debugger: refactor _debugger.js

* `==` -> `===`
* use white space in array to improve readability

PR-URL: https://github.com/nodejs/node/pull/9860
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/_debugger.js

@@ -186,7 +186,7 @@ Client.prototype._addScript = function(desc) {
   this.scripts[desc.id] = desc;
   if (desc.name) {
     desc.isNative = (desc.name.replace('.js', '') in natives) ||
-                    desc.name == 'node.js';
+                    desc.name === 'node.js';
   }
 };
 
@@ -201,7 +201,7 @@ Client.prototype._onResponse = function(res) {
   var index = -1;
 
   this._reqCallbacks.some(function(fn, i) {
-    if (fn.request_seq == res.body.request_seq) {
+    if (fn.request_seq === res.body.request_seq) {
       cb = fn;
       index = i;
       return true;
@@ -211,25 +211,25 @@ Client.prototype._onResponse = function(res) {
   var self = this;
   var handled = false;
 
-  if (res.headers.Type == 'connect') {
+  if (res.headers.Type === 'connect') {
     // Request a list of scripts for our own storage.
     self.reqScripts();
     self.emit('ready');
     handled = true;
 
-  } else if (res.body && res.body.event == 'break') {
+  } else if (res.body && res.body.event === 'break') {
     this.emit('break', res.body);
     handled = true;
 
-  } else if (res.body && res.body.event == 'exception') {
+  } else if (res.body && res.body.event === 'exception') {
     this.emit('exception', res.body);
     handled = true;
 
-  } else if (res.body && res.body.event == 'afterCompile') {
+  } else if (res.body && res.body.event === 'afterCompile') {
     this._addHandle(res.body.body.script);
     handled = true;
 
-  } else if (res.body && res.body.event == 'scriptCollected') {
+  } else if (res.body && res.body.event === 'scriptCollected') {
     // ???
     this._removeScript(res.body.body.script);
     handled = true;
@@ -327,7 +327,7 @@ Client.prototype.reqScopes = function(cb) {
 Client.prototype.reqEval = function(expression, cb) {
   var self = this;
 
-  if (this.currentFrame == NO_FRAME) {
+  if (this.currentFrame === NO_FRAME) {
     // Only need to eval in global scope.
     this.reqFrameEval(expression, NO_FRAME, cb);
     return;
@@ -357,7 +357,7 @@ Client.prototype.reqEval = function(expression, cb) {
 
 // Finds the first scope in the array in which the expression evals.
 Client.prototype._reqFramesEval = function(expression, evalFrames, cb) {
-  if (evalFrames.length == 0) {
+  if (evalFrames.length === 0) {
     // Just eval in global scope.
     this.reqFrameEval(expression, NO_FRAME, cb);
     return;
@@ -381,7 +381,7 @@ Client.prototype.reqFrameEval = function(expression, frame, cb) {
     arguments: { expression: expression }
   };
 
-  if (frame == NO_FRAME) {
+  if (frame === NO_FRAME) {
     req.arguments.global = true;
   } else {
     req.arguments.frame = frame;
@@ -528,9 +528,9 @@ Client.prototype.mirrorObject = function(handle, depth, cb) {
       var mirror;
       var waiting = 1;
 
-      if (handle.className == 'Array') {
+      if (handle.className === 'Array') {
         mirror = [];
-      } else if (handle.className == 'Date') {
+      } else if (handle.className === 'Date') {
         mirror = new Date(handle.value);
       } else {
         mirror = {};
@@ -770,10 +770,20 @@ function Interface(stdin, stdout, args) {
   process.once('SIGHUP', process.exit.bind(process, 0));
 
   var proto = Interface.prototype;
-  const ignored = ['pause', 'resume', 'exitRepl', 'handleBreak',
-                   'requireConnection', 'killChild', 'trySpawn',
-                   'controlEval', 'debugEval', 'print', 'childPrint',
-                   'clearline'];
+  const ignored = [
+    'pause',
+    'resume',
+    'exitRepl',
+    'handleBreak',
+    'requireConnection',
+    'killChild',
+    'trySpawn',
+    'controlEval',
+    'debugEval',
+    'print',
+    'childPrint',
+    'clearline'
+  ];
   const shortcut = {
     'run': 'r',
     'cont': 'c',
@@ -1093,14 +1103,14 @@ Interface.prototype.list = function(delta) {
       var lineno = res.fromLine + i + 1;
       if (lineno < from || lineno > to) continue;
 
-      const current = lineno == 1 + client.currentSourceLine;
+      const current = lineno === 1 + client.currentSourceLine;
       const breakpoint = client.breakpoints.some(function(bp) {
         return (bp.scriptReq === client.currentScript ||
                 bp.script === client.currentScript) &&
-                bp.line == lineno;
+                bp.line === lineno;
       });
 
-      if (lineno == 1) {
+      if (lineno === 1) {
         // The first line needs to have the module wrapper filtered out of
         // it.
         var wrapper = Module.wrapper[0];
@@ -1147,7 +1157,7 @@ Interface.prototype.backtrace = function() {
       return;
     }
 
-    if (bt.totalFrames == 0) {
+    if (bt.totalFrames === 0) {
       self.print('(empty stack)');
     } else {
       const trace = [];
@@ -1189,10 +1199,10 @@ Interface.prototype.scripts = function() {
     var script = client.scripts[id];
     if (script !== null && typeof script === 'object' && script.name) {
       if (displayNatives ||
-          script.name == client.currentScript ||
+          script.name === client.currentScript ||
           !script.isNative) {
         scripts.push(
-            (script.name == client.currentScript ? '* ' : '  ') +
+            (script.name === client.currentScript ? '* ' : '  ') +
             id + ': ' +
             path.basename(script.name)
         );