Add comprehensive tests for DisplayManager functionality

Author: hovancik

test/displayManager.js

@@ -0,0 +1,251 @@
+import { vi, describe, it, beforeEach, expect } from 'vitest'
+import 'chai/register-should'
+import { screen } from 'electron'
+import DisplayManager from '../app/utils/displayManager.js'
+
+vi.mock('electron', () => {
+  const mockScreen = {
+    getAllDisplays: vi.fn(() => [
+      { id: 0, bounds: { x: 0, y: 0, width: 1920, height: 1080 } },
+      { id: 1, bounds: { x: 1920, y: 0, width: 1440, height: 900 } }
+    ]),
+    getPrimaryDisplay: vi.fn(() => ({ id: 0, bounds: { x: 0, y: 0, width: 1920, height: 1080 } })),
+    getDisplayNearestPoint: vi.fn(() => ({ id: 0, bounds: { x: 0, y: 0, width: 1920, height: 1080 } })),
+    getCursorScreenPoint: vi.fn(() => ({ x: 960, y: 540 }))
+  }
+  return { screen: mockScreen }
+})
+
+describe('DisplayManager', function () {
+  let displayManager
+  let mockSettings
+  let mockLog
+
+  beforeEach(function () {
+    vi.clearAllMocks()
+    mockSettings = {
+      get: vi.fn()
+    }
+    mockLog = {
+      warn: vi.fn()
+    }
+  })
+
+  describe('Mathematical Calculations', function () {
+    beforeEach(function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return true
+        return null
+      })
+      displayManager = new DisplayManager(mockSettings, mockLog)
+    })
+
+    it('centers window horizontally correctly', function () {
+      const result = displayManager.getDisplayX(0, 800, false)
+      result.should.equal(560)
+    })
+
+    it('centers window vertically correctly', function () {
+      const result = displayManager.getDisplayY(0, 600, false)
+      result.should.equal(240)
+    })
+
+    it('returns display origin for fullscreen X', function () {
+      const result = displayManager.getDisplayX(1, 800, true)
+      result.should.equal(1920)
+    })
+
+    it('returns display origin for fullscreen Y', function () {
+      const result = displayManager.getDisplayY(1, 600, true)
+      result.should.equal(0)
+    })
+
+    it('handles small windows correctly', function () {
+      const result = displayManager.getDisplayX(0, 100, false)
+      result.should.equal(910)
+    })
+
+    it('handles large windows correctly', function () {
+      const result = displayManager.getDisplayX(0, 2000, false)
+      result.should.equal(-40)
+    })
+
+    it('returns floored display width', function () {
+      const result = displayManager.getDisplayWidth(0)
+      result.should.equal(1920)
+    })
+
+    it('returns floored display height', function () {
+      const result = displayManager.getDisplayHeight(0)
+      result.should.equal(1080)
+    })
+
+    it('handles secondary display positioning', function () {
+      const x = displayManager.getDisplayX(1, 800, false)
+      const y = displayManager.getDisplayY(1, 600, false)
+      x.should.equal(2240)
+      y.should.equal(150)
+    })
+  })
+
+  describe('Method Integration', function () {
+    beforeEach(function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return true
+        return null
+      })
+      displayManager = new DisplayManager(mockSettings, mockLog)
+    })
+
+    it('getWindowPosition returns consistent windowed positioning', function () {
+      const position = displayManager.getWindowPosition(0, { width: 800, height: 600, fullscreen: false })
+      position.should.have.property('x', 560)
+      position.should.have.property('y', 240)
+      position.should.have.property('width', 800)
+      position.should.have.property('height', 600)
+    })
+
+    it('getWindowPosition returns consistent fullscreen positioning', function () {
+      const position = displayManager.getWindowPosition(0, { width: 800, height: 600, fullscreen: true })
+
+      position.should.have.property('x', 0)
+      position.should.have.property('y', 0)
+      position.should.have.property('width', 1920)
+      position.should.have.property('height', 1080)
+    })
+
+    it('uses default parameters correctly', function () {
+      const position = displayManager.getWindowPosition()
+
+      position.should.have.property('x', 560)
+      position.should.have.property('y', 240)
+      position.should.have.property('width', 800)
+      position.should.have.property('height', 600)
+    })
+
+    it('individual methods match getWindowPosition results', function () {
+      const width = 1000
+      const height = 700
+      const displayID = 0
+
+      const position = displayManager.getWindowPosition(displayID, { width, height, fullscreen: false })
+      const x = displayManager.getDisplayX(displayID, width, false)
+      const y = displayManager.getDisplayY(displayID, height, false)
+
+      position.x.should.equal(x)
+      position.y.should.equal(y)
+      position.width.should.equal(width)
+      position.height.should.equal(height)
+    })
+
+    it('all methods return valid numbers', function () {
+      const x = displayManager.getDisplayX()
+      const y = displayManager.getDisplayY()
+      const width = displayManager.getDisplayWidth()
+      const height = displayManager.getDisplayHeight()
+      const position = displayManager.getWindowPosition()
+
+      x.should.be.a('number')
+      y.should.be.a('number')
+      width.should.be.a('number')
+      height.should.be.a('number')
+      position.x.should.be.a('number')
+      position.y.should.be.a('number')
+      position.width.should.be.a('number')
+      position.height.should.be.a('number')
+
+      Number.isNaN(x).should.equal(false)
+      Number.isNaN(y).should.equal(false)
+      Number.isNaN(width).should.equal(false)
+      Number.isNaN(height).should.equal(false)
+    })
+  })
+
+  describe('Settings Integration', function () {
+    beforeEach(function () {
+      displayManager = new DisplayManager(mockSettings, mockLog)
+    })
+
+    it('uses cursor position when allScreens is true', function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return true
+        return null
+      })
+      displayManager.getTargetDisplay()
+      expect(screen.getDisplayNearestPoint).toHaveBeenCalled()
+    })
+
+    it('uses primary display when screen preference is "primary"', function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return false
+        if (key === 'screen') return 'primary'
+        return null
+      })
+      displayManager.getTargetDisplay()
+      expect(screen.getPrimaryDisplay).toHaveBeenCalled()
+    })
+
+    it('uses cursor display when screen preference is "cursor"', function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return false
+        if (key === 'screen') return 'cursor'
+        return null
+      })
+      displayManager.getTargetDisplay()
+      expect(screen.getDisplayNearestPoint).toHaveBeenCalled()
+    })
+
+    it('uses correct display with numeric screen setting', function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return false
+        if (key === 'screen') return '1'
+        return null
+      })
+      const target = displayManager.getTargetDisplay()
+      expect(screen.getAllDisplays).toHaveBeenCalled()
+      target.id.should.equal(1)
+    })
+  })
+
+  describe('Error Handling', function () {
+    beforeEach(function () {
+      mockSettings.get.mockImplementation((key) => {
+        if (key === 'allScreens') return true
+        return null
+      })
+      displayManager = new DisplayManager(mockSettings, mockLog)
+    })
+
+    it('handles invalid displayID by falling back and logging a warning', () => {
+      const target = displayManager.getTargetDisplay(5)
+      expect(mockLog.warn).toHaveBeenCalledWith('Stretchly: invalid displayID 5, falling back to cursor display')
+      expect(screen.getDisplayNearestPoint).toHaveBeenCalled()
+      target.id.should.equal(0)
+    })
+
+    it('handles boundary displayID values', function () {
+      const target1 = displayManager.getTargetDisplay(0)
+      const target2 = displayManager.getTargetDisplay(1)
+      target1.id.should.equal(0)
+      target2.id.should.equal(1)
+    })
+
+    it('handles extreme window sizes', function () {
+      const verySmall = displayManager.getDisplayX(0, 1, false)
+      const veryLarge = displayManager.getDisplayX(0, 5000, false)
+
+      verySmall.should.be.a('number')
+      veryLarge.should.be.a('number')
+      Number.isNaN(verySmall).should.equal(false)
+      Number.isNaN(veryLarge).should.equal(false)
+    })
+
+    it('handles zero dimensions gracefully', function () {
+      const zeroWidth = displayManager.getDisplayX(0, 0, false)
+      const zeroHeight = displayManager.getDisplayY(0, 0, false)
+
+      zeroWidth.should.equal(960)
+      zeroHeight.should.equal(540)
+    })
+  })
+})