feat: Add `Deno.exitCode` API (#23609)

This commits adds the ability to set a would-be exit code 
for the Deno process without forcing an immediate exit, 
through the new `Deno.exitCode` API.

- **Implements `Deno.exitCode` getter and setter**: Adds support for
setting
and retrieving a would-be exit code via `Deno.exitCode`.
This allows for asynchronous cleanup before process termination 
without immediately exiting.
- **Ensures type safety**: The setter for `Deno.exitCode` validates that
the provided value is a number, throwing a TypeError if not, to ensure
that
only valid exit codes are set.

Closes to #23605

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/runtime/ops/os/mod.rs b/runtime/ops/os/mod.rs
index 7a71590ba..f6f55f68f 100644
--- a/runtime/ops/os/mod.rs
+++ b/runtime/ops/os/mod.rs
@@ -32,6 +32,7 @@ deno_core::extension!(
     op_os_uptime,
     op_set_env,
     op_set_exit_code,
+    op_get_exit_code,
     op_system_memory_info,
     op_uid,
     op_runtime_memory_usage,
@@ -60,12 +61,13 @@ deno_core::extension!(
     op_os_uptime,
     op_set_env,
     op_set_exit_code,
+    op_get_exit_code,
     op_system_memory_info,
     op_uid,
     op_runtime_memory_usage,
   ],
   middleware = |op| match op.name {
-    "op_exit" | "op_set_exit_code" =>
+    "op_exit" | "op_set_exit_code" | "op_get_exit_code" =>
       op.with_implementation_from(&deno_core::op_void_sync()),
     _ => op,
   },
@@ -165,6 +167,12 @@ fn op_set_exit_code(state: &mut OpState, #[smi] code: i32) {
 }
 
 #[op2(fast)]
+#[smi]
+fn op_get_exit_code(state: &mut OpState) -> i32 {
+  state.borrow_mut::<ExitCode>().get()
+}
+
+#[op2(fast)]
 fn op_exit(state: &mut OpState) {
   let code = state.borrow::<ExitCode>().get();
   std::process::exit(code)