turborepo-shim

Purpose

Handles version resolution and delegation for the turbo binary. Finds and invokes the correct version of turbo based on the repository's local installation, enabling per-repo version pinning.

Architecture

User runs `turbo`
    └── Shim logic
        ├── Check for local turbo in node_modules
        │   └── If found: spawn local turbo as child process
        └── If not found: run current binary directly

Uses trait-based dependency injection (TurboRunner) to avoid circular dependencies with turborepo-lib.

Key components:

• ShimArgs - Parsed arguments needed for shim decisions
• TurboState - Tracks which turbo binary should execute
• run() - Main entry point for shim logic

Notes

The shim ensures that running turbo always uses the version specified in a project's package.json, even if a different global version is installed. This is critical for reproducible builds across team members.