dotenv-linter — Linter for .env files

⚡️ Lightning-fast linter for .env files. Written in Rust 🦀

It checks .env files for problems that may cause the application to malfunction:

     ✅  Duplicated Key
     ✅  Ending Blank Line (will be available in v2.0.0)
     ✅  Extra Blank Line (will be available in v2.0.0)
     ✅  Incorrect delimiter
     ✅  Key without value
     ✅  Leading character
     ✅  Lowercase key
     ✅  Quote character (will be available in v2.0.0)
     ✅  Space character
     ✅  Trailing whitespace (will be available in v2.0.0)
     ✅  Unordered Key

The key features:

     ⚡️  Lightning-fast because it is written in Rust 🦀
     💣  Can be used on any project regardless of the programming language 💥
     🚀  Can be integrated with reviewdog and other CI services (including GitHub Actions) 🔥

Articles about dotenv-linter:

• In English
• In Russian

Dotenv-linter is created & supported by Evrone. What else we develop with Rust.

👨‍💻 Installation

Binary

# Linux
$ curl https://github.com/dotenv-linter/dotenv-linter/releases/download/v1.2.0/dotenv-linter-linux-x86_64.tar.gz -sSfL | tar -xzf -

# Alpine Linux
$ wget https://github.com/dotenv-linter/dotenv-linter/releases/download/v1.2.0/dotenv-linter-alpine-x86_64.tar.gz -O - -q | tar -xzf -

# macOS
$ curl https://github.com/dotenv-linter/dotenv-linter/releases/download/v1.2.0/dotenv-linter-darwin-x86_64.tar.gz -sSfL | tar -xzf -

Homebrew / Linuxbrew

$ brew install dotenv-linter/tap/dotenv-linter

Arch Linux / AUR

# use your favourite AUR-helper
$ trizen -S dotenv-linter-bin # for the binary distribution
$ trizen -S dotenv-linter-git # for the current master branch

Docker

$ docker run --rm -v `pwd`:/app -w /app dotenvlinter/dotenv-linter

Cargo

If you are a Rust programmer, you can install dotenv-linter via cargo:

$ cargo install dotenv-linter

GitHub Action

name: dotenv-linter
on: [pull_request]
jobs:
  dotenv-linter:
    name: runner / dotenv-linter
    runs-on: ubuntu-latest
    steps:
      - name: Check out code
        uses: actions/[email protected]
      - name: dotenv-linter
        uses: dotenv-linter/[email protected]
        with:
          github_token: ${{ secrets.github_token }}

CircleCI

version: 2.1
jobs:
  dotenv-linter:
    docker:
      - image: circleci/rust:latest
    steps:
      - checkout
      - run:
          name: Run dotenv-linter
          command: |
            DOTENV_LINTER_VERSION=v1.2.0
            wget https://github.com/dotenv-linter/dotenv-linter/releases/download/$DOTENV_LINTER_VERSION/dotenv-linter-alpine-x86_64.tar.gz \
            -O - -q | tar -xzf -
            ./dotenv-linter

🚀 Usage

By default, dotenv-linter checks all .env files in the current directory:

$ dotenv-linter
.env:2 DuplicatedKey: The FOO key is duplicated
.env:3 UnorderedKey: The BAR key should go before the FOO key
.env.test:1 LeadingCharacter: Invalid leading character detected

To check another directory, just pass its path as an argument. The same approach works if you need to check any files individually:

$ dotenv-linter dir1 dir2/.my-env-file
dir1/.env:1 LeadingCharacter: Invalid leading character detected
dir1/.env:3 IncorrectDelimiter: The FOO-BAR key has incorrect delimiter
dir2/.my-env-file:1 LowercaseKey: The bar key should be in uppercase

If you need to exclude a file from check, you can use the argument --exclude FILE_PATH or its short version -e FILE_PATH:

$ dotenv-linter --exclude .env.test
.env:2 DuplicatedKey: The FOO key is duplicated
.env:3 UnorderedKey: The BAR key should go before the FOO key

If you need to skip some checks, you can use the argument --skip CHECK_NAME or its short version -s CHECK_NAME (will be available in v2.0.0):

$ dotenv-linter --skip UnorderedKey EndingBlankLine
.env:2 DuplicatedKey: The FOO key is duplicated

If you need to view all available checks, you can use the argument --show-checks (will be available in v2.0.0):

$ dotenv-linter --show-checks
DuplicatedKey
EndingBlankLine
ExtraBlankLine
IncorrectDelimiter
KeyWithoutValue
LeadingCharacter
LowercaseKey
QuoteCharacter
SpaceCharacter
UnorderedKey

✅ Checks

Duplicated Key

Detects if a key is not unique:

❌ Wrong
FOO=BAR
FOO=BAR

✅ Correct
FOO=BAR
BAR=FOO

Ending Blank Line (will be available in v2.0.0)

Detects if a file doesn't have a blank line at the end:

❌ Wrong
FOO=BAR

✅ Correct
FOO=BAR

Extra Blank Line (will be available in v2.0.0)

Detects if a file contains more than one blank line in a row:

❌ Wrong
A=B


FOO=BAR

❌ Wrong
A=B
FOO=BAR

✅ Correct
A=B

FOO=BAR

✅ Correct
A=B
FOO=BAR

Incorrect delimiter

Detects if a key does not use an underscore to separate words:

❌ Wrong
FOO-BAR=FOOBAR

✅ Correct
FOO_BAR=FOOBAR

Key without value

Detects if a line has a key without a value:

❌ Wrong
FOO

✅ Correct
FOO=

✅ Correct
FOO=BAR

Leading character

Detects if a line starts with an unallowed character (characters from A to Z and _ (underscore) are allowed):

❌ Wrong
 FOO=BAR

❌ Wrong
.FOO=BAR

❌ Wrong
*FOO=BAR

❌ Wrong
1FOO=BAR

✅ Correct
FOO=BAR

✅ Correct
_FOO=BAR

Lowercase key

Detects if a key has lowercase characters:

❌ Wrong
FOo_BAR=FOOBAR

❌ Wrong
foo_bar=FOOBAR

✅ Correct
FOO_BAR=FOOBAR

Quote character (will be available in v2.0.0)

Detects if a value is wrapped in quotes:

❌ Wrong
FOO="BAR"

❌ Wrong
FOO='BAR'

✅ Correct
FOO=BAR

Space character

Detects lines with a whitespace around equal sign character =:

❌ Wrong
FOO =BAR

❌ Wrong
FOO= BAR

❌ Wrong
FOO = BAR

✅ Correct
FOO=BAR

Trailing whitespace (will be available in v2.0.0)

Detects if a line has a trailing whitespace.

Unordered Key

Detects if a key is not alphabetically ordered:

❌ Wrong
FOO=BAR
BAR=FOO

✅ Correct
BAR=FOO
FOO=BAR

🤝 Contributing

If you've ever wanted to contribute to open source, now you have a great opportunity:

• How to set up the project
• How to add a new check

👍 Similar projects

• wemake-services/dotenv-linter (Python)

✨ Contributors

This project exists thanks to all the people who contribute. [Contribute].

♥️ Sponsors

Become a financial contributor and help us sustain our community.

📃 License

MIT