lib: load fewer builtins when bootstrapping without a snapshot

Contexts that are not deserialized from the built-in snapshot -- worker
threads, and the main context of embedders that create their own
isolate or of `node --no-node-snapshot` -- compile (with the code cache
at best) every builtin the bootstrap touches, so each eagerly required
builtin is startup time (~0.15-0.4 ms apiece). A number of them are only
required eagerly so that they end up in the snapshot, or for features
the bootstrap path never uses.
Load lazily what those paths do not need:
- is_main_thread.js: preload util, url, the ESM loader (translators,
resolver, module_job/map, source maps, node:module, vm modules, mime,
data_url, the TypeScript stripper), internal/blob and
internal/dns/utils only while building a snapshot; they load on first
use otherwise.
- fs: internal/blob (+ internal/encoding and its tables) is only used
by fs.openAsBlob().
- internal/url: internal/data_url (+ internal/mime) is only used by the
Buffer-returning file URL helpers.
- internal/process/execution, the CommonJS loader, esm/translators and
esm/load: the TypeScript stripper and data: URL helpers are only
needed for TypeScript sources / data: URLs.
- pre_execution: internal/dns/utils (+ internal/net) is only needed up
front to validate an explicit --dns-result-order or to register the
resolver's snapshot serializer; the default order becomes the
variable's initializer.
- internal/worker: event_loop_utilization and error_serdes are only
needed once a sub-worker's ELU is read or it reports an error.
- worker_threads: `locks` is defined lazily, like util's lazy exports.
Main-thread startup with the snapshot is unchanged (the same modules
are preloaded into it; the bootstrap-modules test lists are adjusted).
A bare worker compiles 95 -> 83 builtins (cold start -5%); without the
snapshot an empty CommonJS entry point compiles 76 -> 59 builtins and an
empty ES module entry point 76 -> 69.
Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
PR-URL: #65329
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Aviv Keller <me@aviv.sh>

Author: codebytere

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of

lib/fs.js

@@ -64,8 +64,6 @@ const { isArrayBufferView } = require('internal/util/types');
 
 constbinding=internalBinding('fs');
 
-const{ createBlobFromFilePath }=require('internal/blob');
-
 const{ Buffer }=require('buffer');
 const{isBuffer: BufferIsBuffer}=Buffer;
 constBufferToString=uncurryThis(Buffer.prototype.toString);
@@ -784,6 +782,7 @@ function openAsBlob(path, options = kEmptyObject) {
 // To give ourselves flexibility to maybe return the Blob asynchronously,
 // this API returns a Promise.
 path=getValidatedPath(path);
+const{ createBlobFromFilePath }=require('internal/blob');
 returnPromiseResolve(createBlobFromFilePath(path,{ type }));
 }
 

lib/internal/bootstrap/switches/is_main_thread.js

@@ -292,12 +292,27 @@ rawMethods.resetStdioForTesting = function() {
 
 // Needed by the module loader and generally needed everywhere.
 require('fs');
-require('util');
-require('url');// eslint-disable-line no-restricted-modules
 internalBinding('module_wrap');
 require('internal/modules/cjs/loader');
-require('internal/modules/esm/loader');
 require('internal/modules/esm/utils');
+if(isBuildingSnapshot()){
+// Preloaded so that they are part of the snapshot, where they cost nothing
+// at startup. When bootstrapping WITHOUT a snapshot (worker threads,
+// embedders that create their own isolate, --no-node-snapshot) they are
+// loaded on first use instead: the ESM loader (with its translators,
+// resolver and their dependencies) by run_main/import(), the public util
+// and url modules by whoever requires them, data: URL and TypeScript
+// support by the module loaders, internal/blob by fs.openAsBlob(), and the
+// DNS helpers by node:dns or an explicit --dns-result-order (see
+// pre_execution).
+require('util');
+require('url');// eslint-disable-line no-restricted-modules
+require('internal/modules/esm/loader');
+require('internal/data_url');
+require('internal/modules/typescript');
+require('internal/blob');
+require('internal/dns/utils');
+}
 
 // Needed to refresh the time origin.
 require('internal/perf/utils');
@@ -311,8 +326,6 @@ internalBinding('wasm_web_api');
 internalBinding('worker');
 // Needed by most execution modes.
 require('internal/modules/run_main');
-// Needed to refresh DNS configurations.
-require('internal/dns/utils');
 // Needed by almost all execution modes. It's fine to
 // load them into the snapshot as long as we don't run
 // any of the initialization.

lib/internal/dns/utils.js

@@ -214,15 +214,15 @@ class ResolverBase {
 }
 
 letdefaultResolver;
-letdnsOrder;
+// May already hold a value chosen by the snapshotted application; a
+// --dns-result-order flag given at runtime overrides it in initializeDns().
+letdnsOrder='verbatim';
 constvalidDnsOrders=['verbatim','ipv4first','ipv6first'];
 constvalidFamilies=[0,4,6];
 
 functioninitializeDns(){
 constorderFromCLI=getOptionValue('--dns-result-order');
-if(!orderFromCLI){
-dnsOrder??='verbatim';
-}else{
+if(orderFromCLI){
 // Allow the deserialized application to override order from CLI.
 validateOneOf(orderFromCLI,'--dns-result-order',validDnsOrders);
 dnsOrder=orderFromCLI;

lib/internal/modules/cjs/loader.js

@@ -180,7 +180,7 @@ const {
  resolveWithHooks,
  validateLoadStrict,
 }=require('internal/modules/customization_hooks');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+constlazyTypeScript=getLazy(()=>require('internal/modules/typescript'));
 constpackageJsonReader=require('internal/modules/package_json_reader');
 const{ getOptionValue, getEmbedderOptions }=require('internal/options');
 constshouldReportRequiredModules=getLazy(()=>process.env.WATCH_REPORT_DEPENDENCIES);
@@ -1885,7 +1885,7 @@ function wrapSafe(filename, content, cjsModuleInstance, format) {
 Module.prototype._compile=function(content,filename,format){
 if(format==='commonjs-typescript'||format==='module-typescript'||format==='typescript'){
 this[kURL]??=convertCJSFilenameToURL(filename);
-content=stripTypeScriptModuleTypes(content,filename,this[kURL]);
+content=lazyTypeScript().stripTypeScriptModuleTypes(content,filename,this[kURL]);
 switch(format){
 case'commonjs-typescript': {
 format='commonjs';

lib/internal/modules/esm/load.js

@@ -20,9 +20,6 @@ const {
 ERR_UNSUPPORTED_ESM_URL_SCHEME,
 }=require('internal/errors').codes;
 
-const{
- dataURLProcessor,
-}=require('internal/data_url');
 
 /**
  * @param {URL} url URL to the module
@@ -40,6 +37,7 @@ function getSourceSync(url, context) {
 // Prefer module.registerHooks() or other more formal fs hooks released in the future.
 source=fs.readFileSync(url);
 }elseif(protocol==='data:'){
+const{ dataURLProcessor }=require('internal/data_url');// Only for data: URLs.
 constresult=dataURLProcessor(url);
 if(result==='failure'){
 thrownewERR_INVALID_URL(responseURL);

lib/internal/modules/esm/translators.js

@@ -30,7 +30,10 @@ const {
  stripBOM,
  urlToFilename,
 }=require('internal/modules/helpers');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,url){
+// Only needed for TypeScript sources; keep it out of the loader's startup path.
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,url);
+}
 const{
  kIsCachedByESMLoader,
 Module: CJSModule,

lib/internal/process/execution.js

@@ -25,7 +25,9 @@ const {
  kSourcePhase,
  kEvaluationPhase,
 }=internalBinding('module_wrap');
-const{ stripTypeScriptModuleTypes }=require('internal/modules/typescript');
+functionstripTypeScriptModuleTypes(source,filename){
+returnrequire('internal/modules/typescript').stripTypeScriptModuleTypes(source,filename);
+}
 
 const{
  executionAsyncId,

lib/internal/process/pre_execution.js

@@ -137,7 +137,12 @@ function prepareExecution(options) {
 
 initializeConfigFileSupport();
 
-require('internal/dns/utils').initializeDns();
+// internal/dns/utils (and internal/net behind it) is only needed up front
+// to validate an explicit --dns-result-order or to register the resolver's
+// snapshot serialization; otherwise it is loaded with node:dns.
+if(getOptionValue('--dns-result-order')||isBuildingSnapshot()){
+require('internal/dns/utils').initializeDns();
+}
 
 if(isMainThread){
 assert(internalBinding('worker').isMainThread);

lib/internal/url.js

@@ -93,7 +93,11 @@ const {
  kValidateObjectAllowObjects,
 }=require('internal/validators');
 
-const{ percentDecode }=require('internal/data_url');
+letpercentDecode;
+functionlazyPercentDecode(input){
+percentDecode??=require('internal/data_url').percentDecode;
+returnpercentDecode(input);
+}
 
 constquerystring=require('querystring');
 
@@ -1560,7 +1564,7 @@ function getPathBufferFromURLWin32(url) {
 // percent encoded characters and we take the string as is. Any invalid
 // percent encodings, e.g. `%ZZ` are ignored and are passed through
 // literally.
-constdecodedu8=percentDecode(Buffer.from(pathname,'utf8'));
+constdecodedu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 constdecodedPathname=Buffer.from(TypedArrayPrototypeGetBuffer(decodedu8),
 TypedArrayPrototypeGetByteOffset(decodedu8),
 TypedArrayPrototypeGetByteLength(decodedu8));
@@ -1635,7 +1639,7 @@ function getPathBufferFromURLPosix(url) {
 // won't scan for the slashes at all, and instead will decode the bytes
 // literally into the returned Buffer. We're going to do the best we can and
 // just interpret the input url as a sequence of bytes.
-constu8=percentDecode(Buffer.from(pathname,'utf8'));
+constu8=lazyPercentDecode(Buffer.from(pathname,'utf8'));
 returnBuffer.from(TypedArrayPrototypeGetBuffer(u8),
 TypedArrayPrototypeGetByteOffset(u8),
 TypedArrayPrototypeGetByteLength(u8));

lib/internal/worker.js

@@ -30,10 +30,6 @@ const {
 constEventEmitter=require('events');
 constassert=require('internal/assert');
 constpath=require('path');
-const{
- internalEventLoopUtilization,
-}=require('internal/perf/event_loop_utilization');
-
 consterrorCodes=require('internal/errors').codes;
 const{
 ERR_WORKER_NOT_RUNNING,
@@ -60,7 +56,6 @@ const {
  WritableWorkerStdio,
 }=workerIo;
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
-const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 const{
  constructSharedArrayBuffer,
@@ -415,6 +410,7 @@ class Worker extends EventEmitter {
 
 [kOnErrorMessage](serialized){
 // This is what is called for uncaught exceptions.
+const{ deserializeError }=require('internal/error_serdes');
 consterror=deserializeError(serialized);
 this.emit('error',error);
 }
@@ -697,6 +693,7 @@ function makeResourceLimits(float64arr) {
 }
 
 functioneventLoopUtilization(util1,util2){
+const{ internalEventLoopUtilization }=require('internal/perf/event_loop_utilization');
 // TODO(trevnorris): Works to solve the thread-safe read/write issue of
 // loopTime, but has the drawback that it can't be set until the event loop
 // has had a chance to turn. So it will be impossible to read the ELU of