From 330676049092bf96ed601e92966613b9ceaf5f1a Mon Sep 17 00:00:00 2001
From: shoheiyokoyama <shohei.yok0602@gmail.com>
Date: Thu, 30 Apr 2020 16:07:28 +0900
Subject: [PATCH] Adds condition

---
 Chausie/PageViewController.swift                 | 2 +-
 ChausieTests/Tests/PageViewControllerTests.swift | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Chausie/PageViewController.swift b/Chausie/PageViewController.swift
index 09a3e8a..a744466 100644
--- a/Chausie/PageViewController.swift
+++ b/Chausie/PageViewController.swift
@@ -195,7 +195,7 @@ public final class PageViewController: UIViewController {
     public override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
         super.viewWillTransition(to: size, with: coordinator)
 
-        guard scrollView.bounds.width > 0 else { return }
+        guard viewIfLoaded?.window != nil && scrollView.bounds.width > 0 else { return }
 
         isTransitioning = true
 
diff --git a/ChausieTests/Tests/PageViewControllerTests.swift b/ChausieTests/Tests/PageViewControllerTests.swift
index af25a44..6577930 100644
--- a/ChausieTests/Tests/PageViewControllerTests.swift
+++ b/ChausieTests/Tests/PageViewControllerTests.swift
@@ -80,6 +80,8 @@ private final class PageViewControllerTests: XCTestCase {
     }
 
     func testViewFrameAfterRotation() {
+        let window = UIWindow()
+        window.addSubview(pageViewController.view)
         let currentSize = pageViewController.view.bounds.size
         let newSize = CGSize(width: currentSize.height, height: currentSize.width)