Fix HTLC conversion to and from plain format (#568)

* Encode hash algorithm in plain HTLC
* Add test for HTLC conversion to and from plain format
* Update types

dist/types.d.ts

@@ -1015,6 +1015,7 @@ export class Hash extends Serializable {
         SHA256: 3;
         SHA512: 4;
         toString(hashAlgorithm: Hash.Algorithm): string;
+        fromString(str: string): Hash.Algorithm;
     };
     public static light(arr: Uint8Array): Hash;
     public static blake2b(arr: Uint8Array): Hash;
@@ -1408,6 +1409,7 @@ export class HashedTimeLockedContract extends Contract {
         balance: number,
         sender: string,
         recipient: string,
+        hashAlgorithm: string,
         hashRoot: string,
         hashCount: number,
         timeout: number,

src/main/generic/consensus/base/account/HashedTimeLockedContract.js

@@ -73,7 +73,7 @@ class HashedTimeLockedContract extends Contract {
      */
     static fromPlain(plain) {
         if (!plain) throw new Error('Invalid account');
-        return new HashedTimeLockedContract(plain.balance, Address.fromAny(plain.sender), Address.fromAny(plain.recipient), Hash.fromAny(plain.hashRoot), plain.hashCount, plain.timeout, plain.totalAmount);
+        return new HashedTimeLockedContract(plain.balance, Address.fromAny(plain.sender), Address.fromAny(plain.recipient), Hash.fromAny(plain.hashRoot, Hash.Algorithm.fromString(plain.hashAlgorithm)), plain.hashCount, plain.timeout, plain.totalAmount);
     }
 
 
@@ -150,6 +150,7 @@ class HashedTimeLockedContract extends Contract {
         const plain = super.toPlain();
         plain.sender = this.sender.toPlain();
         plain.recipient = this.recipient.toPlain();
+        plain.hashAlgorithm = Hash.Algorithm.toString(this.hashRoot.algorithm);
         plain.hashRoot = this.hashRoot.toPlain();
         plain.hashCount = this.hashCount;
         plain.timeout = this.timeout;

src/main/generic/consensus/base/primitive/Hash.js

@@ -334,6 +334,20 @@ Hash.Algorithm.toString = function(hashAlgorithm) {
     throw new Error('Invalid hash algorithm');
 };
 
+/**
+ * @param {string} str
+ * @returns {Hash.Algorithm}
+ */
+Hash.Algorithm.fromString = function (str) {
+    switch (str) {
+        case 'blake2b': return Hash.Algorithm.BLAKE2B;
+        case 'argon2d': return Hash.Algorithm.ARGON2D;
+        case 'sha256': return Hash.Algorithm.SHA256;
+        case 'sha512': return Hash.Algorithm.SHA512;
+    }
+    throw new Error('Invalid string');
+}
+
 /**
  * @type {Map<Hash.Algorithm, number>}
  */

src/test/specs/generic/consensus/base/account/HashedTimeLockedContract.spec.js

@@ -531,4 +531,27 @@ describe('HashedTimeLockedContract', () => {
         expect(plain.creatorPublicKey).toEqual(keyPair.publicKey.toHex());
         expect(plain.creatorPathLength).toEqual(0);
     });
+
+    it('can convert itself to and from plain', () => {
+        const keyPair1 = KeyPair.generate();
+        const addr1 = keyPair1.publicKey.toAddress();
+        const keyPair2 = KeyPair.generate();
+        const addr2 = keyPair2.publicKey.toAddress();
+
+        const hashRoot = Hash.sha256(Hash.NULL.array);
+
+        const htlc = new HashedTimeLockedContract(1e5, addr1, addr2, hashRoot, 1, 1000);
+        const plain = htlc.toPlain();
+        const revived = HashedTimeLockedContract.fromPlain(plain);
+
+        expect(revived.sender.equals(addr1)).toBe(true);
+        expect(revived.recipient.equals(addr2)).toBe(true);
+        expect(revived.balance).toBe(1e5);
+        expect(revived.hashRoot.equals(hashRoot)).toBe(true);
+        expect(revived.hashRoot.algorithm).toBe(Hash.Algorithm.SHA256);
+        expect(revived.hashCount).toBe(1);
+        expect(revived.totalAmount).toBe(1e5);
+
+        expect(htlc.equals(revived)).toBe(true);
+    });
 });