Add redundant-nesting linter

tomdl89 · Nov 6, 2023 · dce2aad · dce2aad
1 parent 8034c65
commit dce2aad
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Showing 3 changed files with 25 additions and 2 deletions.
diff --git a/src/clj_kondo/impl/config.clj b/src/clj_kondo/impl/config.clj
@@ -107,6 +107,7 @@
               :unused-import {:level :warning}
               :single-operand-comparison {:level :warning}
               :single-logical-operand {:level :warning}
+              :redundant-nesting {:level :warning}
               :single-key-in {:level :off}
               :missing-clause-in-try {:level :warning}
               :missing-body-in-when {:level :warning}

diff --git a/src/clj_kondo/impl/core.clj b/src/clj_kondo/impl/core.clj
@@ -658,7 +658,8 @@
                  (and (not= :redundant-do type)
                       (not= :redundant-call type)
                       (not= :redundant-let type)
-                      (not= :single-logical-operand type))
+                      (not= :single-logical-operand type)
+                      (not= :redundant-nesting type))
                  ;; but if we get here, then the amount of findings has to be bigger than 1
                  (> (count findings) 1))
           f (collapse-cljc-findings findings)

diff --git a/src/clj_kondo/impl/linters.clj b/src/clj_kondo/impl/linters.clj
@@ -207,6 +207,20 @@
          :single-logical-operand
          (format "Single arg use of %s always returns the arg itself" call-name))))))
 
+(defn lint-redundant-nesting
+  "Lints calls of variadic functions/macros when nested."
+  [call]
+  (let [[[call-ns call-name] parent] (:callstack call)]
+    (when (and (utils/one-of call-ns [clojure.core cljs.core])
+               (utils/one-of call-name [* *' + +' and comp concat every-pred
+                                        lazy-cat max merge min or some-fn str])
+               (= [call-ns call-name] parent))
+      (node->line
+       (:filename call)
+       (:expr call)
+       :redundant-nesting
+       (format "Nested use of %s is redunant" call-name) ))))
+
 #_(require 'clojure.pprint)
 
 (defn lint-var-usage
@@ -394,7 +408,11 @@
                   single-logical-operand-error
                   (and call?
                        (not (utils/linter-disabled? call :single-logical-operand))
-                       (lint-single-logical-operand call))]]
+                       (lint-single-logical-operand call))
+                  redundant-nesting-error
+                  (and call?
+                       (not (utils/linter-disabled? call :redundant-nesting))
+                       (lint-redundant-nesting call))]]
       (when (and (not call?)
                  (identical? :fn (:type called-fn)))
         (when (:condition call)
@@ -415,6 +433,9 @@
       (when single-logical-operand-error
         (findings/reg-finding! ctx
                                single-logical-operand-error))
+      (when redundant-nesting-error
+        (findings/reg-finding! ctx
+                               redundant-nesting-error))
       (when (and (:private called-fn)
                  (not= caller-ns-sym
                        fn-ns)