ci: Add testing against Qt 6

.appveyor.yml

@@ -1,24 +1,48 @@
 version: "1.5.0+{build}"
 
 environment:
-    CTEST_OUTPUT_ON_FAILURE: '1'
     matrix:
-        - CMAKE_GENERATOR: Visual Studio 15 2017 Win64
-          QT_DIR: C:\Qt\5.12\msvc2017_64
+        - job_name: VS 2019 x64, Qt 6.2
+          APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+          CMAKE_GENERATOR: Visual Studio 16 2019
+          QT_DIR: C:\Qt\6.2\msvc2019_64
+          VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x64'
+          CMAKE_INSTALL_PATH: 'C:\Program Files\CMake'
+
+        - job_name: VS 2019 x64, Qt 5.15
+          APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+          CMAKE_GENERATOR: Visual Studio 16 2019
+          QT_DIR: C:\Qt\5.15\msvc2019_64
+          VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x64'
+          CMAKE_INSTALL_PATH: 'C:\Program Files\CMake'
+
+        - job_name: VS 2017 x64, Qt 5.12
           APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+          CMAKE_GENERATOR: Visual Studio 15 2017 Win64
+          QT_DIR: C:\Qt\5.12\msvc2017_64
           VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars64.bat"'
-        - CMAKE_GENERATOR: Visual Studio 14 2015
-          QT_DIR: C:\Qt\5.9\msvc2015
+          CMAKE_INSTALL_PATH: 'C:\Program Files (x86)\CMake'
+
+        - job_name: VS 2015 x86, Qt 5.9
           APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+          CMAKE_GENERATOR: Visual Studio 14 2015
+          QT_DIR: C:\Qt\5.9\msvc2015
           VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x86'
-        - CMAKE_GENERATOR: Visual Studio 14 2015
-          QT_DIR: C:\Qt\5.6\msvc2015
+          CMAKE_INSTALL_PATH: 'C:\Program Files (x86)\CMake'
+
+        - job_name: VS 2015 x86, Qt 5.6
           APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+          CMAKE_GENERATOR: Visual Studio 14 2015
+          QT_DIR: C:\Qt\5.6\msvc2015
           VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x86'
-        - CMAKE_GENERATOR: Visual Studio 12 2013
-          QT_DIR: C:\Qt\5.6\msvc2013
+          CMAKE_INSTALL_PATH: 'C:\Program Files (x86)\CMake'
+
+        - job_name: VS 2013 x86, Qt 5.6
           APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+          CMAKE_GENERATOR: Visual Studio 12 2013
+          QT_DIR: C:\Qt\5.6\msvc2013
           VCVARS_COMMANDLINE: '"C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" x86'
+          CMAKE_INSTALL_PATH: 'C:\Program Files (x86)\CMake'
 
 cache:
     - C:\.hunter -> .appveyor.yml, **\CMakeLists.txt, **\*.cmake
@@ -37,4 +61,4 @@ build:
 
 
 test_script:
-    - msbuild "%APPVEYOR_BUILD_FOLDER%\tests\_build\RUN_TESTS.vcxproj" /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
+    - '"%CMAKE_INSTALL_PATH%\bin\ctest.exe" --output-on-failure -C Debug'

tests/CMakeLists.txt

@@ -64,11 +64,20 @@ if(CXX_SUPPORTS_STRONG_ENUMS)
 endif()
 
 set(CMAKE_AUTOMOC ON)
-find_package(Qt5 COMPONENTS Core OPTIONAL_COMPONENTS Network)
-if (Qt5_FOUND)
-	set(QTCORE_LIB Qt5::Core)
-	if (Qt5Network_FOUND)
-		set(QTNETWORK_LIB Qt5::Network)
+find_package(Qt6 COMPONENTS Core OPTIONAL_COMPONENTS Network)
+if (Qt6_FOUND)
+	set(QTCORE_LIB Qt6::Core)
+	if (Qt6Network_FOUND)
+		set(QTNETWORK_LIB Qt6::Network)
+	endif()
+endif()
+if (NOT QTCORE_LIB)
+	find_package(Qt5 COMPONENTS Core OPTIONAL_COMPONENTS Network)
+	if (Qt5_FOUND)
+		set(QTCORE_LIB Qt5::Core)
+		if (Qt5Network_FOUND)
+			set(QTNETWORK_LIB Qt5::Network)
+		endif()
 	endif()
 endif()
 if (NOT QTCORE_LIB)