refactor: convert some classes to ES6 classes (#5928)

* refactor: move optional function declarations into the constructor

* refactor: convert options.js to es6 class

* refactor: convert generator.js to es6 class

* refactor: convert workspace_events.js to es6 class

* refactor: convert events_abstract.js to an es6 class

* chore: format

* chore: fix lint

* chore: rebuild

* chore: respond to PR feedback

core/events/events.js

@@ -17,7 +17,7 @@ goog.module('Blockly.Events');
 
 const deprecation = goog.require('Blockly.utils.deprecation');
 const eventUtils = goog.require('Blockly.Events.utils');
-const {Abstract} = goog.require('Blockly.Events.Abstract');
+const {Abstract: AbstractEvent} = goog.require('Blockly.Events.Abstract');
 const {BlockBase} = goog.require('Blockly.Events.BlockBase');
 const {BlockChange} = goog.require('Blockly.Events.BlockChange');
 const {BlockCreate} = goog.require('Blockly.Events.BlockCreate');
@@ -47,7 +47,7 @@ const {ViewportChange} = goog.require('Blockly.Events.ViewportChange');
 
 
 // Events.
-exports.Abstract = Abstract;
+exports.Abstract = AbstractEvent;
 exports.BubbleOpen = BubbleOpen;
 exports.BlockBase = BlockBase;
 exports.BlockChange = BlockChange;

core/events/events_abstract.js

@@ -24,98 +24,109 @@ const {Workspace} = goog.requireType('Blockly.Workspace');
 
 /**
  * Abstract class for an event.
- * @constructor
- * @alias Blockly.Events.Abstract
+ * @abstract
  */
-const Abstract = function() {
+class Abstract {
   /**
-   * Whether or not the event is blank (to be populated by fromJson).
-   * @type {?boolean}
+   * @alias Blockly.Events.Abstract
    */
-  this.isBlank = null;
+  constructor() {
+    /**
+     * Whether or not the event is blank (to be populated by fromJson).
+     * @type {?boolean}
+     */
+    this.isBlank = null;
+
+    /**
+     * The workspace identifier for this event.
+     * @type {string|undefined}
+     */
+    this.workspaceId = undefined;
+
+    /**
+     * The event group id for the group this event belongs to. Groups define
+     * events that should be treated as an single action from the user's
+     * perspective, and should be undone together.
+     * @type {string}
+     */
+    this.group = eventUtils.getGroup();
+
+    /**
+     * Sets whether the event should be added to the undo stack.
+     * @type {boolean}
+     */
+    this.recordUndo = eventUtils.getRecordUndo();
+
+    /**
+     * Whether or not the event is a UI event.
+     * @type {boolean}
+     */
+    this.isUiEvent = false;
+
+    /**
+     * Type of this event.
+     * @type {string|undefined}
+     */
+    this.type = undefined;
+  }
 
   /**
-   * The workspace identifier for this event.
-   * @type {string|undefined}
+   * Encode the event as JSON.
+   * @return {!Object} JSON representation.
    */
-  this.workspaceId = undefined;
+  toJson() {
+    const json = {'type': this.type};
+    if (this.group) {
+      json['group'] = this.group;
+    }
+    return json;
+  }
 
   /**
-   * The event group id for the group this event belongs to. Groups define
-   * events that should be treated as an single action from the user's
-   * perspective, and should be undone together.
-   * @type {string}
+   * Decode the JSON event.
+   * @param {!Object} json JSON representation.
    */
-  this.group = eventUtils.getGroup();
+  fromJson(json) {
+    this.isBlank = false;
+    this.group = json['group'];
+  }
 
   /**
-   * Sets whether the event should be added to the undo stack.
-   * @type {boolean}
+   * Does this event record any change of state?
+   * @return {boolean} True if null, false if something changed.
    */
-  this.recordUndo = eventUtils.getRecordUndo();
+  isNull() {
+    return false;
+  }
 
   /**
-   * Whether or not the event is a UI event.
-   * @type {boolean}
+   * Run an event.
+   * @param {boolean} _forward True if run forward, false if run backward
+   *     (undo).
    */
-  this.isUiEvent = false;
-};
-
-/**
- * Encode the event as JSON.
- * @return {!Object} JSON representation.
- */
-Abstract.prototype.toJson = function() {
-  const json = {'type': this.type};
-  if (this.group) {
-    json['group'] = this.group;
+  run(_forward) {
+    // Defined by subclasses.
   }
-  return json;
-};
-
-/**
- * Decode the JSON event.
- * @param {!Object} json JSON representation.
- */
-Abstract.prototype.fromJson = function(json) {
-  this.isBlank = false;
-  this.group = json['group'];
-};
 
-/**
- * Does this event record any change of state?
- * @return {boolean} True if null, false if something changed.
- */
-Abstract.prototype.isNull = function() {
-  return false;
-};
-
-/**
- * Run an event.
- * @param {boolean} _forward True if run forward, false if run backward (undo).
- */
-Abstract.prototype.run = function(_forward) {
-  // Defined by subclasses.
-};
-
-/**
- * Get workspace the event belongs to.
- * @return {!Workspace} The workspace the event belongs to.
- * @throws {Error} if workspace is null.
- * @protected
- */
-Abstract.prototype.getEventWorkspace_ = function() {
-  let workspace;
-  if (this.workspaceId) {
-    const {Workspace} = goog.module.get('Blockly.Workspace');
-    workspace = Workspace.getById(this.workspaceId);
-  }
-  if (!workspace) {
-    throw Error(
-        'Workspace is null. Event must have been generated from real' +
-        ' Blockly events.');
+  /**
+   * Get workspace the event belongs to.
+   * @return {!Workspace} The workspace the event belongs to.
+   * @throws {Error} if workspace is null.
+   * @protected
+   */
+  getEventWorkspace_() {
+    let workspace;
+    if (this.workspaceId) {
+      const {Workspace} = goog.module.get('Blockly.Workspace');
+      workspace = Workspace.getById(this.workspaceId);
+    }
+    if (!workspace) {
+      throw Error(
+          'Workspace is null. Event must have been generated from real' +
+          ' Blockly events.');
+    }
+    return workspace;
   }
-  return workspace;
-};
+}
 
 exports.Abstract = Abstract;

core/events/events_block_base.js

@@ -15,16 +15,16 @@
  */
 goog.module('Blockly.Events.BlockBase');
 
-const {Abstract} = goog.require('Blockly.Events.Abstract');
+const {Abstract: AbstractEvent} = goog.require('Blockly.Events.Abstract');
 /* eslint-disable-next-line no-unused-vars */
 const {Block} = goog.requireType('Blockly.Block');
 
 
 /**
  * Abstract class for a block event.
- * @extends {Abstract}
+ * @extends {AbstractEvent}
  */
-class BlockBase extends Abstract {
+class BlockBase extends AbstractEvent {
   /**
    * @param {!Block=} opt_block The block this event corresponds to.
    *     Undefined for a blank event.

core/events/events_comment_base.js

@@ -18,7 +18,7 @@ goog.module('Blockly.Events.CommentBase');
 const Xml = goog.require('Blockly.Xml');
 const eventUtils = goog.require('Blockly.Events.utils');
 const utilsXml = goog.require('Blockly.utils.xml');
-const {Abstract} = goog.require('Blockly.Events.Abstract');
+const {Abstract: AbstractEvent} = goog.require('Blockly.Events.Abstract');
 /* eslint-disable-next-line no-unused-vars */
 const {CommentCreate} = goog.requireType('Blockly.Events.CommentCreate');
 /* eslint-disable-next-line no-unused-vars */
@@ -29,9 +29,9 @@ const {WorkspaceComment} = goog.requireType('Blockly.WorkspaceComment');
 
 /**
  * Abstract class for a comment event.
- * @extends {Abstract}
+ * @extends {AbstractEvent}
  */
-class CommentBase extends Abstract {
+class CommentBase extends AbstractEvent {
   /**
    * @param {!WorkspaceComment=} opt_comment The comment this event
    *     corresponds to.  Undefined for a blank event.

core/events/events_ui_base.js

@@ -17,7 +17,7 @@
  */
 goog.module('Blockly.Events.UiBase');
 
-const {Abstract} = goog.require('Blockly.Events.Abstract');
+const {Abstract: AbstractEvent} = goog.require('Blockly.Events.Abstract');
 
 
 /**
@@ -26,9 +26,9 @@ const {Abstract} = goog.require('Blockly.Events.Abstract');
  * editing to work (e.g. scrolling the workspace, zooming, opening toolbox
  * categories).
  * UI events do not undo or redo.
- * @extends {Abstract}
+ * @extends {AbstractEvent}
  */
-class UiBase extends Abstract {
+class UiBase extends AbstractEvent {
   /**
    * @param {string=} opt_workspaceId The workspace identifier for this event.
    *    Undefined for a blank event.

core/events/events_var_base.js

@@ -15,16 +15,16 @@
  */
 goog.module('Blockly.Events.VarBase');
 
-const {Abstract} = goog.require('Blockly.Events.Abstract');
+const {Abstract: AbstractEvent} = goog.require('Blockly.Events.Abstract');
 /* eslint-disable-next-line no-unused-vars */
 const {VariableModel} = goog.requireType('Blockly.VariableModel');
 
 
 /**
  * Abstract class for a variable event.
- * @extends {Abstract}
+ * @extends {AbstractEvent}
  */
-class VarBase extends Abstract {
+class VarBase extends AbstractEvent {
   /**
    * @param {!VariableModel=} opt_variable The variable this event
    *     corresponds to.  Undefined for a blank event.

core/events/utils.js

@@ -22,6 +22,8 @@ const registry = goog.require('Blockly.registry');
 /* eslint-disable-next-line no-unused-vars */
 const {Abstract} = goog.requireType('Blockly.Events.Abstract');
 /* eslint-disable-next-line no-unused-vars */
+const {BlockChange} = goog.requireType('Blockly.Events.BlockChange');
+/* eslint-disable-next-line no-unused-vars */
 const {BlockCreate} = goog.requireType('Blockly.Events.BlockCreate');
 /* eslint-disable-next-line no-unused-vars */
 const {BlockMove} = goog.requireType('Blockly.Events.BlockMove');
@@ -32,6 +34,8 @@ const {CommentCreate} = goog.requireType('Blockly.Events.CommentCreate');
 /* eslint-disable-next-line no-unused-vars */
 const {CommentMove} = goog.requireType('Blockly.Events.CommentMove');
 /* eslint-disable-next-line no-unused-vars */
+const {ViewportChange} = goog.requireType('Blockly.Events.ViewportChange');
+/* eslint-disable-next-line no-unused-vars */
 const {Workspace} = goog.requireType('Blockly.Workspace');
 
 
@@ -307,6 +311,7 @@ exports.BUMP_EVENTS = BUMP_EVENTS;
 
 /**
  * List of events queued for firing.
+ * @type {!Array<!Abstract>}
  */
 const FIRE_QUEUE = [];
 
@@ -365,7 +370,9 @@ const filter = function(queueIn, forward) {
     if (!event.isNull()) {
       // Treat all UI events as the same type in hash table.
       const eventType = event.isUiEvent ? UI : event.type;
-      const key = [eventType, event.blockId, event.workspaceId].join(' ');
+      // TODO(#5927): Ceck whether `blockId` exists before accessing it.
+      const blockId = /** @type {*} */ (event).blockId;
+      const key = [eventType, blockId, event.workspaceId].join(' ');
 
       const lastEntry = hash[key];
       const lastEvent = lastEntry ? lastEntry.event : null;
@@ -376,22 +383,25 @@ const filter = function(queueIn, forward) {
         hash[key] = {event: event, index: i};
         mergedQueue.push(event);
       } else if (event.type === MOVE && lastEntry.index === i - 1) {
+        const moveEvent = /** @type {!BlockMove} */ (event);
         // Merge move events.
-        lastEvent.newParentId = event.newParentId;
-        lastEvent.newInputName = event.newInputName;
-        lastEvent.newCoordinate = event.newCoordinate;
+        lastEvent.newParentId = moveEvent.newParentId;
+        lastEvent.newInputName = moveEvent.newInputName;
+        lastEvent.newCoordinate = moveEvent.newCoordinate;
         lastEntry.index = i;
       } else if (
           event.type === CHANGE && event.element === lastEvent.element &&
           event.name === lastEvent.name) {
+        const changeEvent = /** @type {!BlockChange} */ (event);
         // Merge change events.
-        lastEvent.newValue = event.newValue;
+        lastEvent.newValue = changeEvent.newValue;
       } else if (event.type === VIEWPORT_CHANGE) {
+        const viewportEvent = /** @type {!ViewportChange} */ (event);
         // Merge viewport change events.
-        lastEvent.viewTop = event.viewTop;
-        lastEvent.viewLeft = event.viewLeft;
-        lastEvent.scale = event.scale;
-        lastEvent.oldScale = event.oldScale;
+        lastEvent.viewTop = viewportEvent.viewTop;
+        lastEvent.viewLeft = viewportEvent.viewLeft;
+        lastEvent.scale = viewportEvent.scale;
+        lastEvent.oldScale = viewportEvent.oldScale;
       } else if (event.type === CLICK && lastEvent.type === BUBBLE_OPEN) {
         // Drop click events caused by opening/closing bubbles.
       } else {
@@ -546,12 +556,13 @@ exports.get = get;
  */
 const disableOrphans = function(event) {
   if (event.type === MOVE || event.type === CREATE) {
-    if (!event.workspaceId) {
+    const blockEvent = /** @type {!BlockMove|!BlockCreate} */ (event);
+    if (!blockEvent.workspaceId) {
       return;
     }
     const {Workspace} = goog.module.get('Blockly.Workspace');
-    const eventWorkspace = Workspace.getById(event.workspaceId);
-    let block = eventWorkspace.getBlockById(event.blockId);
+    const eventWorkspace = Workspace.getById(blockEvent.workspaceId);
+    let block = eventWorkspace.getBlockById(blockEvent.blockId);
     if (block) {
       // Changing blocks as part of this event shouldn't be undoable.
       const initialUndoFlag = recordUndo;