Some Guidelines on Clojure Style

General Style

Try to keep lines ≤ 80 columns long

Declaring Functions

Unless the function is "trivial"¹, put the parameters vector on its own line

; OKAY
(defn foo [x] (inc x))

; OKAY
(defn bar
  [{:keys [a b c]}]
  (println a b c))

; Pls don't
(defn quux [things]
  (for [thing things]
    (println thing)))

¹: Where "trivial" is deliberately left subjective

Namespaces

Based on How I NS

In summary, things should look like this:

(ns com.example.my-application.server
  "Example application HTTP server and routing."
  (:refer-clojure :exclude [send])
  (:require
   [clojure.core.async :as async :refer [<! <!! >! >!!]]
   [com.example.my-application.base]
   [com.example.my-application.server.sse :as server.sse]
   [io.pedestal.http :as http]
   [io.pedestal.http.sse :as http.sse]
   [ring.util.response :as response])
  (:import
   (java.nio.file Files LinkOption)
   (org.apache.commons.io FileUtils)))

Order of Elements in ns Form

Forms in the ns macro should be:

1. :refer-clojure if any
2. :require if any
3. :import if any

Sort imports and requires alphabetically

The :require and :import keywords should be followed by a newline, with all the following namespaces sorted alphabetically

Always Wrap require'd namespaces in vectors

; OKAY
(ns foo.stuff
  (:require
    [clojure.string :as string]
    [foo.things]))

; Pls don't
(ns foo.bloop
  (:require
    [clojure.string :as string]
    foo.things))

Always wrap import'd packages in parenthesis

; OKAY
(ns foo.blaap
  (:import
    (java.nio.file Files)))

; Pls don't
(ns foo.quupx
  (:import
    java.nio.file.Files)))