files-that-must-not-have-dedicated-tests

Files That Must NOT Have Dedicated Tests

Do not create test files for source files with no runtime logic — they are covered when consumed:

• Pure constants — only literal values, no computation or side effects
• Enums with no computed members / string-union types
• Type-only files — only type/interface declarations
• Index files (index.ts) — a list of re-exports; code imports the files it lists, never the index file

A file qualifies for testing only when it contains executable logic. If a constant file does contain logic (e.g., env-var fallback), test the logic paths — not the static value.

Exception — a package's published entry

The index.ts a package names in its exports map is the one index file that is not covered when consumed, because nothing inside the repo consumes it. It is the contract with the outside world: a name dropped from it in a rename or a merge breaks every downstream build while every other test in the suite keeps passing.

A dedicated test on that file may pin only what no other test can reach:

• the exact set of exported names
• that each one arrived as a value rather than erasing to undefined

It must not re-prove what the exported things do — that belongs to each one's own test file.