feat(node): new child_process.fork (#2700)

.gitignore

@@ -1,9 +1,5 @@
 .DS_Store
 .idea
-deno.d.ts
-/node_modules
-package.json
-package-lock.json
 .vscode/settings.json
 **/cov/
 /crypto/_wasm_crypto/target

node/child_process.ts

@@ -37,20 +37,23 @@ import { getSystemErrorName, promisify } from "./util.ts";
 import { createDeferredPromise } from "./internal/util.mjs";
 import { process } from "./process.ts";
 import { Buffer } from "./buffer.ts";
-import { notImplemented } from "./_utils.ts";
 import { convertToValidSignal, kEmptyObject } from "./internal/util.mjs";
 
 const MAX_BUFFER = 1024 * 1024;
 
+type ForkOptions = ChildProcessOptions;
+
 /**
- * Spawns a new Node.js process + fork. Not implmeneted yet.
+ * Spawns a new Node.js process + fork.
  * @param modulePath
  * @param args
  * @param option
  * @returns
  */
 export function fork(
-  modulePath: string, /* args?: string[], options?: ForkOptions*/
+  modulePath: string,
+  _args?: string[],
+  _options?: ForkOptions,
 ) {
   validateString(modulePath, "modulePath");
 
@@ -109,8 +112,10 @@ export function fork(
     stringifiedV8Flags.push("--v8-flags=" + v8Flags.join(","));
   }
   args = [
-    // TODO(kt3k): Find corrct args for `fork` execution
-    ...[],
+    "run",
+    "--unstable", // TODO(kt3k): Remove when npm: is stable
+    "--node-modules-dir",
+    "-A",
     ...stringifiedV8Flags,
     ...execArgv,
     modulePath,
@@ -133,7 +138,13 @@ export function fork(
   options.execPath = options.execPath || Deno.execPath();
   options.shell = false;
 
-  notImplemented("child_process.fork");
+  Object.assign(options.env ??= {}, {
+    // deno-lint-ignore no-explicit-any
+    DENO_DONT_USE_INTERNAL_NODE_COMPAT_STATE: (Deno as any).core.ops
+      .op_npm_process_state(),
+  });
+
+  return spawn(options.execPath, args, options);
 }
 
 // deno-lint-ignore no-empty-interface

node/child_process_test.ts

@@ -507,3 +507,28 @@ Deno.test({
     await p;
   },
 });
+
+Deno.test({
+  name: "[node/child_process] child_process.fork",
+  async fn() {
+    const testdataDir = path.join(
+      path.dirname(path.fromFileUrl(import.meta.url)),
+      "testdata",
+    );
+    const script = path.join(
+      testdataDir,
+      "node_modules",
+      "foo",
+      "index.js",
+    );
+    const p = deferred();
+    const cp = CP.fork(script, [], { cwd: testdataDir, stdio: "pipe" });
+    let output = "";
+    cp.on("exit", () => p.resolve());
+    cp.stdout?.on("data", (data) => {
+      output += data;
+    });
+    await p;
+    assertEquals(output, "foo\ntrue\ntrue\ntrue\n");
+  },
+});

node/testdata/deno.json

@@ -0,0 +1,3 @@
+{
+  "//": "this file is necessary for child_process.fork test case"
+}

node/testdata/node_modules/foo/index.js

@@ -0,0 +1,4 @@
+console.log("foo");
+console.log(typeof require === "function");
+console.log(typeof module === "object");
+console.log(typeof exports === "object");

node/testdata/node_modules/foo/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "foo"
+}