Quickstart

This walks through a scan and how to read what comes back. It assumes you’ve installed Necro.

Run a scan

Point necro scan at a directory (defaults to the current directory):

necro scan src/

Necro discovers your TypeScript files, builds a symbol graph with the compiler API, resolves entry points, and reports anything unreachable.

Read the output

The default output is a summary line followed by one evidence chain per finding, sorted worst-first:

3 findings (1 certain, 1 likely, 1 test-only)

deadFn  src/util.ts:2   tier: certain
  ✓ 0 static references (TS compiler)
  • coverage: not available
  ✓ not in package.json exports
  ✓ no dynamic-import taint in scope
  → safe to remove

lonelyExport  src/util.ts:3   tier: likely
  ✓ 0 static references (TS compiler)
  • coverage: not available
  ✓ not in package.json exports
  ✓ no dynamic-import taint in scope
  → exported but unused — confirm no external use, then remove

testUtil  src/util.ts:4   tier: maybe
  ✓ 0 production references
  ✗ referenced only in test files
  • coverage: not available
  → prod-dead — delete fn + test, or wire into prod

What this tells you:

• deadFn is private and unreferenced → certain, safe to remove.
• lonelyExport is exported but unused internally → likely; it might be consumed externally, so Necro asks you to confirm.
• testUtil is reached only through test files → the test-only verdict.

Read more in Understanding results and Evidence chains.

Other output modes

necro scan src/ --json      # machine-readable JSON
necro scan src/ --top 10    # only the 10 worst findings

See CI integration for using JSON in a pipeline.