Testing

Overview

Type	Framework	Command	Location
E2E visual regression	Playwright	`bun run test`	`tests/e2e/`
Figma CDP reference	Playwright	`bun run test:figma`	`tests/figma/`
Unit tests	bun:test	`bun run test:unit`	`tests/engine/`

E2E Visual Regression

Playwright creates shapes on the canvas and compares screenshots against baseline PNGs.

bun run test              # Run tests, compare against baselines
bun run test:update       # Regenerate baseline screenshots

How It Works

Tests load the editor in a headless browser
The editor signals readiness via a data-ready HTML attribute
Tests create shapes via the editor's API
Screenshots are taken and compared against baselines using toMatchSnapshot
Page is reused across test cases for speed (~2s total)

No-Chrome Test Mode

The editor supports a test mode that hides UI chrome (toolbar, panels) for clean screenshot capture. Activated via URL parameter.

Figma CDP Reference Tests

A separate Playwright project connects to Figma via Chrome DevTools Protocol to capture reference screenshots for pixel-perfect comparison.

bun run figma:debug       # Launch Figma with debugging port
bun run test:figma        # Connect to Figma, capture references

Requires Figma desktop app running with --remote-debugging-port=9222.

Unit Tests

Engine unit tests use bun:test and target < 50ms execution:

bun run test:unit

Tests cover:

Scene graph CRUD operations
Parent-child relationships
Z-ordering
Hit testing

Writing Unit Tests

import { describe, expect, it } from 'bun:test'
import { SceneGraph } from '../../src/engine/scene-graph'

describe('SceneGraph', () => {
  it('creates and retrieves a node', () => {
    const sg = new SceneGraph()
    const node = sg.createNode('RECTANGLE', sg.root, { name: 'Test' })
    expect(sg.getNode(node.guid)).toBeDefined()
  })
})

Test Helpers

File	Purpose
`tests/helpers/canvas.ts`	Canvas setup and interaction utilities
`tests/helpers/figma.ts`	Figma CDP connection helpers

Performance Targets

Metric	Target
E2E suite total	< 3s
Unit test suite total	< 50ms
Screenshot comparison	toMatchSnapshot (pixel-level)

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