Don't use constants for tag prefixes

Because the taggedHash API is typed, these are compile-time checked and
it's more clear w/o the constants.

Author: reardencode

src/payments/taprootutils.js

@@ -5,9 +5,6 @@ const buffer_1 = require('buffer');
 const bcrypto = require('../crypto');
 const bufferutils_1 = require('../bufferutils');
 const types_1 = require('../types');
-const TAP_LEAF_TAG = 'TapLeaf';
-const TAP_BRANCH_TAG = 'TapBranch';
-const TAP_TWEAK_TAG = 'TapTweak';
 exports.LEAF_VERSION_TAPSCRIPT = 0xc0;
 function rootHashFromPath(controlBlock, tapleafMsg) {
   const k = [tapleafMsg];
@@ -70,7 +67,7 @@ exports.findScriptPath = findScriptPath;
 function tapleafHash(leaf) {
   const version = leaf.version || exports.LEAF_VERSION_TAPSCRIPT;
   return bcrypto.taggedHash(
-    TAP_LEAF_TAG,
+    'TapLeaf',
     buffer_1.Buffer.concat([
       buffer_1.Buffer.from([version]),
       serializeScript(leaf.output),
@@ -80,13 +77,13 @@ function tapleafHash(leaf) {
 exports.tapleafHash = tapleafHash;
 function tapTweakHash(pubKey, h) {
   return bcrypto.taggedHash(
-    TAP_TWEAK_TAG,
+    'TapTweak',
     buffer_1.Buffer.concat(h ? [pubKey, h] : [pubKey]),
   );
 }
 exports.tapTweakHash = tapTweakHash;
 function tapBranchHash(a, b) {
-  return bcrypto.taggedHash(TAP_BRANCH_TAG, buffer_1.Buffer.concat([a, b]));
+  return bcrypto.taggedHash('TapBranch', buffer_1.Buffer.concat([a, b]));
 }
 function serializeScript(s) {
   const varintLen = bufferutils_1.varuint.encodingLength(s.length);

ts_src/payments/taprootutils.ts

@@ -4,10 +4,6 @@ import * as bcrypto from '../crypto';
 import { varuint } from '../bufferutils';
 import { Tapleaf, Taptree, isTapleaf } from '../types';
 
-const TAP_LEAF_TAG = 'TapLeaf';
-const TAP_BRANCH_TAG = 'TapBranch';
-const TAP_TWEAK_TAG = 'TapTweak';
-
 export const LEAF_VERSION_TAPSCRIPT = 0xc0;
 
 export function rootHashFromPath(
@@ -86,20 +82,20 @@ export function findScriptPath(node: HashTree, hash: Buffer): Buffer[] {
 export function tapleafHash(leaf: Tapleaf): Buffer {
   const version = leaf.version || LEAF_VERSION_TAPSCRIPT;
   return bcrypto.taggedHash(
-    TAP_LEAF_TAG,
+    'TapLeaf',
     NBuffer.concat([NBuffer.from([version]), serializeScript(leaf.output)]),
   );
 }
 
 export function tapTweakHash(pubKey: Buffer, h: Buffer | undefined): Buffer {
   return bcrypto.taggedHash(
-    TAP_TWEAK_TAG,
+    'TapTweak',
     NBuffer.concat(h ? [pubKey, h] : [pubKey]),
   );
 }
 
 function tapBranchHash(a: Buffer, b: Buffer): Buffer {
-  return bcrypto.taggedHash(TAP_BRANCH_TAG, NBuffer.concat([a, b]));
+  return bcrypto.taggedHash('TapBranch', NBuffer.concat([a, b]));
 }
 
 function serializeScript(s: Buffer): Buffer {