convert clerk_utils.clj to cljc (#29)

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 ## [0.5.0]
 
+- #29 converts `mentat.clerk-utils` to `cljc`. The CLJS side doesn't do
+  anything, but this allows the require and macro calls to live inside `cljc`
+  files.
+
 - #28:
 
   - Removes the `babashka` dependency from `mentat.clerk-utils.build`

src/mentat/clerk_utils.clj → src/mentat/clerk_utils.cljc

@@ -4,28 +4,33 @@
 
   Expect this namespace to fission off into more specific namespaces as the
   catalogue of functions grows."
-  (:import (java.io FileNotFoundException)))
-
-(defn- ns-present?
-  "Returns true if `sym` corresponds to a namespace present on the classpath and
+  #?(:clj
+     (:import (java.io FileNotFoundException)))
+  #?(:cljs
+     (:require-macros [mentat.clerk-utils])))
+
+#?(:clj
+   (defn- ns-present?
+     "Returns true if `sym` corresponds to a namespace present on the classpath and
   available for loading, false otherwise.
 
   NOTE that calling [[ns-present?]] will `require` the namespace as a
   side-effect."
-  [sym]
-  (try (nil? (require sym))
-       (catch FileNotFoundException _ false)))
+     [sym]
+     (try (nil? (require sym))
+          (catch FileNotFoundException _ false))))
 
-(defn- try-resolve
-  "Takes a namespaced symbol `sym` and delegates to
+#?(:clj
+   (defn- try-resolve
+     "Takes a namespaced symbol `sym` and delegates to
   `clojure.core/requiring-resolve` if its namespace is present on the classpath,
   returns `nil` otherwise.
 
   NOTE that calling [[try-resolve]] will `require` the `sym`'s namespace as a
   side-effect."
-  [sym]
-  (try (requiring-resolve sym)
-       (catch FileNotFoundException _ nil)))
+     [sym]
+     (try (requiring-resolve sym)
+          (catch FileNotFoundException _ nil))))
 
 ;; ## Visibility Macros
 
@@ -37,8 +42,10 @@
   Like `comment`, body must still be written in well-formed Clojure that can be
   parsed by the reader."
   [& body]
-  (when (ns-present? 'nextjournal.clerk)
-    `(do ~@body)))
+  (when-not (:ns &env)
+    (when #?(:clj (ns-present? 'nextjournal.clerk)
+             :cljs false)
+      `(do ~@body))))
 
 (defmacro ->clerk-only
   "If `nextjournal.clerk` is present on the classpath AND Clerk is evaluating
@@ -48,7 +55,9 @@
   Use this macro to supply examples and forms that should render in a Clerk
   environment but not affect normal Clojure evaluation in any way."
   ([& body]
-   (when (some-> (try-resolve
-                  'nextjournal.clerk.config/*in-clerk*)
-                 deref)
-     `(do ~@body))))
+   (when-not (:ns &env)
+     (when #?(:clj (some-> (try-resolve
+                            'nextjournal.clerk.config/*in-clerk*)
+                           deref)
+              :cljs false)
+       `(do ~@body)))))