Support p2tr with 1 script and no tree

* Also added caching of `hashTree`, per todo.
* Added a test for this functionality

Author: reardencode

src/payments/p2tr.js

@@ -73,6 +73,11 @@ function p2tr(a, opts) {
     }
     return a.witness.slice();
   });
+  const _hashTree = lazy.value(() => {
+    if (a.scriptTree) return (0, taprootutils_1.toHashTree)(a.scriptTree);
+    if (a.hash) return { hash: a.hash };
+    return;
+  });
   const network = a.network || networks_1.bitcoin;
   const o = { name: 'p2tr', network };
   lazy.prop(o, 'address', () => {
@@ -82,8 +87,8 @@ function p2tr(a, opts) {
     return bech32_1.bech32m.encode(network.bech32, words);
   });
   lazy.prop(o, 'hash', () => {
-    if (a.hash) return a.hash;
-    if (a.scriptTree) return (0, taprootutils_1.toHashTree)(a.scriptTree).hash;
+    const hashTree = _hashTree();
+    if (hashTree) return hashTree.hash;
     const w = _witness();
     if (w && w.length > 1) {
       const controlBlock = w[w.length - 1];
@@ -144,9 +149,8 @@ function p2tr(a, opts) {
   });
   lazy.prop(o, 'witness', () => {
     if (a.witness) return a.witness;
-    if (a.scriptTree && a.redeem && a.redeem.output && a.internalPubkey) {
-      // todo: optimize/cache
-      const hashTree = (0, taprootutils_1.toHashTree)(a.scriptTree);
+    const hashTree = _hashTree();
+    if (hashTree && a.redeem && a.redeem.output && a.internalPubkey) {
       const leafHash = (0, taprootutils_1.tapleafHash)({
         output: a.redeem.output,
         version: o.redeemVersion,
@@ -204,7 +208,7 @@ function p2tr(a, opts) {
         throw new TypeError('Invalid pubkey for p2tr');
     }
     if (a.hash && a.scriptTree) {
-      const hash = (0, taprootutils_1.toHashTree)(a.scriptTree).hash;
+      const hash = _hashTree().hash;
       if (!a.hash.equals(hash)) throw new TypeError('Hash mismatch');
     }
     const witness = _witness();

test/fixtures/p2tr.json

@@ -312,6 +312,28 @@
         "witness": null
       }
     },
+    {
+      "description": "address, pubkey, and output from internalPubkey redeem, and hash (one leaf, no tree)",
+      "arguments": {
+        "internalPubkey": "aba457d16a8d59151c387f24d1eb887efbe24644c1ee64b261282e7baebdb247",
+        "redeem": {
+          "output": "50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac4 OP_CHECKSIG"
+        },
+        "hash": "b424dea09f840b932a00373cdcdbd25650b8c3acfe54a9f4a641a286721b8d26"
+      },
+      "expected": {
+        "name": "p2tr",
+        "address": "bc1pnxyp0ahcg53jzgrzj57hnlgdtqtzn7qqhmgjgczk8hzhcltq974qazepzf",
+        "pubkey": "998817f6f84523212062953d79fd0d581629f800bed12460563dc57c7d602faa",
+        "output": "OP_1 998817f6f84523212062953d79fd0d581629f800bed12460563dc57c7d602faa",
+        "signature": null,
+        "input": null,
+        "witness": [
+          "2050929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac4ac",
+          "c0aba457d16a8d59151c387f24d1eb887efbe24644c1ee64b261282e7baebdb247"
+        ]
+      }
+    },
     {
       "description": "address, pubkey, output and hash from internalPubkey and a script tree with seven leafs (2)",
       "arguments": {

ts_src/payments/p2tr.ts

@@ -88,6 +88,12 @@ export function p2tr(a: Payment, opts?: PaymentOpts): Payment {
     return a.witness.slice();
   });
 
+  const _hashTree = lazy.value(() => {
+    if (a.scriptTree) return toHashTree(a.scriptTree);
+    if (a.hash) return { hash: a.hash };
+    return;
+  });
+
   const network = a.network || BITCOIN_NETWORK;
   const o: Payment = { name: 'p2tr', network };
 
@@ -100,8 +106,8 @@ export function p2tr(a: Payment, opts?: PaymentOpts): Payment {
   });
 
   lazy.prop(o, 'hash', () => {
-    if (a.hash) return a.hash;
-    if (a.scriptTree) return toHashTree(a.scriptTree).hash;
+    const hashTree = _hashTree();
+    if (hashTree) return hashTree.hash;
     const w = _witness();
     if (w && w.length > 1) {
       const controlBlock = w[w.length - 1];
@@ -161,9 +167,8 @@ export function p2tr(a: Payment, opts?: PaymentOpts): Payment {
 
   lazy.prop(o, 'witness', () => {
     if (a.witness) return a.witness;
-    if (a.scriptTree && a.redeem && a.redeem.output && a.internalPubkey) {
-      // todo: optimize/cache
-      const hashTree = toHashTree(a.scriptTree);
+    const hashTree = _hashTree();
+    if (hashTree && a.redeem && a.redeem.output && a.internalPubkey) {
       const leafHash = tapleafHash({
         output: a.redeem.output,
         version: o.redeemVersion,
@@ -227,7 +232,7 @@ export function p2tr(a: Payment, opts?: PaymentOpts): Payment {
     }
 
     if (a.hash && a.scriptTree) {
-      const hash = toHashTree(a.scriptTree).hash;
+      const hash = _hashTree()!.hash;
       if (!a.hash.equals(hash)) throw new TypeError('Hash mismatch');
     }