📎 Improve clj-kondo hooks, including if-let

.clj-kondo/config.edn

@@ -24,9 +24,10 @@
    shadow.lazy/loadable hooks.export/rumext-lazycomponent
    app.util.i18n/tr hooks.i18n/tr-dynamic
    app.common.i18n/tr hooks.i18n/tr-dynamic
-   benches.render-wasm.declarations/defscene hooks.export/benches-defscene
-   benches.render-wasm.declarations/defcase hooks.export/benches-defcase
-   }}
+   clojure.core/let hooks.core/check-let
+   cljs.core/let hooks.core/check-let
+   benches.render-wasm.declarations/defscene hooks.benches/defscene
+   benches.render-wasm.declarations/defcase hooks.benches/defcase}}
 
  :output
  {:exclude-files
@@ -103,6 +104,10 @@
 
   :unused-binding
   {:exclude-destructured-as true
-   :exclude-destructured-keys-in-fn-args false
-   }
-  }}
+   :exclude-destructured-keys-in-fn-args false}
+
+  :core/use-if-let
+  {:level :warning}
+
+  :core/use-when-let
+  {:level :warning}}}

.clj-kondo/hooks/benches.clj

@@ -0,0 +1,26 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS SUBSIDIARY SL
+
+(ns hooks.benches
+  (:require [clj-kondo.hooks-api :as api]))
+
+(defn defscene
+  "Analyzes scene options and its compiled builder body."
+  [{:keys [node]}]
+  (let [[_ _ opts argv & body] (:children node)]
+    (if (and argv (api/vector-node? argv))
+      {:node (api/list-node [(api/token-node (quote do)) opts
+                             (api/list-node (into [(api/token-node (quote fn)) argv] body))])}
+      {:node node})))
+
+(defn defcase
+  "Analyzes case options and its compiled operation body."
+  [{:keys [node]}]
+  (let [[_ _ opts argv & body] (:children node)]
+    (if (and (seq body) argv (api/vector-node? argv))
+      {:node (api/list-node [(api/token-node (quote do)) opts
+                             (api/list-node (into [(api/token-node (quote fn)) argv] body))])}
+      {:node node})))

.clj-kondo/hooks/core.clj

@@ -0,0 +1,97 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS SUBSIDIARY SL
+
+(ns hooks.core
+  (:require [clj-kondo.hooks-api :as api]))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; if-let, when-let
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defn- use-if-let?
+  [form]
+  (let [[_ bindings & body] form]
+    (and
+     ;; Exactly one binding pair.
+     (vector? bindings)
+     (= 2 (count bindings))
+
+     ;; Exactly one body form.
+     (= 1 (count body))
+
+     (let [[binding-sym _] bindings
+           if-form         (first body)]
+       (and
+        ;; Exclude destructuring for v0.
+        (symbol? binding-sym)
+
+        ;; Exactly: (if binding-sym then else)
+        (seq? if-form)
+        (= 4 (count if-form))
+        (= 'if (first if-form))
+        (= binding-sym (second if-form)))))))
+
+
+(defn- use-if-let
+  "Flags:
+
+  (let [x (foo)]
+    (if x
+      (bar x)
+      (baz)))
+  "
+  [{:keys [node]}]
+  (when (use-if-let? (api/sexpr node))
+    (api/reg-finding!
+     (assoc (meta (first (:children node)))
+            :type :core/use-if-let
+            :message "Use if-let instead of let followed by if.")))
+  nil)
+
+(defn- use-when-let?
+  [form]
+  (let [[_ bindings & body] form]
+    (and
+     ;; Exactly one binding pair.
+     (vector? bindings)
+     (= 2 (count bindings))
+
+     ;; Exactly one body form.
+     (= 1 (count body))
+
+     (let [[binding-sym _] bindings
+           when-form       (first body)]
+       (and
+        ;; Exclude destructuring for v0.
+        (symbol? binding-sym)
+
+        ;; (when binding-sym & body) with at least one body form.
+        (seq? when-form)
+        (<= 3 (count when-form))
+        (= 'when (first when-form))
+        (= binding-sym (second when-form)))))))
+
+(defn- use-when-let
+  "Flags:
+
+  (let [x (foo)]
+    (when x
+      (bar x)))
+  "
+  [{:keys [node]}]
+  (when (use-when-let? (api/sexpr node))
+    (api/reg-finding!
+     (assoc (meta (first (:children node)))
+            :type :core/use-when-let
+            :message "Use when-let instead of let followed by when.")))
+  nil)
+
+(defn check-let
+  "Runs the let-body checks (if-let, when-let)."
+  [{:keys [node] :as m}]
+  (use-if-let m)
+  (use-when-let m)
+  nil)

.clj-kondo/hooks/export.clj

@@ -1,3 +1,9 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS SUBSIDIARY SL
+
 (ns hooks.export
   (:require [clj-kondo.hooks-api :as api]))
 
@@ -10,20 +16,6 @@
                   sname])]
     {:node result}))
 
-(defn benches-defscene
-  [{:keys [node]}]
-  (let [[_ _ opts argv & body] (:children node)]
-    (if (and argv (api/vector-node? argv))
-      {:node (api/list-node (into [(api/token-node (quote fn)) argv] body))}
-      {:node node})))
-
-(defn benches-defcase
-  [{:keys [node]}]
-  (let [[_ _ opts argv & body] (:children node)]
-    (if (and (seq body) argv (api/vector-node? argv))
-      {:node (api/list-node (into [(api/token-node (quote fn)) argv] body))}
-      {:node node})))
-
 (def registry (atom {}))