duolingo / splinter

Simple pattern-based linter :rat:

Splinter

Here's a dead simple,
pattern-based linter for code
in any language.

It's not that smart, but
it needs only Bash and runs
on any Unix.

Define your rules in
a text file as a list of
message/regex pairs.

Usage

1. Copy-paste splinter into your project and make it executable:

   chmod +x splinter

2. Create a rule file named something like rules.txt:

   # This is a comment and will be ignored.
   # Each rule is defined as an error message followed
   # by the regex (POSIX ERE) that should trigger it.
   
   Remove trailing whitespace
   \s$
   
   Use `assert.strictEqual()` instead of `assert.equal()`
   assert\.equal
   

3. Run Splinter:

   # The rule file is the only required argument. Optionally, provide
   # a list of files/directories to lint (default: current directory)
   ./splinter rules.txt index.js src

4. See the output! The exit code will be 1 if violations are found - useful for CI.

   index.js:25:Remove trailing whitespace
   index.js:26:Remove trailing whitespace
   src/foobar.test.js:130:Use `assert.strictEqual()` instead of `assert.equal()`
   

Splinter will ignore violations on any line of code that contains splinter:ignore in a comment.

Running with pre-commit

You can also set up this repo as a pre-commit hook. For example:

- repo: https://github.com/duolingo/splinter.git
  rev: 1.4.0
  hooks:
    - id: splinter
      args:
        - config/splinter-rules-py.txt
      files: \.py$

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