envalid-unused

Detect unused environment variables by comparing process.env with envalid's cleanEnv result.

Installation

npm install envalid-unused

Usage

import { cleanEnv, str, num } from 'envalid';
import { warnUnused } from 'envalid-unused';

const env = cleanEnv(process.env, {
  API_URL: str(),
  PORT: num(),
});

// Warn about any env variables not defined in the schema
warnUnused(env);
// Output: [envalid-unused] Found 2 unused environment variable(s): DATABASE_URL, SECRET_KEY

API

warnUnused(cleanedEnv, options?)

Parameters

• cleanedEnv - The result from envalid's cleanEnv function
• options - Optional configuration object:
  • warn - Custom warning function (default: console.warn)
  • ignorePrefixes - Array of prefixes to ignore (default: common system prefixes like npm_, NODE_, etc.)
  • ignore - Array of specific variable names to ignore

Returns

Array of unused environment variable names.

Example with options

const unused = warnUnused(env, {
  warn: (msg) => logger.warn(msg),
  ignorePrefixes: ['npm_', 'NODE_', 'CI_'],
  ignore: ['DEBUG', 'VERBOSE'],
});

if (unused.length > 0) {
  // Handle unused variables
}

DEFAULT_IGNORE_PREFIXES

Export of the default prefixes that are ignored:

import { DEFAULT_IGNORE_PREFIXES } from 'envalid-unused';

// Extend the defaults
warnUnused(env, {
  ignorePrefixes: [...DEFAULT_IGNORE_PREFIXES, 'MY_PREFIX_'],
});

License

MIT