fix(): typeAssertions not respecting subclasses

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [next]
 
+- fix(): `typeAssertions` not respecting subclasses [#8931](https://github.com/fabricjs/fabric.js/pull/8931)
 - fix(TS): extending canvas and object event types (`type` => `interface`) [#8926](https://github.com/fabricjs/fabric.js/pull/8926)
 - chore(build) simple deps update [#8929](https://github.com/fabricjs/fabric.js/pull/8929)
 - fix(Canvas): sync cleanup of dom elements in dispose [#8903](https://github.com/fabricjs/fabric.js/pull/8903)

src/gradient/Gradient.ts

@@ -203,7 +203,7 @@ export class Gradient<
     }
     if (
       object instanceof BaseFabricObject &&
-      object.isType('Path') &&
+      object.is('path') &&
       this.gradientUnits !== 'percentage'
     ) {
       offsetX -= object.pathOffset.x;

src/shapes/ActiveSelection.ts

@@ -4,6 +4,10 @@ import { Group } from './Group';
 import type { FabricObject } from './Object/FabricObject';
 
 export class ActiveSelection extends Group {
+  static TAGS = {
+    selection: true,
+  };
+
   declare _objects: FabricObject[];
 
   /**

src/shapes/IText/IText.ts

@@ -103,6 +103,11 @@ export class IText<
   extends ITextClickBehavior<Props, SProps, EventSpec>
   implements UniqueITextProps
 {
+  static TAGS = {
+    text: true,
+    interactive: true,
+  };
+
   /**
    * Index where text selection starts (or where cursor is when there is no selection)
    * @type Number

src/shapes/Object/Object.ts

@@ -98,6 +98,18 @@ export class FabricObject<
   extends AnimatableObject<EventSpec>
   implements ObjectProps
 {
+  static TAGS: Record<string, boolean> = {};
+
+  /**
+   * A workaroud instead of using `type` that is deprecated or `instanceof` that cause import cycles
+   * @param tags
+   * @returns
+   */
+  is(...tags: string[]) {
+    const { TAGS } = this.constructor as typeof FabricObject;
+    return tags.every((tag) => TAGS[tag]);
+  }
+
   declare minScaleLimit: number;
 
   declare opacity: number;
@@ -1443,6 +1455,7 @@ export class FabricObject<
 
   /**
    * Returns true if any of the specified types is identical to the type of an instance
+   * @deprecated use `instanceof` or `is`
    * @param {String} type Type to check against
    * @return {Boolean}
    */

src/shapes/Path.ts

@@ -49,6 +49,10 @@ export class Path<
   SProps extends SerializedPathProps = SerializedPathProps,
   EventSpec extends ObjectEvents = ObjectEvents
 > extends FabricObject<Props, SProps, EventSpec> {
+  static TAGS = {
+    path: true,
+  };
+
   /**
    * Array of path points
    * @type Array

src/shapes/Text/Text.ts

@@ -109,6 +109,10 @@ export class Text<
   extends StyledText<Props, SProps, EventSpec>
   implements UniqueTextProps
 {
+  static TAGS = {
+    text: true,
+  };
+
   /**
    * Properties that requires a text layout recalculation when changed
    * @type string[]

src/util/typeAssertions.ts

@@ -40,23 +40,23 @@ export const isCollection = (
 export const isActiveSelection = (
   fabricObject?: FabricObject
 ): fabricObject is ActiveSelection => {
-  return !!fabricObject && fabricObject.isType('ActiveSelection');
+  return !!fabricObject && fabricObject.is('selection');
 };
 
 export const isTextObject = (
   fabricObject?: FabricObject
 ): fabricObject is Text => {
   // we could use instanceof but that would mean pulling in Text code for a simple check
   // @todo discuss what to do and how to do
-  return !!fabricObject && fabricObject.isType('Text', 'IText', 'Textbox');
+  return !!fabricObject && fabricObject.is('text');
 };
 
 export const isInteractiveTextObject = (
   fabricObject?: FabricObject
 ): fabricObject is IText | Textbox => {
   // we could use instanceof but that would mean pulling in Text code for a simple check
   // @todo discuss what to do and how to do
-  return !!fabricObject && fabricObject.isType('IText', 'Textbox');
+  return !!fabricObject && fabricObject.is('text', 'interactive');
 };
 
 export const isFabricObjectCached = (

test/unit/activeselection.js

@@ -38,6 +38,7 @@
 
     assert.ok(group);
     assert.ok(group instanceof fabric.ActiveSelection, 'should be instance of fabric.ActiveSelection');
+    assert.ok(group.is('selection'), 'TAG');
   });
 
   QUnit.test('toString', function(assert) {

test/unit/itext.js

@@ -66,6 +66,7 @@
 
       assert.ok(iText instanceof fabric.IText);
       assert.ok(iText instanceof fabric.Text);
+      assert.ok(iText.is('text', 'interactive'), 'TAG');
     });
 
     QUnit.test('initial properties', function(assert) {

test/unit/path.js

@@ -79,7 +79,8 @@
     makePathObject(function(path) {
       assert.ok(path instanceof fabric.Path);
       assert.ok(path instanceof fabric.Object);
-
+
+      assert.ok(path.is('path'), 'TAG');
       assert.equal(path.constructor.name, 'Path');
 
       var error;

test/unit/text.js

@@ -75,6 +75,7 @@
     assert.ok(text instanceof fabric.Text);
     assert.ok(text instanceof fabric.Object);
 
+    assert.ok(text.is('text'), 'TAG');
     assert.equal(text.constructor.name, 'Text');
     assert.equal(text.get('text'), 'x');
   });

test/unit/textbox.js

@@ -81,6 +81,7 @@
     assert.ok(textbox instanceof fabric.Textbox);
     assert.ok(textbox instanceof fabric.IText);
     assert.ok(textbox instanceof fabric.Text);
+    assert.ok(textbox.is('text', 'interactive'), 'TAG');
   });
 
   QUnit.test('constructor with width', function(assert) {