Production mode

Production mode restricts analysis to code that ships to users, ignoring test and development files.

fallow dead-code --production

Or set it in your config:

// .fallowrc.json
{
  "production": true
}

What changes in production mode

Behavior	Default	Production
Test files (*.test.*, *.spec.*, __tests__/)	Included	Excluded
Story files (*.stories.*)	Included	Excluded
Mock files (__mocks__/)	Included	Excluded
Package.json scripts analyzed	All	Only start, build, serve, preview, prepare, prepublishOnly, postinstall, and pre/post lifecycle hooks for start, build, serve, install
Unused devDependencies	Reported	Skipped
Type-only dependencies	Not flagged	Flagged (should be devDependencies)

● Unused exports (2)
  src/utils/format.ts
    :12 formatCurrency
    :28 formatPercentage
  Exported symbols with zero references: https://docs.fallow.tools/explanations/dead-code#unused-exports

● Unused dependencies (1)
  moment
  Packages in dependencies never imported: https://docs.fallow.tools/explanations/dead-code#unused-dependencies

● Type-only dependencies (1)
  zod  →  move to devDependencies (only imported via 'import type')
  Production dependencies only used as types: https://docs.fallow.tools/explanations/dead-code#type-only-dependencies

✗ 4 issues (19ms, production mode, 623/847 files)

Type-only dependency detection

In production mode, fallow detects dependencies that are only imported via import type:

import type { Config } from 'some-package';  // Type-only, erased at runtime

These packages belong in devDependencies since types are erased at runtime and don't need to be installed in production.

Per-analysis production mode

Combined mode (bare fallow) and fallow audit can enable production mode per analysis instead of globally:

// .fallowrc.json
{
  "production": {
    "health": true,
    "deadCode": false,
    "dupes": false
  }
}

Use --production-health, --production-dead-code, or --production-dupes for one invocation, or FALLOW_PRODUCTION_HEALTH=true and the related env vars in CI. The global --production flag still enables production mode for every analysis.

Precedence (highest to lowest): CLI flags, per-analysis env var, global FALLOW_PRODUCTION, config. CLI flags only enable; env vars and config can also disable. Worked examples:

# Run health in production mode, dead-code and dupes on the full tree
fallow --production-health

# Same, via env var (useful in CI templates that pass env-only)
FALLOW_PRODUCTION_HEALTH=true fallow

# Per-analysis env wins over the global env, so this runs health in production
# mode even though the global env says off (the typical CI-template case)
FALLOW_PRODUCTION=false FALLOW_PRODUCTION_HEALTH=true fallow

# CLI flags beat env vars; this enables all three regardless of FALLOW_PRODUCTION_* env
fallow --production

See also