fix(ext/node): add missing _preloadModules hook (denoland#18447)

This internal node hook is used by libraries such as `ts-node` when used
as a require hook `node -r ts-node/register`. That combination is often
used with test frameworks like `mocha` or `jasmine`.

We had a reference to `Module._preloadModules` in our code, but the
implementation was missing. While fixing this I also noticed that the
`fakeParent` module that we create internally always threw because of
the `pathDirname` check on the module id in the constructor of `Mdoule`.
So this code path was probably broken for a while.

```txt
✖ ERROR: Error: Empty filepath.
    at pathDirname (ext:deno_node/01_require.js:245:11)
    at new Module (ext:deno_node/01_require.js:446:15)
    at Function.Module._resolveFilename (ext:deno_node/01_require.js:754:28)
    at Function.resolve (ext:deno_node/01_require.js:1015:19)
```

cli/tests/unit_node/module_test.ts

@@ -0,0 +1,14 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+import { Module } from "node:module";
+import { assertStrictEquals } from "../../../test_util/std/testing/asserts.ts";
+
+Deno.test("[node/module _preloadModules] has internal require hook", () => {
+ // Check if it's there
+ // deno-lint-ignore no-explicit-any
+ (Module as any)._preloadModules([
+ "./cli/tests/unit_node/testdata/add_global_property.js",
+ ]);
+ // deno-lint-ignore no-explicit-any
+ assertStrictEquals((globalThis as any).foo, "Hello");
+});

cli/tests/unit_node/testdata/add_global_property.js

@@ -0,0 +1 @@
+globalThis.foo = "Hello";

ext/node/polyfills/01_require.js

@@ -241,8 +241,10 @@ setupBuiltinModules();
 const cjsParseCache = new SafeWeakMap();
 
 function pathDirname(filepath) {
- if (filepath == null || filepath === "") {
+ if (filepath == null) {
  throw new Error("Empty filepath.");
+ } else if (filepath === "") {
+ return ".";
  }
  return ops.op_require_path_dirname(filepath);
 }
@@ -605,10 +607,10 @@ Module._nodeModulePaths = function (fromPath) {
 Module._resolveLookupPaths = function (request, parent) {
  const paths = [];
 
- if (ops.op_require_is_request_relative(request) && parent?.filename) {
+ if (ops.op_require_is_request_relative(request)) {
  ArrayPrototypePush(
  paths,
- ops.op_require_path_dirname(parent.filename),
+ parent?.filename ? ops.op_require_path_dirname(parent.filename) : ".",
  );
  return paths;
  }
@@ -752,7 +754,6 @@ Module._resolveFilename = function (
  paths = options.paths;
  } else {
  const fakeParent = new Module("", null);
-
  paths = [];
 
  for (let i = 0; i < options.paths.length; i++) {
@@ -828,6 +829,25 @@ Module._resolveFilename = function (
  throw err;
 };
 
+/**
+ * Internal CommonJS API to always require modules before requiring the actual
+ * one when calling `require("my-module")`. This is used by require hooks such
+ * as `ts-node/register`.
+ * @param {string[]} requests List of modules to preload
+ */
+Module._preloadModules = function (requests) {
+ if (!ArrayIsArray(requests) || requests.length === 0) {
+ return;
+ }
+
+ const parent = new Module("internal/preload", null);
+ // All requested files must be resolved against cwd
+ parent.paths = Module._nodeModulePaths(process.cwd());
+ for (let i = 0; i < requests.length; i++) {
+ parent.require(requests[i]);
+ }
+};
+
 Module.prototype.load = function (filename) {
  if (this.loaded) {
  throw Error("Module already loaded");
@@ -954,7 +974,7 @@ Module._extensions[".js"] = function (module, filename) {
  const content = ops.op_require_read_file(filename);
 
  if (StringPrototypeEndsWith(filename, ".js")) {
- const pkg = ops.op_require_read_closest_package_json(filename);
+ const pkg = ops.op_require_read_package_scope(filename);
  if (pkg && pkg.exists && pkg.typ == "module") {
  let message = `Trying to import ESM module: ${filename}`;