openpencil/openspec/specs/testing/spec.md

testing Specification

Purpose

Test infrastructure. Playwright visual regression (E2E with Figma CDP reference), bun:test unit tests, no-chrome test mode, data-ready synchronization, and page reuse optimization.

Requirements

Requirement: Playwright visual regression testing

E2E tests SHALL use Playwright to create shapes and compare screenshots against baseline snapshots.

Scenario: Visual regression test pass

• WHEN bun run test is executed
• THEN Playwright tests create shapes, take screenshots, and compare against baseline PNGs

Requirement: Figma CDP reference tests

A separate Playwright project SHALL connect to Figma via Chrome DevTools Protocol (CDP) to capture reference screenshots for pixel-perfect comparison.

Scenario: Figma reference capture

• WHEN bun run test:figma is executed with Figma running in debug mode
• THEN Playwright connects to Figma via CDP and captures reference screenshots

Requirement: No-chrome test mode

The editor SHALL support a test mode (activated via URL param or environment) that hides Chrome/UI elements for clean screenshot capture.

Scenario: Test mode rendering

• WHEN the editor loads in test mode
• THEN only canvas content is rendered, without toolbar, panels, or other UI chrome

Requirement: Data-ready optimization

The editor SHALL signal readiness via a data-ready attribute for E2E test synchronization, replacing unreliable timeouts.

Scenario: Wait for ready

• WHEN a Playwright test waits for the data-ready attribute
• THEN it proceeds only when the canvas is fully rendered

Requirement: Page reuse for speed

E2E tests SHALL reuse the browser page across test cases to minimize overhead. Target: all E2E tests complete in <3s.

Scenario: Fast E2E execution

• WHEN the full E2E test suite runs
• THEN it completes in under 3 seconds by reusing the page

Requirement: bun:test unit tests

Engine unit tests SHALL use bun:test and complete in <50ms.

Scenario: Unit test speed

• WHEN bun test ./tests/engine is run
• THEN all unit tests pass in under 50ms

Requirement: Fig-import unit tests

Unit tests SHALL verify the .fig import pipeline: node type mapping, transform extraction, fill/stroke/effect import, gradient stops, image fills, arc data, stroke properties, and nested frame hierarchies.

Scenario: Run fig-import tests

• WHEN bun test ./tests/engine/fig-import.test.ts is executed
• THEN all import pipeline tests pass covering tier 1 rendering features

Requirement: Layout unit tests

Unit tests SHALL verify Yoga auto-layout computation: direction, gap, padding, justify, align, child sizing (fixed/fill/hug), cross-axis sizing, wrap, and nested layouts.

Scenario: Run layout tests

• WHEN bun test ./tests/engine/layout.test.ts is executed
• THEN all layout computation tests pass

Requirement: Layers panel E2E tests

E2E tests SHALL verify the layers panel: node visibility in tree, expand/collapse frames, selection sync between canvas and layers panel.

Scenario: Run layers panel E2E

• WHEN the layers panel E2E tests run
• THEN all tests pass verifying tree structure, visibility toggles, and selection sync

Requirement: Component-instance sync unit tests

Unit tests SHALL cover the component-instance sync lifecycle: instance creation with componentId mapping on children, sync propagation of property changes, override preservation during sync, new child addition to instances, and detach breaking the link.

Scenario: Instance child mapping test

• WHEN bun test ./tests/engine/scene-graph.test.ts runs
• THEN the test verifies instance children have componentId pointing to component children

Scenario: Sync propagation test

• WHEN a component's text child changes and sync is triggered
• THEN the test verifies instance children receive the updated text and fontSize

Scenario: Override preservation test

• WHEN an instance child has an overridden text value
• THEN the test verifies the override is preserved while non-overridden properties sync

Scenario: New child addition test

• WHEN a new child is added to a component and sync runs
• THEN the test verifies existing instances gain the new child

Scenario: Detach test

• WHEN an instance is detached
• THEN the test verifies type becomes FRAME, componentId is null, and the component's instance list no longer includes it