ENH: Add itk::RelabelComponenetsImageFilter signedness test

Add a test to check that the `itk::RelabelComponenetsImageFilter` class
does not trigger compiler warnings with signed pixel types.

Ensures regressions are not introduced after the fix in commit 108a2cf.

Modules/Segmentation/ConnectedComponents/test/CMakeLists.txt

@@ -1,6 +1,7 @@
 itk_module_test()
 set(ITKConnectedComponentsTests
     itkRelabelComponentImageFilterTest.cxx
+    itkRelabelComponentImageFilterSignednessTest.cxx
     itkHardConnectedComponentImageFilterTest.cxx
     itkConnectedComponentImageFilterTestRGB.cxx
     itkConnectedComponentImageFilterTest.cxx
@@ -26,6 +27,12 @@ itk_add_test(
   ${ITK_TEST_OUTPUT_DIR}/RelabelComponentImageFilterTest.png
   130
   145)
+itk_add_test(
+  NAME
+  itkRelabelComponentImageFilterSignednessTest
+  COMMAND
+  ITKConnectedComponentsTestDriver
+  itkRelabelComponentImageFilterSignednessTest)
 itk_add_test(
   NAME
   itkHardConnectedComponentImageFilterTest

Modules/Segmentation/ConnectedComponents/test/itkRelabelComponentImageFilterSignednessTest.cxx

@@ -0,0 +1,52 @@
+/*=========================================================================
+ *
+ *  Copyright NumFOCUS
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         https://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *=========================================================================*/
+
+#include "itkImage.h"
+#include "itkRelabelComponentImageFilter.h"
+#include "itkTestingMacros.h"
+
+
+int
+itkRelabelComponentImageFilterSignednessTest(int, char *[])
+{
+
+  constexpr unsigned int Dimension = 3;
+  // Use a signed type
+  using PixelType = signed short;
+
+  using ImageType = itk::Image<PixelType, Dimension>;
+  using FilterType = itk::RelabelComponentImageFilter<ImageType, ImageType>;
+  using LabelType = FilterType::LabelType;
+
+  auto relabeler = FilterType::New();
+
+  // Call itk::RelabelComponentImageFilter methods to ensure that using a signed image does not raise any
+  // signedness compilation warning in them
+  LabelType          label{};
+  itk::SizeValueType obj{};
+
+  ITK_TEST_EXPECT_EQUAL(0, relabeler->GetSizeOfObjectInPixels(label));
+  ITK_TEST_EXPECT_EQUAL(0, relabeler->GetSizeOfObjectInPixels(obj));
+
+  ITK_TEST_EXPECT_EQUAL(0, relabeler->GetSizeOfObjectInPhysicalUnits(label));
+  ITK_TEST_EXPECT_EQUAL(0, relabeler->GetSizeOfObjectInPhysicalUnits(obj));
+
+
+  std::cout << "Test finished." << std::endl;
+  return EXIT_SUCCESS;
+}