Correct conversion of strings to tree-sitter query syntax

The treesitter query syntax for string literals differs from that of
Elisp so we cannot just use the Lisp printer (bug#64017).

* src/treesit.c (treesit_query_string_string): New function.
(Ftreesit_pattern_expand): Use it.
* test/src/treesit-tests.el (treesit-query-api): Add test case.

1 files changed, 6 insertions, 1 deletions

diff --git a/test/src/treesit-tests.el b/test/src/treesit-tests.el
index 7a8e53924eb..04aa91ddca6 100644
--- a/test/src/treesit-tests.el
+++ b/test/src/treesit-tests.el
@@ -461,7 +461,12 @@ BODY is the test body."
         "(type field: (_) @capture .) ? * + \"return\""
         (treesit-query-expand
          '((type field: (_) @capture :anchor)
-           :? :* :+ "return")))))))
+           :? :* :+ "return"))))
+
+      ;; Test string conversion in `treesit-pattern-expand'.
+      (should (equal
+               (treesit-pattern-expand "a\nb\rc\td\0e\"f\1g")
+               "\"a\\nb\\rc\\td\\0e\\\"f\1g\"")))))
 
 ;;; Narrow