ADD: HP BIP84 can fetch utxo

Electrum.test.js

@@ -113,4 +113,25 @@ describe('Electrum', () => {
     assert.strictEqual(balances.addresses['bc1qcg6e26vtzja0h8up5w2m7utex0fsu4v0e0e7uy'].confirmed, 50000);
     assert.strictEqual(balances.addresses['bc1qcg6e26vtzja0h8up5w2m7utex0fsu4v0e0e7uy'].unconfirmed, 0);
   });
+
+  it('BlueElectrum can do multiGetUtxoByAddress()', async () => {
+    let utxos = await BlueElectrum.multiGetUtxoByAddress(
+      [
+        'bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh',
+        'bc1qvd6w54sydc08z3802svkxr7297ez7cusd6266p',
+        'bc1qwp58x4c9e5cplsnw5096qzdkae036ug7a34x3r',
+        'bc1qcg6e26vtzja0h8up5w2m7utex0fsu4v0e0e7uy',
+      ],
+      3,
+    );
+
+    assert.strictEqual(Object.keys(utxos).length, 4);
+    assert.strictEqual(
+      utxos['bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh'][0].tx_hash,
+      'ad00a92409d8982a1d7f877056dbed0c4337d2ebab70b30463e2802279fb936d',
+    );
+    assert.strictEqual(utxos['bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh'][0].tx_pos, 1);
+    assert.strictEqual(utxos['bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh'][0].value, 50000);
+    assert.strictEqual(utxos['bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh'][0].address, 'bc1qt4t9xl2gmjvxgmp5gev6m8e6s9c85979ta7jeh');
+  });
 });

HDBech32Wallet.test.js

@@ -114,6 +114,26 @@ describe('Bech32 Segwit HD (BIP84)', () => {
     }
   });
 
+  it('can fetch UTXO', async () => {
+    if (!process.env.HD_MNEMONIC) {
+      console.error('process.env.HD_MNEMONIC not set, skipped');
+      return;
+    }
+    jasmine.DEFAULT_TIMEOUT_INTERVAL = 90 * 1000;
+    let hd = new HDSegwitBech32Wallet();
+    hd.setSecret(process.env.HD_MNEMONIC);
+    assert.ok(hd.validateMnemonic());
+
+    await hd.fetchBalance();
+    await hd.fetchUtxo();
+    let utxo = hd.getUtxo();
+    assert.strictEqual(utxo.length, 4);
+    assert.ok(utxo[0].tx_hash);
+    assert.ok(utxo[0].tx_pos === 0 || utxo[0].tx_pos === 1);
+    assert.ok(utxo[0].value);
+    assert.ok(utxo[0].address);
+  });
+
   it('can generate addresses only via zpub', function() {
     let zpub = 'zpub6rFR7y4Q2AijBEqTUquhVz398htDFrtymD9xYYfG1m4wAcvPhXNfE3EfH1r1ADqtfSdVCToUG868RvUUkgDKf31mGDtKsAYz2oz2AGutZYs';
     let hd = new HDSegwitBech32Wallet();

class/hd-segwit-bech32-wallet.js

@@ -52,6 +52,8 @@ export class HDSegwitBech32Wallet extends AbstractHDWallet {
 
     this._txs_by_external_index = {};
     this._txs_by_internal_index = {};
+
+    this._utxo = [];
   }
 
   /**
@@ -344,6 +346,32 @@ export class HDSegwitBech32Wallet extends AbstractHDWallet {
     this._lastBalanceFetch = +new Date();
   }
 
+  async fetchUtxo() {
+    // considering only confirmed balance
+    let addressess = [];
+
+    for (let c = 0; c < this.next_free_address_index + this.gap_limit; c++) {
+      if (this._balances_by_external_index[c] && this._balances_by_external_index[c].c && this._balances_by_external_index[c].c > 0) {
+        addressess.push(this._getExternalAddressByIndex(c));
+      }
+    }
+
+    for (let c = 0; c < this.next_free_change_address_index + this.gap_limit; c++) {
+      if (this._balances_by_internal_index[c] && this._balances_by_internal_index[c].c && this._balances_by_internal_index[c].c > 0) {
+        addressess.push(this._getInternalAddressByIndex(c));
+      }
+    }
+
+    this._utxo = [];
+    for (let arr of Object.values(await BlueElectrum.multiGetUtxoByAddress(addressess))) {
+      this._utxo = this._utxo.concat(arr);
+    }
+  }
+
+  getUtxo() {
+    return this._utxo;
+  }
+
   weOwnAddress(address) {
     for (let c = 0; c < this.next_free_address_index + this.gap_limit; c++) {
       if (this._getExternalAddressByIndex(c) === address) return true;