cljfmt

cljfmt is a tool for formatting Clojure code.

It can turn something like this:

( let [x 3
    y 4]
  (+ (* x x
  )(* y y)
  ))

Into nicely formatted Clojure code like this:

(let [x 3
      y 4]
  (+ (* x x) (* y y)))

Installation

The easiest way to get started with cljfmt is to add the lein-cljfmt plugin to your Leiningen project map:

:plugins [[lein-cljfmt "0.1.1"]

Usage

To check the formatting of your source files, use:

lein cljfmt check

If the formatting of any source file is incorrect, a diff will be supplied showing the problem, and what cljfmt thinks it should be.

If you want to check only a specific file, or several specific files, you can do that, too:

lein cljfmt check src/foo/core.clj

Once you've identified formatting issues, you can choose to ignore them, fix them manually, or let cljfmt fix them with:

lein cljfmt fix

As with the check task, you can choose to fix a specific file:

lein cljfmt fix src/foo/core.clj

Configuration

You can configure lein-cljfmt by adding a :cljfmt map to your project:

:cljfmt {}

cljfmt has several different formatting rules, and these can be selectively enabled or disabled:

• :indentation? - true if cljfmt should correct the indentation of your code. Defaults to true.

• :remove-surrounding-whitespace? - true if cljfmt should remove whitespace surrounding inner forms. This will convert ( foo ) to (foo). Defaults to true.

• :insert-missing-whitespace? - true if cljfmt should insert whitespace missing from between elements. This will convert (foo(bar)) to (foo (bar)). Defaults to true.

• :file-pattern - determines which files to scan, #”\.clj[sx]?” by default.

You can also customize the indentation rules cljfmt uses. Rules are defined as a map of symbols to vectors:

{symbol [& rules]}

There are two types of indentation rule, :inner and :block.

Inner rules

An :inner rule will apply a constant indentation to all elements at a fixed depth. So an indent rule:

{foo [[:inner 0]]}

Will indent all elements inside a foo form by two spaces:

(foo bar
  baz
  bang)

While an indent rule like:

{foo [[:inner 1]]}

Will indent all subforms one level in:

(foo bar
 baz
 (bang
   quz
   qoz))

Block rules

A :block rule is a little smarter. This will act like an inner indent only if there's a line break before a certain number of arguments, otherwise it acts like a normal list form.

For example, an indent rule:

{foo [[:block 0]]}

Indents like this, if there are more than 0 arguments on the same line as the symbol:

(foo bar
     baz
     bang)

But indents at a constant two spaces otherwise:

(foo
  bar
  baz
  bang)

License

Copyright © 2015 James Reeves

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.