fix: make getSourceBlock nullable again (#6542)

* fix: make getSourceBlock nullable again

* chore: format

* chore: move to a specific error

* chore: also update procedures with new error

* chore: format

core/field.ts

@@ -255,10 +255,7 @@ export abstract class Field implements IASTNodeLocationSvg,
    * @returns The block containing this field.
    * @throws An error if the source block is not defined.
    */
-  getSourceBlock(): Block {
+  getSourceBlock(): Block|null {
-    if (!this.sourceBlock_) {
-      throw new Error(`The source block is ${this.sourceBlock_}.`);
-    }
     return this.sourceBlock_;
   }
 
@@ -476,10 +473,11 @@ export abstract class Field implements IASTNodeLocationSvg,
   /** Add or remove the UI indicating if this field is editable or not. */
   updateEditable() {
     const group = this.fieldGroup_;
-    if (!this.EDITABLE || !group) {
+    const block = this.getSourceBlock();
+    if (!this.EDITABLE || !group || !block) {
       return;
     }
-    if (this.enabled_ && this.getSourceBlock().isEditable()) {
+    if (this.enabled_ && block.isEditable()) {
       dom.addClass(group, 'blocklyEditableText');
       dom.removeClass(group, 'blocklyNonEditableText');
       group.style.cursor = this.CURSOR;
@@ -756,7 +754,7 @@ export abstract class Field implements IASTNodeLocationSvg,
     this.textElement_.setAttribute(
         'x',
         `${
-            this.getSourceBlock().RTL ?
+            this.getSourceBlock()?.RTL ?
                 this.size_.width - contentWidth - xOffset :
                 xOffset}`);
     this.textElement_.setAttribute(
@@ -819,12 +817,17 @@ export abstract class Field implements IASTNodeLocationSvg,
     let scaledWidth;
     let scaledHeight;
     let xy;
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
+
     if (!this.borderRect_) {
       // Browsers are inconsistent in what they return for a bounding box.
       // - Webkit / Blink: fill-box / object bounding box
       // - Gecko: stroke-box
       const bBox = (this.sourceBlock_ as BlockSvg).getHeightWidth();
-      const scale = (this.getSourceBlock().workspace as WorkspaceSvg).scale;
+      const scale = (block.workspace as WorkspaceSvg).scale;
       xy = this.getAbsoluteXY_();
       scaledWidth = (bBox.width + 1) * scale;
       scaledHeight = (bBox.height + 1) * scale;
@@ -1158,6 +1161,9 @@ export abstract class Field implements IASTNodeLocationSvg,
   getParentInput(): Input {
     let parentInput = null;
     const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const inputs = block.inputList;
 
     for (let idx = 0; idx < block.inputList.length; idx++) {
@@ -1241,7 +1247,11 @@ export abstract class Field implements IASTNodeLocationSvg,
 
   /** Redraw any attached marker or cursor svgs if needed. */
   protected updateMarkers_() {
-    const workspace = this.getSourceBlock().workspace as WorkspaceSvg;
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
+    const workspace = block.workspace as WorkspaceSvg;
     if (workspace.keyboardAccessibilityMode && this.cursorSvg_) {
       workspace.getCursor()!.draw();
     }
@@ -1264,3 +1274,17 @@ export interface FieldConfig {
  * in descendants, though they should contain all of Field's prototype methods.
  */
 export type FieldProto = Pick<typeof Field, 'prototype'>;
+
+/**
+ * Represents an error where the field is trying to access its block or
+ * information about its block before it has actually been attached to said
+ * block.
+ */
+export class UnattachedFieldError extends Error {
+  /** @internal */
+  constructor() {
+    super(
+        'The field has not yet been attached to its input. ' +
+        'Call appendField to attach it.');
+  }
+}

core/field_angle.ts

@@ -16,7 +16,7 @@ import {BlockSvg} from './block_svg.js';
 import * as browserEvents from './browser_events.js';
 import * as Css from './css.js';
 import * as dropDownDiv from './dropdowndiv.js';
-import {Field} from './field.js';
+import {Field, UnattachedFieldError} from './field.js';
 import * as fieldRegistry from './field_registry.js';
 import {FieldTextInputConfig, FieldTextInput} from './field_textinput.js';
 import * as dom from './utils/dom.js';
@@ -412,15 +412,19 @@ export class FieldAngle extends FieldTextInput {
    */
   protected override onHtmlInputKeyDown_(e: Event) {
     super.onHtmlInputKeyDown_(e);
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
 
     const keyboardEvent = e as KeyboardEvent;
     let multiplier;
     if (keyboardEvent.keyCode === KeyCodes.LEFT) {
       // decrement (increment in RTL)
-      multiplier = this.getSourceBlock().RTL ? 1 : -1;
+      multiplier = block.RTL ? 1 : -1;
     } else if (keyboardEvent.keyCode === KeyCodes.RIGHT) {
       // increment (decrement in RTL)
-      multiplier = this.getSourceBlock().RTL ? -1 : 1;
+      multiplier = block.RTL ? -1 : 1;
     } else if (keyboardEvent.keyCode === KeyCodes.DOWN) {
       // decrement
       multiplier = -1;

core/field_dropdown.ts

@@ -16,7 +16,7 @@ goog.declareModuleId('Blockly.FieldDropdown');
 
 import type {BlockSvg} from './block_svg.js';
 import * as dropDownDiv from './dropdowndiv.js';
-import {FieldConfig, Field} from './field.js';
+import {FieldConfig, Field, UnattachedFieldError} from './field.js';
 import * as fieldRegistry from './field_registry.js';
 import {Menu} from './menu.js';
 import {MenuItem} from './menuitem.js';
@@ -217,16 +217,16 @@ export class FieldDropdown extends Field {
   protected shouldAddBorderRect_(): boolean {
     return !this.getConstants()!.FIELD_DROPDOWN_NO_BORDER_RECT_SHADOW ||
         this.getConstants()!.FIELD_DROPDOWN_NO_BORDER_RECT_SHADOW &&
-        !this.getSourceBlock().isShadow();
+        !this.getSourceBlock()?.isShadow();
   }
 
   /** Create a tspan based arrow. */
   protected createTextArrow_() {
     this.arrow_ = dom.createSvgElement(Svg.TSPAN, {}, this.textElement_);
     this.arrow_!.appendChild(document.createTextNode(
-        this.getSourceBlock().RTL ? FieldDropdown.ARROW_CHAR + ' ' :
+        this.getSourceBlock()?.RTL ? FieldDropdown.ARROW_CHAR + ' ' :
-                                    ' ' + FieldDropdown.ARROW_CHAR));
+                                     ' ' + FieldDropdown.ARROW_CHAR));
-    if (this.getSourceBlock().RTL) {
+    if (this.getSourceBlock()?.RTL) {
       // AnyDuringMigration because:  Argument of type 'SVGTSpanElement | null'
       // is not assignable to parameter of type 'Node'.
       this.getTextElement().insertBefore(
@@ -258,6 +258,10 @@ export class FieldDropdown extends Field {
    *     undefined if triggered programmatically.
    */
   protected override showEditor_(opt_e?: Event) {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     this.dropdownCreate_();
     // AnyDuringMigration because:  Property 'clientX' does not exist on type
     // 'Event'.
@@ -279,11 +283,10 @@ export class FieldDropdown extends Field {
     dom.addClass(menuElement, 'blocklyDropdownMenu');
 
     if (this.getConstants()!.FIELD_DROPDOWN_COLOURED_DIV) {
-      const primaryColour = this.getSourceBlock().isShadow() ?
+      const primaryColour =
-          this.getSourceBlock().getParent()!.getColour() :
+          block.isShadow() ? block.getParent()!.getColour() : block.getColour();
-          this.getSourceBlock().getColour();
+      const borderColour = block.isShadow() ?
-      const borderColour = this.getSourceBlock().isShadow() ?
+          (block.getParent() as BlockSvg).style.colourTertiary :
-          (this.getSourceBlock().getParent() as BlockSvg).style.colourTertiary :
           (this.sourceBlock_ as BlockSvg).style.colourTertiary;
       dropDownDiv.setColour(primaryColour, borderColour);
     }
@@ -304,6 +307,10 @@ export class FieldDropdown extends Field {
 
   /** Create the dropdown editor. */
   private dropdownCreate_() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const menu = new Menu();
     menu.setRole(aria.Role.LISTBOX);
     this.menu_ = menu;
@@ -322,7 +329,7 @@ export class FieldDropdown extends Field {
       }
       const menuItem = new MenuItem(content, value);
       menuItem.setRole(aria.Role.OPTION);
-      menuItem.setRightToLeft(this.getSourceBlock().RTL);
+      menuItem.setRightToLeft(block.RTL);
       menuItem.setCheckable(true);
       menu.addChild(menuItem);
       menuItem.setChecked(value === this.value_);
@@ -540,6 +547,10 @@ export class FieldDropdown extends Field {
    * @param imageJson Selected option that must be an image.
    */
   private renderSelectedImage_(imageJson: ImageProperties) {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     this.imageElement_!.style.display = '';
     this.imageElement_!.setAttributeNS(
         dom.XLINK_NS, 'xlink:href', imageJson.src);
@@ -578,7 +589,7 @@ export class FieldDropdown extends Field {
     this.size_.height = height;
 
     let arrowX = 0;
-    if (this.getSourceBlock().RTL) {
+    if (block.RTL) {
       const imageX = xPadding + arrowWidth;
       this.imageElement_!.setAttribute('x', imageX.toString());
     } else {
@@ -634,12 +645,16 @@ export class FieldDropdown extends Field {
     if (!this.svgArrow_) {
       return 0;
     }
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const hasBorder = !!this.borderRect_;
     const xPadding =
         hasBorder ? this.getConstants()!.FIELD_BORDER_RECT_X_PADDING : 0;
     const textPadding = this.getConstants()!.FIELD_DROPDOWN_SVG_ARROW_PADDING;
     const svgArrowSize = this.getConstants()!.FIELD_DROPDOWN_SVG_ARROW_SIZE;
-    const arrowX = this.getSourceBlock().RTL ? xPadding : x + textPadding;
+    const arrowX = block.RTL ? xPadding : x + textPadding;
     this.svgArrow_.setAttribute(
         'transform', 'translate(' + arrowX + ',' + y + ')');
     return svgArrowSize + textPadding;

core/field_multilineinput.ts

@@ -13,7 +13,7 @@ import * as goog from '../closure/goog/goog.js';
 goog.declareModuleId('Blockly.FieldMultilineInput');
 
 import * as Css from './css.js';
-import {Field} from './field.js';
+import {Field, UnattachedFieldError} from './field.js';
 import * as fieldRegistry from './field_registry.js';
 import {FieldTextInputConfig, FieldTextInput} from './field_textinput.js';
 import * as aria from './utils/aria.js';
@@ -163,6 +163,10 @@ export class FieldMultilineInput extends FieldTextInput {
    * @returns Currently displayed text.
    */
   protected override getDisplayText_(): string {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     let textLines = this.getText();
     if (!textLines) {
       // Prevent the field from disappearing if empty.
@@ -189,7 +193,7 @@ export class FieldMultilineInput extends FieldTextInput {
         textLines += '\n';
       }
     }
-    if (this.getSourceBlock().RTL) {
+    if (block.RTL) {
       // The SVG is LTR, force value to be RTL.
       textLines += '\u200F';
     }
@@ -212,6 +216,10 @@ export class FieldMultilineInput extends FieldTextInput {
 
   /** Updates the text of the textElement. */
   protected override render_() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     // Remove all text group children.
     let currentChild;
     while (currentChild = this.textGroup_.firstChild) {
@@ -248,7 +256,7 @@ export class FieldMultilineInput extends FieldTextInput {
     this.updateSize_();
 
     if (this.isBeingEdited_) {
-      if (this.getSourceBlock().RTL) {
+      if (block.RTL) {
         // in RTL, we need to let the browser reflow before resizing
         // in order to get the correct bounding box of the borderRect
         // avoiding issue #2777.

core/field_textinput.ts

@@ -21,7 +21,7 @@ import * as dialog from './dialog.js';
 import * as dom from './utils/dom.js';
 import * as dropDownDiv from './dropdowndiv.js';
 import * as eventUtils from './events/utils.js';
-import {FieldConfig, Field} from './field.js';
+import {FieldConfig, Field, UnattachedFieldError} from './field.js';
 import * as fieldRegistry from './field_registry.js';
 import {Msg} from './msg.js';
 import * as aria from './utils/aria.js';
@@ -127,13 +127,17 @@ export class FieldTextInput extends Field {
 
   /** @internal */
   override initView() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     if (this.getConstants()!.FULL_BLOCK_FIELDS) {
       // Step one: figure out if this is the only field on this block.
       // Rendering is quite different in that case.
       let nFields = 0;
       let nConnections = 0;
       // Count the number of fields, excluding text fields
-      for (let i = 0, input; input = this.getSourceBlock().inputList[i]; i++) {
+      for (let i = 0, input; input = block.inputList[i]; i++) {
         for (let j = 0; input.fieldRow[j]; j++) {
           nFields++;
         }
@@ -143,8 +147,8 @@ export class FieldTextInput extends Field {
       }
       // The special case is when this is the only non-label field on the block
       // and it has an output but no inputs.
-      this.fullBlockClickTarget_ = nFields <= 1 &&
+      this.fullBlockClickTarget_ =
-          this.getSourceBlock().outputConnection && !nConnections;
+          nFields <= 1 && block.outputConnection && !nConnections;
     } else {
       this.fullBlockClickTarget_ = false;
     }
@@ -307,8 +311,11 @@ export class FieldTextInput extends Field {
    * @param quietInput True if editor should be created without focus.
    */
   private showInlineEditor_(quietInput: boolean) {
-    WidgetDiv.show(
+    const block = this.getSourceBlock();
-        this, this.getSourceBlock().RTL, this.widgetDispose_.bind(this));
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
+    WidgetDiv.show(this, block.RTL, this.widgetDispose_.bind(this));
     this.htmlInput_ = this.widgetCreate_() as HTMLInputElement;
     this.isBeingEdited_ = true;
 
@@ -326,6 +333,10 @@ export class FieldTextInput extends Field {
    * @returns The newly created text input editor.
    */
   protected widgetCreate_(): HTMLElement {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     eventUtils.setGroup(true);
     const div = WidgetDiv.getDiv();
 
@@ -351,8 +362,8 @@ export class FieldTextInput extends Field {
       // Override border radius.
       borderRadius = (bBox.bottom - bBox.top) / 2 + 'px';
       // Pull stroke colour from the existing shadow block
-      const strokeColour = this.getSourceBlock().getParent() ?
+      const strokeColour = block.getParent() ?
-          (this.getSourceBlock().getParent() as BlockSvg).style.colourTertiary :
+          (block.getParent() as BlockSvg).style.colourTertiary :
           (this.sourceBlock_ as BlockSvg).style.colourTertiary;
       htmlInput.style.border = 1 * scale + 'px solid ' + strokeColour;
       div!.style.borderRadius = borderRadius;
@@ -510,6 +521,10 @@ export class FieldTextInput extends Field {
 
   /** Resize the editor to fit the text. */
   protected resizeEditor_() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const div = WidgetDiv.getDiv();
     const bBox = this.getScaledBBox();
     div!.style.width = bBox.right - bBox.left + 'px';
@@ -517,8 +532,7 @@ export class FieldTextInput extends Field {
 
     // In RTL mode block fields and LTR input fields the left edge moves,
     // whereas the right edge is fixed.  Reposition the editor.
-    const x =
+    const x = block.RTL ? bBox.right - div!.offsetWidth : bBox.left;
-        this.getSourceBlock().RTL ? bBox.right - div!.offsetWidth : bBox.left;
     const xy = new Coordinate(x, bBox.top);
 
     div!.style.left = xy.x + 'px';

core/field_variable.ts

@@ -16,7 +16,7 @@ goog.declareModuleId('Blockly.FieldVariable');
 import './events/events_block_change.js';
 
 import type {Block} from './block.js';
-import {Field, FieldConfig} from './field.js';
+import {Field, FieldConfig, UnattachedFieldError} from './field.js';
 import {FieldDropdown} from './field_dropdown.js';
 import * as fieldRegistry from './field_registry.js';
 import * as internalConstants from './internal_constants.js';
@@ -135,20 +135,27 @@ export class FieldVariable extends FieldDropdown {
    * @internal
    */
   override initModel() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     if (this.variable_) {
       return;  // Initialization already happened.
     }
     const variable = Variables.getOrCreateVariablePackage(
-        this.getSourceBlock().workspace, null, this.defaultVariableName,
+        block.workspace, null, this.defaultVariableName, this.defaultType_);
-        this.defaultType_);
     // Don't call setValue because we don't want to cause a rerender.
     this.doValueUpdate_(variable.getId());
   }
 
   override shouldAddBorderRect_() {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     return super.shouldAddBorderRect_() &&
         (!this.getConstants()!.FIELD_DROPDOWN_NO_BORDER_RECT_SHADOW ||
-         this.getSourceBlock().type !== 'variables_get');
+         block.type !== 'variables_get');
   }
 
   /**
@@ -158,6 +165,10 @@ export class FieldVariable extends FieldDropdown {
    *     field's state.
    */
   override fromXml(fieldElement: Element) {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const id = fieldElement.getAttribute('id');
     const variableName = fieldElement.textContent;
     // 'variabletype' should be lowercase, but until July 2019 it was sometimes
@@ -168,8 +179,7 @@ export class FieldVariable extends FieldDropdown {
     // AnyDuringMigration because:  Argument of type 'string | null' is not
     // assignable to parameter of type 'string | undefined'.
     const variable = Variables.getOrCreateVariablePackage(
-        this.getSourceBlock().workspace, id, variableName as AnyDuringMigration,
+        block.workspace, id, variableName as AnyDuringMigration, variableType);
-        variableType);
 
     // This should never happen :)
     if (variableType !== null && variableType !== variable.type) {
@@ -233,12 +243,16 @@ export class FieldVariable extends FieldDropdown {
    * @internal
    */
   override loadState(state: AnyDuringMigration) {
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     if (this.loadLegacyState(FieldVariable, state)) {
       return;
     }
     // This is necessary so that blocks in the flyout can have custom var names.
     const variable = Variables.getOrCreateVariablePackage(
-        this.getSourceBlock().workspace, state['id'] || null, state['name'],
+        block.workspace, state['id'] || null, state['name'],
         state['type'] || '');
     this.setValue(variable.getId());
   }
@@ -315,9 +329,12 @@ export class FieldVariable extends FieldDropdown {
     if (opt_newValue === null) {
       return null;
     }
+    const block = this.getSourceBlock();
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
     const newId = opt_newValue as string;
-    const variable =
+    const variable = Variables.getVariable(block.workspace, newId);
-        Variables.getVariable(this.getSourceBlock().workspace, newId);
     if (!variable) {
       console.warn(
           'Variable id doesn\'t point to a real variable! ' +
@@ -343,8 +360,11 @@ export class FieldVariable extends FieldDropdown {
    * @param newId The value to be saved.
    */
   protected override doValueUpdate_(newId: AnyDuringMigration) {
-    this.variable_ =
+    const block = this.getSourceBlock();
-        Variables.getVariable(this.getSourceBlock().workspace, newId as string);
+    if (!block) {
+      throw new UnattachedFieldError();
+    }
+    this.variable_ = Variables.getVariable(block.workspace, newId as string);
     super.doValueUpdate_(newId);
   }
 

core/interfaces/i_ast_node_location_with_block.ts

@@ -28,5 +28,5 @@ export interface IASTNodeLocationWithBlock extends IASTNodeLocation {
    *
    * @returns The source block.
    */
-  getSourceBlock(): Block;
+  getSourceBlock(): Block|null;
 }

core/keyboard_nav/ast_node.ts

@@ -176,6 +176,10 @@ export class ASTNode {
     const location = this.location_ as Field;
     const input = location.getParentInput();
     const block = location.getSourceBlock();
+    if (!block) {
+      throw new Error(
+          'The current AST location is not associated with a block');
+    }
     const curIdx = block.inputList.indexOf((input));
     let fieldIdx = input.fieldRow.indexOf(location) + 1;
     for (let i = curIdx; i < block.inputList.length; i++) {
@@ -235,6 +239,10 @@ export class ASTNode {
     const location = this.location_ as Field;
     const parentInput = location.getParentInput();
     const block = location.getSourceBlock();
+    if (!block) {
+      throw new Error(
+          'The current AST location is not associated with a block');
+    }
     const curIdx = block.inputList.indexOf((parentInput));
     let fieldIdx = parentInput.fieldRow.indexOf(location) - 1;
     for (let i = curIdx; i >= 0; i--) {
@@ -270,7 +278,10 @@ export class ASTNode {
     // TODO(#6097): Use instanceof checks to exit early for values of
     // curLocation that don't make sense.
     if ((curLocation as IASTNodeLocationWithBlock).getSourceBlock) {
-      curLocation = (curLocation as IASTNodeLocationWithBlock).getSourceBlock();
+      const block = (curLocation as IASTNodeLocationWithBlock).getSourceBlock();
+      if (block) {
+        curLocation = block;
+      }
     }
     // TODO(#6097): Use instanceof checks to exit early for values of
     // curLocation that don't make sense.
@@ -531,7 +542,12 @@ export class ASTNode {
       }
       case ASTNode.types.FIELD: {
         const field = this.location_ as Field;
-        return ASTNode.createBlockNode(field.getSourceBlock());
+        const block = field.getSourceBlock();
+        if (!block) {
+          throw new Error(
+              'The current AST location is not associated with a block');
+        }
+        return ASTNode.createBlockNode(block);
       }
       case ASTNode.types.INPUT: {
         const connection = this.location_ as Connection;

core/procedures.ts

@@ -22,7 +22,7 @@ import * as common from './common.js';
 import type {Abstract} from './events/events_abstract.js';
 import type {BubbleOpen} from './events/events_bubble_open.js';
 import * as eventUtils from './events/utils.js';
-import type {Field} from './field.js';
+import {Field, UnattachedFieldError} from './field.js';
 import {Msg} from './msg.js';
 import {Names} from './names.js';
 import * as utilsXml from './utils/xml.js';
@@ -180,14 +180,19 @@ export function isNameUsed(
  * @alias Blockly.Procedures.rename
  */
 export function rename(this: Field, name: string): string {
+  const block = this.getSourceBlock();
+  if (!block) {
+    throw new UnattachedFieldError();
+  }
+
   // Strip leading and trailing whitespace.  Beyond this, all names are legal.
   name = name.trim();
 
-  const legalName = findLegalName(name, (this.getSourceBlock()));
+  const legalName = findLegalName(name, block);
   const oldName = this.getValue();
   if (oldName !== name && oldName !== legalName) {
     // Rename any callers.
-    const blocks = this.getSourceBlock().workspace.getAllBlocks(false);
+    const blocks = block.workspace.getAllBlocks(false);
     for (let i = 0; i < blocks.length; i++) {
       // Assume it is a procedure so we can check.
       const procedureBlock = blocks[i] as unknown as ProcedureBlock;