test: measure rendered progress thumb alignment

Sources/App/TerebiApp.swift

@@ -2028,6 +2028,9 @@ private struct PlaybackSlider: NSViewRepresentable {
         var volume = false
         var bufferedRange: ClosedRange<Double>?
         var intervals: [MiruroInterval] = []
+        #if PLAYER_CHECK
+        var renderedKnob = NSRect.zero
+        #endif
         func visibleKnobRect(_ rect: NSRect) -> NSRect {
             let width: CGFloat = volume ? 16 : 3
             let height: CGFloat = volume ? 12 : 15
@@ -2076,6 +2079,9 @@ private struct PlaybackSlider: NSViewRepresentable {
         }
         override func drawKnob(_ rect: NSRect) {
             let knob = visibleKnobRect(rect)
+            #if PLAYER_CHECK
+            renderedKnob = knob
+            #endif
             let color = isEnabled ? (volume ? SunsetPalette.text : SunsetPalette.secondaryText)
                                   : SunsetPalette.disabledThumb
             color.setFill()
@@ -2091,14 +2097,14 @@ func castVolumeSliderFeedbackCheck() -> Bool { PlaybackSlider.Slider.feedbackChe
 func playbackSliderHitCheck() -> Bool {
     let window = NSWindow(contentRect: NSRect(x: 0, y: 0, width: 320, height: 80),
                           styleMask: [.borderless], backing: .buffered, defer: false)
-    let slider = PlaybackSlider.Slider(frame: NSRect(x: 20, y: 20, width: 280, height: 24))
+    let slider = PlaybackSlider.Slider(frame: NSRect(x: 20, y: 20, width: 280, height: 14))
     slider.cell = PlaybackSlider.Cell()
     slider.minValue = 0
     slider.maxValue = 100
     slider.isContinuous = true
     window.contentView!.addSubview(slider)
     window.display()
-    let cell = slider.cell as! NSSliderCell
+    let cell = slider.cell as! PlaybackSlider.Cell
     slider.doubleValue = slider.minValue
     let left = cell.knobRect(flipped: slider.isFlipped).midX
     slider.doubleValue = slider.maxValue
@@ -2126,7 +2132,8 @@ func playbackSliderHitCheck() -> Bool {
             NSApp.postEvent(drag, atStart: true)
         }
         slider.mouseDown(with: down)
-        let movedKnob = cell.knobRect(flipped: slider.isFlipped)
+        slider.display()
+        let movedKnob = cell.renderedKnob
         let expectedMovement = movement + offset
         let expectedX = min(right, max(left, knob.midX + expectedMovement))
         guard abs(movedKnob.midX - expectedX) < 0.5 else { return false }