Fix treesit--things-around (bug#60355)

Current implementation of treesit--things-around only searches forward
for REGEXP and go up the tree until it finds a valid thing, if nothing
matches it gives up.  This makes it sometimes miss defuns.  The new
implementation tries multiple times (of search forward + go up) until
it exhausts all possible defun nodes.

* lisp/treesit.el (treesit--things-around): New implementation.
(treesit--navigate-defun): Refactor to use treesit-node-top-level to
simplify code, and add some guards in the predicate function.
* test/src/treesit-tests.el:
(treesit--ert-defun-navigation-elixir-program): New variable.
(treesit-defun-navigation-nested-4): New test.

1 files changed, 39 insertions, 1 deletions

diff --git a/test/src/treesit-tests.el b/test/src/treesit-tests.el
index b0fbed4b06c..ec686c69642 100644
--- a/test/src/treesit-tests.el
+++ b/test/src/treesit-tests.el
@@ -940,7 +940,28 @@ and \"]\"."
 [999]}
 [110]
 "
-  "Javascript source for navigation test.")
+  "Bash source for navigation test.")
+
+(defvar treesit--ert-defun-navigation-elixir-program
+  "[100]
+[101]def bar() do
+[999]end
+[102]
+[103]defmodule Example do[0]
+[999] @impl true
+[104] [1]def bar() do[2]
+[999] end[3]
+[105] [4]
+[106] [5]def baz() do[6]
+[999] end[7]
+[107] [8]
+[999]end[9]
+[108]
+[109]def bar() do
+[999]end
+[110]
+"
+  "Elixir source for navigation test.")
 
 (defvar treesit--ert-defun-navigation-nested-master
   ;; START PREV-BEG NEXT-END PREV-END NEXT-BEG
@@ -1022,6 +1043,23 @@ the prev-beg, now point should be at marker 103\", etc.")
      treesit--ert-defun-navigation-bash-program
      treesit--ert-defun-navigation-nested-master)))
 
+(ert-deftest treesit-defun-navigation-nested-4 ()
+  "Test defun navigation using Elixir.
+This tests bug#60355."
+  (skip-unless (treesit-language-available-p 'bash))
+  ;; Nested defun navigation
+  (let ((treesit-defun-tactic 'nested)
+        (pred (lambda (node)
+                (member (treesit-node-text
+                         (treesit-node-child-by-field-name node "target"))
+                        '("def" "defmodule")))))
+    (treesit--ert-test-defun-navigation
+     (lambda ()
+       (treesit-parser-create 'elixir)
+       (setq-local treesit-defun-type-regexp `("call" . ,pred)))
+     treesit--ert-defun-navigation-elixir-program
+     treesit--ert-defun-navigation-nested-master)))
+
 (ert-deftest treesit-defun-navigation-top-level ()
   "Test top-level only defun navigation."
   (skip-unless (treesit-language-available-p 'python))