# packages/adapter-javascript/src/utils/executable-resolver.ts
@source-hash: 839840ffa428c4ca
@generated: 2026-02-10T00:41:06Z
## Cross-Platform Node.js Executable Resolver
**Primary Purpose**: Provides deterministic Node.js executable path resolution across platforms without spawning processes, with configurable filesystem abstraction for testing.
### Key Functions
**`findNode(preferredPath?, fileSystem?): Promise<string>` (L74-109)**
- Core resolver implementing 4-tier precedence strategy:
1. preferredPath (if exists)
2. process.execPath (if exists)
3. PATH search with platform-specific candidates
4. Deterministic fallback to process.execPath
- Always returns absolute paths via `path.resolve()`
- Graceful error handling with try-catch blocks ignoring filesystem errors
**`whichInPath(names, fileSystem?): string | undefined` (L42-63)**
- PATH-aware binary search respecting directory precedence
- Iterates directories first, then candidate names within each directory
- Returns first match as absolute path or undefined if none found
- Platform-agnostic implementation using `process.env.PATH`
**`isWindows(): boolean` (L33-35)**
- Platform detection utility checking `process.platform === 'win32'`
**`resolveNodeExecutable(preferredPath?): Promise<string>` (L111-113)**
- Convenience wrapper around `findNode()` using default filesystem
### Architecture Patterns
**Dependency Injection**: FileSystem abstraction (L20-31) enables testing via `setDefaultFileSystem()`
- Default: NodeFileSystem instance (L23)
- Injectable via optional parameters in core functions
**Platform-Specific Behavior**:
- Windows candidates: `['node.exe', 'node']` (L101)
- POSIX candidates: `['node']` (L101)
**Error Resilience**: All filesystem operations wrapped in try-catch blocks to maintain deterministic behavior during testing
### Dependencies
- `path`: Node.js path manipulation
- `@debugmcp/shared`: FileSystem interface and NodeFileSystem implementation
### Critical Constraints
- Must return absolute paths in all cases
- No process spawning (deterministic, cross-platform)
- Respects PATH environment variable ordering
- Graceful degradation with guaranteed fallback to process.execPath
