child_process: add support for URL to cp.fork

PR-URL: #41225
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/child_process.md

@@ -385,7 +385,14 @@ controller.abort();
 <!-- YAML
 added: v0.5.0
 changes:
-  - version: v16.4.0
+  - version:
+      - REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/41225
+    description: The `modulePath` parameter can be a WHATWG `URL` object using
+                 `file:` protocol.
+  - version:
+      - v16.4.0
+      - v14.18.0
     pr-url: https://github.com/nodejs/node/pull/38862
     description: The `cwd` option can be a WHATWG `URL` object using
                  `file:` protocol.
@@ -411,7 +418,7 @@ changes:
     description: The `stdio` option is supported now.
 -->
 
-* `modulePath` {string} The module to run in the child.
+* `modulePath` {string|URL} The module to run in the child.
 * `args` {string\[]} List of string arguments.
 * `options` {Object}
   * `cwd` {string|URL} Current working directory of the child process.

lib/child_process.js

@@ -91,7 +91,7 @@ const MAX_BUFFER = 1024 * 1024;
 
 /**
  * Spawns a new Node.js process + fork.
- * @param {string} modulePath
+ * @param {string|URL} modulePath
  * @param {string[]} [args]
  * @param {{
  *   cwd?: string;
@@ -112,7 +112,7 @@ const MAX_BUFFER = 1024 * 1024;
  * @returns {ChildProcess}
  */
 function fork(modulePath /* , args, options */) {
-  validateString(modulePath, 'modulePath');
+  modulePath = getValidatedPath(modulePath, 'modulePath');
 
   // Get options and args arguments.
   let execArgv;

test/parallel/test-child-process-fork-url.mjs

@@ -0,0 +1,11 @@
+import { mustCall } from '../common/index.mjs';
+import { fork } from 'child_process';
+
+if (process.argv[2] === 'child') {
+  process.disconnect();
+} else {
+  const child = fork(new URL(import.meta.url), ['child']);
+
+  child.on('disconnect', mustCall());
+  child.once('exit', mustCall());
+}