fix(ext/node): Add Immediate class to mirror NodeJS.Immediate (#22808)

Fixes #21660

Adds a basic `Immediate` class to mirror `NodeJS.Immediate`, and changes
`setImmediate` and `clearImmediate` to return and accept (respectively)
`Immediate` objects.

Note that for now {ref,unref,hasRef} are effectively stubs, as deno_core
doesn't really natively support immediates (they're currently modeled as
timers with delay of 0). Eventually we probably want to actually
implement these properly.

1 files changed, 11 insertions, 5 deletions

diff --git a/ext/node/polyfills/timers.ts b/ext/node/polyfills/timers.ts
index 9a7d59ab2..033afd952 100644
--- a/ext/node/polyfills/timers.ts
+++ b/ext/node/polyfills/timers.ts
@@ -11,6 +11,7 @@ const {
 
 import {
   activeTimers,
+  Immediate,
   setUnrefTimeout,
   Timeout,
 } from "ext:deno_node/internal/timers.mjs";
@@ -21,7 +22,6 @@ import * as timers from "ext:deno_web/02_timers.js";
 
 const clearTimeout_ = timers.clearTimeout;
 const clearInterval_ = timers.clearInterval;
-const setImmediate_ = timers.setImmediate;
 
 export function setTimeout(
   callback: (...args: unknown[]) => void,
@@ -70,15 +70,21 @@ export function clearInterval(timeout?: Timeout | number | string) {
   }
   clearInterval_(id);
 }
-// TODO(bartlomieju): implement the 'NodeJS.Immediate' versions of the timers.
-// https://github.com/DefinitelyTyped/DefinitelyTyped/blob/1163ead296d84e7a3c80d71e7c81ecbd1a130e9a/types/node/v12/globals.d.ts#L1120-L1131
 export function setImmediate(
   cb: (...args: unknown[]) => void,
   ...args: unknown[]
 ): Timeout {
-  return setImmediate_(cb, ...args);
+  return new Immediate(cb, ...args);
+}
+export function clearImmediate(immediate: Immediate) {
+  if (immediate == null) {
+    return;
+  }
+
+  // FIXME(nathanwhit): will probably change once
+  //  deno_core has proper support for immediates
+  clearTimeout_(immediate._immediateId);
 }
-export const clearImmediate = clearTimeout;
 
 export default {
   setTimeout,