From 4f6196050cdd2166fe03955c53811a07fc1d30c0 Mon Sep 17 00:00:00 2001
From: ExE Boss <3889017+ExE-Boss@users.noreply.github.com>
Date: Sat, 6 Feb 2021 12:10:00 +0100
Subject: [PATCH] =?UTF-8?q?module:=20add=C2=A0support=20for=C2=A0`node:`?=
 =?UTF-8?q?=E2=80=91prefixed=20`require(=E2=80=A6)`=C2=A0calls?=
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Fixes: https://github.com/nodejs/node/issues/36098
---
 lib/internal/modules/cjs/loader.js        | 14 ++++++++--
 test/parallel/test-require-node-prefix.js | 34 +++++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-require-node-prefix.js

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index 5abfa465e0407d..3608007ea5bd1c 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -109,7 +109,8 @@ let hasLoadedAnyUserCJSModule = false;
 const {
   ERR_INVALID_ARG_VALUE,
   ERR_INVALID_MODULE_SPECIFIER,
-  ERR_REQUIRE_ESM
+  ERR_REQUIRE_ESM,
+  ERR_UNKNOWN_BUILTIN_MODULE,
 } = require('internal/errors').codes;
 const { validateString } = require('internal/validators');
 const pendingDeprecation = getOptionValue('--pending-deprecation');
@@ -766,6 +767,14 @@ Module._load = function(request, parent, isMain) {
   }
 
   const filename = Module._resolveFilename(request, parent, isMain);
+  if (StringPrototypeStartsWith(filename, 'node:')) {
+    const specifier = StringPrototypeSlice(filename, 5);
+
+    const mod = loadNativeModule(specifier, request);
+    if (mod && mod.canBeRequiredByUsers) return mod.exports;
+
+    throw new ERR_UNKNOWN_BUILTIN_MODULE(specifier);
+  }
 
   const cachedModule = Module._cache[filename];
   if (cachedModule !== undefined) {
@@ -837,7 +846,8 @@ Module._load = function(request, parent, isMain) {
 };
 
 Module._resolveFilename = function(request, parent, isMain, options) {
-  if (NativeModule.canBeRequiredByUsers(request)) {
+  if (StringPrototypeStartsWith(request, 'node:') ||
+      NativeModule.canBeRequiredByUsers(request)) {
     return request;
   }
 
diff --git a/test/parallel/test-require-node-prefix.js b/test/parallel/test-require-node-prefix.js
new file mode 100644
index 00000000000000..7582ca4bffc9c3
--- /dev/null
+++ b/test/parallel/test-require-node-prefix.js
@@ -0,0 +1,34 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const fs = require('fs');
+
+// For direct use of require expressions inside of CJS modules,
+// including via eval, all kinds of specifiers should work without issue.
+{
+  // Importing a built-in, both direct & via eval
+  assert.strictEqual(require('fs'), fs);
+  assert.strictEqual(eval('require("fs")'), fs);
+  assert.strictEqual(require('node:fs'), fs);
+  assert.strictEqual(eval('require("node:fs")'), fs);
+
+  assert.throws(
+    () => require('node:unknown'),
+    { code: 'ERR_UNKNOWN_BUILTIN_MODULE' },
+  );
+}
+
+// `node:`-prefixed `require(...)` calls bypass the require cache:
+{
+  const fakeModule = {};
+
+  require.cache.fs = { exports: fakeModule };
+
+  assert.strictEqual(require('fs'), fakeModule);
+  assert.strictEqual(eval('require("fs")'), fakeModule);
+  assert.strictEqual(require('node:fs'), fs);
+  assert.strictEqual(eval('require("node:fs")'), fs);
+
+  delete require.cache.fs;
+}