diff --git a/src/DragAndScale.ts b/src/DragAndScale.ts
index 608de53aa..8a5698860 100644
--- a/src/DragAndScale.ts
+++ b/src/DragAndScale.ts
@@ -92,7 +92,7 @@ export class DragAndScale {
   }
 
   computeVisibleArea(viewport: Rect | undefined): void {
-    const { scale, offset } = this
+    const { scale, offset, visible_area } = this
 
     if (this.#stateHasChanged()) {
       this.onChanged?.(scale, offset)
@@ -100,11 +100,10 @@ export class DragAndScale {
     }
 
     if (!this.element) {
-      this.visible_area[0] = this.visible_area[1] = this.visible_area[2] = this.visible_area[3] = 0
+      visible_area[0] = visible_area[1] = visible_area[2] = visible_area[3] = 0
       return
     }
-    let width = this.element.width
-    let height = this.element.height
+    let { width, height } = this.element
     let startx = -offset[0]
     let starty = -offset[1]
     if (viewport) {
@@ -115,10 +114,9 @@ export class DragAndScale {
     }
     const endx = startx + width / scale
     const endy = starty + height / scale
-    this.visible_area[0] = startx
-    this.visible_area[1] = starty
-    this.visible_area[2] = endx - startx
-    this.visible_area[3] = endy - starty
+    visible_area[0] = startx
+    visible_area[1] = starty
+    visible_area.resizeBottomRight(endx, endy)
   }
 
   toCanvasContext(ctx: CanvasRenderingContext2D): void {
diff --git a/src/infrastructure/Rectangle.ts b/src/infrastructure/Rectangle.ts
index b200dd0b6..9a40b57d3 100644
--- a/src/infrastructure/Rectangle.ts
+++ b/src/infrastructure/Rectangle.ts
@@ -162,10 +162,10 @@ export class Rectangle extends Float64Array {
    */
   containsXy(x: number, y: number): boolean {
     const { x: left, y: top, width, height } = this
-    return left <= x &&
-      top <= y &&
-      left + width >= x &&
-      top + height >= y
+    return x >= left &&
+      x < left + width &&
+      y >= top &&
+      y < top + height
   }
 
   /**
@@ -244,6 +244,37 @@ export class Rectangle extends Float64Array {
     return [this[0] - x, this[1] - y]
   }
 
+  /** Resizes the rectangle without moving it, setting its top-left corner to [{@link x}, {@link y}]. */
+  resizeTopLeft(x1: number, y1: number) {
+    this[2] += this[0] - x1
+    this[3] += this[1] - y1
+
+    this[0] = x1
+    this[1] = y1
+  }
+
+  /** Resizes the rectangle without moving it, setting its bottom-left corner to [{@link x}, {@link y}]. */
+  resizeBottomLeft(x1: number, y2: number) {
+    this[2] += this[0] - x1
+    this[3] = y2 - this[1]
+
+    this[0] = x1
+  }
+
+  /** Resizes the rectangle without moving it, setting its top-right corner to [{@link x}, {@link y}]. */
+  resizeTopRight(x2: number, y1: number) {
+    this[2] = x2 - this[0]
+    this[3] += this[1] - y1
+
+    this[1] = y1
+  }
+
+  /** Resizes the rectangle without moving it, setting its bottom-right corner to [{@link x}, {@link y}]. */
+  resizeBottomRight(x2: number, y2: number) {
+    this[2] = x2 - this[0]
+    this[3] = y2 - this[1]
+  }
+
   /** Sets the width without moving the right edge (changes position) */
   setWidthRightAnchored(width: number) {
     const currentWidth = this[2]
diff --git a/test/infrastructure/Rectangle.test.ts b/test/infrastructure/Rectangle.test.ts
index 9c549cc2d..839b301ec 100644
--- a/test/infrastructure/Rectangle.test.ts
+++ b/test/infrastructure/Rectangle.test.ts
@@ -13,7 +13,7 @@ const test = baseTest.extend<{ rect: Rectangle }>({
 })
 
 describe("Rectangle", () => {
-  describe("constructor", () => {
+  describe("constructor and basic properties", () => {
     test("should create a default rectangle", ({ rect }) => {
       expect(rect.x).toBe(0)
       expect(rect.y).toBe(0)
@@ -21,6 +21,7 @@ describe("Rectangle", () => {
       expect(rect.height).toBe(0)
       expect(rect.length).toBe(4)
     })
+
     test("should create a rectangle with specified values", () => {
       const rect = new Rectangle(1, 2, 3, 4)
       expect(rect.x).toBe(1)
@@ -28,9 +29,18 @@ describe("Rectangle", () => {
       expect(rect.width).toBe(3)
       expect(rect.height).toBe(4)
     })
+
+    test("should update the rectangle values", ({ rect }) => {
+      const newValues: [number, number, number, number] = [1, 2, 3, 4]
+      rect.updateTo(newValues)
+      expect(rect.x).toBe(1)
+      expect(rect.y).toBe(2)
+      expect(rect.width).toBe(3)
+      expect(rect.height).toBe(4)
+    })
   })
 
-  describe("subarray", () => {
+  describe("array operations", () => {
     test("should return a Float64Array representing the subarray", () => {
       const rect = new Rectangle(10, 20, 30, 40)
       const sub = rect.subarray(1, 3)
@@ -39,6 +49,7 @@ describe("Rectangle", () => {
       expect(sub[0]).toBe(20) // y
       expect(sub[1]).toBe(30) // width
     })
+
     test("should return a Float64Array for the entire array if no args", () => {
       const rect = new Rectangle(10, 20, 30, 40)
       const sub = rect.subarray()
@@ -49,9 +60,22 @@ describe("Rectangle", () => {
       expect(sub[2]).toBe(30)
       expect(sub[3]).toBe(40)
     })
+
+    test("should return an array with [x, y, width, height]", () => {
+      const rect = new Rectangle(1, 2, 3, 4)
+      const arr = rect.toArray()
+      expect(arr).toEqual([1, 2, 3, 4])
+      expect(Array.isArray(arr)).toBe(true)
+      expect(arr).not.toBeInstanceOf(Float64Array)
+
+      const exported = rect.export()
+      expect(exported).toEqual([1, 2, 3, 4])
+      expect(Array.isArray(exported)).toBe(true)
+      expect(exported).not.toBeInstanceOf(Float64Array)
+    })
   })
 
-  describe("pos", () => {
+  describe("position and size properties", () => {
     test("should get the position", ({ rect }) => {
       rect.x = 10
       rect.y = 20
@@ -60,12 +84,14 @@ describe("Rectangle", () => {
       expect(pos[1]).toBe(20)
       expect(pos.length).toBe(2)
     })
+
     test("should set the position", ({ rect }) => {
       const newPos: Point = [5, 15]
       rect.pos = newPos
       expect(rect.x).toBe(5)
       expect(rect.y).toBe(15)
     })
+
     test("should update the rectangle when the returned pos object is modified", ({ rect }) => {
       rect.x = 1
       rect.y = 2
@@ -75,9 +101,7 @@ describe("Rectangle", () => {
       expect(rect.x).toBe(100)
       expect(rect.y).toBe(200)
     })
-  })
 
-  describe("size", () => {
     test("should get the size", ({ rect }) => {
       rect.width = 30
       rect.height = 40
@@ -86,12 +110,14 @@ describe("Rectangle", () => {
       expect(size[1]).toBe(40)
       expect(size.length).toBe(2)
     })
+
     test("should set the size", ({ rect }) => {
       const newSize: Size = [35, 45]
       rect.size = newSize
       expect(rect.width).toBe(35)
       expect(rect.height).toBe(45)
     })
+
     test("should update the rectangle when the returned size object is modified", ({ rect }) => {
       rect.width = 3
       rect.height = 4
@@ -103,79 +129,73 @@ describe("Rectangle", () => {
     })
   })
 
-  // #region Property accessors
-  describe("x", () => {
+  describe("edge properties", () => {
     test("should get x", ({ rect }) => {
       rect[0] = 5
       expect(rect.x).toBe(5)
     })
+
     test("should set x", ({ rect }) => {
       rect.x = 10
       expect(rect[0]).toBe(10)
     })
-  })
 
-  describe("y", () => {
     test("should get y", ({ rect }) => {
       rect[1] = 6
       expect(rect.y).toBe(6)
     })
+
     test("should set y", ({ rect }) => {
       rect.y = 11
       expect(rect[1]).toBe(11)
     })
-  })
 
-  describe("width", () => {
     test("should get width", ({ rect }) => {
       rect[2] = 7
       expect(rect.width).toBe(7)
     })
+
     test("should set width", ({ rect }) => {
       rect.width = 12
       expect(rect[2]).toBe(12)
     })
-  })
 
-  describe("height", () => {
     test("should get height", ({ rect }) => {
       rect[3] = 8
       expect(rect.height).toBe(8)
     })
+
     test("should set height", ({ rect }) => {
       rect.height = 13
       expect(rect[3]).toBe(13)
     })
-  })
 
-  describe("left", () => {
     test("should get left", ({ rect }) => {
       rect[0] = 1
       expect(rect.left).toBe(1)
     })
+
     test("should set left", ({ rect }) => {
       rect.left = 2
       expect(rect[0]).toBe(2)
     })
-  })
 
-  describe("top", () => {
     test("should get top", ({ rect }) => {
       rect[1] = 3
       expect(rect.top).toBe(3)
     })
+
     test("should set top", ({ rect }) => {
       rect.top = 4
       expect(rect[1]).toBe(4)
     })
-  })
 
-  describe("right", () => {
     test("should get right", ({ rect }) => {
       rect[0] = 1
       rect[2] = 10
       expect(rect.right).toBe(11)
     })
+
     test("should set right", ({ rect }) => {
       rect.x = 1
       rect.width = 10 // right is 11
@@ -183,14 +203,13 @@ describe("Rectangle", () => {
       expect(rect.x).toBe(10) // x = right - width = 20 - 10
       expect(rect.width).toBe(10)
     })
-  })
 
-  describe("bottom", () => {
     test("should get bottom", ({ rect }) => {
       rect[1] = 2
       rect[3] = 20
       expect(rect.bottom).toBe(22)
     })
+
     test("should set bottom", ({ rect }) => {
       rect.y = 2
       rect.height = 20 // bottom is 22
@@ -198,9 +217,7 @@ describe("Rectangle", () => {
       expect(rect.y).toBe(10) // y = bottom - height = 30 - 20
       expect(rect.height).toBe(20)
     })
-  })
 
-  describe("centreX", () => {
     test("should get centreX", () => {
       const rect = new Rectangle(0, 0, 10, 0)
       expect(rect.centreX).toBe(5)
@@ -209,9 +226,7 @@ describe("Rectangle", () => {
       rect.width = 20
       expect(rect.centreX).toBe(15) // 5 + (20 * 0.5)
     })
-  })
 
-  describe("centreY", () => {
     test("should get centreY", () => {
       const rect = new Rectangle(0, 0, 0, 10)
       expect(rect.centreY).toBe(5)
@@ -221,38 +236,81 @@ describe("Rectangle", () => {
       expect(rect.centreY).toBe(15) // 5 + (20 * 0.5)
     })
   })
-  // #endregion Property accessors
 
-  describe("updateTo", () => {
-    test("should update the rectangle values", ({ rect }) => {
-      const newValues: [number, number, number, number] = [1, 2, 3, 4]
-      rect.updateTo(newValues)
-      expect(rect.x).toBe(1)
-      expect(rect.y).toBe(2)
-      expect(rect.width).toBe(3)
-      expect(rect.height).toBe(4)
+  describe("geometric operations", () => {
+    test("should return the centre point", () => {
+      const rect = new Rectangle(10, 20, 30, 40) // centreX = 10 + 15 = 25, centreY = 20 + 20 = 40
+      const centre = rect.getCentre()
+      expect(centre[0]).toBe(25)
+      expect(centre[1]).toBe(40)
+      expect(centre).not.toBe(rect.pos) // Should be a new Point
+    })
+
+    test("should return the area", () => {
+      expect(new Rectangle(0, 0, 5, 10).getArea()).toBe(50)
+      expect(new Rectangle(1, 1, 0, 10).getArea()).toBe(0)
+    })
+
+    test("should return the perimeter", () => {
+      expect(new Rectangle(0, 0, 5, 10).getPerimeter()).toBe(30) // 2 * (5+10)
+      expect(new Rectangle(0, 0, 0, 0).getPerimeter()).toBe(0)
+    })
+
+    test("should return the top-left point", () => {
+      const rect = new Rectangle(1, 2, 3, 4)
+      const tl = rect.getTopLeft()
+      expect(tl[0]).toBe(1)
+      expect(tl[1]).toBe(2)
+      expect(tl).not.toBe(rect.pos)
+    })
+
+    test("should return the bottom-right point", () => {
+      const rect = new Rectangle(1, 2, 10, 20) // right=11, bottom=22
+      const br = rect.getBottomRight()
+      expect(br[0]).toBe(11)
+      expect(br[1]).toBe(22)
+    })
+
+    test("should return the size", () => {
+      const rect = new Rectangle(1, 2, 30, 40)
+      const s = rect.getSize()
+      expect(s[0]).toBe(30)
+      expect(s[1]).toBe(40)
+      expect(s).not.toBe(rect.size)
+    })
+
+    test("should return the offset from top-left to the point", () => {
+      const rect = new Rectangle(10, 20, 5, 5)
+      const offset = rect.getOffsetTo([12, 23])
+      expect(offset[0]).toBe(2) // 12 - 10
+      expect(offset[1]).toBe(3) // 23 - 20
+    })
+
+    test("should return the offset from the point to the top-left", () => {
+      const rect = new Rectangle(10, 20, 5, 5)
+      const offset = rect.getOffsetFrom([12, 23])
+      expect(offset[0]).toBe(-2) // 10 - 12
+      expect(offset[1]).toBe(-3) // 20 - 23
     })
   })
 
-  describe("containsXy", () => {
+  describe("containment and overlap", () => {
     const rect = new Rectangle(10, 10, 20, 20) // x: 10, y: 10, right: 30, bottom: 30
+
     test.each([
       [10, 10, true], // top-left corner
-      [30, 30, true], // bottom-right corner
+      [29, 29, true], // bottom-right corner
       [15, 15, true], // inside
       [5, 15, false], // outside left
-      [35, 15, false], // outside right
+      [30, 15, false], // outside right
       [15, 5, false], // outside top
-      [15, 35, false], // outside bottom
-      [10, 30, true], // on bottom edge
-      [30, 10, true], // on right edge
-    ])("should return %s when checking if (%s, %s) is inside", (x, y, expected) => {
+      [15, 30, false], // outside bottom
+      [10, 29, true], // on bottom edge
+      [29, 10, true], // on right edge
+    ])("when checking if (%s, %s) is inside, should return %s", (x, y, expected) => {
       expect(rect.containsXy(x, y)).toBe(expected)
     })
-  })
 
-  describe("containsPoint", () => {
-    const rect = new Rectangle(0, 0, 10, 10) // x:0, y:0, r:10, b:10
     test.each([
       [[0, 0] as Point, true],
       [[10, 10] as Point, true],
@@ -262,12 +320,10 @@ describe("Rectangle", () => {
       [[5, -1] as Point, false],
       [[5, 11] as Point, false],
     ])("should return %s for point %j", (point: Point, expected: boolean) => {
+      rect.updateTo([0, 0, 10, 10])
       expect(rect.containsPoint(point)).toBe(expected)
     })
-  })
 
-  describe("containsRect", () => {
-    const outer = new Rectangle(0, 0, 100, 100)
     test.each([
       // Completely inside
       [new Rectangle(10, 10, 10, 10), true],
@@ -286,7 +342,9 @@ describe("Rectangle", () => {
       // Same size
       [new Rectangle(0, 0, 100, 100), true],
     ])("should return %s when checking if %s is inside outer rect", (inner: Rectangle, expectedOrOuter: boolean | Rectangle, expectedIfThreeArgs?: boolean) => {
-      let testOuter = outer
+      let testOuter = rect
+      rect.updateTo([0, 0, 100, 100])
+
       let testExpected = expectedOrOuter as boolean
       if (typeof expectedOrOuter !== "boolean") {
         testOuter = expectedOrOuter as Rectangle
@@ -294,10 +352,7 @@ describe("Rectangle", () => {
       }
       expect(testOuter.containsRect(inner)).toBe(testExpected)
     })
-  })
 
-  describe("overlaps", () => {
-    const rect1 = new Rectangle(10, 10, 20, 20) // 10,10 to 30,30
     test.each([
       // Completely overlapping
       [new Rectangle(15, 15, 10, 10), true], // r2 inside r1
@@ -319,84 +374,87 @@ describe("Rectangle", () => {
       // rect1 inside rect2
       [new Rectangle(0, 0, 100, 100), true],
     ])("should return %s for overlap with %s", (rect2, expected) => {
-      expect(rect1.overlaps(rect2)).toBe(expected)
+      const rect = new Rectangle(10, 10, 20, 20) // 10,10 to 30,30
+
+      expect(rect.overlaps(rect2)).toBe(expected)
       // Overlap should be commutative
-      expect(rect2.overlaps(rect1)).toBe(expected)
+      expect(rect2.overlaps(rect)).toBe(expected)
     })
   })
 
-  describe("getCentre", () => {
-    test("should return the centre point", () => {
-      const rect = new Rectangle(10, 20, 30, 40) // centreX = 10 + 15 = 25, centreY = 20 + 20 = 40
-      const centre = rect.getCentre()
-      expect(centre[0]).toBe(25)
-      expect(centre[1]).toBe(40)
-      expect(centre).not.toBe(rect.pos) // Should be a new Point
+  describe("resize operations", () => {
+    test("should resize from top-left corner while maintaining bottom-right", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20]) // x: 10, y: 10, width: 20, height: 20
+      rect.resizeTopLeft(5, 5)
+      expect(rect.x).toBe(5)
+      expect(rect.y).toBe(5)
+      expect(rect.width).toBe(25) // 20 + (10 - 5)
+      expect(rect.height).toBe(25) // 20 + (10 - 5)
     })
-  })
 
-  describe("getArea", () => {
-    test("should return the area", () => {
-      expect(new Rectangle(0, 0, 5, 10).getArea()).toBe(50)
-      expect(new Rectangle(1, 1, 0, 10).getArea()).toBe(0)
+    test("should handle negative coordinates for top-left resize", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeTopLeft(-5, -5)
+      expect(rect.x).toBe(-5)
+      expect(rect.y).toBe(-5)
+      expect(rect.width).toBe(35) // 20 + (10 - (-5))
+      expect(rect.height).toBe(35) // 20 + (10 - (-5))
     })
-  })
 
-  describe("getPerimeter", () => {
-    test("should return the perimeter", () => {
-      expect(new Rectangle(0, 0, 5, 10).getPerimeter()).toBe(30) // 2 * (5+10)
-      expect(new Rectangle(0, 0, 0, 0).getPerimeter()).toBe(0)
+    test("should resize from bottom-left corner while maintaining top-right", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeBottomLeft(5, 35)
+      expect(rect.x).toBe(5)
+      expect(rect.y).toBe(10)
+      expect(rect.width).toBe(25) // 20 + (10 - 5)
+      expect(rect.height).toBe(25) // 35 - 10
     })
-  })
 
-  describe("getTopLeft", () => {
-    test("should return the top-left point", () => {
-      const rect = new Rectangle(1, 2, 3, 4)
-      const tl = rect.getTopLeft()
-      expect(tl[0]).toBe(1)
-      expect(tl[1]).toBe(2)
-      expect(tl).not.toBe(rect.pos)
+    test("should handle negative coordinates for bottom-left resize", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeBottomLeft(-5, 35)
+      expect(rect.x).toBe(-5)
+      expect(rect.y).toBe(10)
+      expect(rect.width).toBe(35) // 20 + (10 - (-5))
+      expect(rect.height).toBe(25) // 35 - 10
     })
-  })
 
-  describe("getBottomRight", () => {
-    test("should return the bottom-right point", () => {
-      const rect = new Rectangle(1, 2, 10, 20) // right=11, bottom=22
-      const br = rect.getBottomRight()
-      expect(br[0]).toBe(11)
-      expect(br[1]).toBe(22)
+    test("should resize from top-right corner while maintaining bottom-left", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeTopRight(35, 5)
+      expect(rect.x).toBe(10)
+      expect(rect.y).toBe(5)
+      expect(rect.width).toBe(25) // 35 - 10
+      expect(rect.height).toBe(25) // 20 + (10 - 5)
     })
-  })
 
-  describe("getSize", () => {
-    test("should return the size", () => {
-      const rect = new Rectangle(1, 2, 30, 40)
-      const s = rect.getSize()
-      expect(s[0]).toBe(30)
-      expect(s[1]).toBe(40)
-      expect(s).not.toBe(rect.size)
+    test("should handle negative coordinates for top-right resize", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeTopRight(35, -5)
+      expect(rect.x).toBe(10)
+      expect(rect.y).toBe(-5)
+      expect(rect.width).toBe(25) // 35 - 10
+      expect(rect.height).toBe(35) // 20 + (10 - (-5))
     })
-  })
 
-  describe("getOffsetTo", () => {
-    test("should return the offset from top-left to the point", () => {
-      const rect = new Rectangle(10, 20, 5, 5)
-      const offset = rect.getOffsetTo([12, 23])
-      expect(offset[0]).toBe(2) // 12 - 10
-      expect(offset[1]).toBe(3) // 23 - 20
+    test("should resize from bottom-right corner while maintaining top-left", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeBottomRight(35, 35)
+      expect(rect.x).toBe(10)
+      expect(rect.y).toBe(10)
+      expect(rect.width).toBe(25) // 35 - 10
+      expect(rect.height).toBe(25) // 35 - 10
     })
-  })
 
-  describe("getOffsetFrom", () => {
-    test("should return the offset from the point to the top-left", () => {
-      const rect = new Rectangle(10, 20, 5, 5)
-      const offset = rect.getOffsetFrom([12, 23])
-      expect(offset[0]).toBe(-2) // 10 - 12
-      expect(offset[1]).toBe(-3) // 20 - 23
+    test("should handle negative coordinates for bottom-right resize", ({ rect }) => {
+      rect.updateTo([10, 10, 20, 20])
+      rect.resizeBottomRight(35, -5)
+      expect(rect.x).toBe(10)
+      expect(rect.y).toBe(10)
+      expect(rect.width).toBe(25) // 35 - 10
+      expect(rect.height).toBe(-15) // -5 - 10
     })
-  })
 
-  describe("setWidthRightAnchored", () => {
     test("should set width, anchoring the right edge", () => {
       const rect = new Rectangle(10, 0, 20, 0) // x:10, width:20 -> right:30
       rect.setWidthRightAnchored(15) // new width 15
@@ -404,9 +462,7 @@ describe("Rectangle", () => {
       expect(rect.x).toBe(15) // x = oldX + (oldWidth - newWidth) = 10 + (20 - 15) = 15
       expect(rect.right).toBe(30) // right should remain 30 (15+15)
     })
-  })
 
-  describe("setHeightBottomAnchored", () => {
     test("should set height, anchoring the bottom edge", () => {
       const rect = new Rectangle(0, 10, 0, 20) // y:10, height:20 -> bottom:30
       rect.setHeightBottomAnchored(15) // new height 15
@@ -416,22 +472,7 @@ describe("Rectangle", () => {
     })
   })
 
-  describe("toArray / export", () => {
-    test("should return an array with [x, y, width, height]", () => {
-      const rect = new Rectangle(1, 2, 3, 4)
-      const arr = rect.toArray()
-      expect(arr).toEqual([1, 2, 3, 4])
-      expect(Array.isArray(arr)).toBe(true)
-      expect(arr).not.toBeInstanceOf(Float64Array)
-
-      const exported = rect.export()
-      expect(exported).toEqual([1, 2, 3, 4])
-      expect(Array.isArray(exported)).toBe(true)
-      expect(exported).not.toBeInstanceOf(Float64Array)
-    })
-  })
-
-  describe("_drawDebug", () => {
+  describe("debug drawing", () => {
     test("should call canvas context methods", () => {
       const rect = new Rectangle(10, 20, 30, 40)
       const mockCtx = {
@@ -454,6 +495,7 @@ describe("Rectangle", () => {
       // For simplicity, we're assuming the implementation is correct if strokeRect was called with correct params.
       // A more robust test could involve spying on property assignments if vitest supports it easily.
     })
+
     test("should use default color if not provided", () => {
       const rect = new Rectangle(1, 2, 3, 4)
       const mockCtx = {