QmlDesigner: Fix flacky test AsynchronousImageCache.WaitForFinished

Change-Id: I94afa8ec2925b85f5dbf44e7b2ad5db484f48148
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/designercore/imagecache/asynchronousimagecache.cpp

@@ -158,8 +158,8 @@ std::tuple<bool, AsynchronousImageCache::Entry> AsynchronousImageCache::getEntry
     if (m_entries.empty())
         return {false, Entry{}};
 
-    Entry entry = m_entries.back();
-    m_entries.pop_back();
+    Entry entry = m_entries.front();
+    m_entries.pop_front();
 
     return {true, entry};
 }

src/plugins/qmldesigner/designercore/include/asynchronousimagecache.h

@@ -28,6 +28,7 @@
 #include "asynchronousimagecacheinterface.h"
 
 #include <condition_variable>
+#include <deque>
 #include <functional>
 #include <mutex>
 #include <thread>
@@ -117,7 +118,7 @@ private:
     void wait();
 
 private:
-    std::vector<Entry> m_entries;
+    std::deque<Entry> m_entries;
     mutable std::mutex m_mutex;
     std::condition_variable m_condition;
     std::thread m_backgroundThread;

tests/unit/unittest/asynchronousimagecache-test.cpp

@@ -323,7 +323,11 @@ TEST_F(AsynchronousImageCache, AfterCleanNewJobsWorks)
 
 TEST_F(AsynchronousImageCache, WaitForFinished)
 {
-    ON_CALL(mockStorage, fetchImage(_, _))
+    ON_CALL(mockStorage, fetchImage(Eq("/path/to/Component1.qml"), _)).WillByDefault([&](auto, auto) {
+        waitInThread.notify();
+        return QmlDesigner::ImageCacheStorageInterface::ImageEntry{image1, true};
+    });
+    ON_CALL(mockStorage, fetchImage(Eq("/path/to/Component2.qml"), _))
         .WillByDefault(Return(QmlDesigner::ImageCacheStorageInterface::ImageEntry{image1, true}));
     cache.requestImage("/path/to/Component1.qml",
                        mockCaptureCallback.AsStdFunction(),
@@ -334,6 +338,7 @@ TEST_F(AsynchronousImageCache, WaitForFinished)
 
     EXPECT_CALL(mockCaptureCallback, Call(_)).Times(2);
 
+    waitInThread.wait();
     cache.waitForFinished();
 }