fix(node): track SIG* listeners in process.listeners (#23890)

Some npm libraries like `signal-exit` rely on the length of the listener
array returned by `process.listeners("SIGNT")` to be correct to
function. We weren't tracking `SIG*` events there, which broke those npm
libraries.

Fixes #22892

ext/node/polyfills/process.ts

@@ -469,6 +469,7 @@ Process.prototype.on = function (
  } else if (event === "SIGTERM" && Deno.build.os === "windows") {
  // Ignores SIGTERM on windows.
  } else {
+ EventEmitter.prototype.on.call(this, event, listener);
  Deno.addSignalListener(event as Deno.Signal, listener);
  }
  } else {
@@ -494,6 +495,7 @@ Process.prototype.off = function (
  } else if (event === "SIGTERM" && Deno.build.os === "windows") {
  // Ignores SIGTERM on windows.
  } else {
+ EventEmitter.prototype.off.call(this, event, listener);
  Deno.removeSignalListener(event as Deno.Signal, listener);
  }
  } else {
@@ -537,6 +539,7 @@ Process.prototype.prependListener = function (
  if (event === "SIGBREAK" && Deno.build.os !== "windows") {
  // Ignores SIGBREAK if the platform is not windows.
  } else {
+ EventEmitter.prototype.prependListener.call(this, event, listener);
  Deno.addSignalListener(event as Deno.Signal, listener);
  }
  } else {

tests/unit_node/process_test.ts

@@ -1108,3 +1108,19 @@ Deno.test({
  process.constructor.call({});
  },
 });
+
+// Test for https://github.com/denoland/deno/issues/22892
+Deno.test("process.listeners - include SIG* events", () => {
+ const listener = () => console.log("SIGINT");
+ process.on("SIGINT", listener);
+ assertEquals(process.listeners("SIGINT").length, 1);
+
+ const listener2 = () => console.log("SIGINT");
+ process.prependListener("SIGINT", listener2);
+ assertEquals(process.listeners("SIGINT").length, 2);
+
+ process.off("SIGINT", listener);
+ assertEquals(process.listeners("SIGINT").length, 1);
+ process.off("SIGINT", listener2);
+ assertEquals(process.listeners("SIGINT").length, 0);
+});