fix(highlight): Ignore empty rects when rendering highlight canvas rects

src/highlight/HighlightCanvas.tsx

@@ -67,6 +67,12 @@ export default class HighlightCanvas extends React.PureComponent<Props> {
 
         shapesArray.forEach(rect => {
             const { height, isActive, isHover, width, x, y } = rect;
+
+            // Ignore empty rects with a width or height of 0
+            if (width === 0 || height === 0) {
+                return;
+            }
+
             const rectHeight = (height / 100) * canvasHeight;
             const rectWidth = (width / 100) * canvasWidth;
             const x1 = (x / 100) * canvasWidth;

src/highlight/__mocks__/data.ts

@@ -8,6 +8,22 @@ export const rect: Rect = {
     y: 5,
 };
 
+export const noWidthRect: Rect = {
+    type: 'rect' as const,
+    height: 10,
+    width: 0,
+    x: 5,
+    y: 5,
+};
+
+export const noHeightRect: Rect = {
+    type: 'rect' as const,
+    height: 0,
+    width: 20,
+    x: 5,
+    y: 5,
+};
+
 export const target: TargetHighlight = {
     location: {
         type: 'page' as const,
@@ -55,3 +71,10 @@ export const selection = {
         },
     ],
 };
+
+export const canvasContext = {
+    fillRect: jest.fn(),
+    restore: jest.fn(),
+    save: jest.fn(),
+    strokeRect: jest.fn(),
+};

src/highlight/__tests__/HighlightCanvas-test.tsx

@@ -1,7 +1,7 @@
 import React from 'react';
 import { shallow, ShallowWrapper } from 'enzyme';
 import HighlightCanvas, { Props } from '../HighlightCanvas';
-import { rect as mockRect } from '../__mocks__/data';
+import { canvasContext, rect as mockRect, noWidthRect, noHeightRect } from '../__mocks__/data';
 
 describe('HighlightCanvas', () => {
     const defaults: Props = {
@@ -56,5 +56,23 @@ describe('HighlightCanvas', () => {
             const wrapper = getWrapper();
             expect(wrapper.find('canvas').hasClass('ba-HighlightCanvas')).toBe(true);
         });
+
+        test('should render, excluding 0 width and height values', () => {
+            const wrapper = getWrapper({ shapes: [mockRect, noWidthRect, noHeightRect] });
+            const instance = wrapper.instance() as HighlightCanvas;
+
+            instance.canvasRef = {
+                current: {
+                    // eslint-disable-next-line @typescript-eslint/ban-ts-ignore
+                    // @ts-ignore
+                    getContext: () => canvasContext,
+                },
+            };
+
+            instance.renderRects();
+
+            expect(canvasContext.fillRect).toHaveBeenCalledTimes(1);
+            expect(canvasContext.strokeRect).toHaveBeenCalledTimes(1);
+        });
     });
 });

src/highlight/__tests__/highlightUtil-test.ts

@@ -166,6 +166,46 @@ describe('highlightUtil', () => {
             expect(result[1]).toEqual(rects[3]);
             expect(result[2]).toEqual(rects[4]);
         });
+
+        test('should combine rects by row, excluding 0 width and height values', () => {
+            const validRect1 = {
+                height: 20,
+                width: 100,
+                x: 100,
+                y: 200,
+            };
+
+            const validRect2 = {
+                height: 21,
+                width: 100,
+                x: 500,
+                y: 200,
+            };
+
+            const noHeightRect = {
+                height: 0,
+                width: 100,
+                x: 200,
+                y: 200,
+            };
+
+            const noWidthRect = {
+                height: 23,
+                width: 0,
+                x: 400,
+                y: 300,
+            };
+
+            const result = combineRects([validRect1, noHeightRect, validRect2, noWidthRect]);
+            expect(result).toHaveLength(2);
+            expect(result[0]).toEqual({
+                height: 20,
+                width: 100,
+                x: 100,
+                y: 200,
+            });
+            expect(result[1]).toEqual(validRect2);
+        });
     });
 
     describe('getShapeRelativeToContainer', () => {

src/highlight/highlightUtil.ts

@@ -103,6 +103,12 @@ export const combineRects = (rects: Shape[]): Shape[] => {
 
     dedupeRects(rects).forEach(rect => {
         const { height, width, x, y } = rect;
+
+        // Ignore empty rects with a width or height of 0
+        if (width === 0 || height === 0) {
+            return;
+        }
+
         const lastRect = result.pop();
 
         if (!lastRect) {