Comparing Packages Across Monorepo Workspaces

Monorepo Package Consistency

In monorepos (using npm workspaces, Yarn workspaces, pnpm workspaces, or Turborepo), each workspace has its own package.json. Keeping dependency versions consistent across workspaces prevents subtle bugs caused by version mismatches.

Common inconsistency patterns

# packages/web/package.json vs packages/api/package.json

dependencies:
  ~ zod: ^3.21.0 -> ^3.22.0        [MINOR]
  ~ typescript: ^5.2.0 -> ^5.3.0   [MINOR]
  + @prisma/client: ^5.0.0         [ADDED - only in api]
  - react: ^18.2.0                 [REMOVED - only in web]

Why consistency matters

Issue	Consequence
Different TypeScript versions	Incompatible type definitions across packages
Mismatched shared library versions	Runtime errors when passing data between packages
Missing peer dependencies	Warnings or silent failures
Duplicate dependencies	Increased node_modules size

How to use the diff for monorepo auditing

1. Copy the package.json from workspace A (e.g., packages/web/package.json)
2. Paste it into the left panel
3. Copy the package.json from workspace B (e.g., packages/api/package.json)
4. Paste it into the right panel
5. Click Compare and filter to Changed only to see version discrepancies

Fixing inconsistencies

After identifying mismatches, you can:

• Use the root package.json overrides field (npm) or resolutions field (Yarn) to enforce versions
• Create a shared tsconfig.base.json that all workspaces extend
• Use tools like syncpack to automatically align versions