lib: support fs_event_wrap in the snapshot and load more modules eagerly

lib/fs.js

@@ -138,13 +138,14 @@ const {
   validateInteger,
 } = require('internal/validators');
 
+const watchers = require('internal/fs/watchers');
+const ReadFileContext = require('internal/fs/read_file_context');
+
 let truncateWarn = true;
 let fs;
 
 // Lazy loaded
 let promises = null;
-let watchers;
-let ReadFileContext;
 let ReadStream;
 let WriteStream;
 let rimraf;
@@ -369,8 +370,6 @@ function checkAborted(signal, callback) {
 function readFile(path, options, callback) {
   callback = maybeCallback(callback || options);
   options = getOptions(options, { flag: 'r' });
-  if (!ReadFileContext)
-    ReadFileContext = require('internal/fs/read_file_context');
   const context = new ReadFileContext(callback, options.encoding);
   context.isUserFd = isFd(path); // File descriptor ownership
 
@@ -2234,8 +2233,6 @@ function watch(filename, options, listener) {
   if (options.recursive === undefined) options.recursive = false;
   if (options.recursive && !(isOSX || isWindows))
     throw new ERR_FEATURE_UNAVAILABLE_ON_PLATFORM('watch recursively');
-  if (!watchers)
-    watchers = require('internal/fs/watchers');
   const watcher = new watchers.FSWatcher();
   watcher[watchers.kFSWatchStart](filename,
                                   options.persistent,
@@ -2301,8 +2298,6 @@ function watchFile(filename, options, listener) {
   stat = statWatchers.get(filename);
 
   if (stat === undefined) {
-    if (!watchers)
-      watchers = require('internal/fs/watchers');
     stat = new watchers.StatWatcher(options.bigint);
     stat[watchers.kFSStatWatcherStart](filename,
                                        options.persistent, options.interval);

lib/internal/crypto/cipher.js

@@ -60,8 +60,7 @@ const LazyTransform = require('internal/streams/lazy_transform');
 
 const { normalizeEncoding } = require('internal/util');
 
-// Lazy loaded for startup performance.
-let StringDecoder;
+const { StringDecoder } = require('string_decoder');
 
 function rsaFunctionFor(method, defaultPadding, keyType) {
   return (options, buffer) => {
@@ -93,8 +92,6 @@ const privateDecrypt = rsaFunctionFor(_privateDecrypt, RSA_PKCS1_OAEP_PADDING,
 
 function getDecoder(decoder, encoding) {
   encoding = normalizeEncoding(encoding);
-  if (StringDecoder === undefined)
-    StringDecoder = require('string_decoder').StringDecoder;
   decoder = decoder || new StringDecoder(encoding);
   assert(decoder.encoding === encoding, 'Cannot change encoding');
   return decoder;

lib/internal/streams/pipeline.js

@@ -8,7 +8,7 @@ const {
   SymbolAsyncIterator,
 } = primordials;
 
-let eos;
+const eos = require('internal/streams/end-of-stream');
 
 const { once } = require('internal/util');
 const destroyImpl = require('internal/streams/destroy');
@@ -39,7 +39,6 @@ function destroyer(stream, reading, writing, callback) {
     finished = true;
   });
 
-  if (eos === undefined) eos = require('internal/streams/end-of-stream');
   eos(stream, { readable: reading, writable: writing }, (err) => {
     finished = !err;
 

lib/internal/streams/readable.js

@@ -65,9 +65,8 @@ const {
 
 const kPaused = Symbol('kPaused');
 
-// Lazy loaded to improve the startup performance.
-let StringDecoder;
-let from;
+const { StringDecoder } = require('string_decoder');
+const from = require('internal/streams/from');
 
 ObjectSetPrototypeOf(Readable.prototype, Stream.prototype);
 ObjectSetPrototypeOf(Readable, Stream);
@@ -170,8 +169,6 @@ function ReadableState(options, stream, isDuplex) {
   this.decoder = null;
   this.encoding = null;
   if (options && options.encoding) {
-    if (!StringDecoder)
-      StringDecoder = require('string_decoder').StringDecoder;
     this.decoder = new StringDecoder(options.encoding);
     this.encoding = options.encoding;
   }
@@ -333,8 +330,6 @@ Readable.prototype.isPaused = function() {
 
 // Backwards compatibility.
 Readable.prototype.setEncoding = function(enc) {
-  if (!StringDecoder)
-    StringDecoder = require('string_decoder').StringDecoder;
   const decoder = new StringDecoder(enc);
   this._readableState.decoder = decoder;
   // If setEncoding(null), decoder.encoding equals utf8.
@@ -1340,8 +1335,5 @@ function endWritableNT(state, stream) {
 }
 
 Readable.from = function(iterable, opts) {
-  if (from === undefined) {
-    from = require('internal/streams/from');
-  }
   return from(Readable, iterable, opts);
 };

lib/stream.js

@@ -33,8 +33,7 @@ const pipeline = require('internal/streams/pipeline');
 const eos = require('internal/streams/end-of-stream');
 const internalBuffer = require('internal/buffer');
 
-// Lazy loaded
-let promises = null;
+const promises = require('stream/promises');
 
 const Stream = module.exports = require('internal/streams/legacy').Stream;
 Stream.Readable = require('internal/streams/readable');
@@ -47,30 +46,25 @@ const { addAbortSignal } = require('internal/streams/add-abort-signal');
 Stream.addAbortSignal = addAbortSignal;
 Stream.finished = eos;
 
-function lazyLoadPromises() {
-  if (promises === null) promises = require('stream/promises');
-  return promises;
-}
-
 ObjectDefineProperty(Stream, 'promises', {
   configurable: true,
   enumerable: true,
   get() {
-    return lazyLoadPromises();
+    return promises;
   }
 });
 
 ObjectDefineProperty(pipeline, customPromisify, {
   enumerable: true,
   get() {
-    return lazyLoadPromises().pipeline;
+    return promises.pipeline;
   }
 });
 
 ObjectDefineProperty(eos, customPromisify, {
   enumerable: true,
   get() {
-    return lazyLoadPromises().finished;
+    return promises.finished;
   }
 });
 

lib/stream/promises.js

@@ -18,11 +18,10 @@ const {
   isStream,
 } = require('internal/streams/utils');
 
-let pl;
-let eos;
+const pl = require('internal/streams/pipeline');
+const eos = require('internal/streams/end-of-stream');
 
 function pipeline(...streams) {
-  if (!pl) pl = require('internal/streams/pipeline');
   return new Promise((resolve, reject) => {
     let signal;
     const lastArg = streams[streams.length - 1];
@@ -47,7 +46,6 @@ function pipeline(...streams) {
 }
 
 function finished(stream, opts) {
-  if (!eos) eos = require('internal/streams/end-of-stream');
   return new Promise((resolve, reject) => {
     eos(stream, opts, (err) => {
       if (err) {

src/fs_event_wrap.cc

@@ -21,11 +21,11 @@
 
 #include "async_wrap-inl.h"
 #include "env-inl.h"
-#include "node.h"
 #include "handle_wrap.h"
+#include "node.h"
+#include "node_external_reference.h"
 #include "string_bytes.h"
 
-
 namespace node {
 
 using v8::Context;
@@ -52,6 +52,7 @@ class FSEventWrap: public HandleWrap {
                          Local<Value> unused,
                          Local<Context> context,
                          void* priv);
+  static void RegisterExternalReferences(ExternalReferenceRegistry* registry);
   static void New(const FunctionCallbackInfo<Value>& args);
   static void Start(const FunctionCallbackInfo<Value>& args);
   static void GetInitialized(const FunctionCallbackInfo<Value>& args);
@@ -117,6 +118,12 @@ void FSEventWrap::Initialize(Local<Object> target,
   env->SetConstructorFunction(target, "FSEvent", t);
 }
 
+void FSEventWrap::RegisterExternalReferences(
+    ExternalReferenceRegistry* registry) {
+  registry->Register(New);
+  registry->Register(Start);
+  registry->Register(GetInitialized);
+}
 
 void FSEventWrap::New(const FunctionCallbackInfo<Value>& args) {
   CHECK(args.IsConstructCall());
@@ -229,3 +236,5 @@ void FSEventWrap::OnEvent(uv_fs_event_t* handle, const char* filename,
 }  // namespace node
 
 NODE_MODULE_CONTEXT_AWARE_INTERNAL(fs_event_wrap, node::FSEventWrap::Initialize)
+NODE_MODULE_EXTERNAL_REFERENCE(fs_event_wrap,
+                               node::FSEventWrap::RegisterExternalReferences)

src/node_external_reference.h

@@ -56,6 +56,7 @@ class ExternalReferenceRegistry {
   V(errors)                                                                    \
   V(fs)                                                                        \
   V(fs_dir)                                                                    \
+  V(fs_event_wrap)                                                             \
   V(handle_wrap)                                                               \
   V(heap_utils)                                                                \
   V(messaging)                                                                 \

test/parallel/test-bootstrap-modules.js

@@ -56,6 +56,7 @@ const expectedModules = new Set([
   'NativeModule internal/fs/dir',
   'NativeModule internal/fs/utils',
   'NativeModule internal/fs/promises',
+  'NativeModule internal/fs/read_file_context',
   'NativeModule internal/fs/rimraf',
   'NativeModule internal/fs/watchers',
   'NativeModule internal/heap_utils',
@@ -92,6 +93,7 @@ const expectedModules = new Set([
   'NativeModule internal/streams/destroy',
   'NativeModule internal/streams/duplex',
   'NativeModule internal/streams/end-of-stream',
+  'NativeModule internal/streams/from',
   'NativeModule internal/streams/legacy',
   'NativeModule internal/streams/passthrough',
   'NativeModule internal/streams/pipeline',
@@ -115,6 +117,8 @@ const expectedModules = new Set([
   'NativeModule async_hooks',
   'NativeModule path',
   'NativeModule stream',
+  'NativeModule stream/promises',
+  'NativeModule string_decoder',
   'NativeModule timers',
   'NativeModule url',
   'NativeModule util',