diff --git a/src/engine/blocks.js b/src/engine/blocks.js
index 896e9c8b4..bb4505352 100644
--- a/src/engine/blocks.js
+++ b/src/engine/blocks.js
@@ -1,207 +1,207 @@
 /**
-* @fileoverview
+ * @fileoverview
  * Store and mutate the VM block representation,
  * and handle updates from Scratch Blocks events.
  */
 
- function Blocks () {
-     /**
-      * All blocks in the workspace.
-      * Keys are block IDs, values are metadata about the block.
-      * @type {Object.<string, Object>}
-      */
-     this._blocks = {};
+function Blocks () {
+    /**
+     * All blocks in the workspace.
+     * Keys are block IDs, values are metadata about the block.
+     * @type {Object.<string, Object>}
+     */
+    this._blocks = {};
 
-     /**
-      * All stacks in the workspace.
-      * A list of block IDs that represent stacks (first block in stack).
-      * @type {Array.<String>}
-      */
-     this._stacks = [];
- }
+    /**
+     * All stacks in the workspace.
+     * A list of block IDs that represent stacks (first block in stack).
+     * @type {Array.<String>}
+     */
+    this._stacks = [];
+}
 
 /**
  * Provide an object with metadata for the requested block ID.
  * @param {!string} blockId ID of block we have stored.
  * @return {?Object} Metadata about the block, if it exists.
  */
- Blocks.prototype.getBlock = function (blockId) {
-     return this._blocks[blockId];
- };
+Blocks.prototype.getBlock = function (blockId) {
+    return this._blocks[blockId];
+};
 
 /**
  * Get all known top-level blocks that start stacks.
  * @return {Array.<string>} List of block IDs.
  */
- Blocks.prototype.getStacks = function () {
-     return this._stacks;
- };
+Blocks.prototype.getStacks = function () {
+    return this._stacks;
+};
 
  /**
   * Get the next block for a particular block
   * @param {?string} id ID of block to get the next block for
   * @return {?string} ID of next block in the sequence
   */
- Blocks.prototype.getNextBlock = function (id) {
-     if (typeof this._blocks[id] === 'undefined') return null;
-     return this._blocks[id].next;
- };
+Blocks.prototype.getNextBlock = function (id) {
+    if (typeof this._blocks[id] === 'undefined') return null;
+    return this._blocks[id].next;
+};
 
- /**
-  * Get the substack for a particular C-shaped block
-  * @param {?string} id ID for block to get the substack for
-  * @param {?number} substackNum Which substack to select (e.g. for if-else)
-  * @return {?string} ID of block in the substack
-  */
- Blocks.prototype.getSubstack = function (id, substackNum) {
-     var block = this._blocks[id];
-     if (typeof block === 'undefined') return null;
-     if (!substackNum) substackNum = 1;
+/**
+ * Get the substack for a particular C-shaped block
+ * @param {?string} id ID for block to get the substack for
+ * @param {?number} substackNum Which substack to select (e.g. for if-else)
+ * @return {?string} ID of block in the substack
+ */
+Blocks.prototype.getSubstack = function (id, substackNum) {
+    var block = this._blocks[id];
+    if (typeof block === 'undefined') return null;
+    if (!substackNum) substackNum = 1;
 
-     var inputName = 'SUBSTACK';
-     if (substackNum > 1) {
-         inputName += substackNum;
-     }
+    var inputName = 'SUBSTACK';
+    if (substackNum > 1) {
+        inputName += substackNum;
+    }
 
-     // Empty C-block?
-     if (!(inputName in block.inputs)) return null;
-     return block.inputs[inputName].block;
- };
+    // Empty C-block?
+    if (!(inputName in block.inputs)) return null;
+    return block.inputs[inputName].block;
+};
 
- /**
-  * Get the opcode for a particular block
-  * @param {?string} id ID of block to query
-  * @return {?string} the opcode corresponding to that block
-  */
- Blocks.prototype.getOpcode = function (id) {
-     if (typeof this._blocks[id] === 'undefined') return null;
-     return this._blocks[id].opcode;
- };
+/**
+ * Get the opcode for a particular block
+ * @param {?string} id ID of block to query
+ * @return {?string} the opcode corresponding to that block
+ */
+Blocks.prototype.getOpcode = function (id) {
+    if (typeof this._blocks[id] === 'undefined') return null;
+    return this._blocks[id].opcode;
+};
 
- // ---------------------------------------------------------------------
+// ---------------------------------------------------------------------
 
- /**
-  * Block management: create blocks and stacks from a `create` event
-  * @param {!Object} block Blockly create event to be processed
-  */
- Blocks.prototype.createBlock = function (block, opt_isFlyoutBlock) {
-     // Create new block
-     this._blocks[block.id] = block;
+/**
+ * Block management: create blocks and stacks from a `create` event
+ * @param {!Object} block Blockly create event to be processed
+ */
+Blocks.prototype.createBlock = function (block, opt_isFlyoutBlock) {
+    // Create new block
+    this._blocks[block.id] = block;
 
-     // Push block id to stacks array.
-     // Blocks are added as a top-level stack if they are marked as a top-block
-     // (if they were top-level XML in the event) and if they are not
-     // flyout blocks.
-     if (!opt_isFlyoutBlock && block.topLevel) {
-         this._addStack(block.id);
-     }
- };
+    // Push block id to stacks array.
+    // Blocks are added as a top-level stack if they are marked as a top-block
+    // (if they were top-level XML in the event) and if they are not
+    // flyout blocks.
+    if (!opt_isFlyoutBlock && block.topLevel) {
+        this._addStack(block.id);
+    }
+};
 
- /**
-  * Block management: change block field values
-  * @param {!Object} args Blockly change event to be processed
-  */
- Blocks.prototype.changeBlock = function (args) {
-     // Validate
-     if (args.element !== 'field') return;
-     if (typeof this._blocks[args.id] === 'undefined') return;
-     if (typeof this._blocks[args.id].fields[args.name] === 'undefined') return;
+/**
+ * Block management: change block field values
+ * @param {!Object} args Blockly change event to be processed
+ */
+Blocks.prototype.changeBlock = function (args) {
+    // Validate
+    if (args.element !== 'field') return;
+    if (typeof this._blocks[args.id] === 'undefined') return;
+    if (typeof this._blocks[args.id].fields[args.name] === 'undefined') return;
 
-     // Update block value
-     this._blocks[args.id].fields[args.name].value = args.value;
- };
+    // Update block value
+    this._blocks[args.id].fields[args.name].value = args.value;
+};
 
- /**
-  * Block management: move blocks from parent to parent
-  * @param {!Object} e Blockly move event to be processed
-  */
- Blocks.prototype.moveBlock = function (e) {
-     // Remove from any old parent.
-     if (e.oldParent !== undefined) {
-         var oldParent = this._blocks[e.oldParent];
-         if (e.oldInput !== undefined &&
-             oldParent.inputs[e.oldInput].block === e.id) {
-             // This block was connected to the old parent's input.
-             oldParent.inputs[e.oldInput].block = null;
-         } else if (oldParent.next === e.id) {
-             // This block was connected to the old parent's next connection.
-             oldParent.next = null;
-         }
-     }
+/**
+ * Block management: move blocks from parent to parent
+ * @param {!Object} e Blockly move event to be processed
+ */
+Blocks.prototype.moveBlock = function (e) {
+    // Remove from any old parent.
+    if (e.oldParent !== undefined) {
+        var oldParent = this._blocks[e.oldParent];
+        if (e.oldInput !== undefined &&
+            oldParent.inputs[e.oldInput].block === e.id) {
+            // This block was connected to the old parent's input.
+            oldParent.inputs[e.oldInput].block = null;
+        } else if (oldParent.next === e.id) {
+            // This block was connected to the old parent's next connection.
+            oldParent.next = null;
+        }
+    }
 
-     // Has the block become a top-level block?
-     if (e.newParent === undefined) {
-         this._addStack(e.id);
-     } else {
-         // Remove stack, if one exists.
-         this._deleteStack(e.id);
-         // Otherwise, try to connect it in its new place.
-         if (e.newInput !== undefined) {
+    // Has the block become a top-level block?
+    if (e.newParent === undefined) {
+        this._addStack(e.id);
+    } else {
+        // Remove stack, if one exists.
+        this._deleteStack(e.id);
+        // Otherwise, try to connect it in its new place.
+        if (e.newInput !== undefined) {
              // Moved to the new parent's input.
-             this._blocks[e.newParent].inputs[e.newInput] = {
-                 name: e.newInput,
-                 block: e.id
-             };
-         } else {
-             // Moved to the new parent's next connection.
-             this._blocks[e.newParent].next = e.id;
-         }
-     }
- };
+            this._blocks[e.newParent].inputs[e.newInput] = {
+                name: e.newInput,
+                block: e.id
+            };
+        } else {
+            // Moved to the new parent's next connection.
+            this._blocks[e.newParent].next = e.id;
+        }
+    }
+};
 
- /**
-  * Block management: delete blocks and their associated stacks
-  * @param {!Object} e Blockly delete event to be processed
-  */
- Blocks.prototype.deleteBlock = function (e) {
-     // @todo In runtime, stop threads running on this stack
+/**
+ * Block management: delete blocks and their associated stacks
+ * @param {!Object} e Blockly delete event to be processed
+ */
+Blocks.prototype.deleteBlock = function (e) {
+    // @todo In runtime, stop threads running on this stack
 
-     // Get block
-     var block = this._blocks[e.id];
+    // Get block
+    var block = this._blocks[e.id];
 
-     // Delete children
-     if (block.next !== null) {
-         this.deleteBlock({id: block.next});
-     }
+    // Delete children
+    if (block.next !== null) {
+        this.deleteBlock({id: block.next});
+    }
 
-     // Delete inputs (including substacks)
-     for (var input in block.inputs) {
-         // If it's null, the block in this input moved away.
-         if (block.inputs[input].block !== null) {
-             this.deleteBlock({id: block.inputs[input].block});
-         }
-     }
+    // Delete inputs (including substacks)
+    for (var input in block.inputs) {
+        // If it's null, the block in this input moved away.
+        if (block.inputs[input].block !== null) {
+            this.deleteBlock({id: block.inputs[input].block});
+        }
+    }
 
-     // Delete stack
-     this._deleteStack(e.id);
+    // Delete stack
+    this._deleteStack(e.id);
 
-     // Delete block
-     delete this._blocks[e.id];
- };
+    // Delete block
+    delete this._blocks[e.id];
+};
 
- // ---------------------------------------------------------------------
+// ---------------------------------------------------------------------
 
- /**
-  * Helper to add a stack to `this._stacks`
-  * @param {?string} id ID of block that starts the stack
-  */
- Blocks.prototype._addStack = function (id) {
-     var i = this._stacks.indexOf(id);
-     if (i > -1) return; // Already in stacks.
-     this._stacks.push(id);
-     // Update `topLevel` property on the top block.
-     this._blocks[id].topLevel = true;
- };
+/**
+ * Helper to add a stack to `this._stacks`
+ * @param {?string} id ID of block that starts the stack
+ */
+Blocks.prototype._addStack = function (id) {
+    var i = this._stacks.indexOf(id);
+    if (i > -1) return; // Already in stacks.
+    this._stacks.push(id);
+    // Update `topLevel` property on the top block.
+    this._blocks[id].topLevel = true;
+};
 
- /**
-  * Helper to remove a stack from `this._stacks`
-  * @param {?string} id ID of block that starts the stack
-  */
- Blocks.prototype._deleteStack = function (id) {
-     var i = this._stacks.indexOf(id);
-     if (i > -1) this._stacks.splice(i, 1);
-     // Update `topLevel` property on the top block.
-     if (this._blocks[id]) this._blocks[id].topLevel = false;
- };
+/**
+ * Helper to remove a stack from `this._stacks`
+ * @param {?string} id ID of block that starts the stack
+ */
+Blocks.prototype._deleteStack = function (id) {
+    var i = this._stacks.indexOf(id);
+    if (i > -1) this._stacks.splice(i, 1);
+    // Update `topLevel` property on the top block.
+    if (this._blocks[id]) this._blocks[id].topLevel = false;
+};
 
- module.exports = Blocks;
+module.exports = Blocks;