read-env-file

Utilities for reading environment variable names & values from files in ".env" format

  ✔ Reads key/value pairs
  ✔ Handles commented & empty lines
  ✔ Allows spaces in quoted values
  ✔ Allows assignment operators in quoted values
  ✔ Reads from "./.env" when no path arg supplied
  ✔ Merges the results of multiple input files

  ✔ Invalid Format (missing key)
  ✔ Invalid Format (missing value)
  ✔ Invalid Format (missing assignment)
  ✔ Invalid Format (space in key)
  ✔ Invalid Format (space in unquoted value)
  ✔ Invalid Format (multiple assignment operators)
  ✔ Invalid Format Error contains accurate line number

Installation

yarn add read-env-file
# or
npm i read-env-file

Usage

Typescript-friendly (type declarations included)

# path/to/.env
key1=foo
key2=bar

# path/.env
key1=foobar
key3=baz

// path/to/dir/index.js
const { readSingle, readMultiple } = require('read-env-file');

readSingle(); // Attempts to read from ./.env

readSingle('path/to/.env');
// Promise<{key1: 'foo', key2: 'bar'}>

readSingle.sync('path/to/.env');
// {key1: 'foo', key2: 'bar'}

readMultiple(['path/to/.env', 'path/.env']);
// Promise<{key1: 'foobar', key2: 'bar', key3: 'baz'}>

readMultiple.sync(['path/to/.env', 'path/.env']);
// {key1: 'foobar', key2: 'bar', key3: 'baz'}

File Formatting

Valid

comments and blank lines are ignored
values quoted (with ', ", or backtick) to include spaces and = character
spaces around keys and values are ignored

Examples:

key=value
# comment starts with "#" (ignored)

# whitespace is trimmed from keys and values
key = value
key =value
key= value

# whitespace in quoted values preserved
key="value with spaces'

# Assignment operators in quoted values preserved
key="value=abc"

Invalid (throws Error)

Errors are informative and specify the cause, file, and line number:

Invalid file format (multiple assignment operators) at /some/path/.env:12

The following conditions cause an invalid format error:

Cause	Error Mssage
missing key	`key undefined`
missing value	`value undefined`
missing assignment	`value undefined`
space in key	`invalid spacing`
space in unquoted value	`invalid spacing`
multiple assignment operators	`multiple assignment operators`

Examples:

# missing key
=value

# missing value
key=

# missing assignment
keyvalue

# space in key
k e y = value

# space in unquoted value
key=value and words

# multiple assignment operators
key=value=invalid

Dependencies

None

License

MIT

csmith14 / read-env-file