feat: add decode invoice function

package.json

@@ -40,8 +40,9 @@
   },
   "dependencies": {
     "crypto-js": "^4.1.1",
-    "nostr-tools": "1.13.1",
-    "events": "^3.3.0"
+    "events": "^3.3.0",
+    "light-bolt11-decoder": "^3.0.0",
+    "nostr-tools": "1.13.1"
   },
   "devDependencies": {
     "@commitlint/cli": "^17.7.1",

src/decodeInvoice.test.ts

@@ -0,0 +1,32 @@
+import { decodeInvoice } from "./decodeInvoice";
+
+const invoice =
+  "lnbc10n1pj4xmazpp5ns890al37jpreen4rlpl6fsw2hlp9n9hm0ts4dvwvcxq8atf4v6qhp50kncf9zk35xg4lxewt4974ry6mudygsztsz8qn3ar8pn3mtpe50scqzzsxqyz5vqsp5k508kdmvfpuac6lvn9wumr9x4mcpnh2t6jyp5kkxcjhueq4xjxqq9qyyssq0m88mwgknhkqfsa9u8e9dp8v93xlm0lqggslzj8mpsnx3mdzm8z5k9ns7g299pfm9zwm4crs00a364cmpraxr54jw5cf2qx9vycucggqz2ggul";
+
+describe("decodeInvoice", () => {
+  test("get amount from invoice", () => {
+    const decodedInvoice = decodeInvoice(invoice);
+    const amountSection = decodedInvoice.sections.find(
+      (section) => section.name === "amount",
+    );
+    if (amountSection?.name !== "amount") {
+      throw new Error("did not find amount section");
+    }
+    const value = amountSection.value;
+    expect(value).toEqual("1000");
+  });
+
+  test("get payment hash from invoice", () => {
+    const decodedInvoice = decodeInvoice(invoice);
+    const paymentHashSection = decodedInvoice.sections.find(
+      (section) => section.name === "payment_hash",
+    );
+    if (paymentHashSection?.name !== "payment_hash") {
+      throw new Error("did not find payment_hash section");
+    }
+    const value = paymentHashSection.value;
+    expect(value).toEqual(
+      "9c0e57f7f1f4823ce6751fc3fd260e55fe12ccb7dbd70ab58e660c03f569ab34",
+    );
+  });
+});

src/decodeInvoice.ts

@@ -0,0 +1,13 @@
+import { decode } from "light-bolt11-decoder";
+export function decodeInvoice(invoice: string) {
+  if (!invoice) {
+    throw new Error("No invoice provided");
+  }
+
+  try {
+    return decode(invoice);
+  } catch (error) {
+    console.error("Failed to decode invoice", error);
+    throw error;
+  }
+}

src/index.ts

@@ -2,3 +2,4 @@ export * as auth from "./auth";
 export * as types from "./types";
 export * as webln from "./webln";
 export { Client } from "./client";
+export * from "./decodeInvoice";

src/light-bolt11-decoder.d.ts

@@ -0,0 +1,90 @@
+// TODO: remove when https://github.com/nbd-wtf/light-bolt11-decoder/pull/4 is merged
+declare module "light-bolt11-decoder" {
+  type NetworkSection = {
+    name: "coin_network";
+    letters: string;
+    value?: {
+      bech32: string;
+      pubKeyHash: number;
+      scriptHash: number;
+      validWitnessVersions: number[];
+    };
+  };
+
+  type FeatureBits = {
+    option_data_loss_protect: string;
+    initial_routing_sync: string;
+    option_upfront_shutdown_script: string;
+    gossip_queries: string;
+    var_onion_optin: string;
+    gossip_queries_ex: string;
+    option_static_remotekey: string;
+    payment_secret: string;
+    basic_mpp: string;
+    option_support_large_channel: string;
+    extra_bits: {
+      start_bit: number;
+      bits: unknown[];
+      has_required: boolean;
+    };
+  };
+
+  type RouteHint = {
+    pubkey: string;
+    short_channel_id: string;
+    fee_base_msat: number;
+    fee_proportional_millionths: number;
+    cltv_expiry_delta: number;
+  };
+
+  type RouteHintSection = {
+    name: "route_hint";
+    tag: "r";
+    letters: string;
+    value: RouteHint[];
+  };
+
+  type FeatureBitsSection = {
+    name: "feature_bits";
+    tag: "9";
+    letters: string;
+    value: FeatureBits;
+  };
+
+  type Section =
+    | { name: "paymentRequest"; value: string }
+    | { name: "expiry"; value: number }
+    | { name: "checksum"; letters: string }
+    | NetworkSection
+    | { name: "amount"; letters: string; value: string }
+    | { name: "separator"; letters: string }
+    | { name: "timestamp"; letters: string; value: number }
+    | { name: "payment_hash"; tag: "p"; letters: string; value: string }
+    | { name: "description"; tag: "d"; letters: string; value: string }
+    | { name: "payment_secret"; tag: "s"; letters: string; value: string }
+    | {
+        name: "min_final_cltv_expiry";
+        tag: "c";
+        letters: string;
+        value: number;
+      }
+    | FeatureBitsSection
+    | RouteHintSection
+    | { name: "signature"; letters: string; value: string };
+
+  type PaymentJSON = {
+    paymentRequest: string;
+    sections: Section[];
+    expiry: number;
+    route_hints: RouteHint[][];
+  };
+
+  type DecodedInvoice = {
+    paymentRequest: string;
+    sections: Section[];
+    expiry: number;
+    route_hints: RouteHint[][];
+  };
+
+  function decode(invoice: string): DecodedInvoice;
+}

yarn.lock

@@ -5412,6 +5412,13 @@ levn@^0.4.1:
     prelude-ls "^1.2.1"
     type-check "~0.4.0"
 
+light-bolt11-decoder@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/light-bolt11-decoder/-/light-bolt11-decoder-3.0.0.tgz#f644576120426c9ef65621bde254f11016055044"
+  integrity sha512-AKvOigD2pmC8ktnn2TIqdJu0K0qk6ukUmTvHwF3JNkm8uWCqt18Ijn33A/a7gaRZ4PghJ59X+8+MXrzLKdBTmQ==
+  dependencies:
+    "@scure/base" "1.1.1"
+
 [email protected], lilconfig@^2.0.3, lilconfig@^2.0.5:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/lilconfig/-/lilconfig-2.1.0.tgz#78e23ac89ebb7e1bfbf25b18043de756548e7f52"