bootstrap: run preload prior to frozen-intrinsics

This is used to allow people to run polyfills. Co-Authored-By: Anna Henningsen <github@addaleax.net> PR-URL: #28940 Reviewed-By: Guy Bedford <guybedford@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: bmeck

doc/api/cli.md

@@ -218,6 +218,9 @@ Support is currently only provided for the root context and no guarantees are
 currently provided that `global.Array` is indeed the default intrinsic
 reference. Code may break under this flag.
 
+`--require` runs prior to freezing intrinsics in order to allow polyfills to
+be added.
+
 ### `--heapsnapshot-signal=signal`
 <!-- YAML
 added: v12.0.0

lib/internal/bootstrap/pre_execution.js

@@ -48,10 +48,10 @@ function prepareMainThreadExecution(expandArgv1 = false) {
  initializeClusterIPC();
 
  initializeDeprecations();
- initializeFrozenIntrinsics();
  initializeCJSLoader();
  initializeESMLoader();
  loadPreloadModules();
+ initializeFrozenIntrinsics();
 }
 
 function patchProcessObject(expandArgv1) {

lib/internal/main/worker_thread.js

@@ -106,10 +106,10 @@ port.on('message', (message) => {
  require('internal/process/policy').setup(manifestSrc, manifestURL);
  }
  initializeDeprecations();
- initializeFrozenIntrinsics();
  initializeCJSLoader();
  initializeESMLoader();
  loadPreloadModules();
+ initializeFrozenIntrinsics();
  publicWorker.parentPort = publicPort;
  publicWorker.workerData = workerData;
 

test/fixtures/intrinsic-mutation.js

@@ -0,0 +1,10 @@
+'use strict';
+Object.defineProperty(
+ Object.prototype,
+ 'flatten', {
+ enumerable: false,
+ // purposefully named something that
+ // would never land in JS itself
+ value: function smoosh() {}
+ }
+);

test/fixtures/print-intrinsic-mutation-name.js

@@ -0,0 +1,2 @@
+'use strict';
+console.log({}.flatten.name);

test/fixtures/worker-from-argv.js

@@ -0,0 +1,3 @@
+'use strict';
+const {Worker} = require('worker_threads');
+new Worker(process.argv[2]).on('exit', process.exit);

test/parallel/test-preload.js

@@ -23,6 +23,9 @@ const fixtureA = fixtures.path('printA.js');
 const fixtureB = fixtures.path('printB.js');
 const fixtureC = fixtures.path('printC.js');
 const fixtureD = fixtures.path('define-global.js');
+const fixtureE = fixtures.path('intrinsic-mutation.js');
+const fixtureF = fixtures.path('print-intrinsic-mutation-name.js');
+const fixtureG = fixtures.path('worker-from-argv.js');
 const fixtureThrows = fixtures.path('throws_error4.js');
 
 // Test preloading a single module works
@@ -62,6 +65,32 @@ childProcess.exec(
  }
 );
 
+// Test that preload can be used with --frozen-intrinsics
+childProcess.exec(
+ `"${nodeBinary}" --frozen-intrinsics ${
+ preloadOption([fixtureE])
+ } ${
+ fixtureF
+ }`,
+ function(err, stdout) {
+ assert.ifError(err);
+ assert.strictEqual(stdout, 'smoosh\n');
+ }
+);
+childProcess.exec(
+ `"${
+ nodeBinary
+ }" --frozen-intrinsics ${
+ preloadOption([fixtureE])
+ } ${
+ fixtureG
+ } ${fixtureF}`,
+ function(err, stdout) {
+ assert.ifError(err);
+ assert.strictEqual(stdout, 'smoosh\n');
+ }
+);
+
 // Test that preload can be used with stdin
 const stdinProc = childProcess.spawn(
  nodeBinary,