Use null-prototype objects for maps

A {} has a bunch of names already defined on it (like ‘toString’).  When using an object as a map with arbitrary keys, it should not inherit from Object.prototype.

build.py

@@ -135,7 +135,7 @@ this.BLOCKLY_BOOT = function(root) {
 
     f.write('\n')
     f.write('// Load Blockly.\n')
-    f.write('goog.require(\'Blockly.requires\')\n')
+    f.write('goog.require(\'Blockly.requires\');\n')
 
     f.write("""
 delete root.BLOCKLY_DIR;

core/component_manager.js

@@ -28,14 +28,14 @@ Blockly.ComponentManager = function() {
    * @type {!Object<string, !Blockly.ComponentManager.ComponentDatum>}
    * @private
    */
-  this.componentData_ = {};
+  this.componentData_ = Object.create(null);
 
   /**
-   * A map of capabilities to component ids.
-   * @type {!Object<string, Array<string>>}
+   * A map of capabilities to component IDs.
+   * @type {!Object<string, !Array<string>>}
    * @private
    */
-  this.capabilityToComponentIds_ = {};
+  this.capabilityToComponentIds_ = Object.create(null);
 };
 
 /**

core/contextmenu_registry.js

@@ -31,11 +31,11 @@ Blockly.ContextMenuRegistry = function() {
   Blockly.ContextMenuRegistry.registry = this;
 
   /**
-   * Registry of all registered RegistryItems, keyed by id.
-   * @type {!Object<string, Blockly.ContextMenuRegistry.RegistryItem>}
+   * Registry of all registered RegistryItems, keyed by ID.
+   * @type {!Object<string, !Blockly.ContextMenuRegistry.RegistryItem>}
    * @private
    */
-  this.registry_ = {};
+  this.registry_ = Object.create(null);
 };
 
 /**
@@ -97,7 +97,7 @@ Blockly.ContextMenuRegistry.registry = null;
  */
 Blockly.ContextMenuRegistry.prototype.register = function(item) {
   if (this.registry_[item.id]) {
-    throw Error('Menu item with id "' + item.id + '" is already registered.');
+    throw Error('Menu item with ID "' + item.id + '" is already registered.');
   }
   this.registry_[item.id] = item;
 };
@@ -108,11 +108,10 @@ Blockly.ContextMenuRegistry.prototype.register = function(item) {
  * @throws {Error} if an item with the given ID does not exist.
  */
 Blockly.ContextMenuRegistry.prototype.unregister = function(id) {
-  if (this.registry_[id]) {
-    delete this.registry_[id];
-  } else {
-    throw new Error('Menu item with id "' + id + '" not found.');
+  if (!this.registry_[id]) {
+    throw new Error('Menu item with ID "' + id + '" not found.');
   }
+  delete this.registry_[id];
 };
 
 /**
@@ -120,10 +119,7 @@ Blockly.ContextMenuRegistry.prototype.unregister = function(id) {
  * @return {?Blockly.ContextMenuRegistry.RegistryItem} RegistryItem or null if not found
  */
 Blockly.ContextMenuRegistry.prototype.getItem = function(id) {
-  if (this.registry_[id]) {
-    return this.registry_[id];
-  }
-  return null;
+  return this.registry_[id] || null;
 };
 
 /**

core/extensions.js

@@ -28,7 +28,7 @@ goog.requireType('Blockly.Block');
  * The set of all registered extensions, keyed by extension name/id.
  * @private
  */
-Blockly.Extensions.ALL_ = {};
+Blockly.Extensions.ALL_ = Object.create(null);
 
 /**
  * Registers a new extension function. Extensions are functions that help

core/names.js

@@ -228,5 +228,6 @@ Blockly.Names.prototype.safeName_ = function(name) {
  * @return {boolean} True if names are the same.
  */
 Blockly.Names.equals = function(name1, name2) {
+  // name1.localeCompare(name2) is slower.
   return name1.toLowerCase() == name2.toLowerCase();
 };

core/procedures.js

@@ -404,7 +404,7 @@ Blockly.Procedures.getDefinition = function(name, workspace) {
         blocks[i]);
       var tuple = procedureBlock.getProcedureDef();
       if (tuple && Blockly.Names.equals(tuple[0], name)) {
-        return blocks[i];
+        return procedureBlock;
       }
     }
   }

core/registry.js

@@ -33,7 +33,7 @@ goog.requireType('Blockly.ToolboxItem');
  *
  * @type {Object<string, Object<string, function(new:?)>>}
  */
-Blockly.registry.typeMap_ = {};
+Blockly.registry.typeMap_ = Object.create(null);
 
 /**
  * The string used to register the default class for a type of plugin.
@@ -137,7 +137,7 @@ Blockly.registry.register = function(
   var typeRegistry = Blockly.registry.typeMap_[type];
   // If the type registry has not been created, create it.
   if (!typeRegistry) {
-    typeRegistry = Blockly.registry.typeMap_[type] = {};
+    typeRegistry = Blockly.registry.typeMap_[type] = Object.create(null);
   }
 
   // Validate that the given class has all the required properties.

core/renderers/common/constants.js

@@ -587,10 +587,10 @@ Blockly.blockRendering.ConstantProvider.prototype.setTheme = function(
 
   /**
    * The block styles map.
-   * @type {Object<string, Blockly.Theme.BlockStyle>}
+   * @type {Object<string, !Blockly.Theme.BlockStyle>}
    * @package
    */
-  this.blockStyles = {};
+  this.blockStyles = Object.create(null);
 
   var blockStyles = theme.blockStyles;
   for (var key in blockStyles) {

core/renderers/zelos/path_object.js

@@ -45,17 +45,17 @@ Blockly.zelos.PathObject = function(root, style, constants) {
 
   /**
    * The selected path of the block.
-   * @type {SVGElement}
+   * @type {?SVGElement}
    * @private
    */
   this.svgPathSelected_ = null;
 
   /**
    * The outline paths on the block.
-   * @type {!Object<string,!SVGElement>}
+   * @type {!Object<string, !SVGElement>}
    * @private
    */
-  this.outlines_ = {};
+  this.outlines_ = Object.create(null);
 
   /**
    * A set used to determine which outlines were used during a draw pass.  The
@@ -98,8 +98,7 @@ Blockly.zelos.PathObject.prototype.applyColour = function(block) {
   }
 
   // Apply colour to outlines.
-  for (var i = 0, keys = Object.keys(this.outlines_),
-    key; (key = keys[i]); i++) {
+  for (var key in this.outlines_) {
     this.outlines_[key].setAttribute('fill', this.style.colourTertiary);
   }
 };
@@ -110,8 +109,7 @@ Blockly.zelos.PathObject.prototype.applyColour = function(block) {
 Blockly.zelos.PathObject.prototype.flipRTL = function() {
   Blockly.zelos.PathObject.superClass_.flipRTL.call(this);
   // Mirror each input outline path.
-  for (var i = 0, keys = Object.keys(this.outlines_),
-    key; (key = keys[i]); i++) {
+  for (var key in this.outlines_) {
     this.outlines_[key].setAttribute('transform', 'scale(-1 1)');
   }
 };
@@ -175,9 +173,8 @@ Blockly.zelos.PathObject.prototype.updateShapeForInputHighlight = function(
  * @package
  */
 Blockly.zelos.PathObject.prototype.beginDrawing = function() {
-  this.remainingOutlines_ = {};
-  for (var i = 0, keys = Object.keys(this.outlines_),
-    key; (key = keys[i]); i++) {
+  this.remainingOutlines_ = Object.create(null);
+  for (var key in this.outlines_) {
     // The value set here isn't used anywhere, we are just using the
     // object as a Set data structure.
     this.remainingOutlines_[key] = 1;
@@ -192,8 +189,7 @@ Blockly.zelos.PathObject.prototype.endDrawing = function() {
   // Go through all remaining outlines that were not used this draw pass, and
   // remove them.
   if (this.remainingOutlines_) {
-    for (var i = 0, keys = Object.keys(this.remainingOutlines_),
-      key; (key = keys[i]); i++) {
+    for (var key in this.remainingOutlines_) {
       this.removeOutlinePath_(key);
     }
   }

core/toolbox/toolbox.js

@@ -125,10 +125,10 @@ Blockly.Toolbox = function(workspace) {
 
   /**
    * A map from toolbox item IDs to toolbox items.
-   * @type {!Object<string, Blockly.IToolboxItem>}
+   * @type {!Object<string, !Blockly.IToolboxItem>}
    * @protected
    */
-  this.contentMap_ = {};
+  this.contentMap_ = Object.create(null);
 
   /**
    * Position of the toolbox and flyout relative to the workspace.
@@ -393,7 +393,7 @@ Blockly.Toolbox.prototype.render = function(toolboxDef) {
     }
   }
   this.contents_ = [];
-  this.contentMap_ = {};
+  this.contentMap_ = Object.create(null);
   this.renderContents_(toolboxDef['contents']);
   this.position();
 };
@@ -537,7 +537,7 @@ Blockly.Toolbox.prototype.getClientRect = function() {
  * @public
  */
 Blockly.Toolbox.prototype.getToolboxItemById = function(id) {
-  return this.contentMap_[id];
+  return this.contentMap_[id] || null;
 };
 
 /**

core/trashcan.js

@@ -411,11 +411,7 @@ Blockly.Trashcan.prototype.openFlyout = function() {
   if (this.contentsIsOpen()) {
     return;
   }
-
-  var xml = [];
-  for (var i = 0, text; (text = this.contents_[i]); i++) {
-    xml[i] = Blockly.Xml.textToDom(text);
-  }
+  var xml = this.contents_.map(Blockly.Xml.textToDom);
   this.flyout.show(xml);
   this.fireUiEvent_(true);
 };
@@ -427,7 +423,6 @@ Blockly.Trashcan.prototype.closeFlyout = function() {
   if (!this.contentsIsOpen()) {
     return;
   }
-
   this.flyout.hide();
   this.fireUiEvent_(false);
 };

core/utils/dom.js

@@ -232,7 +232,7 @@ Blockly.utils.dom.setCssTransform = function(element, transform) {
 Blockly.utils.dom.startTextWidthCache = function() {
   Blockly.utils.dom.cacheReference_++;
   if (!Blockly.utils.dom.cacheWidths_) {
-    Blockly.utils.dom.cacheWidths_ = {};
+    Blockly.utils.dom.cacheWidths_ = Object.create(null);
   }
 };
 

core/utils/toolbox.js

@@ -353,7 +353,7 @@ Blockly.utils.toolbox.xmlToJsonArray_ = function(toolboxDef) {
       obj['contents'] = Blockly.utils.toolbox.xmlToJsonArray_(child);
     }
 
-    // Add xml attributes to object
+    // Add XML attributes to object
     Blockly.utils.toolbox.addAttributes_(child, obj);
     arr.push(obj);
   }

core/warning.js

@@ -36,7 +36,7 @@ Blockly.Warning = function(block) {
   Blockly.Warning.superClass_.constructor.call(this, block);
   this.createIcon();
   // The text_ object can contain multiple warnings.
-  this.text_ = {};
+  this.text_ = Object.create(null);
 };
 Blockly.utils.object.inherits(Blockly.Warning, Blockly.Icon);
 

core/workspace_svg.js

@@ -169,7 +169,7 @@ Blockly.WorkspaceSvg = function(
   * @type {!Object<string, ?function(!Blockly.Workspace):!Array<!Element>>}
   * @private
   */
-  this.toolboxCategoryCallbacks_ = {};
+  this.toolboxCategoryCallbacks_ = Object.create(null);
 
   /**
   * Map from function names to callbacks, for deciding what to do when a button
@@ -177,7 +177,7 @@ Blockly.WorkspaceSvg = function(
   * @type {!Object<string, ?function(!Blockly.FlyoutButton)>}
   * @private
   */
-  this.flyoutButtonCallbacks_ = {};
+  this.flyoutButtonCallbacks_ = Object.create(null);
 
   if (Blockly.Variables && Blockly.Variables.flyoutCategory) {
     this.registerToolboxCategoryCallback(Blockly.VARIABLE_CATEGORY_NAME,

demos/blockfactory/workspacefactory/wfactory_controller.js

@@ -887,7 +887,6 @@ WorkspaceFactoryController.prototype.clearAll = function() {
   if (!confirm(msg)) {
     return;
   }
-  var hasCategories = this.model.hasElements();
   this.model.clearToolboxList();
   this.view.clearToolboxTabs();
   this.model.savePreloadXml(Blockly.utils.xml.createElement('xml'));
@@ -1209,9 +1208,9 @@ WorkspaceFactoryController.prototype.importBlocks = function(file, format) {
       // If an imported block type is already defined, check if the user wants
       // to override the current block definition.
       if (controller.model.hasDefinedBlockTypes(blockTypes)) {
-        var msg = 'An imported block uses the same name as a block '
-          + 'already in your toolbox. Are you sure you want to override the '
-          + 'currently defined block?';
+        var msg = 'An imported block uses the same name as a block ' +
+          'already in your toolbox. Are you sure you want to override the ' +
+          'currently defined block?';
         var continueAnyway = confirm(msg);
         BlocklyDevTools.Analytics.onWarning(msg);
         if (!continueAnyway) {

demos/blockfactory/workspacefactory/wfactory_model.js

@@ -360,7 +360,7 @@ WorkspaceFactoryModel.prototype.addCustomTag = function(category, tag) {
  * @param {!Element} xml The XML to be saved.
  */
 WorkspaceFactoryModel.prototype.savePreloadXml = function(xml) {
-  this.preloadXml = xml
+  this.preloadXml = xml;
 };
 
 /**
@@ -445,8 +445,8 @@ WorkspaceFactoryModel.prototype.updateLibBlockTypes = function(blockTypes) {
  * @return {boolean} True if blockType is defined, false otherwise.
  */
 WorkspaceFactoryModel.prototype.isDefinedBlockType = function(blockType) {
-  var isStandardBlock = StandardCategories.coreBlockTypes.indexOf(blockType)
-      != -1;
+  var isStandardBlock =
+      StandardCategories.coreBlockTypes.indexOf(blockType) != -1;
   var isLibBlock = this.libBlockTypes.indexOf(blockType) != -1;
   var isImportedBlock = this.importedBlockTypes.indexOf(blockType) != -1;
   return (isStandardBlock || isLibBlock || isImportedBlock);

generators/php/procedures.js

@@ -14,12 +14,12 @@ goog.provide('Blockly.PHP.procedures');
 
 goog.require('Blockly.PHP');
 
+
 Blockly.PHP['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   // First, add a 'global' statement for every variable that is not shadowed by
   // a local parameter.
   var globals = [];
-  var varName;
   var workspace = block.workspace;
   var variables = Blockly.Variables.allUsedVarModels(workspace) || [];
   for (var i = 0, variable; variable = variables[i]; i++) {

generators/python/procedures.js

@@ -20,7 +20,6 @@ Blockly.Python['procedures_defreturn'] = function(block) {
   // First, add a 'global' statement for every variable that is not shadowed by
   // a local parameter.
   var globals = [];
-  var varName;
   var workspace = block.workspace;
   var variables = Blockly.Variables.allUsedVarModels(workspace) || [];
   for (var i = 0, variable; variable = variables[i]; i++) {

scripts/gulpfiles/build_tasks.js

@@ -398,7 +398,7 @@ return gulp.src(maybeAddClosureLibrary(['core/**/**/*.js']))
     const requires = `goog.addDependency("base.js", [], []);
 
 // Load Blockly.
-goog.require('Blockly.requires')
+goog.require('Blockly.requires');
 `;
     fs.writeFileSync('blockly_uncompressed.js',
       header +