Calling Rectangle.setSize() wouldn't change the underlying geometry of the Shape Game Object, causing any stroke to be incorrectly rendered after a size change.

src/gameobjects/shape/rectangle/Rectangle.js

@@ -15,9 +15,9 @@ var RectangleRender = require('./RectangleRender');
  * treat it like any other Game Object in your game, such as tweening it, scaling it, or enabling
  * it for input or physics. It provides a quick and easy way for you to render this shape in your
  * game without using a texture, while still taking advantage of being fully batched in WebGL.
- * 
+ *
  * This shape supports both fill and stroke colors.
- * 
+ *
  * You can change the size of the rectangle by changing the `width` and `height` properties.
  *
  * @class Rectangle
@@ -65,6 +65,37 @@ var Rectangle = new Class({
         this.updateData();
     },
 
+    /**
+     * Sets the internal size of this Game Object, as used for frame or physics body creation.
+     *
+     * This will not change the size that the Game Object is rendered in-game.
+     * For that you need to either set the scale of the Game Object (`setScale`) or call the
+     * `setDisplaySize` method, which is the same thing as changing the scale but allows you
+     * to do so by giving pixel values.
+     *
+     * If you have enabled this Game Object for input, changing the size will _not_ change the
+     * size of the hit area. To do this you should adjust the `input.hitArea` object directly.
+     *
+     * @method Phaser.GameObjects.Rectangle#setSize
+     * @since 3.13.0
+     *
+     * @param {number} width - The width of this Game Object.
+     * @param {number} height - The height of this Game Object.
+     *
+     * @return {this} This Game Object instance.
+     */
+    setSize: function (width, height)
+    {
+        this.width = width;
+        this.height = height;
+
+        this.geom.setSize(width, height);
+
+        this.updateData();
+
+        return this;
+    },
+
     /**
      * Internal method that updates the data and path values.
      *