feat(sdk-core): add support for BOLT11 lightning invoices in OFC token

modules/sdk-core/src/coins/ofcToken.ts

@@ -8,7 +8,10 @@ import {
   CoinConstructor,
   SignTransactionOptions as BaseSignTransactionOptions,
   SignedTransaction,
+  ITransactionRecipient,
 } from '../';
+import { isBolt11Invoice, LIGHTNING_INVOICE } from '../lightning';
+
 import { Ofc } from './ofc';
 
 export interface SignTransactionOptions extends BaseSignTransactionOptions {
@@ -21,6 +24,7 @@ export interface SignTransactionOptions extends BaseSignTransactionOptions {
 export { OfcTokenConfig };
 
 const publicIdRegex = /^[a-f\d]{32}$/i;
+
 export class OfcToken extends Ofc {
   public readonly tokenConfig: OfcTokenConfig;
 
@@ -65,6 +69,37 @@ export class OfcToken extends Ofc {
     return this.tokenConfig.type;
   }
 
+  checkRecipient(recipient: ITransactionRecipient): void {
+    if (isBolt11Invoice(recipient.address)) {
+      // should throw error if this isnt bitcoin (mainnet or testnet)
+      if (this.backingCoin !== 'btc' && this.backingCoin !== 'tbtc') {
+        throw new Error(`invalid argument - lightning invoice is only supported for bitcoin`);
+      }
+
+      // amount for bolt11 invoices is either 'invoice' or a non-zero bigint
+      if (recipient.amount === LIGHTNING_INVOICE) {
+        return;
+      }
+      // try to parse the amount as a bigint
+      let amount: bigint;
+      try {
+        amount = BigInt(recipient.amount);
+      } catch (e) {
+        throw new Error(
+          `invalid argument ${recipient.amount} for amount - lightning invoice amount must be >= 0 or ${LIGHTNING_INVOICE}`
+        );
+      }
+      if (amount > 0n) {
+        return;
+      }
+      throw new Error(
+        `invalid argument for amount - lightning invoice amount must be a non-zero bigint or ${LIGHTNING_INVOICE}`
+      );
+    }
+
+    super.checkRecipient(recipient);
+  }
+
   /**
    * Flag for sending value of 0
    * @returns {boolean} True if okay to send 0 value, false otherwise

modules/sdk-core/src/lightning.ts

@@ -0,0 +1,11 @@
+export const LIGHTNING_INVOICE = 'invoice';
+
+export function isBolt11Invoice(value: unknown): value is string {
+  if (typeof value !== 'string') {
+    return false;
+  }
+  if (value.startsWith('lnbc') || value.startsWith('lntb')) {
+    return true;
+  }
+  return false;
+}

modules/sdk-core/test/unit/lightning.ts

@@ -0,0 +1,26 @@
+import 'should';
+
+import { isBolt11Invoice } from '../../src/lightning';
+
+describe('lightning', () => {
+  describe('isBolt11Invoice', () => {
+    it('should return true for a valid bolt11 invoice', () => {
+      const invoice =
+        'lnbc500n1p3zv5vkpp5x0thcaz8wep54clc2xt5895azjdzmthyskzzh9yslggy74qtvl6sdpdg3hkuct5d9hkugrxdaezqjn0dphk2fmnypkk2mtsdahkccqzpgxqyz5vqsp5v80q4vq4pwakq2l0hcqgtelgajsymv4ud4jdcrqtnzhvet55qlus9qyyssquqh2wl2m866qs5n72c5vg6wmqx9vzwhs5ypualq4mcu76h2tdkcq3jtjwtggfff7xwtdqxlnwqk8cxpzryjghrmmq3syraswp9vjr7cqry9l96';
+
+      isBolt11Invoice(invoice).should.equal(true);
+    });
+
+    it('should return false for non-string values', () => {
+      isBolt11Invoice(undefined).should.equal(false);
+      isBolt11Invoice(null as any).should.equal(false);
+      isBolt11Invoice(123 as any).should.equal(false);
+      isBolt11Invoice({} as any).should.equal(false);
+    });
+
+    it('should return false for invalid invoice strings', () => {
+      isBolt11Invoice('').should.equal(false);
+      isBolt11Invoice('not-an-invoice').should.equal(false);
+    });
+  });
+});