Fix typescript-ts-mode tenary indentation (bug#77901)

Fixes indentation for nested ternary expressions:

const a = cond1 ? 1 :
  cond2 ? 2 :
  cond3 ? 3 :
  cond 4: 5;

instead of

const a = cond1 ? 1 :
  cond2 ? 2 :
    cond3 ? 3 :
      cond 4: 5;

* lisp/progmodes/typescript-ts-mode.el:
(typescript-ts--standalone-parent-p): New function.
(typescript-ts-mode):
(tsx-ts-mode): Use new function.

1 files changed, 5 insertions, 0 deletions

diff --git a/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts b/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
index 210bfcabd41..ba41c10c08c 100644
--- a/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
+++ b/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
@@ -96,6 +96,11 @@ const foo = () => {
 Name: Chained ternary expressions
 
 =-=
+const a = cond1 ? 1 :
+  cond2 ? 2 :
+  cond3 ? 3 :
+  cond 4: 5;
+
 const a = cond1 ? 1
   : cond2 ? 2
   : cond3 ? 3