From d70c28b01c050e51e10482eaf39bf9ae8fa9b8a0 Mon Sep 17 00:00:00 2001
From: Nathan Nichols <natenichols@cox.net>
Date: Thu, 4 Feb 2021 14:24:34 -0600
Subject: [PATCH] X-Address Encoding in Issued Currencies (#113)

* feat(account): allow issued currency to use x-address
---
 src/types/account-id.ts | 16 +++++++++++++++-
 test/x-address.test.js  | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/src/types/account-id.ts b/src/types/account-id.ts
index 63abcfa..3134f8e 100644
--- a/src/types/account-id.ts
+++ b/src/types/account-id.ts
@@ -1,4 +1,9 @@
-import { decodeAccountID, encodeAccountID } from "ripple-address-codec";
+import {
+  decodeAccountID,
+  encodeAccountID,
+  isValidXAddress,
+  xAddressToClassicAddress,
+} from "ripple-address-codec";
 import { Hash160 } from "./hash-160";
 import { Buffer } from "buffer/";
 
@@ -45,6 +50,15 @@ class AccountID extends Hash160 {
    * @returns an AccountID object
    */
   static fromBase58(value: string): AccountID {
+    if (isValidXAddress(value)) {
+      const classic = xAddressToClassicAddress(value);
+
+      if (classic.tag !== false)
+        throw new Error("Only allowed to have tag on Account or Destination");
+
+      value = classic.classicAddress;
+    }
+
     return new AccountID(Buffer.from(decodeAccountID(value)));
   }
 
diff --git a/test/x-address.test.js b/test/x-address.test.js
index 1113186..4fc440a 100644
--- a/test/x-address.test.js
+++ b/test/x-address.test.js
@@ -95,6 +95,30 @@ let invalid_json_x_and_tagged = {
   SourceTag: 12345,
 };
 
+let json_issued_x = {
+  TakerPays: {
+    currency: "USD",
+    issuer: "X7WZKEeNVS2p9Tire9DtNFkzWBZbFtJHWxDjN9fCrBGqVA4",
+    value: "7072.8",
+  },
+};
+
+let json_issued_r = {
+  TakerPays: {
+    currency: "USD",
+    issuer: "rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B",
+    value: "7072.8",
+  },
+};
+
+let json_issued_with_tag = {
+  TakerPays: {
+    currency: "USD",
+    issuer: "X7WZKEeNVS2p9Tire9DtNFkzWBZbFtSiS2eDBib7svZXuc2",
+    value: "7072.8",
+  },
+};
+
 describe("X-Address Account is equivalent to a classic address w/ SourceTag", () => {
   let encoded_x = encode(json_x1);
   let encoded_r = encode(json_r1);
@@ -114,6 +138,10 @@ describe("X-Address Account is equivalent to a classic address w/ SourceTag", ()
   test("Throws when X-Address is invalid", () => {
     expect(() => encode(json_invalid_x)).toThrow("checksum_invalid");
   });
+
+  test("Encodes issued currency w/ x-address", () => {
+    expect(encode(json_issued_x)).toEqual(encode(json_issued_r));
+  });
 });
 
 describe("Invalid X-Address behavior", () => {
@@ -128,6 +156,12 @@ describe("Invalid X-Address behavior", () => {
       new Error("Cannot have Account X-Address and SourceTag")
     );
   });
+
+  test("Throws when issued currency has tag", () => {
+    expect(() => encode(json_issued_with_tag)).toThrow(
+      "Only allowed to have tag on Account or Destination"
+    );
+  });
 });
 
 describe("ripple-binary-codec x-address test", function () {