clojure-find-ns: add an option to suppress errors (#654)

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Changes
+
+* `clojure-find-ns`: add an option to never raise errors, returning nil instead on unparseable ns forms.
+
 ## 5.16.1 (2023-06-26)
 
 ### Changes

clojure-mode.el

@@ -2142,23 +2142,30 @@ DIRECTION is `forward' or `backward'."
               (setq candidate (string-remove-prefix "'" (thing-at-point 'symbol))))))))
     candidate))
 
-(defun clojure-find-ns ()
-  "Return the namespace of the current Clojure buffer.
+(defun clojure-find-ns (&optional suppress-errors)
+  "Return the namespace of the current Clojure buffer, honor `SUPPRESS-ERRORS'.
 Return the namespace closest to point and above it.  If there are
 no namespaces above point, return the first one in the buffer.
 
+If `SUPPRESS-ERRORS' is t, errors during ns form parsing will be swallowed,
+and nil will be returned instead of letting this function fail.
+
 The results will be cached if `clojure-cache-ns' is set to t."
   (if (and clojure-cache-ns clojure-cached-ns)
       clojure-cached-ns
-    (let ((ns (save-excursion
-                (save-restriction
-                  (widen)
-
-                  ;; Move to top-level to avoid searching from inside ns
-                  (ignore-errors (while t (up-list nil t t)))
-
-                  (or (clojure--find-ns-in-direction 'backward)
-                      (clojure--find-ns-in-direction 'forward))))))
+    (let* ((f (lambda (direction)
+                (if suppress-errors
+                    (ignore-errors (clojure--find-ns-in-direction direction))
+                  (clojure--find-ns-in-direction direction))))
+           (ns (save-excursion
+                 (save-restriction
+                   (widen)
+
+                   ;; Move to top-level to avoid searching from inside ns
+                   (ignore-errors (while t (up-list nil t t)))
+
+                   (or (funcall f 'backward)
+                       (funcall f 'forward))))))
       (setq clojure-cached-ns ns)
       ns)))
 

test/clojure-mode-sexp-test.el

@@ -167,7 +167,22 @@
             (expect (clojure-find-ns) :to-equal expected)
             ;; After both namespaces
             (goto-char (point-max))
-            (expect (clojure-find-ns) :to-equal expected)))))))
+            (expect (clojure-find-ns) :to-equal expected))))))
+
+  (describe "`suppress-errors' argument"
+    (let ((clojure-cache-ns nil))
+      (describe "given a faulty ns form"
+        (let ((ns-form "(ns )"))
+          (describe "when the argument is `t'"
+            (it "causes `clojure-find-ns' to return nil"
+              (with-clojure-buffer ns-form
+                                   (expect (equal nil (clojure-find-ns t))))))
+
+          (describe "when the argument is `nil'"
+            (it "causes `clojure-find-ns' to return raise an error"
+              (with-clojure-buffer ns-form
+                                   (expect (clojure-find-ns nil)
+                                           :to-throw 'error)))))))))
 
 (describe "clojure-sexp-starts-until-position"
   (it "should return starting points for forms after POINT until POSITION"