module: add releaseLoadedModule

doc/api/module.md

@@ -107,6 +107,18 @@ changes:
 Register a module that exports [hooks][] that customize Node.js module
 resolution and loading behavior. See [Customization hooks][].
 
+### `module.releaseResolvedModule(resolvedURL)`
+
+<!-- YAML
+added: x.x.x
+-->
+
+> Stability: 1 - Experimental
+
+* `resolvedURL` {string} The fully-resolved URL of a module.
+
+Clears the given module from the ESM resolve and load caches.
+
 ### `module.syncBuiltinESMExports()`
 
 <!-- YAML

lib/internal/modules/esm/assert.js

@@ -17,6 +17,7 @@ const {
 
 // The HTML spec has an implied default type of `'javascript'`.
 const kImplicitAssertType = 'javascript';
+const kAnyAssertType = '';
 
 /**
  * Define a map of module formats to import attributes types (the value of
@@ -112,5 +113,6 @@ function handleInvalidType(url, type) {
 
 module.exports = {
  kImplicitAssertType,
+ kAnyAssertType,
  validateAttributes,
 };

lib/internal/modules/esm/loader.js

@@ -20,6 +20,7 @@ const {
  ERR_REQUIRE_ESM,
  ERR_UNKNOWN_MODULE_FORMAT,
 } = require('internal/errors').codes;
+const { kAnyAssertType } = require('internal/modules/esm/assert');
 const { getOptionValue } = require('internal/options');
 const { pathToFileURL, isURL } = require('internal/url');
 const { emitExperimentalWarning } = require('internal/util');
@@ -223,6 +224,14 @@ class ModuleLoader {
  };
  }
 
+ /**
+ * Evict saved result of `resolve` and `load` for the given resolved URL.
+ */
+ evict(resolvedURL) {
+ this.#resolveCache.clearResolvedURL(resolvedURL);
+ this.loadCache.delete(resolvedURL, kAnyAssertType);
+ }
+
  /**
  * Get a (possibly still pending) module job from the cache,
  * or create one and return its Promise.
@@ -618,8 +627,18 @@ function register(specifier, parentURL = undefined, options) {
  );
 }
 
+/**
+ * Release saved results of `resolve` and `load` for the given resolved module
+ * URL.
+ */
+function releaseResolvedModule(resolvedURL) {
+ const moduleLoader = require('internal/process/esm_loader').esmLoader;
+ return moduleLoader.evict(resolvedURL);
+}
+
 module.exports = {
  createModuleLoader,
  getHooksProxy,
  register,
+ releaseResolvedModule,
 };

lib/internal/modules/esm/module_map.js

@@ -8,7 +8,10 @@ const {
  ObjectKeys,
  SafeMap,
 } = primordials;
-const { kImplicitAssertType } = require('internal/modules/esm/assert');
+const {
+ kImplicitAssertType,
+ kAnyAssertType,
+} = require('internal/modules/esm/assert');
 let debug = require('internal/util/debuglog').debuglog('esm', (fn) => {
  debug = fn;
 });
@@ -59,6 +62,27 @@ class ResolveCache extends SafeMap {
  return internalCache;
  }
 
+ /**
+ * @param {string} resolvedURL
+ */
+ clearResolvedURL(resolvedURL) {
+ for (const entry of this.entries()) {
+ const internalCache = entry[1];
+ let isEmpty = true;
+ for (const serializedKey of ObjectKeys(internalCache)) {
+ if (internalCache[serializedKey].url === resolvedURL) {
+ delete internalCache[serializedKey];
+ } else {
+ isEmpty = false;
+ }
+ }
+ if (isEmpty) {
+ const parentURL = entry[0];
+ this.delete(parentURL);
+ }
+ }
+ }
+
  /**
  * @param {string} serializedKey
  * @param {string} parentURL
@@ -88,6 +112,21 @@ class ResolveCache extends SafeMap {
  */
 class LoadCache extends SafeMap {
  constructor(i) { super(i); } // eslint-disable-line no-useless-constructor
+ delete(url, type = kImplicitAssertType) {
+ validateString(url, 'url');
+ validateString(type, 'type');
+ const cachedJobsForUrl = super.get(url);
+ if (cachedJobsForUrl) {
+ if (type === kAnyAssertType) {
+ super.delete(url);
+ return true;
+ }
+ const has = type in cachedJobsForUrl;
+ delete cachedJobsForUrl[type];
+ return has;
+ }
+ return false;
+ }
  get(url, type = kImplicitAssertType) {
  validateString(url, 'url');
  validateString(type, 'type');

lib/module.js

@@ -2,10 +2,11 @@
 
 const { findSourceMap } = require('internal/source_map/source_map_cache');
 const { Module } = require('internal/modules/cjs/loader');
-const { register } = require('internal/modules/esm/loader');
+const { releaseResolvedModule, register } = require('internal/modules/esm/loader');
 const { SourceMap } = require('internal/source_map/source_map');
 
 Module.findSourceMap = findSourceMap;
 Module.register = register;
+Module.releaseResolvedModule = releaseResolvedModule;
 Module.SourceMap = SourceMap;
 module.exports = Module;

test/es-module/test-esm-evict.mjs

@@ -0,0 +1,17 @@
+import '../common/index.mjs';
+import { strictEqual } from 'node:assert';
+import { releaseResolvedModule } from 'node:module';
+
+const specifier = 'data:application/javascript,export default globalThis.value;';
+
+globalThis.value = 1;
+const instance1 = await import(specifier);
+strictEqual(instance1.default, 1);
+globalThis.value = 2;
+const instance2 = await import(specifier);
+strictEqual(instance2.default, 1);
+
+releaseResolvedModule(specifier);
+const instance3 = await import(specifier);
+strictEqual(instance3.default, 2);
+delete globalThis.value;