refactor(path): drop Windows tilde branch and consolidate helpers

- Remove dead `~\` expansion branch and its test; only POSIX is supported.
- Add overload so resolvePathFromCwd accepts string | undefined, dropping
  the ternary at app-path-resolver call sites.
- Replace duplicate tilde handling in snapshot-tests/output-parsers with
  the shared expandHomePrefix helper.
- Add defensive empty-input guard and clarified doc comments to
  expandHomePrefix; document that ~userName prefixes are not expanded.
- Cover whitespace, multi-byte, and undefined cases in path.test.ts.
- Note absolute-path normalization in the CHANGELOG fix entry.

Author: cameroncooke

CHANGELOG.md

@@ -15,7 +15,7 @@
 
 ### Fixed
 
-- Expanded leading `~` (and `~/` or `~\` on Windows) prefixes in configured `derivedDataPath`, `projectPath`, `workspacePath`, `axePath`, and the iOS/macOS template paths so values like `~/.foo/derivedData` resolve under the user's home directory instead of creating a literal `~` directory under the project root ([#283](https://github.com/getsentry/XcodeBuildMCP/issues/283), supersedes [#301](https://github.com/getsentry/XcodeBuildMCP/pull/301) by [@trmquang93](https://github.com/trmquang93)).
+- Expanded leading `~` and `~/` prefixes in configured `derivedDataPath`, `projectPath`, `workspacePath`, `axePath`, and the iOS/macOS template paths so values like `~/.foo/derivedData` resolve under the user's home directory instead of creating a literal `~` directory under the project root. As part of this change, configured absolute paths are now lexically normalized (e.g. `/a/b/../c` collapses to `/a/c`) before being passed to `xcodebuild` ([#283](https://github.com/getsentry/XcodeBuildMCP/issues/283), supersedes [#301](https://github.com/getsentry/XcodeBuildMCP/pull/301) by [@trmquang93](https://github.com/trmquang93)).
 
 ## [2.3.2]
 

src/snapshot-tests/output-parsers.ts

@@ -1,4 +1,4 @@
-import os from 'node:os';
+import { expandHomePrefix } from '../utils/path.ts';
 
 export interface SnapshotSimulatorEntry {
   name: string;
@@ -7,10 +7,7 @@ export interface SnapshotSimulatorEntry {
 }
 
 export function expandSnapshotPath(pathValue: string): string {
-  if (pathValue.startsWith('~/')) {
-    return `${os.homedir()}${pathValue.slice(1)}`;
-  }
-  return pathValue;
+  return expandHomePrefix(pathValue);
 }
 
 export function extractAppPathFromSnapshotOutput(output: string): string {

src/utils/__tests__/path.test.ts

@@ -12,10 +12,6 @@ describe('expandHomePrefix', () => {
     expect(expandHomePrefix('~/foo/bar')).toBe(path.join(homedir(), 'foo/bar'));
   });
 
-  it('expands a leading ~\\ on Windows-style separators', () => {
-    expect(expandHomePrefix('~\\foo\\bar')).toBe(path.join(homedir(), 'foo\\bar'));
-  });
-
   it('returns absolute paths unchanged', () => {
     expect(expandHomePrefix('/absolute/path')).toBe('/absolute/path');
   });
@@ -32,6 +28,14 @@ describe('expandHomePrefix', () => {
     expect(expandHomePrefix('foo/~/bar')).toBe('foo/~/bar');
   });
 
+  it('does not expand a leading ~ followed by whitespace', () => {
+    expect(expandHomePrefix(' ~/foo')).toBe(' ~/foo');
+  });
+
+  it('preserves multi-byte characters in the expanded segment', () => {
+    expect(expandHomePrefix('~/日本語/файл')).toBe(path.join(homedir(), '日本語/файл'));
+  });
+
   it('returns an empty string unchanged', () => {
     expect(expandHomePrefix('')).toBe('');
   });
@@ -75,4 +79,8 @@ describe('resolvePathFromCwd', () => {
   it('normalizes interior traversal segments in absolute paths', () => {
     expect(resolvePathFromCwd('/a/b/../c')).toBe('/a/c');
   });
+
+  it('returns undefined when pathValue is undefined', () => {
+    expect(resolvePathFromCwd(undefined)).toBeUndefined();
+  });
 });

src/utils/app-path-resolver.ts

@@ -46,8 +46,8 @@ export async function resolveAppPathFromBuildSettings(
 ): Promise<string> {
   const command = ['xcodebuild', '-showBuildSettings'];
 
-  const workspacePath = params.workspacePath ? resolvePathFromCwd(params.workspacePath) : undefined;
-  const projectPath = params.projectPath ? resolvePathFromCwd(params.projectPath) : undefined;
+  const workspacePath = resolvePathFromCwd(params.workspacePath);
+  const projectPath = resolvePathFromCwd(params.projectPath);
   const derivedDataPath = resolveEffectiveDerivedDataPath(params.derivedDataPath);
 
   let projectDir: string | undefined;

src/utils/path.ts

@@ -2,26 +2,41 @@ import path from 'node:path';
 import { homedir } from 'node:os';
 
 /**
- * Expand a leading ~ or ~/ (or ~\ on Windows) prefix to the user's home directory.
- * Returns the path unchanged if it does not start with ~ or starts with ~userName.
+ * Expand a leading `~` or `~/` prefix to the user's home directory.
+ * Returns the path unchanged if it does not begin with `~` or `~/`.
+ * Shell-style `~userName` prefixes (e.g. `~bob/foo`) are not expanded
+ * and will be treated as literal path segments by `resolvePathFromCwd`.
  */
 export function expandHomePrefix(inputPath: string): string {
+  if (!inputPath) {
+    return inputPath;
+  }
+
   if (inputPath === '~') {
     return homedir();
   }
 
-  if (inputPath.startsWith('~/') || inputPath.startsWith('~\\')) {
+  if (inputPath.startsWith('~/')) {
     return path.join(homedir(), inputPath.slice(2));
   }
 
   return inputPath;
 }
 
 /**
- * Resolve a user-supplied path: expand ~ then resolve against `cwd`
- * (defaults to process.cwd()). Always returns a normalized absolute path —
- * traversal segments like `/foo/..` collapse to `/`.
+ * Resolve a user-supplied path: expand `~` then resolve against `cwd`
+ * (defaults to `process.cwd()`). Always returns a normalized absolute path —
+ * traversal segments like `/foo/..` collapse to `/`. Returns `undefined`
+ * when `pathValue` is `undefined`.
  */
-export function resolvePathFromCwd(pathValue: string, cwd: string = process.cwd()): string {
+export function resolvePathFromCwd(pathValue: string, cwd?: string): string;
+export function resolvePathFromCwd(pathValue: string | undefined, cwd?: string): string | undefined;
+export function resolvePathFromCwd(
+  pathValue: string | undefined,
+  cwd: string = process.cwd(),
+): string | undefined {
+  if (pathValue === undefined) {
+    return undefined;
+  }
   return path.resolve(cwd, expandHomePrefix(pathValue));
 }