refactor(utxo-lib): move getChainAndIndexFromPath to separate file

Move chain and index parsing function to ScriptId.ts in wallet module for
improved code organization. Add dedicated test file and improved validation.

Issue: BTC-1966

Co-authored-by: llm-git <[email protected]>

Author: OttoAllmendinger

modules/utxo-lib/src/bitgo/parseInput.ts

@@ -1,10 +1,9 @@
 /* eslint no-redeclare: 0 */
 import * as opcodes from 'bitcoin-ops';
-import { TxInput, script as bscript } from 'bitcoinjs-lib';
+import { script as bscript, TxInput } from 'bitcoinjs-lib';
 
 import { isTriple } from './types';
 import { isScriptType2Of3 } from './outputScripts';
-import { ChainCode, isChainCode } from './wallet/chains';
 
 export function isPlaceholderSignature(v: number | Buffer): boolean {
   if (Buffer.isBuffer(v)) {
@@ -699,20 +698,3 @@ export function parsePubScript(
 
   return result;
 }
-
-export function getChainAndIndexFromPath(path: string): { chain: ChainCode; index: number } {
-  const parts = path.split('/');
-  if (parts.length <= 2) {
-    throw new Error(`invalid path "${path}"`);
-  }
-  const chain = Number(parts[parts.length - 2]);
-  const index = Number(parts[parts.length - 1]);
-  if (!isChainCode(chain)) {
-    throw new Error(`invalid chain "${chain}"`);
-  }
-  if (!Number.isInteger(index) || index < 0) {
-    throw new Error(`invalid index "${index}"`);
-  }
-
-  return { chain, index };
-}

modules/utxo-lib/src/bitgo/wallet/ScriptId.ts

@@ -0,0 +1,21 @@
+import { ChainCode, isChainCode } from './chains';
+
+export function getChainAndIndexFromPath(path: string): {
+  chain: ChainCode;
+  index: number;
+} {
+  const parts = path.split('/');
+  if (parts.length <= 2) {
+    throw new Error(`invalid path "${path}"`);
+  }
+  const chain = Number(parts[parts.length - 2]);
+  const index = Number(parts[parts.length - 1]);
+  if (!isChainCode(chain)) {
+    throw new Error(`invalid chain "${chain}"`);
+  }
+  if (!Number.isInteger(index) || index < 0) {
+    throw new Error(`invalid index "${index}"`);
+  }
+
+  return { chain, index };
+}

modules/utxo-lib/src/bitgo/wallet/index.ts

@@ -7,3 +7,4 @@ export * from './WalletScripts';
 export * from './WalletKeys';
 export * from './psbt/PsbtOutputs';
 export * from './psbt/RootNodes';
+export * from './ScriptId';

modules/utxo-lib/test/bitgo/wallet/ScriptId.ts

@@ -0,0 +1,26 @@
+import * as assert from 'assert';
+
+import { getChainAndIndexFromPath } from '../../../src/bitgo/wallet/ScriptId';
+
+describe('getChainAndIndexFromPath', function () {
+  it('should throw if path is not the right length', function () {
+    assert.throws(() => getChainAndIndexFromPath('/'), /invalid path/);
+    assert.throws(() => getChainAndIndexFromPath('m0000ssss'), /invalid path/);
+  });
+
+  it('should throw if the path is not a number', function () {
+    const invalidChain = [-1, 2, 'lol'];
+    const invalidIndex = [-1, 'lol'];
+    for (const chain of invalidChain) {
+      assert.throws(() => getChainAndIndexFromPath(`m/${chain}/0`), /invalid chain/);
+    }
+    for (const index of invalidIndex) {
+      assert.throws(() => getChainAndIndexFromPath(`m/0/${index}`), /invalid index/);
+    }
+  });
+
+  it('should set the chain and index correctly', function () {
+    assert.deepStrictEqual(getChainAndIndexFromPath('m/1/2'), { chain: 1, index: 2 });
+    assert.deepStrictEqual(getChainAndIndexFromPath('m/1/2/3/4/5/10/20'), { chain: 10, index: 20 });
+  });
+});

modules/utxo-lib/test/bitgo/wallet/chains.ts

@@ -2,7 +2,6 @@ import * as assert from 'assert';
 import {
   ChainCode,
   chainCodes,
-  getChainAndIndexFromPath,
   getExternalChainCode,
   getInternalChainCode,
   isChainCode,
@@ -59,26 +58,3 @@ describe('chain codes', function () {
     });
   });
 });
-
-describe('getChainAndIndexFromPath', function () {
-  it('should throw if path is not the right length', function () {
-    assert.throws(() => getChainAndIndexFromPath('/'), /invalid path/);
-    assert.throws(() => getChainAndIndexFromPath('m0000ssss'), /invalid path/);
-  });
-
-  it('should throw if the path is not a number', function () {
-    const invalidChain = [-1, 2, 'lol'];
-    const invalidIndex = [-1, 'lol'];
-    for (const chain of invalidChain) {
-      assert.throws(() => getChainAndIndexFromPath(`m/${chain}/0`), /invalid chain/);
-    }
-    for (const index of invalidIndex) {
-      assert.throws(() => getChainAndIndexFromPath(`m/0/${index}`), /invalid index/);
-    }
-  });
-
-  it('should set the chain and index correctly', function () {
-    assert.deepStrictEqual(getChainAndIndexFromPath('m/1/2'), { chain: 1, index: 2 });
-    assert.deepStrictEqual(getChainAndIndexFromPath('m/1/2/3/4/5/10/20'), { chain: 10, index: 20 });
-  });
-});