fix: make eventUtils throw if event type not registered (#6381)

* chore: update lint rules

* fix: have eventUtils.get throw if event isn't found

* chore: remove nonnull assertion from eventUtils.get and format

core/block.ts

@@ -291,7 +291,7 @@ export class Block implements IASTNodeLocation, IDeletable {
 
       // Fire a create event.
       if (eventUtils.isEnabled()) {
-        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))!(this));
+        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(this));
       }
     } finally {
       if (!existingGroup) {
@@ -323,7 +323,7 @@ export class Block implements IASTNodeLocation, IDeletable {
 
     this.unplug(healStack);
     if (eventUtils.isEnabled()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_DELETE))!(this));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_DELETE))(this));
     }
 
     if (this.onchangeWrapper_) {
@@ -1248,8 +1248,8 @@ export class Block implements IASTNodeLocation, IDeletable {
    */
   setInputsInline(newBoolean: boolean) {
     if (this.inputsInline !== newBoolean) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                      (this, 'inline', null, this.inputsInline, newBoolean));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+          this, 'inline', null, this.inputsInline, newBoolean));
       this.inputsInline = newBoolean;
     }
   }
@@ -1318,8 +1318,8 @@ export class Block implements IASTNodeLocation, IDeletable {
     if (this.isEnabled() !== enabled) {
       const oldValue = this.disabled;
       this.disabled = !enabled;
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                      (this, 'disabled', null, oldValue, !enabled));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+          this, 'disabled', null, oldValue, !enabled));
     }
   }
 
@@ -1357,8 +1357,8 @@ export class Block implements IASTNodeLocation, IDeletable {
    */
   setCollapsed(collapsed: boolean) {
     if (this.collapsed_ !== collapsed) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                      (this, 'collapsed', null, this.collapsed_, collapsed));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+          this, 'collapsed', null, this.collapsed_, collapsed));
       this.collapsed_ = collapsed;
     }
   }
@@ -2064,8 +2064,8 @@ export class Block implements IASTNodeLocation, IDeletable {
     if (this.commentModel.text === text) {
       return;
     }
-    eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                    (this, 'comment', null, this.commentModel.text, text));
+    eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+        this, 'comment', null, this.commentModel.text, text));
     this.commentModel.text = text;
     // AnyDuringMigration because:  Type 'string | null' is not assignable to
     // type 'string | Comment'.
@@ -2111,7 +2111,7 @@ export class Block implements IASTNodeLocation, IDeletable {
       throw Error('Block has parent.');
     }
     const event =
-        new (eventUtils.get(eventUtils.BLOCK_MOVE))!(this) as BlockMove;
+        new (eventUtils.get(eventUtils.BLOCK_MOVE))(this) as BlockMove;
     this.xy_.translate(dx, dy);
     event.recordNew();
     eventUtils.fire(event);

core/block_dragger.ts

@@ -163,8 +163,8 @@ export class BlockDragger implements IBlockDragger {
 
   /** Fire a UI event at the start of a block drag. */
   protected fireDragStartEvent_() {
-    const event = new (eventUtils.get(eventUtils.BLOCK_DRAG))!
-        (this.draggingBlock_, true, this.draggingBlock_.getDescendants(false));
+    const event = new (eventUtils.get(eventUtils.BLOCK_DRAG))(
+        this.draggingBlock_, true, this.draggingBlock_.getDescendants(false));
     eventUtils.fire(event);
   }
 
@@ -312,8 +312,8 @@ export class BlockDragger implements IBlockDragger {
 
   /** Fire a UI event at the end of a block drag. */
   protected fireDragEndEvent_() {
-    const event = new (eventUtils.get(eventUtils.BLOCK_DRAG))!
-        (this.draggingBlock_, false, this.draggingBlock_.getDescendants(false));
+    const event = new (eventUtils.get(eventUtils.BLOCK_DRAG))(
+        this.draggingBlock_, false, this.draggingBlock_.getDescendants(false));
     eventUtils.fire(event);
   }
 
@@ -352,8 +352,8 @@ export class BlockDragger implements IBlockDragger {
 
   /** Fire a move event at the end of a block drag. */
   protected fireMoveEvent_() {
-    const event = new (eventUtils.get(eventUtils.BLOCK_MOVE))!
-        (this.draggingBlock_) as BlockMove;
+    const event = new (eventUtils.get(eventUtils.BLOCK_MOVE))(
+                      this.draggingBlock_) as BlockMove;
     event.oldCoordinate = this.startXY_;
     event.recordNew();
     eventUtils.fire(event);

core/block_svg.ts

@@ -279,8 +279,8 @@ export class BlockSvg extends Block implements IASTNodeLocationSvg,
         eventUtils.enable();
       }
     }
-    const event = new (eventUtils.get(eventUtils.SELECTED))!
-        (oldId, this.id, this.workspace.id);
+    const event = new (eventUtils.get(eventUtils.SELECTED))(
+        oldId, this.id, this.workspace.id);
     eventUtils.fire(event);
     common.setSelected(this);
     this.addSelect();
@@ -294,8 +294,8 @@ export class BlockSvg extends Block implements IASTNodeLocationSvg,
     if (common.getSelected() !== this) {
       return;
     }
-    const event = new (eventUtils.get(eventUtils.SELECTED))!
-        (this.id, null, this.workspace.id);
+    const event = new (eventUtils.get(eventUtils.SELECTED))(
+        this.id, null, this.workspace.id);
     event.workspaceId = this.workspace.id;
     eventUtils.fire(event);
     common.setSelected(null);

core/bubble_dragger.ts

@@ -192,8 +192,8 @@ export class BubbleDragger {
   /** Fire a move event at the end of a bubble drag. */
   private fireMoveEvent_() {
     if (this.bubble instanceof WorkspaceCommentSvg) {
-      const event = new (eventUtils.get(eventUtils.COMMENT_MOVE))!
-          (this.bubble) as CommentMove;
+      const event = new (eventUtils.get(eventUtils.COMMENT_MOVE))(
+                        this.bubble) as CommentMove;
       event.setOldCoordinate(this.startXY_);
       event.recordNew();
       eventUtils.fire(event);

core/comment.ts

@@ -166,9 +166,9 @@ export class Comment extends Icon {
          */
         function(this: Comment, _e: Event) {
           if (this.cachedText_ !== this.model_.text) {
-            eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                            (this.block_, 'comment', null, this.cachedText_,
-                             this.model_.text));
+            eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+                this.block_, 'comment', null, this.cachedText_,
+                this.model_.text));
           }
         });
     this.onInputWrapper_ = browserEvents.conditionalBind(
@@ -232,8 +232,8 @@ export class Comment extends Icon {
     if (visible === this.isVisible()) {
       return;
     }
-    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))!
-                    (this.block_, visible, 'comment'));
+    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))(
+        this.block_, visible, 'comment'));
     this.model_.pinned = visible;
     if (visible) {
       this.createBubble_();

core/connection.ts

@@ -116,7 +116,7 @@ export class Connection implements IASTNodeLocationWithBlock {
     let event;
     if (eventUtils.isEnabled()) {
       event =
-          new (eventUtils.get(eventUtils.BLOCK_MOVE))!(childBlock) as BlockMove;
+          new (eventUtils.get(eventUtils.BLOCK_MOVE))(childBlock) as BlockMove;
     }
     connectReciprocally(this, childConnection);
     childBlock.setParent(parentBlock);
@@ -293,7 +293,7 @@ export class Connection implements IASTNodeLocationWithBlock {
     let event;
     if (eventUtils.isEnabled()) {
       event =
-          new (eventUtils.get(eventUtils.BLOCK_MOVE))!(childBlock) as BlockMove;
+          new (eventUtils.get(eventUtils.BLOCK_MOVE))(childBlock) as BlockMove;
     }
     const otherConnection = this.targetConnection;
     if (otherConnection) {

core/contextmenu.ts

@@ -249,7 +249,7 @@ export function callbackFactory(block: Block, xml: Element): Function {
       eventUtils.enable();
     }
     if (eventUtils.isEnabled() && !newBlock.isShadow()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))!(newBlock));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(newBlock));
     }
     newBlock.select();
   };

core/dropdowndiv.ts

@@ -328,6 +328,7 @@ export function show(
 const internal = {
   /**
    * Get sizing info about the bounding element.
+   *
    * @return An object containing size information about the bounding element
    *     (bounding box and width/height).
    */
@@ -348,6 +349,7 @@ const internal = {
   /**
    * Helper to position the drop-down and the arrow, maintaining bounds.
    * See explanation of origin points in show.
+   *
    * @param primaryX Desired origin point x, in absolute px.
    * @param primaryY Desired origin point y, in absolute px.
    * @param secondaryX Secondary/alternative origin point x, in absolute px.

core/events/utils.ts

@@ -507,12 +507,16 @@ export function fromJson(
  * Gets the class for a specific event type from the registry.
  *
  * @param eventType The type of the event to get.
- * @returns The event class with the given type or null if none exists.
+ * @returns The event class with the given type.
  * @alias Blockly.Events.utils.get
  */
 export function get(eventType: string):
-    (new (...p1: AnyDuringMigration[]) => Abstract)|null {
-  return registry.getClass(registry.Type.EVENT, eventType);
+    (new (...p1: AnyDuringMigration[]) => Abstract) {
+  const event = registry.getClass(registry.Type.EVENT, eventType);
+  if (!event) {
+    throw new Error(`Event type ${eventType} not found in registry.`);
+  }
+  return event;
 }
 
 /**

core/field.ts

@@ -967,8 +967,8 @@ export abstract class Field implements IASTNodeLocationSvg,
 
     this.doValueUpdate_(newValue);
     if (source && eventUtils.isEnabled()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                      (source, 'field', this.name || null, oldValue, newValue));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+          source, 'field', this.name || null, oldValue, newValue));
     }
     if (this.isDirty_) {
       this.forceRerender();

core/field_textinput.ts

@@ -187,9 +187,9 @@ export class FieldTextInput extends Field {
       // Revert value when the text becomes invalid.
       this.value_ = this.htmlInput_!.getAttribute('data-untyped-default-value');
       if (this.sourceBlock_ && eventUtils.isEnabled()) {
-        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                        (this.sourceBlock_, 'field', this.name || null,
-                         oldValue, this.value_));
+        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+            this.sourceBlock_, 'field', this.name || null, oldValue,
+            this.value_));
       }
     }
   }

core/flyout_base.ts

@@ -991,13 +991,13 @@ export abstract class Flyout extends DeleteArea implements IFlyout {
       // Fire a VarCreate event for each (if any) new variable created.
       for (let i = 0; i < newVariables.length; i++) {
         const thisVariable = newVariables[i];
-        eventUtils.fire(new (eventUtils.get(eventUtils.VAR_CREATE))!
-                        (thisVariable));
+        eventUtils.fire(
+            new (eventUtils.get(eventUtils.VAR_CREATE))(thisVariable));
       }
 
       // Block events come after var events, in case they refer to newly created
       // variables.
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))!(newBlock));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(newBlock));
     }
     if (this.autoClose) {
       this.hide();

core/gesture.ts

@@ -625,8 +625,8 @@ export class Gesture {
    * @param ws The workspace that a user clicks on.
    */
   private fireWorkspaceClick_(ws: WorkspaceSvg) {
-    eventUtils.fire(new (eventUtils.get(eventUtils.CLICK))!
-                    (null, ws.id, 'workspace'));
+    eventUtils.fire(
+        new (eventUtils.get(eventUtils.CLICK))(null, ws.id, 'workspace'));
   }
 
   /**
@@ -712,8 +712,8 @@ export class Gesture {
       }
     } else {
       // Clicks events are on the start block, even if it was a shadow.
-      const event = new (eventUtils.get(eventUtils.CLICK))!
-          (this.startBlock_, this.startWorkspace_.id, 'block');
+      const event = new (eventUtils.get(eventUtils.CLICK))(
+          this.startBlock_, this.startWorkspace_.id, 'block');
       eventUtils.fire(event);
     }
     this.bringBlockToFront_();

core/mutator.ts

@@ -301,8 +301,8 @@ export class Mutator extends Icon {
       // No change.
       return;
     }
-    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))!
-                    (this.block_, visible, 'mutator'));
+    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))(
+        this.block_, visible, 'mutator'));
     if (visible) {
       // Create the bubble.
       this.bubble_ = new Bubble(
@@ -460,7 +460,7 @@ export class Mutator extends Icon {
 
       const newExtraState = BlockChange.getExtraBlockState_(block);
       if (oldExtraState !== newExtraState) {
-        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!(
+        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
             block, 'mutation', null, oldExtraState, newExtraState));
         // Ensure that any bump is part of this mutation's event group.
         const mutationGroup = eventUtils.getGroup();

core/procedures.ts

@@ -423,8 +423,8 @@ export function mutateCallers(defBlock: Block) {
       // undo action since it is deterministically tied to the procedure's
       // definition mutation.
       eventUtils.setRecordUndo(false);
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!
-                      (caller, 'mutation', null, oldMutation, newMutation));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))(
+          caller, 'mutation', null, oldMutation, newMutation));
       eventUtils.setRecordUndo(oldRecordUndo);
     }
   }

core/renderers/common/marker_svg.ts

@@ -562,8 +562,8 @@ export class MarkerSvg {
    */
   private fireMarkerEvent_(oldNode: ASTNode, curNode: ASTNode) {
     const curBlock = curNode.getSourceBlock();
-    const event = new (eventUtils.get(eventUtils.MARKER_MOVE))!
-        (curBlock, this.isCursor(), oldNode, curNode);
+    const event = new (eventUtils.get(eventUtils.MARKER_MOVE))(
+        curBlock, this.isCursor(), oldNode, curNode);
     eventUtils.fire(event);
   }
 

core/serialization/blocks.ts

@@ -361,7 +361,7 @@ export function appendInternal(
   const block = appendPrivate(state, workspace, {parentConnection, isShadow});
 
   eventUtils.enable();
-  eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))!(block));
+  eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(block));
   eventUtils.setGroup(existingGroup);
   eventUtils.setRecordUndo(prevRecordUndo);
 

core/serialization/workspaces.ts

@@ -96,8 +96,7 @@ export function load(
   }
   dom.stopTextWidthCache();
 
-  eventUtils.fire(new (eventUtils.get(eventUtils.FINISHED_LOADING))!
-                  (workspace));
+  eventUtils.fire(new (eventUtils.get(eventUtils.FINISHED_LOADING))(workspace));
 
   eventUtils.setGroup(existingGroup);
   eventUtils.setRecordUndo(prevRecordUndo);

core/toolbox/toolbox.ts

@@ -928,8 +928,8 @@ export class Toolbox extends DeleteArea implements IAutoHideable,
     if (oldItem === newItem) {
       newElement = null;
     }
-    const event = new (eventUtils.get(eventUtils.TOOLBOX_ITEM_SELECT))!
-        (oldElement, newElement, this.workspace_.id);
+    const event = new (eventUtils.get(eventUtils.TOOLBOX_ITEM_SELECT))(
+        oldElement, newElement, this.workspace_.id);
     eventUtils.fire(event);
   }
 

core/trashcan.ts

@@ -503,8 +503,8 @@ export class Trashcan extends DeleteArea implements IAutoHideable,
    * @param trashcanOpen Whether the flyout is opening.
    */
   private fireUiEvent_(trashcanOpen: boolean) {
-    const uiEvent = new (eventUtils.get(eventUtils.TRASHCAN_OPEN))!
-        (trashcanOpen, this.workspace.id);
+    const uiEvent = new (eventUtils.get(eventUtils.TRASHCAN_OPEN))(
+        trashcanOpen, this.workspace.id);
     eventUtils.fire(uiEvent);
   }
 

core/variable_map.ts

@@ -103,8 +103,8 @@ export class VariableMap {
    */
   private renameVariableAndUses_(
       variable: VariableModel, newName: string, blocks: Block[]) {
-    eventUtils.fire(new (eventUtils.get(eventUtils.VAR_RENAME))!
-                    (variable, newName));
+    eventUtils.fire(
+        new (eventUtils.get(eventUtils.VAR_RENAME))(variable, newName));
     variable.name = newName;
     for (let i = 0; i < blocks.length; i++) {
       blocks[i].updateVarName(variable);
@@ -139,7 +139,7 @@ export class VariableMap {
       blocks[i].renameVarById(variable.getId(), conflictVar.getId());
     }
     // Finally delete the original variable, which is now unreferenced.
-    eventUtils.fire(new (eventUtils.get(eventUtils.VAR_DELETE))!(variable));
+    eventUtils.fire(new (eventUtils.get(eventUtils.VAR_DELETE))(variable));
     // And remove it from the list.
     arrayUtils.removeElem(this.variableMap.get(type)!, variable);
   }
@@ -200,8 +200,8 @@ export class VariableMap {
         const tempVar = variableList[i];
         if (tempVar.getId() === variableId) {
           variableList.splice(i, 1);
-          eventUtils.fire(new (eventUtils.get(eventUtils.VAR_DELETE))!
-                          (variable));
+          eventUtils.fire(
+              new (eventUtils.get(eventUtils.VAR_DELETE))(variable));
           return;
         }
       }

core/variable_model.ts

@@ -59,7 +59,7 @@ export class VariableModel {
      */
     this.id_ = opt_id || idGenerator.genUid();
 
-    eventUtils.fire(new (eventUtils.get(eventUtils.VAR_CREATE))!(this));
+    eventUtils.fire(new (eventUtils.get(eventUtils.VAR_CREATE))(this));
   }
 
   /** @returns The ID for the variable. */

core/warning.ts

@@ -88,8 +88,8 @@ export class Warning extends Icon {
     if (visible === this.isVisible()) {
       return;
     }
-    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))!
-                    (this.block_, visible, 'warning'));
+    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))(
+        this.block_, visible, 'warning'));
     if (visible) {
       this.createBubble_();
     } else {

core/workspace_comment.ts

@@ -97,7 +97,7 @@ export class WorkspaceComment {
     }
 
     if (eventUtils.isEnabled()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_DELETE))!(this));
+      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_DELETE))(this));
     }
     // Remove from the list of top comments and the comment database.
     this.workspace.removeTopComment(this);
@@ -167,7 +167,7 @@ export class WorkspaceComment {
    */
   moveBy(dx: number, dy: number) {
     const event =
-        new (eventUtils.get(eventUtils.COMMENT_MOVE))!(this) as CommentMove;
+        new (eventUtils.get(eventUtils.COMMENT_MOVE))(this) as CommentMove;
     this.xy_.translate(dx, dy);
     event.recordNew();
     eventUtils.fire(event);
@@ -252,8 +252,8 @@ export class WorkspaceComment {
    */
   setContent(content: string) {
     if (this.content_ !== content) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_CHANGE))!
-                      (this, this.content_, content));
+      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_CHANGE))(
+          this, this.content_, content));
       this.content_ = content;
     }
   }
@@ -314,8 +314,8 @@ export class WorkspaceComment {
         eventUtils.setGroup(true);
       }
       try {
-        eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_CREATE))!
-                        (comment));
+        eventUtils.fire(
+            new (eventUtils.get(eventUtils.COMMENT_CREATE))(comment));
       } finally {
         if (!existingGroup) {
           eventUtils.setGroup(false);

core/workspace_comment_svg.ts

@@ -146,7 +146,7 @@ export class WorkspaceCommentSvg extends WorkspaceComment implements
     }
 
     if (eventUtils.isEnabled()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_DELETE))!(this));
+      eventUtils.fire(new (eventUtils.get(eventUtils.COMMENT_DELETE))(this));
     }
 
     dom.removeNode(this.svgGroup_);
@@ -234,8 +234,8 @@ export class WorkspaceCommentSvg extends WorkspaceComment implements
         eventUtils.enable();
       }
     }
-    const event = new (eventUtils.get(eventUtils.SELECTED))!
-        (oldId, this.id, this.workspace.id);
+    const event = new (eventUtils.get(eventUtils.SELECTED))(
+        oldId, this.id, this.workspace.id);
     eventUtils.fire(event);
     common.setSelected(this);
     this.addSelect();
@@ -250,8 +250,8 @@ export class WorkspaceCommentSvg extends WorkspaceComment implements
     if (common.getSelected() !== this) {
       return;
     }
-    const event = new (eventUtils.get(eventUtils.SELECTED))!
-        (this.id, null, this.workspace.id);
+    const event = new (eventUtils.get(eventUtils.SELECTED))(
+        this.id, null, this.workspace.id);
     eventUtils.fire(event);
     common.setSelected(null);
     this.removeSelect();
@@ -350,7 +350,7 @@ export class WorkspaceCommentSvg extends WorkspaceComment implements
    */
   override moveBy(dx: number, dy: number) {
     const event =
-        new (eventUtils.get(eventUtils.COMMENT_MOVE))!(this) as CommentMove;
+        new (eventUtils.get(eventUtils.COMMENT_MOVE))(this) as CommentMove;
     // TODO: Do I need to look up the relative to surface XY position here?
     const xy = this.getRelativeToSurfaceXY();
     this.translate(xy.x + dx, xy.y + dy);

core/workspace_svg.ts

@@ -577,8 +577,8 @@ export class WorkspaceSvg extends Workspace implements IASTNodeLocationSvg {
       this.setVisible(true);
     }
 
-    const event = new (eventUtils.get(eventUtils.THEME_CHANGE))!
-        (this.getTheme().name, this.id);
+    const event = new (eventUtils.get(eventUtils.THEME_CHANGE))(
+        this.getTheme().name, this.id);
     eventUtils.fire(event);
   }
 
@@ -1141,8 +1141,8 @@ export class WorkspaceSvg extends Workspace implements IASTNodeLocationSvg {
       // of negligible changes in viewport top/left.
       return;
     }
-    const event = new (eventUtils.get(eventUtils.VIEWPORT_CHANGE))!
-        (top, left, scale, this.id, this.oldScale_);
+    const event = new (eventUtils.get(eventUtils.VIEWPORT_CHANGE))(
+        top, left, scale, this.id, this.oldScale_);
     this.oldScale_ = scale;
     this.oldTop_ = top;
     this.oldLeft_ = left;
@@ -1469,7 +1469,7 @@ export class WorkspaceSvg extends Workspace implements IASTNodeLocationSvg {
       eventUtils.enable();
     }
     if (eventUtils.isEnabled() && !block!.isShadow()) {
-      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))!(block!));
+      eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(block!));
     }
     block!.select();
     return block!;

core/xml.ts

@@ -503,8 +503,7 @@ export function domToWorkspace(xml: Element, workspace: Workspace): string[] {
   if ((workspace as WorkspaceSvg).setResizesEnabled) {
     (workspace as WorkspaceSvg).setResizesEnabled(true);
   }
-  eventUtils.fire(new (eventUtils.get(eventUtils.FINISHED_LOADING))!
-                  (workspace));
+  eventUtils.fire(new (eventUtils.get(eventUtils.FINISHED_LOADING))(workspace));
   return newBlockIds;
 }
 
@@ -618,12 +617,12 @@ export function domToBlock(xmlBlock: Element, workspace: Workspace): Block {
     // Fire a VarCreate event for each (if any) new variable created.
     for (let i = 0; i < newVariables.length; i++) {
       const thisVariable = newVariables[i];
-      eventUtils.fire(new (eventUtils.get(eventUtils.VAR_CREATE))!
-                      (thisVariable));
+      eventUtils.fire(
+          new (eventUtils.get(eventUtils.VAR_CREATE))(thisVariable));
     }
     // Block events come after var events, in case they refer to newly created
     // variables.
-    eventUtils.fire(new (eventUtils.get(eventUtils.CREATE))!(topBlock));
+    eventUtils.fire(new (eventUtils.get(eventUtils.CREATE))(topBlock));
   }
   return topBlock;
 }

core/zoom_controls.ts

@@ -414,8 +414,8 @@ export class ZoomControls implements IPositionable {
 
   /** Fires a zoom control UI event. */
   private fireZoomEvent_() {
-    const uiEvent = new (eventUtils.get(eventUtils.CLICK))!
-        (null, this.workspace.id, 'zoom_controls');
+    const uiEvent = new (eventUtils.get(eventUtils.CLICK))(
+        null, this.workspace.id, 'zoom_controls');
     eventUtils.fire(uiEvent);
   }
 }