ENH: Add ChangeInformationImageFilter.CheckNew GTest unit test

Modules/Filtering/ImageGrid/test/CMakeLists.txt

@@ -330,6 +330,7 @@ itk_add_test(NAME itkPadImageFilterTest
       COMMAND ITKImageGridTestDriver itkPadImageFilterTest)
 
 set(ITKImageGridGTests
+  itkChangeInformationImageFilterGTest.cxx
   itkResampleImageFilterGTest.cxx
   itkSliceImageFilterTest.cxx
   itkTileImageFilterGTest.cxx

Modules/Filtering/ImageGrid/test/itkChangeInformationImageFilterGTest.cxx

@@ -0,0 +1,57 @@
+/*=========================================================================
+ *
+ *  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.
+ *
+ *=========================================================================*/
+
+// First include the header file to be tested:
+#include "itkChangeInformationImageFilter.h"
+#include "itkImage.h"
+#include <gtest/gtest.h>
+
+
+// Checks the properties of a newly created ChangeInformationImageFilter.
+TEST(ChangeInformationImageFilter, CheckNew)
+{
+  const auto check = [](const auto & newChangeInformationImageFilter) {
+    ASSERT_NE(newChangeInformationImageFilter, nullptr);
+
+    EXPECT_EQ(newChangeInformationImageFilter->GetReferenceImage(), nullptr);
+
+    EXPECT_FALSE(newChangeInformationImageFilter->GetChangeSpacing());
+    EXPECT_FALSE(newChangeInformationImageFilter->GetChangeOrigin());
+    EXPECT_FALSE(newChangeInformationImageFilter->GetChangeDirection());
+    EXPECT_FALSE(newChangeInformationImageFilter->GetChangeRegion());
+    EXPECT_FALSE(newChangeInformationImageFilter->GetCenterImage());
+    EXPECT_FALSE(newChangeInformationImageFilter->GetUseReferenceImage());
+
+    EXPECT_TRUE(newChangeInformationImageFilter->GetOutputDirection().GetVnlMatrix().is_identity());
+
+    const auto expectAllEqualTo = [](const auto & range, const auto expectedValue) {
+      // Expects that all elements are equal to the expected value.
+      for (const auto element : range)
+      {
+        EXPECT_EQ(element, expectedValue);
+      }
+    };
+
+    expectAllEqualTo(newChangeInformationImageFilter->GetOutputSpacing(), 1.0);
+    expectAllEqualTo(newChangeInformationImageFilter->GetOutputOrigin(), 0.0);
+    expectAllEqualTo(newChangeInformationImageFilter->GetOutputOffset(), 0);
+  };
+
+  check(itk::ChangeInformationImageFilter<itk::Image<int, 2>>::New());
+  check(itk::ChangeInformationImageFilter<itk::Image<float, 3>>::New());
+}