DevTools: object formatter renders arrays the same way as printArrayResult()

third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js

Index: third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js
diff --git a/third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js b/third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js
index 40c57590953542fb5f39dbb1c92aae913e42ddd1..d699ac7ab4ae2f8344bf17043dd920dd55d44fdf 100644
--- a/third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js
+++ b/third_party/WebKit/Source/devtools/front_end/components/RemoteObjectPreviewFormatter.js
@@ -16,14 +16,22 @@ Components.RemoteObjectPreviewFormatter = class {
       parentElement.appendChild(this.renderPropertyPreview(preview.type, preview.subtype, description));
       return;
     }
-    if (description && preview.subtype !== 'array' && preview.subtype !== 'typedarray') {
+    var isArray = preview.subtype === 'array' || preview.subtype === 'typedarray';
+    if (description && !isArray) {
       var text = preview.subtype ? description : this._abbreviateFullQualifiedClassName(description);
       parentElement.createTextChildren(text, ' ');
     }
+
+    parentElement.createTextChild(isArray ? '[' : '{');
     if (preview.entries)
       this._appendEntriesPreview(parentElement, preview);
+    else if (isArray)
+      this._appendArrayPropertiesPreview(parentElement, preview, objectForAccessing);
     else
       this._appendPropertiesPreview(parentElement, preview, objectForAccessing);
+    if (preview.overflow)
+      parentElement.createChild('span').textContent = '\u2026';
+    parentElement.createTextChild(isArray ? ']' : '}');
   }
 
   /**
@@ -43,13 +51,7 @@ Components.RemoteObjectPreviewFormatter = class {
    * @param {!SDK.RemoteObject=} objectForAccessing
    */
   _appendPropertiesPreview(parentElement, preview, objectForAccessing) {
-    var isArray = preview.subtype === 'array' || preview.subtype === 'typedarray';
-    var arrayLength = SDK.RemoteObject.arrayLength(preview);
-    var properties = preview.properties;
-    if (isArray)
-      properties = properties.slice().stableSort(compareIndexesFirst);
-    else
-      properties = properties.slice().stableSort(compareFunctionsLast);
+    var properties = preview.properties.slice().stableSort(compareFunctionsLast);
 
     /**
      * @param {!Protocol.Runtime.PropertyPreview} a
@@ -63,6 +65,59 @@ Components.RemoteObjectPreviewFormatter = class {
       return 0;
     }
 
+    for (var i = 0; i < properties.length; ++i) {
+      if (i > 0)
+        parentElement.createTextChild(', ');
+
+      var property = properties[i];
+      var name = property.name;
+      if (/^\s|\s$|^$|\n/.test(name))
+        parentElement.createChild('span', 'name').createTextChildren('"', name.replace(/\n/g, '\u21B5'), '"');
+      else
+        parentElement.createChild('span', 'name').textContent = name;
+      parentElement.createTextChild(': ');
+      parentElement.appendChild(this.renderPropertyPreviewOrAccessor([property], objectForAccessing));
+    }
+  }
+
+  /**
+   * @param {!Element} parentElement
+   * @param {!Protocol.Runtime.ObjectPreview} preview
+   * @param {!SDK.RemoteObject=} objectForAccessing
+   */
+  _appendArrayPropertiesPreview(parentElement, preview, objectForAccessing) {
+    var arrayLength = SDK.RemoteObject.arrayLength(preview);
+    var properties = preview.properties.slice().stableSort(compareIndexesFirst);
+    var lastNonEmptyArrayIndex = -1;
+    for (var i = 0; i < properties.length; ++i) {
+      var property = properties[i];
+      var name = property.name;
+      if (isNaN(name))
+        continue;
+      if (i > 0)
+        parentElement.createTextChild(', ');
+      var index = parseInt(name, 10);
+      if (index - lastNonEmptyArrayIndex > 1) {
+        appendUndefined(index);
+        parentElement.createTextChild(', ');
+      }
+      parentElement.appendChild(this.renderPropertyPreviewOrAccessor([property], objectForAccessing));
+      lastNonEmptyArrayIndex = index;
+    }
+    if (lastNonEmptyArrayIndex > -1 && arrayLength - lastNonEmptyArrayIndex > 1) {
+      parentElement.createTextChild(', ');
+      appendUndefined(arrayLength);
+    }
+
+    /**
+     * @param {number} index
+     */
+    function appendUndefined(index) {
+      var span = parentElement.createChild('span', 'object-value-undefined');
+      var gapSize = index - lastNonEmptyArrayIndex - 1;
+      span.textContent = gapSize > 1 ? Common.UIString('undefined × %d', gapSize) : Common.UIString('undefined');
+    }
+
     /**
      * @param {!Protocol.Runtime.PropertyPreview} a
      * @param {!Protocol.Runtime.PropertyPreview} b
@@ -85,27 +140,6 @@ Components.RemoteObjectPreviewFormatter = class {
         return index;
       return -1;
     }
-
-    parentElement.createTextChild(isArray ? '[' : '{');
-    for (var i = 0; i < properties.length; ++i) {
-      if (i > 0)
-        parentElement.createTextChild(', ');
-
-      var property = properties[i];
-      var name = property.name;
-      if (!isArray || name !== String(i) || i >= arrayLength) {
-        if (/^\s|\s$|^$|\n/.test(name))
-          parentElement.createChild('span', 'name').createTextChildren('"', name.replace(/\n/g, '\u21B5'), '"');
-        else
-          parentElement.createChild('span', 'name').textContent = name;
-        parentElement.createTextChild(': ');
-      }
-
-      parentElement.appendChild(this.renderPropertyPreviewOrAccessor([property], objectForAccessing));
-    }
-    if (preview.overflow)
-      parentElement.createChild('span').textContent = '\u2026';
-    parentElement.createTextChild(isArray ? ']' : '}');
   }
 
   /**
@@ -113,7 +147,6 @@ Components.RemoteObjectPreviewFormatter = class {
    * @param {!Protocol.Runtime.ObjectPreview} preview
    */
   _appendEntriesPreview(parentElement, preview) {
-    parentElement.createTextChild('{');
     for (var i = 0; i < preview.entries.length; ++i) {
       if (i > 0)
         parentElement.createTextChild(', ');
@@ -125,9 +158,6 @@ Components.RemoteObjectPreviewFormatter = class {
       }
       this.appendObjectPreview(parentElement, entry.value);
     }
-    if (preview.overflow)
-      parentElement.createChild('span').textContent = '\u2026';
-    parentElement.createTextChild('}');
   }
 
   /**