environment

The environment package provides functions read from the execution environment.

Types

MissingVarError

Resembles the error when the environment variable doesn't exist for a read attempt.

interface MissingVarError {
  kind: 'missing-var-error';
  key: string;
}

Production

Interface representing a production environment.

interface Production {
  kind: 'production';
}

Development

Interface representing a development environment.

interface Development {
  kind: 'development';
}

Unknown

Interface representing an unknown environment.

interface Unknown {
  kind: 'unknown';
}

Environment

type Environment = Production | Development | Unknown;

Functions

missingVarError

This function takes an environment variable name and constructs a MissingVarError type from it.

import { missingVarError, MissingVarError } from '@execonline-inc/environment';

const result: MissingVarError = missingVarError('SOME_ENV_VAR');
// { kind: 'missing-var-error', key: 'SOME_ENV_VAR' }

readVarM

This function reads for a given key from process.env and wraps the value in a Maybe. When a value exists for the key, the result is a Just, otherwise it is a Nothing.

import { readVarM } from '@execonline-inc/environment';
import { Maybe } from 'maybeasy';

const result: Maybe<string> = readVarM('SOME_ENV_VAR');

readVarR

Like readVarM, but the condition for no value is an error Result.

import { MissingVarError, readVarR } from '@execonline-inc/environment';
import { Result } from 'resulty';

const result: Result<MissingVarError, string> = readVarR('SOME_ENV_VAR');

readVarT

Like readVarR, but as a Task instead of a Result.

import { MissingVarError, readVarT } from '@execonline-inc/environment';
import Task from 'taskarian';

const result: Task<MissingVarError, string> = readVarT('SOME_ENV_VAR');

environment

This function reads the NODE_ENV environment variable and returns an object representing the detected environment.

import { environment, Environment } from '@execonline-inc/environment';

const result: Environment = environment();