Allow lookup of function symbol when cursor is on opening paren

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### New features
 
+* [#2738](https://github.com/clojure-emacs/cider/pull/2738): Add ability to lookup a function symbol when cursor is at the opening paren.
 * [#2735](https://github.com/clojure-emacs/cider/pull/2735): New debugger command `P` to inspect an arbitrary expression, it was previously bound to `p` which now inspects the current value.
 * [#2729](https://github.com/clojure-emacs/cider/pull/2729): New cider inspector command `cider-inspector-def-current-val` lets you define a var with the current inspector value.
 

cider-util.el

@@ -134,6 +134,8 @@ find a symbol if there isn't one at point."
       (when look-back
         (save-excursion
           (ignore-errors
+            (when (looking-at "(")
+              (forward-char 1))
             (while (not (looking-at "\\sw\\|\\s_\\|\\`"))
               (forward-sexp -1)))
           (cider-symbol-at-point)))))

test/cider-util-tests.el

@@ -97,6 +97,13 @@
       (spy-on 'thing-at-point :and-return-value nil)
       (expect (cider-symbol-at-point) :not :to-be-truthy)))
 
+  (describe "when on an opening paren"
+    (it "returns the following symbol"
+      (with-temp-buffer
+        (insert "(some function call)")
+        (goto-char (point-min))
+        (expect (cider-symbol-at-point 'look-back) :to-equal "some"))))
+
   (it "can identify symbols in a repl, ignoring the repl prompt"
     ;; ignores repl prompts
     (spy-on 'thing-at-point :and-return-value (propertize "user>" 'field 'cider-repl-prompt))