lib: add assertion for user ESM execution

Previously we only had an internal assertion to ensure certain
code is executed before any user-provided CJS is run. This patch
adds another assertion for ESM.

Note that this internal state is not updated during source text
module execution via vm because to run any code via vm, some
user JS code must have already been executed anyway.

In addition this patch moves the states into internal/modules/helpers
to avoid circular dependencies. Also moves toggling the states to
true *right before* user code execution instead of after in case
we are half-way in the execution when internals try to check them.

PR-URL: #51748
Reviewed-By: Antoine du Hamel <[email protected]>
Reviewed-By: Geoffrey Booth <[email protected]>

Author: joyeecheung

lib/internal/modules/cjs/loader.js

@@ -76,7 +76,6 @@ module.exports = {
   initializeCJS,
   Module,
   wrapSafe,
-  get hasLoadedAnyUserCJSModule() { return hasLoadedAnyUserCJSModule; },
 };
 
 const { BuiltinModule } = require('internal/bootstrap/realm');
@@ -113,6 +112,7 @@ const {
   initializeCjsConditions,
   loadBuiltinModule,
   makeRequireFunction,
+  setHasStartedUserCJSExecution,
   stripBOM,
   toRealPath,
 } = require('internal/modules/helpers');
@@ -127,9 +127,6 @@ const permission = require('internal/process/permission');
 const {
   vm_dynamic_import_default_internal,
 } = internalBinding('symbols');
-// Whether any user-provided CJS modules had been loaded (executed).
-// Used for internal assertions.
-let hasLoadedAnyUserCJSModule = false;
 
 const {
   codes: {
@@ -1363,14 +1360,14 @@ Module.prototype._compile = function(content, filename) {
   const thisValue = exports;
   const module = this;
   if (requireDepth === 0) { statCache = new SafeMap(); }
+  setHasStartedUserCJSExecution();
   if (inspectorWrapper) {
     result = inspectorWrapper(compiledWrapper, thisValue, exports,
                               require, module, filename, dirname);
   } else {
     result = ReflectApply(compiledWrapper, thisValue,
                           [exports, require, module, filename, dirname]);
   }
-  hasLoadedAnyUserCJSModule = true;
   if (requireDepth === 0) { statCache = null; }
   return result;
 };

lib/internal/modules/esm/module_job.js

@@ -27,7 +27,9 @@ const {
 } = require('internal/source_map/source_map_cache');
 const assert = require('internal/assert');
 const resolvedPromise = PromiseResolve();
-
+const {
+  setHasStartedUserESMExecution,
+} = require('internal/modules/helpers');
 const noop = FunctionPrototype;
 
 let hasPausedEntry = false;
@@ -206,6 +208,7 @@ class ModuleJob {
     this.instantiated = PromiseResolve();
     const timeout = -1;
     const breakOnSigint = false;
+    setHasStartedUserESMExecution();
     this.module.evaluate(timeout, breakOnSigint);
     return { __proto__: null, module: this.module };
   }
@@ -214,6 +217,7 @@ class ModuleJob {
     await this.instantiate();
     const timeout = -1;
     const breakOnSigint = false;
+    setHasStartedUserESMExecution();
     try {
       await this.module.evaluate(timeout, breakOnSigint);
     } catch (e) {

lib/internal/modules/helpers.js

@@ -319,6 +319,19 @@ function normalizeReferrerURL(referrerName) {
   assert.fail('Unreachable code reached by ' + inspect(referrerName));
 }
 
+
+// Whether we have started executing any user-provided CJS code.
+// This is set right before we call the wrapped CJS code (not after,
+// in case we are half-way in the execution when internals check this).
+// Used for internal assertions.
+let _hasStartedUserCJSExecution = false;
+// Similar to _hasStartedUserCJSExecution but for ESM. This is set
+// right before ESM evaluation in the default ESM loader. We do not
+// update this during vm SourceTextModule execution because at that point
+// some user code must already have been run to execute code via vm
+// there is little value checking whether any user JS code is run anyway.
+let _hasStartedUserESMExecution = false;
+
 module.exports = {
   addBuiltinLibsToObject,
   getCjsConditions,
@@ -328,4 +341,16 @@ module.exports = {
   normalizeReferrerURL,
   stripBOM,
   toRealPath,
+  hasStartedUserCJSExecution() {
+    return _hasStartedUserCJSExecution;
+  },
+  setHasStartedUserCJSExecution() {
+    _hasStartedUserCJSExecution = true;
+  },
+  hasStartedUserESMExecution() {
+    return _hasStartedUserESMExecution;
+  },
+  setHasStartedUserESMExecution() {
+    _hasStartedUserESMExecution = true;
+  },
 };

lib/internal/process/pre_execution.js

@@ -191,8 +191,12 @@ function setupSymbolDisposePolyfill() {
 function setupUserModules(forceDefaultLoader = false) {
   initializeCJSLoader();
   initializeESMLoader(forceDefaultLoader);
-  const CJSLoader = require('internal/modules/cjs/loader');
-  assert(!CJSLoader.hasLoadedAnyUserCJSModule);
+  const {
+    hasStartedUserCJSExecution,
+    hasStartedUserESMExecution,
+  } = require('internal/modules/helpers');
+  assert(!hasStartedUserCJSExecution());
+  assert(!hasStartedUserESMExecution());
   // Do not enable preload modules if custom loaders are disabled.
   // For example, loader workers are responsible for doing this themselves.
   // And preload modules are not supported in ShadowRealm as well.