Ideas for linter checks

linting_ideas.md

Merge with map literal

(merge a {:a 1 :b 2}) -> (assoc a :a 1 :b2)

(-> foo (merge {:foo :bar}) -> (-> foo (assoc :foo :bar))

Reasoning:

• Performance
• Easier to read?

Assoc-in or update-in with concat

(assoc-in m (concat [:foo :bar] path) v) -> (update-in m [:foo :bar] assoc-in path v)

Reasoning:

• Performance
• Easier to read?

Assoc-in or other path operation with single item literal path

(assoc-in m [:foo] v) -> (assoc m :foo v)

(get-in m [:foo]) -> (:foo m)

(update-in m [:foo] f) -> (update m :foo f)

Reasoning:

• Performance
• Easier to read

Use ns alias or refer instead of full namespaced symbol

(clojure.string/split v #"/") -> (str/split v #"/")

Reasoning:

• Easy to accidentally use namespace that is not required
• Even with core ns that are always available, good practice to ensure they are required

If branches with nearly identical call

(if x
  (f 1)
  (f 2))
=>
(f (if x 1 2))

Indentation check

Custom forms?

(re/reg-sub :view
           (fn [db _]
             (get-in db [:view])))
=>
(re/reg-sub :view
  (fn [db _]
    (get-in db [:view])))

Reasoning:

• Easy to forget to configure IntelliJ
• Needs a way to configure indentation for special forms?
  • Macro definitions might contain metadata: https://github.com/metosin/compojure-api/blob/master/src/compojure/api/core.clj#L58-L67

maybe_bad_ideas.md

Let as lone child inside for/doseq etc.

(for [...]
  (let [...]
    ...))
=>
(for [...
      :let [...]]
  ...)

• Less indentation?
• More complex/magical -> bad idea?