add Issue type and tests for Asset/Asset2

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

@@ -11,6 +11,7 @@ import { Currency } from './currency'
 import { Hash128 } from './hash-128'
 import { Hash160 } from './hash-160'
 import { Hash256 } from './hash-256'
+import { Issue } from './issue'
 import { PathSet } from './path-set'
 import { STArray } from './st-array'
 import { STObject } from './st-object'
@@ -28,6 +29,7 @@ const coreTypes = {
   Hash128,
   Hash160,
   Hash256,
+  Issue,
   PathSet,
   STArray,
   STObject,

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

@@ -0,0 +1,96 @@
+import { BinaryParser } from '../serdes/binary-parser'
+
+import { AccountID } from './account-id'
+import { Currency } from './currency'
+import { JsonObject, SerializedType } from './serialized-type'
+import { Buffer } from 'buffer/'
+
+/**
+ * Interface for JSON objects that represent amounts
+ */
+interface IssueObject extends JsonObject {
+  currency: string
+  issuer?: string
+}
+
+/**
+ * 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'
+}
+
+/**
+ * Class for serializing/Deserializing Amounts
+ */
+class Issue extends SerializedType {
+  static readonly ZERO_ISSUED_CURRENCY: Issue = new Issue(Buffer.alloc(20))
+
+  constructor(bytes: Buffer) {
+    super(bytes ?? Issue.ZERO_ISSUED_CURRENCY.bytes)
+  }
+
+  /**
+   * Construct an amount from an IOU or string amount
+   *
+   * @param value An Amount, object representing an IOU, or a string
+   *     representing an integer amount
+   * @returns An Amount object
+   */
+  static from<T extends Issue | IssueObject | string>(value: T): Issue {
+    if (value instanceof Issue) {
+      return value
+    }
+
+    if (isIssueObject(value)) {
+      const currency = Currency.from(value.currency).toBytes()
+      if (value.issuer == null) {
+        return new Issue(currency)
+      }
+      const issuer = AccountID.from(value.issuer).toBytes()
+      return new Issue(Buffer.concat([currency, issuer]))
+    }
+
+    throw new Error('Invalid type to construct an Amount')
+  }
+
+  /**
+   * Read an amount from a BinaryParser
+   *
+   * @param parser BinaryParser to read the Amount from
+   * @returns An Amount object
+   */
+  static fromParser(parser: BinaryParser): Issue {
+    const currency = parser.read(20)
+    if (new Currency(currency).toJSON() === 'XRP') {
+      return new Issue(currency)
+    }
+    const currencyAndIssuer = [currency, parser.read(20)]
+    return new Issue(Buffer.concat(currencyAndIssuer))
+  }
+
+  /**
+   * Get the JSON representation of this Amount
+   *
+   * @returns the JSON interpretation of this.bytes
+   */
+  toJSON(): IssueObject {
+    const parser = new BinaryParser(this.toString())
+    const currency = Currency.fromParser(parser) as Currency
+    if (currency.toJSON() === 'XRP') {
+      return { currency: currency.toJSON() }
+    }
+    const issuer = AccountID.fromParser(parser) as AccountID
+
+    return {
+      currency: currency.toJSON(),
+      issuer: issuer.toJSON(),
+    }
+  }
+}
+
+export { Issue, IssueObject }