') {
       return new Issue(currency)
@@ -79,7 +111,15 @@ class Issue extends SerializedType {
    * @returns the JSON interpretation of this.bytes
    */
   toJSON(): IssueObject {
+    // If the buffer is exactly 24 bytes, treat it as an MPT amount.
+    if (this.toBytes().length === Hash192.width) {
+      return {
+        mpt_issuance_id: this.toHex().toUpperCase(),
+      }
+    }
+
     const parser = new BinaryParser(this.toString())
+
     const currency = Currency.fromParser(parser) as Currency
     if (currency.toJSON() === 'XRP') {
       return { currency: currency.toJSON() }

packages/ripple-binary-codec/test/issue.test.ts

@@ -0,0 +1,86 @@
+import { BinaryParser } from '../src/binary'
+import { Issue } from '../src/types/issue'
+
+describe('Issue type conversion functions', () => {
+  it(`test from value xrp`, () => {
+    const xrpJson = { currency: 'XRP' }
+    const xrpIssue = Issue.from(xrpJson)
+    expect(xrpIssue.toJSON()).toMatchObject(xrpJson)
+  })
+
+  it(`test from value issued currency`, () => {
+    const iouJson = {
+      currency: 'USD',
+      issuer: 'rG1QQv2nh2gr7RCZ1P8YYcBUKCCN633jCn',
+    }
+    const iouIssue = Issue.from(iouJson)
+    expect(iouIssue.toJSON()).toMatchObject(iouJson)
+  })
+
+  it(`test from value nonstandard currency`, () => {
+    const iouJson = {
+      currency: '0123456789ABCDEF0123456789ABCDEF01234567',
+      issuer: 'rG1QQv2nh2gr7RCZ1P8YYcBUKCCN633jCn',
+    }
+    const iouIssue = Issue.from(iouJson)
+    expect(iouIssue.toJSON()).toMatchObject(iouJson)
+  })
+
+  it(`test from value mpt`, () => {
+    const mptJson = {
+      // value: '100', // MPT amounts must be an integer string (no decimal point)
+      mpt_issuance_id: 'BAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00D',
+    }
+    const mptIssue = Issue.from(mptJson)
+    expect(mptIssue.toJSON()).toMatchObject(mptJson)
+  })
+
+  it(`test from parser xrp`, () => {
+    const xrpJson = { currency: 'XRP' }
+    const xrpIssue = Issue.from(xrpJson)
+    const parser = new BinaryParser(xrpIssue.toHex())
+    const parserIssue = Issue.fromParser(parser)
+    expect(parserIssue.toJSON()).toMatchObject(xrpJson)
+  })
+
+  it(`test from parser issued currency`, () => {
+    const iouJson = {
+      currency: 'EUR',
+      issuer: 'rLUEXYuLiQptky37CqLcm9USQpPiz5rkpD',
+    }
+    const iouIssue = Issue.from(iouJson)
+    const parser = new BinaryParser(iouIssue.toHex())
+    const parserIssue = Issue.fromParser(parser)
+    expect(parserIssue.toJSON()).toMatchObject(iouJson)
+  })
+
+  it(`test from parser nonstandard currency`, () => {
+    const iouJson = {
+      currency: '0123456789ABCDEF0123456789ABCDEF01234567',
+      issuer: 'rLUEXYuLiQptky37CqLcm9USQpPiz5rkpD',
+    }
+    const iouIssue = Issue.from(iouJson)
+    const parser = new BinaryParser(iouIssue.toHex())
+    const parserIssue = Issue.fromParser(parser)
+    expect(parserIssue.toJSON()).toMatchObject(iouJson)
+  })
+
+  it(`test from parser mpt`, () => {
+    const mptJson = {
+      // value: '100', // MPT amounts must be an integer string (no decimal point)
+      mpt_issuance_id: 'BAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00D',
+    }
+    const mptIssue = Issue.from(mptJson)
+    const parser = new BinaryParser(mptIssue.toHex())
+    const parserIssue = Issue.fromParser(parser, 24)
+    expect(parserIssue.toJSON()).toMatchObject(mptJson)
+  })
+
+  it(`throws with invalid input`, () => {
+    const invalidJson = { random: 123 }
+    expect(() => {
+      // @ts-expect-error -- need to test error message
+      Issue.from(invalidJson)
+    }).toThrow(new Error('Invalid type to construct an Amount'))
+  })
+})