nllint

Linter to check newlines at the end of files

--

$ echo -n {} > foo.json
$ echo -n "{}\n\n" > bar.json

$ nllint foo.json bar.json
ERRO[0000] a file is invalid                             error="a newline at the end of file is missing" file_path=foo.json nllint_version= program=nllint

# --trim-space (-s): Check leading and trailing white spaces in files
$ nllint -s foo.json bar.json
ERRO[0000] a file is invalid                             error="a newline at the end of file is missing" file_path=foo.json nllint_version= program=nllint
ERRO[0000] a file is invalid                             error="leading and trailing white spaces in files should be trimmed" file_path=bar.json nllint_version= program=nllint

# -fix (-f): Fix files and outputs fixed file paths to the stdout
$ nllint -s -fix foo.json bar.json
WARN[0000] a newline at the end of file is missing       file_path=foo.json nllint_version= program=nllint
foo.json
WARN[0000] leading and trailing white spaces in files should be trimmed  file_path=bar.json nllint_version= program=nllint
bar.json

Motivation

Each line should have a newline of the end of line because that’s how the POSIX standard defines a line:

Please see https://stackoverflow.com/a/729795/6364492

Install

nllint is a single binary written in Go. So you only need to install an execurable file into $PATH.

1. Homebrew

brew install suzuki-shunsuke/nllint/nllint

2. Scoop

scoop bucket add suzuki-shunsuke https://github.com/suzuki-shunsuke/scoop-bucket
scoop install nllint

3. aqua

aqua g -i suzuki-shunsuke/nllint

4. Download a prebuilt binary from GitHub Releases and install it into $PATH

Usage

$ nllint help
nllint - Check newlines at the end of files

https://github.com/suzuki-shunsuke/nllint

Usage:
  nllint [-fix (-f)] [-trim-space (-s)] [-ignore-notfound (-i)] <file path> [<file path>...]

Options:
  -help, -h             Show help
  -version, -v          Show version
  -fix, -f              Fix files
  -trim-space, -s       Disallow leading and trailing white spaces in files
  -ignore-notfound, -i  Ignore not found files

💡 Auto Fix by CI

--

It's useful to format code automatically with nllint and push a commit to the remote branch in CI.

1. List changed files
2. Run nllint -f [-s] [<changed files>...]
3. Push a commit to the remote branch

Please refer to this repository's workflows as the example.

• test.yaml
• wc-test.yaml

nllint is enough fast, so we think it's also okay to lint all files instead of only changed files.

git ls-files | xargs nllint -f -s

LICENSE

MIT