FIX: HD wallet update if it was heavily used externally (closes #495)

HDWallet.test.js

@@ -86,10 +86,21 @@ it('HD (BIP49) can work with a gap', async function() {
 it('Segwit HD (BIP49) can batch fetch many txs', async function() {
   jasmine.DEFAULT_TIMEOUT_INTERVAL = 300 * 1000;
   let hd = new HDSegwitP2SHWallet();
-  hd._xpub = 'ypub6WZ2c7YJ1SQ1rBYftwMqwV9bBmybXzETFxWmkzMz25bCf6FkDdXjNgR7zRW8JGSnoddNdUH7ZQS7JeQAddxdGpwgPskcsXFcvSn1JdGVcPQ'; // cant fetch txs
+  hd._xpub = 'ypub6WZ2c7YJ1SQ1rBYftwMqwV9bBmybXzETFxWmkzMz25bCf6FkDdXjNgR7zRW8JGSnoddNdUH7ZQS7JeQAddxdGpwgPskcsXFcvSn1JdGVcPQ';
   await hd.fetchBalance();
   await hd.fetchTransactions();
-  assert.ok(hd.transactions.length > 0);
+  assert.ok(hd.getTransactions().length === 153);
+});
+
+it('Segwit HD (BIP49) can fetch more data if pointers to last_used_addr are lagging behind', async function() {
+  jasmine.DEFAULT_TIMEOUT_INTERVAL = 300 * 1000;
+  let hd = new HDSegwitP2SHWallet();
+  hd._xpub = 'ypub6WZ2c7YJ1SQ1rBYftwMqwV9bBmybXzETFxWmkzMz25bCf6FkDdXjNgR7zRW8JGSnoddNdUH7ZQS7JeQAddxdGpwgPskcsXFcvSn1JdGVcPQ';
+  hd.next_free_change_address_index = 40;
+  hd.next_free_address_index = 50;
+  await hd.fetchBalance();
+  await hd.fetchTransactions();
+  assert.strictEqual(hd.getTransactions().length, 153);
 });
 
 it('Segwit HD (BIP49) can generate addressess only via ypub', function() {

class/abstract-hd-wallet.js

@@ -17,7 +17,7 @@ export class AbstractHDWallet extends LegacyWallet {
     this._xpub = ''; // cache
     this.usedAddresses = [];
     this._address_to_wif_cache = {};
-    this.gap_limit = 3;
+    this.gap_limit = 20;
   }
 
   prepareForSerialization() {
@@ -115,7 +115,7 @@ export class AbstractHDWallet extends LegacyWallet {
     // looking for free external address
     let freeAddress = '';
     let c;
-    for (c = 0; c < Math.max(5, this.usedAddresses.length); c++) {
+    for (c = 0; c < this.gap_limit + 1; c++) {
       if (this.next_free_address_index + c < 0) continue;
       let address = this._getExternalAddressByIndex(this.next_free_address_index + c);
       this.external_addresses_cache[this.next_free_address_index + c] = address; // updating cache just for any case
@@ -153,7 +153,7 @@ export class AbstractHDWallet extends LegacyWallet {
     // looking for free internal address
     let freeAddress = '';
     let c;
-    for (c = 0; c < Math.max(5, this.usedAddresses.length); c++) {
+    for (c = 0; c < this.gap_limit + 1; c++) {
       if (this.next_free_change_address_index + c < 0) continue;
       let address = this._getInternalAddressByIndex(this.next_free_change_address_index + c);
       this.internal_addresses_cache[this.next_free_change_address_index + c] = address; // updating cache just for any case
@@ -432,6 +432,32 @@ export class AbstractHDWallet extends LegacyWallet {
   }
 
   async _fetchBalance() {
+    // probing future addressess in hierarchy whether they have any transactions, in case
+    // our 'next free addr' pointers are lagging behind
+    let tryAgain = false;
+    let txs = await BlueElectrum.getTransactionsByAddress(
+      this._getExternalAddressByIndex(this.next_free_address_index + this.gap_limit - 1),
+    );
+    if (txs.length > 0) {
+      // whoa, someone uses our wallet outside! better catch up
+      this.next_free_address_index += this.gap_limit;
+      tryAgain = true;
+    }
+
+    txs = await BlueElectrum.getTransactionsByAddress(
+      this._getInternalAddressByIndex(this.next_free_change_address_index + this.gap_limit - 1),
+    );
+    if (txs.length > 0) {
+      this.next_free_change_address_index += this.gap_limit;
+      tryAgain = true;
+    }
+
+    // FIXME: refactor me ^^^ can be batched in single call
+
+    if (tryAgain) return this._fetchBalance();
+
+    // next, business as usuall. fetch balances
+
     this.usedAddresses = [];
     // generating all involved addresses:
     for (let c = 0; c < this.next_free_address_index + this.gap_limit; c++) {

class/hd-segwit-bech32-wallet.js

@@ -52,8 +52,6 @@ export class HDSegwitBech32Wallet extends AbstractHDWallet {
 
     this._txs_by_external_index = {};
     this._txs_by_internal_index = {};
-
-    this.gap_limit = 20;
   }
 
   /**
@@ -264,6 +262,32 @@ export class HDSegwitBech32Wallet extends AbstractHDWallet {
   }
 
   async _fetchBalance() {
+    // probing future addressess in hierarchy whether they have any transactions, in case
+    // our 'next free addr' pointers are lagging behind
+    let tryAgain = false;
+    let txs = await BlueElectrum.getTransactionsByAddress(
+      this._getExternalAddressByIndex(this.next_free_address_index + this.gap_limit - 1),
+    );
+    if (txs.length > 0) {
+      // whoa, someone uses our wallet outside! better catch up
+      this.next_free_address_index += this.gap_limit;
+      tryAgain = true;
+    }
+
+    txs = await BlueElectrum.getTransactionsByAddress(
+      this._getInternalAddressByIndex(this.next_free_change_address_index + this.gap_limit - 1),
+    );
+    if (txs.length > 0) {
+      this.next_free_change_address_index += this.gap_limit;
+      tryAgain = true;
+    }
+
+    // FIXME: refactor me ^^^ can be batched in single call
+
+    if (tryAgain) return this._fetchBalance();
+
+    // next, business as usuall. fetch balances
+
     let addresses2fetch = [];
 
     // generating all involved addresses.

screen/selftest.js

@@ -270,8 +270,7 @@ export default class Selftest extends Component {
         await hd4.fetchBalance();
         if (hd4.getBalance() !== 200000) throw new Error('Could not fetch HD Bech32 balance');
         await hd4.fetchTransactions();
-        if (hd4.getTransactions().length !== 4)
-          throw new Error('Could not fetch HD Bech32 transactions');
+        if (hd4.getTransactions().length !== 4) throw new Error('Could not fetch HD Bech32 transactions');
       } else {
         console.warn('skipping RN-specific test');
       }