Heavily inspired by dotenv and dotenv-expand, snackables is a simple to use zero-dependency package module that automatically loads environment variables from a predefined Env variable. When it comes to .env.* file naming, snackables is unopinionated, so you can name them anything you'd like or you can follow the The Twelve-Factor App methodology.
✔️ Loads .env.* files between 40%-70% faster than dotenv and dotenv-expand: demo, metrics
✔️ Typescript source with included type declarations
✔️ Zero dependencies
✔️ Compiled and minified ES5 CommonJS
✔️ Experimental ESM support (beta)
✔️ Unopinionated about .env.* naming
✔️ Supports loading multiple .env.* files at once
✔️ Supports manually importing or parsing .env.* files
✔️ Supports overriding Envs in process.env
✔️ Supports Env interpolation
✔️ Supports Env preloading
✔️ Supports loading Envs via an Env Configuration File or by an ENV_LOAD variable
- Should I commit my .env files?
- How does snackables work and will it override already set or predefined variables?
- Why doesn't the parse method automatically assign Envs?
- Are the Env variables required?
- How do I use ES modules?
# with npm
npm install snackables
# or with yarn
yarn add snackablesIn a CLI or within your package.json, under the scripts property, define ENV variables before running a process. Snackables loads .env.* files according to their defined order (left to right), where the last imported file will take precedence over any previously imported files.
For example, .env.* files can loaded by an Env Configuration File file via LOAD_CONFIG:
{
"scripts": {
"dev": "LOAD_CONFIG=development node test.js",
"staging": "LOAD_CONFIG=staging node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}Or, .env.* files can be loaded by their filename (assuming they're located in the project's root) via ENV_LOAD:
{
"scripts": {
"dev": "ENV_LOAD=.env.base node test.js",
"staging": "ENV_LOAD=.env.base,.env.staging node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}All you need to do now is require/import the snackables base package as early as possible:
require("snackables");
// import 'snackables';Optionally, you can preload your .env.* files instead!
The easiest and cleanest way to load .env.* files is to create an env.config.json configuration file located at the project's root directory. The configuration file will be a JSON object that follows the config argument options pattern. The environment configuration naming is unopinionated -- they can be named anything you'd like (for example: dev, staging, prepublish, testing, and so on):
env.config.json
{
"development": {
"debug": true,
"paths": [".env.base", ".env.dev"],
"override": true
},
"production": {
"paths": ".env.prod",
},
"test": {
"dir": "custom/path/to/directory",
"paths": [".env.base", ".env.dev"],
}
}Then in your package.json, add a LOAD_CONFIG variable to load one of the configurations by an environment name (the environment name must match one of environments specified in the configuration file above):
{
"scripts": {
"dev": "LOAD_CONFIG=development node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}Then, either preload or import the snackables package as early as possible to load the development Envs.
{
"development": {
"debug": true,
"paths": [".env.base", ".env.dev"],
"override": true
}
}By defining a LOAD_CONFIG variable, this will let snackables know you'd like to load an env.config.json configuration file according to a specific environment name. The environment naming is unopinionated -- they can be named anything you'd like (for example: dev, staging, prepublish, testing and so on); however, the environment name must match one of environments specified in the configuration file.
{
"scripts": {
"dev": "LOAD_CONFIG=development node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}env.config.json
{
"development": {
"debug": true,
"paths": [".env.base", ".env.dev"],
"override": true
},
"production": {
"paths": ".env.prod",
},
"test": {
"dir": "custom/path/to/directory",
"paths": [".env.base", ".env.dev"],
}
}LOAD_CONFIG. For example, if you mistakely use LOAD_CONFIG with ENV_LOAD, then ENV_LOAD will take precendence.
By utilizing any of the Env variables defined below, you will only need to preload or import the base package to automatically load Envs:
require("snackables")
// import "snackables"Note: Defining any of the Env variables below WILL NOT change the default behavior of config, load or parse methods.
By defining an ENV_LOAD variable, this will let snackables know you'd like to immediately load some .env.* files when the package is imported. You can pass a single file name or a list of file names separated by commas. By default, snackables attempts to load them from within the project's root directory.
For example:
{
"scripts": {
"dev": "ENV_LOAD=.env.base,.env.local,.env.dev node app.js",
"prod": "ENV_LOAD=.env.prod node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}By defining an ENV_DIR variable, this will let snackables know you'd like to load .env.* files from a custom directory.
{
"scripts": {
"dev": "ENV_DIR=custom/path/to/directory ENV_LOAD=.env.base,.env.dev node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}By defining an ENV_ENCODE variable, this will let snackables know you'd like to set the encoding type of the .env.* file(s). The following file encode types are supported:
ascii
utf8
utf-8 (default)
utf16le
ucs2
ucs-2
base64
latin1
binary
hex
For example:
{
"scripts": {
"dev": "ENV_LOAD=.env.dev ENV_ENCODE=latin1 node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}By defining an ENV_OVERRIDE variable, this will let snackables know you'd like to override Envs in process.env.
For example:
{
"scripts": {
"dev": "ENV_LOAD=.env.dev ENV_DEBUG=true ENV_OVERRIDE=true node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}By defining an ENV_DEBUG variable within one of your package.json scripts, this will let snackables know you'd like to be in debug mode and output the results of extracting/loading Envs.
For example:
{
"scripts": {
"dev": "ENV_LOAD=.env.dev ENV_DEBUG=true node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}You can use the --require (-r) command line option with snackables to preload your .env.* files! By doing so, you do not need to require/import the snackables package within your project.
CLI:
$ LOAD_CONFIG=dev node -r snackables app.jsPackage.json:
{
"scripts": {
"dev": "LOAD_CONFIG=dev node -r snackables app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}If you wish to manaully import .env.* files, then the config method will read your .env.* files, parse the contents, assign them to process.env, and return an Object with parsed and extracted Envs:
const result = snackables.config();
console.log("parsed", result.parsed); // process.env with loaded Envs
console.log("extracted", result.extracted); // extracted Envs within a { KEY: VALUE } objectAdditionally, you can pass argument options to config.
The config method accepts a single Object argument with the following properties:
{
dir?: string,
paths?: string | string[],
encoding?: BufferEncoding,
override?: boolean | string,
debug?: boolean | string
}Default: process.cwd() (project root directory)
You may specify a single directory path if your files are located elsewhere.
A single directory path as a string:
require("snackables").config({ dir: "custom/path/to/directory" });
// import { config } from "snackables"
// config({ dir: "custom/path/to/directory" });Default: [".env"]
You may specify custom paths if your files are located elsewhere (recommended to use absolute path(s) from your root directory).
A single file path as a string:
require("snackables").config({ paths: "custom/path/to/.env" });
// import { config } from "snackables"
// config({ paths: "custom/path/to/.env" });Multiple file paths as a single string separated by commas:
require("snackables").config({
paths: "custom/path/to/.env,custom/path/to/.env.base"
});
// import { config } from "snackables"
// config({ paths: "custom/path/to/.env,custom/path/to/.env.base" });Or multiple file paths as an Array of strings:
require("snackables").config({
paths: ["custom/path/to/.env", "custom/path/to/.env.base"]
});
// import { config } from "snackables"
// config({ paths: ["custom/path/to/.env", "custom/path/to/.env.base"] });It's highly recommended that you utilize dir if you're loading from a single custom directory:
require("snackables").config({ dir: "custom/path/to/directory", paths: [".env", ".env.base"] });
// import { config } from "snackables"
// config({ dir: "custom/path/to/directory", paths: [".env", ".env.base"] });Default: utf-8
You may specify the encoding type of your file containing environment variables.
require("snackables").config({ encoding: "latin1" });
// import { config } from "snackables"
// config({ encoding: "latin1" });Default: false
You may specify whether or not to override Envs in process.env.
require("snackables").config({ override: true });
// import { config } from "snackables"
// config({ override: true });Default: undefined
You may turn on logging to help debug file loading.
require("snackables").config({ debug: true });
// import { config } from "snackables"
// config({ debug: true });If you wish to manually parse Envs, then you can utilize parse to read a string or Buffer and parse their contents.
The parse method accepts two arguments in the following order:
src: string | Buffer,
override: boolean | string | undefined
For some use cases, you may want to pass parse a string or Buffer which returns parsed extracted keys/values as a single Object. These will NOT be assigned to process.env. Why not?
const { readFileSync } = require("fs");
const { parse } = require("snackables");
// import { readFileSync } from "fs";
// import { parse } from "snackables";
const config = parse(Buffer.from("BASIC=basic")); // will return an object
console.log(typeof config, config); // object { BASIC : 'basic' }
const results = parse(readFileSync("path/to/.env.file", { encoding: "utf8" })); // will return an object
console.log(typeof results, results); // object { KEY : 'value' }Note: If you're attempting to parse Envs that have already been defined within process.env, then you must pass parse an override argument.
If you wish to extract and potentially override Envs in process.env, then you can pass a boolean or string (passing "false" will still be truthy) as a second argument to parse. These will NOT be assigned to process.env. Why not?
const { readFileSync } = require("fs");
const { parse } = require("snackables");
// import { readFileSync } from "fs";
// import { parse } from "snackables";
const config = parse(Buffer.from("BASIC=basic"), true); // will return an object
console.log(typeof config, config); // object { BASIC : 'basic' }
const result = parse(readFileSync("path/to/.env.file", { encoding: "utf8" }), true); // will return an object
console.log(typeof result, result); // object { OVERRIDEKEY : 'value' }The parsing method currently supports the following rules:
-
BASIC=basicbecomes{BASIC: 'basic'} - empty lines are skipped
- lines beginning with
#are treated as comments - empty values become empty strings (
EMPTY=becomes{EMPTY: ''}) - inner quotes are maintained (think JSON) (
JSON={"foo": "bar"}becomes{JSON:"{\"foo\": \"bar\"}") - single and double quoted values are escaped (
SINGLE_QUOTE='quoted'becomes{SINGLE_QUOTE: "quoted"}) - single and double quoted values maintain whitespace from both ends (
FOO=" some value "becomes{FOO: ' some value '}) - double quoted values expand new lines
MULTILINE="new\nline"becomes
{MULTILINE: 'new
line'}
If you wish to manually load the env.config.json configuration file, then you can utilize the load method. Please note that this synchronously retrieves the environment configuration from the env.config.json configuration file, but will not automatically assign any Envs; instead, you'll have to manually pass its returned environment configuration to the config method.
The load method accepts two arguments in the following order:
env: string,
dir: string | undefined
For some use cases, you may want to manually load the env.config.json configuration file and pass its returned environment configuration to the config method. To do so, pass load an environment name as the first argument:
const { config, load } = require("snackables");
// import { config, load } from "snackables";
const configArgs = load("development"); // will return an object of config arguments
console.log(typeof configArgs, configArgs) // object { paths: ".env.dev", debug: true }
config(configArgs) // parses .env.dev and assigns it to process.envFor some use cases, you may want to manually load an env.config.json configuration file that is not located at the project's root directory and pass its returned environment configuration to the config method. To do so, pass load an environment name as the first argument and an absolute directory path as a second argument:
const { config, load } = require("snackables");
// import { config, load } from "snackables";
const configArgs = load("development", "path/to/custom/directory"); // will return an object of config arguments
console.log(typeof configArgs, configArgs) // object { paths: ".env.dev", debug: true }
config(configArgs) // parses .env.dev and assigns it to process.envEnv values can be interpolated based upon a process.env value, a KEY within the .env.* file, a command line substitution and/or a fallback value.
To interpolate a value from process.env or .env.*, simply define it with either $KEY or within brackets ${KEY}, for example:
Input:
MESSAGE=Hello
INTERP_MESSAGE=$MESSAGE World
INTERP_MESSAGE_BRACKETS=${MESSAGE} World
ENVIRONMENT=$NODE_ENVOutput:
MESSAGE=Hello
INTERP_MESSAGE=Hello World
INTERP_MESSAGE_BRACKETS=Hello World
ENVIRONMENT=developmentTo interpolate a value with a single fallback value use the | symbol beside a $KEY or inside a ${KEY}, for example:
Input:
MESSAGE=Hello
INTERP_MESSAGE=$MESSAGE|Hello World
INTERP_MESSAGE_BRACKETS=${MESSAGE|Hello} World
FALLBACK_VALUE=$UNDEFINED_KEY|Hello
FALLBACK_VALUE_BRAKCETS=${UNDEFINED_KEY|Hello}
FALLBACK_VALUE_WITH_INTERP=$UNDEFINED_KEY|$MESSAGEOutput:
MESSAGE=Hello
INTERP_MESSAGE=Hello World
INTERP_MESSAGE_BRACKETS=Hello World
FALLBACK_VALUE=Hello
FALLBACK_VALUE_BRAKCETS=Hello
FALLBACK_VALUE_WITH_INTERP=HelloTo interpolate a command line substitution, simply define it within parentheses $(KEY) for example:
Input:
USER=$(whoami)
MULTICOMMAND=$(echo 'I Would Have Been Your Daddy' | sed 's/[^A-Z]//g')Output:
USER=Jane
MULTICOMMAND=IWHBYD- Values can be interpolated based upon a
process.envvalue:BASIC=$NODE_ENV||BASIC=${NODE_ENV} - Values in
process.envtake precedence over interpolated values in.env.*files - Interpolated values can't be referenced across multiple
.env.*s, instead they must only be referenced within the same file - Command line substitutions can NOT contain bash commands that use parentheses:
EX=$(info=$(uname -a); echo $info;), instead its recommended to use.shfiles instead:EX=$(bash ./path/to/info.sh) - Fallback values can NOT be used with command line substitutions
- The
$character must be escaped when it doesn't refer to another key within the.env.*file:\$1234 - Do not use escaped
\$within a value when it's key is referenced by another key:
Input:
A=\$example
B=$AOutput:
A=$example
B=Fix:
A=example
B=\$$AOutput:
A=example
B=$exampleNo. It's strongly recommended not to commit your .env.* files to version control. They'll include environment-specific values such as database passwords and API keys that should not be public. Commiting the env.config.json file is OK, as it won't/shouldn't contain any secrets.
On the same note, most CI (continous integration) services like Github Actions and CircleCI offer their own Env configuration options for CI actions, so commiting .env.* files is unnecessary.
By default, snackables will look for the .env.* file(s) defined within a LOAD_CONFIG environment variable and append them to process.env.
For example, LOAD_CONFIG=development loads two files .env.base and .env.dev from env.config.json:
{
"scripts": {
"dev": "LOAD_CONFIG=development node app.js"
},
"dependencies": {
"snackables": "^x.x.x"
}
}in a local environment, .env.base may have static shared database variables:
DB_HOST=localhost
DB_USER=root
DB_PASS=passwordwhile .env.dev may have environment specific variables:
DB_PASS=password123
HOST=http://localhost
PORT=3000snackables will parse the files and append the Envs in the order of how they were defined in paths. In the example above, the DB_PASS variable within .env.base would be overidden by .env.dev because .env.dev file was imported last and, as a result, its DB_PASS will be assigned to process.env.
By default, Envs that are pre-set or defined within process.env WILL NOT be overidden. If you wish to override variables in process.env see ENV_OVERRIDE or Config Override or Parse Override.
In short, parse can not automatically assign Envs as they're extracted.
Why?
Under the hood, the config method utilizes the parse method to extract one or multiple .env.* files as it loops over the config paths argument. The config method expects parse to return a single Object of extracted Envs that will be accumulated with other files' extracted Envs. The result of these accumulated Envs is then assigned to process.env once -- this approach has the added benefit of prioritizing Envs without using any additional logic since the last set of extracted Envs automatically override any previous Envs (by leveraging Object.assign). While allowing Envs to be assigned multiple times to process.env doesn't appear to be much different in terms of performance, it unforuntately requires quite a bit more additional overhead logic to determine which .env.* has priority and whether or not to conditionally assign them (including times when you might want to parse Envs, but not neccesarily assign them). A workaround to this limitation is to simply assign them yourself:
const { assign, parse } = require("snackables");
// import { assign, parse } from "snackables";
const parsed = parse(Buffer.from("BASIC=basic")); // parse/interpolate Envs not defined in process.env
// const parsed = parse(Buffer.from("BASIC=basic"), true); // parse/interpolate and override any Envs in process.env
assign(parsed); // assigns parsed Envs to process.envTo be as flexible as possible, the Env variables are not required to set Envs to process.env. However, you will then be required to use this package similarly to how you would use dotenv. See Config Method:
const { config } = require("snackables");
// import { config } from "snackables";
config({ ... });As of Node v12.17.0+, node removed the experimental flag for ES modules. Unfortunately, most of development world has yet to adopt ESM as the standard. Therefore, until there's more widespread support, this documentation will caution against using ESM and instead opt for CJS. In addition, node doesn't support preloading ESM, since it utilizes Node's require function. That said, snackables offers experimental support for ESM. You can try it out by importing from the esm directory of the package:
import snackables from "snackables/esm";
// import { assign, config, load, parse } from "snackables/esm";See CONTRIBUTING.md
See UPDATESLOG.md