CMake: Add function to add tests that change working directory.

Add a new CMake function that helps to add tests that change their
working directory to somewhere else than the directory with the
libarpack library.

In that case, the environment variable PATH is set to include the
directory with the library on Windows while running the tests.

Use that new CMake function for the three ctests involving the Eigen
library.

CMakeLists.txt

@@ -626,7 +626,23 @@ endif()
 ############################
 # TEST
 ############################
-function(build_tests)  
+
+function(add_test_with_rpath test_name)
+  # Add test which sets a current working directory that doesn't contain the
+  # libarpack library.
+  # Windows doesn't have a mechanism similar to RPATH on Linux or macOS.
+  # On Windows, if a test is running in a working directory that doesn't contain
+  # the ARPACK (and PARPACK) libraries, the path to these libraries has to be
+  # added to the PATH environment variable.
+  add_test(NAME ${test_name} ${ARGN})
+  if (WIN32 AND BUILD_SHARED_LIBS)
+    set_tests_properties(${test_name}
+      PROPERTIES
+      ENVIRONMENT_MODIFICATION "PATH=path_list_prepend:$<TARGET_FILE_DIR:arpack>")
+  endif()
+endfunction()
+
+function(build_tests)
   set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/TESTS)
 
   add_executable(dnsimp_test TESTS/dnsimp.f TESTS/mmio.f TESTS/debug.h)
@@ -704,18 +720,13 @@ function(build_tests)
       configure_file(EXAMPLES/MATRIX_MARKET/B.mtx  ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/B.mtx)
       configure_file(EXAMPLES/MATRIX_MARKET/Bz.mtx ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/Bz.mtx)
       configure_file(EXAMPLES/MATRIX_MARKET/arpackmm.sh ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/arpackmm.sh)
-      add_test(NAME arpackmm_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} arpackmm.sh)
+      add_test_with_rpath(arpackmm_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} arpackmm.sh)
       configure_file(EXAMPLES/MATRIX_MARKET/issue401.mtx ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/issue401.mtx)
       configure_file(EXAMPLES/MATRIX_MARKET/issue401.sh ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/issue401.sh)
-      add_test(NAME issue401_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} issue401.sh)
+      add_test_with_rpath(issue401_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} issue401.sh)
       configure_file(EXAMPLES/MATRIX_MARKET/issue215.mtx ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/issue215.mtx)
       configure_file(EXAMPLES/MATRIX_MARKET/issue215.sh ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/issue215.sh)
-      add_test(NAME issue215_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} issue215.sh)
-      if (WIN32 AND BUILD_SHARED_LIBS)
-        set_tests_properties(arpackmm_tst issue401_tst issue215_tst
-          PROPERTIES
-          ENVIRONMENT_MODIFICATION "PATH=path_list_prepend:$<TARGET_FILE_DIR:arpack>")
-      endif()
+      add_test_with_rpath(issue215_tst WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} COMMAND ${BASH_PROGRAM} issue215.sh)
     endif()
 
     if (PYTHON3)
@@ -800,7 +811,7 @@ endfunction(build_tests)
 
 if(TESTS)
     enable_testing()
-    set(CMAKE_CTEST_COMMAND ctest -V)   
+    set(CMAKE_CTEST_COMMAND ctest -V)
     build_tests()
 endif()