process signal events (#3569)

* signal events

* simple tests

* ignore SIGSTOP

* better tests

* use `EventEmitter`

* use `Bun__getDefaultGlobal`

* progress

* don't use 'Bun__getDefaultGlobal`

* fix tests

* remove signals from map

* update tests

* don't overwrite event emitter methods

* avoid two lookups

* use `std::once`

* releaseEarly()

* Remove signal handler after use

* Update call-raise.js

* Create process-signal-handler.fixture.js

* Don't register duplicates

* Add missing lock

* another test

* update test

* revert some changes

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

3 files changed, 102 insertions, 2 deletions

diff --git a/test/js/node/process/call-raise.js b/test/js/node/process/call-raise.js
new file mode 100644
index 000000000..898906759
--- /dev/null
+++ b/test/js/node/process/call-raise.js
@@ -0,0 +1,15 @@
+import { dlopen } from "bun:ffi";
+
+var lazyRaise;
+export function raise(signal) {
+  if (!lazyRaise) {
+    const suffix = process.platform === "darwin" ? "dylib" : "so.6";
+    lazyRaise = dlopen(`libc.${suffix}`, {
+      raise: {
+        args: ["int"],
+        returns: "int",
+      },
+    }).symbols.raise;
+  }
+  lazyRaise(signal);
+}
diff --git a/test/js/node/process/process-signal-handler.fixture.js b/test/js/node/process/process-signal-handler.fixture.js
new file mode 100644
index 000000000..de5a78bda
--- /dev/null
+++ b/test/js/node/process/process-signal-handler.fixture.js
@@ -0,0 +1,63 @@
+import os from "os";
+import { raise } from "./call-raise";
+
+var counter = 0;
+function done() {
+  counter++;
+  if (counter === 2) {
+    setTimeout(() => {
+      if (counter !== 2) {
+        console.log(counter);
+        console.log("FAIL");
+        process.exit(1);
+      }
+
+      console.log("PASS");
+      process.exit(0);
+    }, 1);
+  }
+}
+
+var counter2 = 0;
+function done2() {
+  counter2++;
+  if (counter2 === 2) {
+    setTimeout(() => {
+      if (counter2 !== 2) {
+        console.log(counter2);
+        console.log("FAIL");
+        process.exit(1);
+      }
+
+      console.log("PASS");
+      process.exit(0);
+    }, 1);
+  }
+}
+
+const SIGUSR1 = os.constants.signals.SIGUSR1;
+const SIGUSR2 = os.constants.signals.SIGUSR2;
+
+switch (process.argv.at(-1)) {
+  case "SIGUSR1": {
+    process.on("SIGUSR1", () => {
+      done();
+    });
+    process.on("SIGUSR1", () => {
+      done();
+    });
+    raise(SIGUSR1);
+    break;
+  }
+  case "SIGUSR2": {
+    process.on("SIGUSR2", () => {
+      done2();
+    });
+    process.emit("SIGUSR2");
+    raise(SIGUSR2);
+    break;
+  }
+  default: {
+    throw new Error("Unknown argument: " + process.argv.at(-1));
+  }
+}
diff --git a/test/js/node/process/process.test.js b/test/js/node/process/process.test.js
index e038383de..51825b2b4 100644
--- a/test/js/node/process/process.test.js
+++ b/test/js/node/process/process.test.js
@@ -1,6 +1,6 @@
-import { resolveSync, spawnSync, which } from "bun";
+import { spawnSync, which } from "bun";
 import { describe, expect, it } from "bun:test";
-import { existsSync, readFileSync, realpathSync } from "fs";
+import { existsSync, readFileSync } from "fs";
 import { bunEnv, bunExe } from "harness";
 import { basename, join, resolve } from "path";
 
@@ -381,6 +381,28 @@ it("process.getuid", () => {
   expect(typeof process.getuid()).toBe("number");
 });
 
+describe("signal", () => {
+  const fixture = join(import.meta.dir, "./process-signal-handler.fixture.js");
+  it("simple case works", async () => {
+    const child = Bun.spawn({
+      cmd: [bunExe(), fixture, "SIGUSR1"],
+      env: bunEnv,
+    });
+
+    expect(await child.exited).toBe(0);
+    expect(await new Response(child.stdout).text()).toBe("PASS\n");
+  });
+  it("process.emit will call signal events", async () => {
+    const child = Bun.spawn({
+      cmd: [bunExe(), fixture, "SIGUSR2"],
+      env: bunEnv,
+    });
+
+    expect(await child.exited).toBe(0);
+    expect(await new Response(child.stdout).text()).toBe("PASS\n");
+  });
+});
+
 const undefinedStubs = [
   "_debugEnd",
   "_debugProcess",