feat(std/node): Add support for process.on("exit") (#8940)

This commit adds support for process.on("exit") by appending a listener to
the unload event. Luckily, unload works pretty much the same as on("exit")
since it won't schedule any additional work in the even loop either.

This commit also solves an error in the Node implementation, since "process.argv"
didn't contained the main module route as it was supposed to.

std/node/process_test.ts

@@ -1,37 +1,12 @@
 // deno-lint-ignore-file no-undef
 // Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
 
-import { assert, assertEquals, assertThrows } from "../testing/asserts.ts";
-import * as path from "../path/mod.ts";
-import * as all from "./process.ts";
-import { argv, env } from "./process.ts";
-import { delay } from "../async/delay.ts";
 import "./global.ts";
-
-// NOTE: Deno.execPath() (and thus process.argv) currently requires --allow-env
-// (Also Deno.env.toObject() (and process.env) requires --allow-env but it's more obvious)
-
-Deno.test({
-  name: "process exports are as they should be",
-  fn() {
-    // * should be the same as process, default, and globalThis.process
-    // without the export aliases, and with properties that are not standalone
-    const allKeys = new Set<string>(Object.keys(all));
-    // without { process } for deno b/c
-    allKeys.delete("process");
-    // without esm default
-    allKeys.delete("default");
-    // with on, stdin, stderr, and stdout, which is not exported via *
-    allKeys.add("on");
-    allKeys.add("stdin");
-    allKeys.add("stderr");
-    allKeys.add("stdout");
-    const allStr = Array.from(allKeys).sort().join(" ");
-    assertEquals(Object.keys(all.default).sort().join(" "), allStr);
-    assertEquals(Object.keys(all.process).sort().join(" "), allStr);
-    assertEquals(Object.keys(process).sort().join(" "), allStr);
-  },
-});
+import { assert, assertEquals, assertThrows } from "../testing/asserts.ts";
+import { stripColor } from "../fmt/colors.ts";
+import * as path from "../path/mod.ts";
+import { delay } from "../async/delay.ts";
+import { env } from "./process.ts";
 
 Deno.test({
   name: "process.cwd and process.chdir success",
@@ -103,7 +78,7 @@ Deno.test({
 
 Deno.test({
   name: "process.on",
-  fn() {
+  async fn() {
     assertEquals(typeof process.on, "function");
     assertThrows(
       () => {
@@ -112,6 +87,33 @@ Deno.test({
       Error,
       "implemented",
     );
+
+    let triggered = false;
+    process.on("exit", () => {
+      triggered = true;
+    });
+    process.emit("exit");
+    assert(triggered);
+
+    const cwd = path.dirname(path.fromFileUrl(import.meta.url));
+
+    const p = Deno.run({
+      cmd: [
+        Deno.execPath(),
+        "run",
+        "./process_exit_test.ts",
+      ],
+      cwd,
+      stdout: "piped",
+    });
+
+    const decoder = new TextDecoder();
+    const rawOutput = await p.output();
+    assertEquals(
+      stripColor(decoder.decode(rawOutput).trim()),
+      "1\n2",
+    );
+    p.close();
   },
 });
 
@@ -119,12 +121,14 @@ Deno.test({
   name: "process.argv",
   fn() {
     assert(Array.isArray(process.argv));
-    assert(Array.isArray(argv));
     assert(
       process.argv[0].match(/[^/\\]*deno[^/\\]*$/),
       "deno included in the file name of argv[0]",
     );
-    // we cannot test for anything else (we see test runner arguments here)
+    assertEquals(
+      process.argv[1],
+      path.fromFileUrl(Deno.mainModule),
+    );
   },
 });
 
@@ -136,9 +140,8 @@ Deno.test({
     assertEquals(typeof (process.env.HELLO), "string");
     assertEquals(process.env.HELLO, "WORLD");
 
-    // TODO(caspervonb) test the globals in a different setting (they're broken)
-    // assertEquals(typeof env.HELLO, "string");
-    // assertEquals(env.HELLO, "WORLD");
+    assertEquals(typeof env.HELLO, "string");
+    assertEquals(env.HELLO, "WORLD");
   },
 });