Merge branch 'master' into invalid-fn-name

CHANGELOG.md

@@ -20,6 +20,7 @@ For a list of breaking changes, check [here](#breaking-changes).
 ## Unreleased
 
 - [#2159](https://github.com/clj-kondo/clj-kondo/issues/2159): New linter, `:invalid-fn-name`
+- [#1753](https://github.com/clj-kondo/clj-kondo/issues/1753): new linter `:underscore-in-namespace`
 - [#2207](https://github.com/clj-kondo/clj-kondo/issues/2207): New `:condition-always-true` linter, see [docs](doc/linters.md)
 - [#2013](https://github.com/clj-kondo/clj-kondo/issues/2013): Fix NPE and similar errors when linting an import with an illegal token
 

README.md

@@ -276,11 +276,15 @@ pod](https://github.com/babashka/babashka.pods).
 ;;=> {:error 0, :warning 0, :info 0, :type :summary, :duration 779}
 ```
 
-## Podcast
+## Podcasts
 
 + [defnpodcast](https://soundcloud.com/defn-771544745)
 + [ClojureScript Podcast](https://clojurescriptpodcast.com/)
 
+## Articles
+
+- [Taking your linting to the next level](https://blog.tvaisanen.com/take-your-linting-game-to-the-next-level?showSharer=true#heading-benefits-of-types-in-the-editor) by Toni Vaisanen
+
 ## Thanks to:
 
 - [joker](https://github.com/candid82/joker) for inspiration

corpus/no_unused_namespace.clj

@@ -1,4 +1,4 @@
-(ns no_unused-namespace
+(ns no-unused-namespace
   (:require [clojure.string :as str]))
 
 (let [{score (if (str/starts-with? "foo" "f")

doc/config.md

@@ -658,6 +658,10 @@ This tells clj-kondo to copy clj-kondo configs from dependencies while linting.
 
 Typically, you will want to check copied configs into version control with your project.
 
+See this
+[article](https://blog.tvaisanen.com/take-your-linting-game-to-the-next-level?showSharer=true#heading-benefits-of-types-in-the-editor)
+by Toni Vaisanen on how to use library configurations and malli!
+
 ## Deprecations
 
 Some configuration keys have been renamed over time. The default configuration

doc/hooks.md

@@ -61,7 +61,7 @@ Use `println` or `prn` for debugging and `time` to measure performance.
 Hooks must be configured in clj-kondo's `config.edn` under `:hooks`, e.g.:
 
 ``` Clojure
-{:hooks {:analyze-call {foo.weird-macro hooks.foo/weird-macro}}}
+{:hooks {:analyze-call {foo/weird-macro hooks.foo/weird-macro}}}
 ```
 
 ## analyze-call

doc/linters.md

@@ -1964,3 +1964,15 @@ namespaces. Defaults to only warning when doing interop.
 
 The value of `:warn-only-on-interop` can be set to `false` to always warn in
 Clojure namespaces.
+
+## Underscore in namespace
+
+*Keyword:* `:underscore-in-namespace`
+
+*Description:* warns about the usage of the `_` character in the declaration of namespaces (as opposed to `-`).
+
+*Default level:* `:warning`
+
+*Example trigger:* `(ns special_files)`
+
+*Example message:* `Avoid underscore in namespace name: special_files`

src/clj_kondo/impl/analyzer/namespace.clj

@@ -548,6 +548,17 @@
                                ns-name-expr
                                :namespace-name-mismatch
                                (str "Namespace name does not match file name: " ns-name)))))))
+
+        _ (when (and (not (identical? :off (-> ctx :config :linters :underscore-in-namespace :level)))
+                     (symbol? ns-name)
+                     (str/includes? (name ns-name) "_"))
+            (findings/reg-finding!
+             ctx
+             (node->line filename
+                         ns-name-expr
+                         :underscore-in-namespace
+                         (str "Avoid underscore in namespace name: " ns-name))))
+
         clauses children
         _ (run! #(utils/handle-ignore ctx %) children)
         kw+libspecs (for [?require-clause clauses

src/clj_kondo/impl/config.clj

@@ -157,7 +157,8 @@
               :protocol-method-varargs {:level :error}
               :unused-alias {:level :off}
               :self-requiring-namespace {:level :off}
-              :condition-always-true {:level :off}}
+              :condition-always-true {:level :off}
+              :underscore-in-namespace {:level :warning}}
     ;; :hooks {:macroexpand ... :analyze-call ...}
     :lint-as {cats.core/->= clojure.core/->
               cats.core/->>= clojure.core/->>

test/clj_kondo/main_test.clj

@@ -3449,6 +3449,19 @@ foo/")))
     (assert-submaps2 expected (lint! "(import 3.14)"))
     (assert-submaps2 expected (lint! "(import -1)"))))
 
+(deftest underscore-in-ns
+
+  (let [expected #(list {:file "<stdin>"
+                         :row 1 :col 5
+                         :level :warning
+                         :message (str "Avoid underscore in namespace name: " %)})]
+
+    (assert-submaps2 (expected "beep_boop") (lint! "(ns beep_boop)"))
+    (assert-submaps2 (expected "beep_") (lint! "(ns beep_)"))
+    (assert-submaps2 (expected "_boop") (lint! "(ns _boop)"))
+    (assert-submaps2 (expected "never_give.you-up") (lint! "(ns never_give.you-up)"))
+    (assert-submaps2 (expected "a.large-smelly_dog") (lint! "(ns a.large-smelly_dog)"))))
+
 ;;;; Scratch
 
 (comment