add clj-kondo hook for parallel let plet

Author: NoahTheDuke

resources/clj-kondo.exports/funcool/promesa/config.edn

@@ -2,7 +2,7 @@
            promesa.core/->>         clojure.core/->>
            promesa.core/as->        clojure.core/as->
            promesa.core/let         clojure.core/let
-           promesa.core/plet        clojure.core/let
+           promesa.core/plet        hooks.promesa/plet
            promesa.core/loop        clojure.core/loop
            promesa.core/recur       clojure.core/recur
            promesa.core/with-redefs clojure.core/with-redefs

resources/clj-kondo.exports/funcool/promesa/hooks/promesa.clj

@@ -0,0 +1,16 @@
+(ns hooks.promesa
+  (:require [clj-kondo.hooks-api :as api]))
+
+(defn plet
+  ;; this effectively rewrites the let to `(let [[bind1 bind2] [(expr-1) (expr-2)] ,,,)
+  ;; making referring to other binding syms produce an error
+  ;; thanks to @NoahBogart on Slack for this
+  [{:keys [:node]}]
+  (let [[_plet binds & body] (:children node)
+        new-bind-syms (api/vector-node (take-nth 2 (:children binds)))
+        new-bind-exprs (api/vector-node (take-nth 2 (rest (:children binds))))
+        new-node (api/list-node
+                  (list* (api/token-node 'clojure.core/let)
+                         (api/vector-node [new-bind-syms new-bind-exprs])
+                         body))]
+    {:node new-node}))