lib: lazy-load deps in source_map_cache.js

So that the file can be snapshotted.

PR-URL: #45849
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>

Author: joyeecheung

lib/internal/source_map/source_map_cache.js

@@ -24,17 +24,19 @@ let debug = require('internal/util/debuglog').debuglog('source_map', (fn) => {
   debug = fn;
 });
 const { getOptionValue } = require('internal/options');
-const { IterableWeakMap } = require('internal/util/iterable_weak_map');
-const {
-  normalizeReferrerURL,
-} = require('internal/modules/helpers');
+
 const { validateBoolean } = require('internal/validators');
 const { setMaybeCacheGeneratedSourceMap } = internalBinding('errors');
+const { getLazy } = require('internal/util');
 
 // Since the CJS module cache is mutable, which leads to memory leaks when
 // modules are deleted, we use a WeakMap so that the source map cache will
 // be purged automatically:
-const cjsSourceMapCache = new IterableWeakMap();
+const getCjsSourceMapCache = getLazy(() => {
+  const { IterableWeakMap } = require('internal/util/iterable_weak_map');
+  return new IterableWeakMap();
+});
+
 // The esm cache is not mutable, so we can use a Map without memory concerns:
 const esmSourceMapCache = new SafeMap();
 // The generated sources is not mutable, so we can use a Map without memory concerns:
@@ -44,6 +46,7 @@ const kSourceMappingURLMagicComment = /\/[*/]#\s+sourceMappingURL=(?<sourceMappi
 const kSourceURLMagicComment = /\/[*/]#\s+sourceURL=(?<sourceURL>[^\s]+)/g;
 
 const { fileURLToPath, pathToFileURL, URL } = require('internal/url');
+
 let SourceMap;
 
 let sourceMapsEnabled;
@@ -114,6 +117,7 @@ function maybeCacheSourceMap(filename, content, cjsModuleInstance, isGeneratedSo
   const sourceMapsEnabled = getSourceMapsEnabled();
   if (!(process.env.NODE_V8_COVERAGE || sourceMapsEnabled)) return;
   try {
+    const { normalizeReferrerURL } = require('internal/modules/helpers');
     filename = normalizeReferrerURL(filename);
   } catch (err) {
     // This is most likely an invalid filename in sourceURL of [eval]-wrapper.
@@ -137,7 +141,7 @@ function maybeCacheSourceMap(filename, content, cjsModuleInstance, isGeneratedSo
   const data = dataFromUrl(filename, sourceMapURL);
   const url = data ? null : sourceMapURL;
   if (cjsModuleInstance) {
-    cjsSourceMapCache.set(cjsModuleInstance, {
+    getCjsSourceMapCache().set(cjsModuleInstance, {
       filename,
       lineLengths: lineLengths(content),
       data,
@@ -291,7 +295,7 @@ function sourceMapCacheToObject() {
 }
 
 function appendCJSCache(obj) {
-  for (const value of cjsSourceMapCache) {
+  for (const value of getCjsSourceMapCache()) {
     obj[ObjectGetValueSafe(value, 'filename')] = {
       lineLengths: ObjectGetValueSafe(value, 'lineLengths'),
       data: ObjectGetValueSafe(value, 'data'),
@@ -309,7 +313,7 @@ function findSourceMap(sourceURL) {
   }
   let sourceMap = esmSourceMapCache.get(sourceURL) ?? generatedSourceMapCache.get(sourceURL);
   if (sourceMap === undefined) {
-    for (const value of cjsSourceMapCache) {
+    for (const value of getCjsSourceMapCache()) {
       const filename = ObjectGetValueSafe(value, 'filename');
       const cachedSourceURL = ObjectGetValueSafe(value, 'sourceURL');
       if (sourceURL === filename || sourceURL === cachedSourceURL) {

test/parallel/test-bootstrap-modules.js

@@ -87,7 +87,6 @@ const expectedModules = new Set([
   'NativeModule internal/util',
   'NativeModule internal/util/debuglog',
   'NativeModule internal/util/inspect',
-  'NativeModule internal/util/iterable_weak_map',
   'NativeModule internal/util/types',
   'NativeModule internal/v8/startup_snapshot',
   'NativeModule internal/validators',