noctcore-contracts/no-direct-process-env

Read environment variables through a typed, validated config accessor — never process.env directly.

Recommended preset: error · Autofix: no · Suggestions: no · Type information: not needed

Why

process.env.X is string | undefined, unvalidated, and reachable from anywhere. A typo or a missing variable fails silently at the point of use, often deep in a request. Funnelling every read through a single typed config module makes the environment a validated contract that fails at boot, and gives every consumer real types.

What it flags

Any process.env access, in every position — property read (process.env.X), computed (process.env[X]), destructure (const { X } = process.env), or the bare value passed / returned / assigned (log(process.env), return process.env). Computed process['env'] cannot bypass it.

Incorrect · 3 reports

const isProd = process.env.NODE_ENV === 'production';
const { DATABASE_URL } = process.env;
const env = process['env'];

Correct

import { config } from '@/config';

const isProd = config.isProduction;

What it does not flag

• Files matched by the allowedFiles glob allowlist are skipped entirely, so bootstrap entrypoints, config files, and tests may still read process.env directly.
• import.meta.env reads and other process properties (process.environment, process.argv): only process.env itself is policed.

Correct · vite.config.ts

const isProd = process.env.NODE_ENV === 'production';

Options

Option	Type	Default	Meaning
configModule	string	'@/config'	Import path of the typed config accessor, named in the report message.
allowedFiles	string[] (globs)	['**/*.config.{ts,js,mjs,cjs}', '**/*.{spec,test}.{ts,tsx}', '**/scripts/**']	Files permitted to read process.env directly.

Globs support *, **, ?, and {a,b} alternation; a leading **/ matches any (or no) directory prefix, so patterns work against both relative and absolute filenames.

'noctcore-contracts/no-direct-process-env': ['error', {
  configModule: '@acme/config',
  allowedFiles: ['**/apps/server/**', '**/*.{spec,test}.{ts,tsx}'],
}]

When not to use it

If you have no config seam yet, or intentionally read process.env throughout (a small script, a Vite-style import.meta.env app), leave this rule off or widen allowedFiles.