lib: remove unnecessary lazy loads

Now that more modules are included in the snapshot, it's not
necessary to lazy load them anymore

PR-URL: #38737
Refs: #35711
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: joyeecheung

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

@@ -66,9 +66,8 @@ const { validateObject } = require('internal/validators');
 
 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);
@@ -171,8 +170,6 @@ 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;
   }
@@ -334,8 +331,6 @@ 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.
@@ -1362,8 +1357,5 @@ 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) {

test/parallel/test-bootstrap-modules.js

@@ -93,6 +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',
@@ -116,6 +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',