lib: switch to Number.isNaN

Number.isNaN is now as fast as `val !== val`. Switch to the more readable version. Also switch all `isNaN` to `Number.isNaN`. PR-URL: #18744 Reviewed-By: Weijia Wang <[email protected]> Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Yuta Hiroto <[email protected]> Reviewed-By: Luigi Pinca <[email protected]>

Author: BridgeAR

.eslintrc.yaml

@@ -74,6 +74,7 @@ rules:
 message: __defineSetter__ is deprecated.
 no-return-await: error
 no-self-assign: error
+no-self-compare: error
 no-throw-literal: error
 no-unused-labels: error
 no-useless-call: error

lib/_stream_readable.js

@@ -348,7 +348,7 @@ function howMuchToRead(n, state){
 return0;
 if(state.objectMode)
 return1;
-if(n!==n){
+if(Number.isNaN(n)){
 // Only flow one buffer at a time
 if(state.flowing&&state.length)
 returnstate.buffer.head.data.length;

lib/buffer.js

@@ -362,8 +362,7 @@ function fromArrayBuffer(obj, byteOffset, length){
 byteOffset=0;
 }else{
 byteOffset=+byteOffset;
-// check for NaN
-if(byteOffset!==byteOffset)
+if(Number.isNaN(byteOffset))
 byteOffset=0;
 }
 
@@ -375,7 +374,7 @@ function fromArrayBuffer(obj, byteOffset, length){
 if(length===undefined){
 length=maxLength;
 }else{
-// convert length to non-negative integer
+// Convert length to non-negative integer.
 length=+length;
 if(length>0){
 if(length>maxLength)
@@ -757,8 +756,7 @@ function bidirectionalIndexOf(buffer, val, byteOffset, encoding, dir){
 // Coerce to Number. Values like null and [] become 0.
 byteOffset=+byteOffset;
 // If the offset is undefined, "foo",{}, coerces to NaN, search whole buffer.
-// `x !== x`-style conditionals are a faster form of `isNaN(x)`
-if(byteOffset!==byteOffset){
+if(Number.isNaN(byteOffset)){
 byteOffset=dir ? 0 : buffer.length;
 }
 dir=!!dir;// Cast to bool.
@@ -989,15 +987,17 @@ function adjustOffset(offset, length){
 // Use Math.trunc() to convert offset to an integer value that can be larger
 // than an Int32. Hence, don't use offset | 0 or similar techniques.
 offset=Math.trunc(offset);
-// `x !== x`-style conditionals are a faster form of `isNaN(x)`
-if(offset===0||offset!==offset){
+if(offset===0){
 return0;
-}elseif(offset<0){
+}
+if(offset<0){
 offset+=length;
 returnoffset>0 ? offset : 0;
-}else{
-returnoffset<length ? offset : length;
 }
+if(offset<length){
+returnoffset;
+}
+returnNumber.isNaN(offset) ? 0 : length;
 }
 
 

lib/events.js

@@ -52,9 +52,7 @@ Object.defineProperty(EventEmitter, 'defaultMaxListeners',{
 returndefaultMaxListeners;
 },
 set: function(arg){
-// check whether the input is a positive number (whose value is zero or
-// greater and not a NaN).
-if(typeofarg!=='number'||arg<0||arg!==arg){
+if(typeofarg!=='number'||arg<0||Number.isNaN(arg)){
 consterrors=lazyErrors();
 thrownewerrors.TypeError('ERR_OUT_OF_RANGE','defaultMaxListeners');
 }
@@ -76,7 +74,7 @@ EventEmitter.init = function(){
 // Obviously not all Emitters should be limited to 10. This function allows
 // that to be increased. Set to zero for unlimited.
 EventEmitter.prototype.setMaxListeners=functionsetMaxListeners(n){
-if(typeofn!=='number'||n<0||isNaN(n)){
+if(typeofn!=='number'||n<0||Number.isNaN(n)){
 consterrors=lazyErrors();
 thrownewerrors.TypeError('ERR_OUT_OF_RANGE','n');
 }

lib/internal/crypto/random.js

@@ -11,7 +11,7 @@ const{kMaxLength } = require('buffer');
 constkMaxUint32=Math.pow(2,32)-1;
 
 functionassertOffset(offset,length){
-if(typeofoffset!=='number'||offset!==offset){
+if(typeofoffset!=='number'||Number.isNaN(offset)){
 thrownewerrors.TypeError('ERR_INVALID_ARG_TYPE','offset','number');
 }
 
@@ -25,7 +25,7 @@ function assertOffset(offset, length){
 }
 
 functionassertSize(size,offset=0,length=Infinity){
-if(typeofsize!=='number'||size!==size){
+if(typeofsize!=='number'||Number.isNaN(size)){
 thrownewerrors.TypeError('ERR_INVALID_ARG_TYPE','size','number');
 }
 

lib/internal/repl.js

@@ -51,7 +51,7 @@ function createRepl(env, opts, cb){
 }
 
 consthistorySize=Number(env.NODE_REPL_HISTORY_SIZE);
-if(!isNaN(historySize)&&historySize>0){
+if(!Number.isNaN(historySize)&&historySize>0){
 opts.historySize=historySize;
 }else{
 // XXX(chrisdickinson): set here to avoid affecting existing applications

lib/net.js

@@ -1277,7 +1277,7 @@ function createServerHandle(address, port, addressType, fd){
 handle=newPipe(PipeConstants.SERVER);
 if(process.platform==='win32'){
 varinstances=parseInt(process.env.NODE_PENDING_PIPE_INSTANCES);
-if(!isNaN(instances)){
+if(!Number.isNaN(instances)){
 handle.setPendingInstances(instances);
 }
 }

lib/readline.js

@@ -103,7 +103,7 @@ function Interface(input, output, completer, terminal){
 }
 
 if(typeofhistorySize!=='number'||
-isNaN(historySize)||
+Number.isNaN(historySize)||
 historySize<0){
 thrownewerrors.RangeError(
 'ERR_INVALID_OPT_VALUE',

lib/repl.js

@@ -476,7 +476,7 @@ function REPLServer(prompt,
 // display next prompt and return.
 if(trimmedCmd){
 if(trimmedCmd.charAt(0)==='.'&&trimmedCmd.charAt(1)!=='.'&&
-isNaN(parseFloat(trimmedCmd))){
+Number.isNaN(parseFloat(trimmedCmd))){
 constmatches=trimmedCmd.match(/^\.([^\s]+)\s*(.*)$/);
 constkeyword=matches&&matches[1];
 constrest=matches&&matches[2];

lib/zlib.js

@@ -177,7 +177,7 @@ function Zlib(opts, mode){
 
 if(opts){
 chunkSize=opts.chunkSize;
-if(chunkSize!==undefined&&chunkSize===chunkSize){
+if(chunkSize!==undefined&&!Number.isNaN(chunkSize)){
 if(chunkSize<Z_MIN_CHUNK||!Number.isFinite(chunkSize))
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE',
 'chunkSize',
@@ -187,15 +187,15 @@ function Zlib(opts, mode){
 }
 
 flush=opts.flush;
-if(flush!==undefined&&flush===flush){
+if(flush!==undefined&&!Number.isNaN(flush)){
 if(flush<Z_NO_FLUSH||flush>Z_BLOCK||!Number.isFinite(flush))
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE','flush',flush);
 }else{
 flush=Z_NO_FLUSH;
 }
 
 finishFlush=opts.finishFlush;
-if(finishFlush!==undefined&&finishFlush===finishFlush){
+if(finishFlush!==undefined&&!Number.isNaN(finishFlush)){
 if(finishFlush<Z_NO_FLUSH||finishFlush>Z_BLOCK||
 !Number.isFinite(finishFlush)){
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE',
@@ -207,7 +207,7 @@ function Zlib(opts, mode){
 }
 
 windowBits=opts.windowBits;
-if(windowBits!==undefined&&windowBits===windowBits){
+if(windowBits!==undefined&&!Number.isNaN(windowBits)){
 if(windowBits<Z_MIN_WINDOWBITS||windowBits>Z_MAX_WINDOWBITS||
 !Number.isFinite(windowBits)){
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE',
@@ -219,7 +219,7 @@ function Zlib(opts, mode){
 }
 
 level=opts.level;
-if(level!==undefined&&level===level){
+if(level!==undefined&&!Number.isNaN(level)){
 if(level<Z_MIN_LEVEL||level>Z_MAX_LEVEL||
 !Number.isFinite(level)){
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE',
@@ -230,7 +230,7 @@ function Zlib(opts, mode){
 }
 
 memLevel=opts.memLevel;
-if(memLevel!==undefined&&memLevel===memLevel){
+if(memLevel!==undefined&&!Number.isNaN(memLevel)){
 if(memLevel<Z_MIN_MEMLEVEL||memLevel>Z_MAX_MEMLEVEL||
 !Number.isFinite(memLevel)){
 thrownewerrors.RangeError('ERR_INVALID_OPT_VALUE',
@@ -241,7 +241,7 @@ function Zlib(opts, mode){
 }
 
 strategy=opts.strategy;
-if(strategy!==undefined&&strategy===strategy){
+if(strategy!==undefined&&!Number.isNaN(strategy)){
 if(strategy<Z_DEFAULT_STRATEGY||strategy>Z_FIXED||
 !Number.isFinite(strategy)){
 thrownewerrors.TypeError('ERR_INVALID_OPT_VALUE',