env-validate

env-validate is a zero-dependency library which validates that the environment variables specified in your .env.template file are set at runtime.

Installation

yarn add env-validate

npm install env-validate --save

Usage

By default, env-validate will look for a .env.template file in one of its parent directories so that you don't have to provide a single argument.

const envValidate = require('env-validate');
 
// Throws if any variable specified in `.env.template` is not set at runtime.
envValidate();

Alternatively, you can explicitly pass in the absolute path of your template file.

Optional Args

Optionally, an object containing any of these properties can be passed as argument:

{
  onError?: Function;
  optionals?: string[];
  templatePath?: string;
}

onError

A custom error callback can be specified. Instead of throwing, env-validate will call the given function.

envValidate({
  onError: envVarName => {
    console.log(envVarName);
  },
});

optionals

If any of the variables declared in your template file should be treated as optional, you can pass them in as array. env-validate will not throw an exception or call onError for optionals.

envValidate({
  optionals: ['FOO'],
});

templatePath

env-validate will try to automatically find your template file by recursively looking for a .env.template in one of its direct parent directories. Should your template file not be found, you can explicitly specify the absolute path of your template file.

envValidate({
  templatePath: '<absolute-path-to-template-file>',
});