increase test coverage

extend test coverage

tests/unit/touch.test.js

@@ -0,0 +1,124 @@
+import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest'
+import { init as initTouch } from '../../packages/svgcanvas/core/touch.js'
+
+const createSvgRoot = () => {
+  const listeners = {}
+  return {
+    listeners,
+    addEventListener (type, handler) { listeners[type] = handler },
+    dispatch (type, event) { listeners[type]?.(event) }
+  }
+}
+
+const OriginalMouseEvent = global.MouseEvent
+
+beforeAll(() => {
+  // JSDOM's MouseEvent requires a real Window; a lightweight stub keeps the adapter logic testable.
+  global.MouseEvent = class extends Event {
+    constructor (type, init = {}) {
+      super(type, init)
+      this.clientX = init.clientX
+      this.clientY = init.clientY
+      this.screenX = init.screenX
+      this.screenY = init.screenY
+      this.button = init.button ?? 0
+      this.relatedTarget = init.relatedTarget ?? null
+    }
+  }
+})
+
+afterAll(() => {
+  global.MouseEvent = OriginalMouseEvent
+})
+
+describe('touch adapter', () => {
+  it('translates single touch to mouse event on target', () => {
+    const svgroot = createSvgRoot()
+    const svgCanvas = { svgroot }
+    initTouch(svgCanvas)
+
+    const target = document.createElement('div')
+    const received = []
+    target.addEventListener('mousedown', (ev) => {
+      received.push({
+        type: ev.type,
+        clientX: ev.clientX,
+        clientY: ev.clientY,
+        screenX: ev.screenX,
+        screenY: ev.screenY
+      })
+    })
+
+    const preventDefault = vi.fn()
+    svgroot.dispatch('touchstart', {
+      type: 'touchstart',
+      changedTouches: [{
+        target,
+        clientX: 12,
+        clientY: 34,
+        screenX: 56,
+        screenY: 78
+      }],
+      preventDefault
+    })
+
+    expect(preventDefault).toHaveBeenCalled()
+    expect(received).toEqual([{
+      type: 'mousedown',
+      clientX: 12,
+      clientY: 34,
+      screenX: 56,
+      screenY: 78
+    }])
+  })
+
+  it('maps move events and ignores multi-touch gestures', () => {
+    const svgroot = createSvgRoot()
+    initTouch({ svgroot })
+
+    const target = document.createElement('div')
+    let mouseDown = 0
+    let mouseMove = 0
+    target.addEventListener('mousedown', () => { mouseDown++ })
+    target.addEventListener('mousemove', () => { mouseMove++ })
+
+    svgroot.dispatch('touchstart', {
+      type: 'touchstart',
+      changedTouches: [
+        { target, clientX: 1, clientY: 2, screenX: 3, screenY: 4 },
+        { target, clientX: 5, clientY: 6, screenX: 7, screenY: 8 }
+      ],
+      preventDefault: vi.fn()
+    })
+
+    expect(mouseDown).toBe(0)
+
+    svgroot.dispatch('touchmove', {
+      type: 'touchmove',
+      changedTouches: [
+        { target, clientX: 9, clientY: 10, screenX: 11, screenY: 12 }
+      ],
+      preventDefault: vi.fn()
+    })
+
+    expect(mouseMove).toBe(1)
+  })
+
+  it('returns early on unknown event types', () => {
+    const svgroot = createSvgRoot()
+    initTouch({ svgroot })
+    const target = document.createElement('div')
+    let mouseCount = 0
+    target.addEventListener('mousedown', () => { mouseCount++ })
+
+    const preventDefault = vi.fn()
+    svgroot.dispatch('touchcancel', {
+      type: 'touchcancel',
+      changedTouches: [{ target, clientX: 0, clientY: 0, screenX: 0, screenY: 0 }],
+      preventDefault
+    })
+
+    expect(preventDefault).toHaveBeenCalled()
+    expect(mouseCount).toBe(0)
+  })
+})