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