COMP: Auto-remove transient single-owner test outputs in itk_add_test

Wire transient-output cleanup into every test whose ${ITK_TEST_OUTPUT_DIR}/
${TEMP} outputs are owned by a single test. Each such test lists its outputs
with an ITK_REMOVE_TEMPORARY_TEST_FILES <file>... argument to itk_add_test,
which registers a FIXTURES_CLEANUP companion that removes them. Gated by the
ITK_REMOVE_TEMPORARY_TEST_FILES option (ON by default); set OFF to retain
outputs for debugging.

The argument keeps each test's cleanup file list co-located with the
itk_add_test call that produces them, rather than a separate
itk_add_file_test_cleanup() companion call. It is the only parsed keyword, so
it must appear last. The gersemi stub declares it so call sites format
correctly.

Detached-header outputs (.mhd, .nhdr) also remove their companion raw data
files, and the cleanup command uses rm -rf so directory outputs (DICOM
series, FileTools dirs) are removed as well as plain files.

1355 tests instrumented across 126 test/CMakeLists.txt. 42 multi-consumer
shared outputs are excluded so the file persists for the consuming test.

Co-authored-by: Bradley Lowekamp <blowekamp@mail.nih.gov>
Co-authored-by: Dženan Zukić <dzenan.zukic@kitware.com>

Author: 3 people

CMake/ITKModuleTest.cmake

@@ -101,21 +101,29 @@ endfunction()
 # to the value of its containing module.
 #
 function(itk_add_test)
+  # Optional ITK_REMOVE_TEMPORARY_TEST_FILES <file>... lists the transient
+  # outputs to remove after the test.  It is the only parsed keyword, so it
+  # must appear LAST: every argument following it is consumed as a file to
+  # remove.  Arguments preceding it form the add_test specification.
+  cmake_parse_arguments(_iat "" "" "ITK_REMOVE_TEMPORARY_TEST_FILES" ${ARGN})
+  set(_iat_args ${_iat_UNPARSED_ARGUMENTS})
+
   # Add tests with data in the ITKData group.
   ExternalData_Add_Test(
     ITKData
-    ${ARGN}
+    ${_iat_args}
   )
 
-  if("NAME" STREQUAL "${ARGV0}")
-    set(_iat_testname ${ARGV1})
+  list(GET _iat_args 0 _iat_arg0)
+  if("NAME" STREQUAL "${_iat_arg0}")
+    list(GET _iat_args 1 _iat_testname)
   else()
-    set(_iat_testname ${ARGV0})
+    set(_iat_testname ${_iat_arg0})
   endif()
 
   if(itk-module)
     set(_label ${itk-module})
-    if(TARGET ${itk-module}-all AND "${ARGN}" MATCHES "DATA{")
+    if(TARGET ${itk-module}-all AND "${_iat_args}" MATCHES "DATA{")
       add_dependencies(${itk-module}-all ITKData)
     endif()
   else()
@@ -129,6 +137,13 @@ function(itk_add_test)
       LABELS
         ${_label}
   )
+
+  if(_iat_ITK_REMOVE_TEMPORARY_TEST_FILES)
+    itk_add_file_test_cleanup(
+      ${_iat_testname}
+      ${_iat_ITK_REMOVE_TEMPORARY_TEST_FILES}
+    )
+  endif()
 endfunction()
 
 #-----------------------------------------------------------------------------
@@ -343,15 +358,19 @@ function(itk_memcheck_ignore)
 endfunction()
 
 #-----------------------------------------------------------------------------
-# Option to automatically remove large test output files after completion.
-# BigIO write-read tests can produce multi-gigabyte temporary files
-# that exhaust disk space on CI runners and local builds.
+# Removing transient test outputs is the default behavior: each wired test
+# gets a companion cleanup test that deletes its ${ITK_TEST_OUTPUT_DIR}
+# outputs, which otherwise accumulate (BigIO write-read tests alone produce
+# multi-gigabyte files that exhaust disk on CI runners and local builds).
+# Cleanup runs unconditionally after the test (pass, fail, or skip); a
+# developer who needs to inspect outputs must opt out by configuring with
+# -DITK_REMOVE_TEMPORARY_TEST_FILES=OFF, which retains all test outputs.
 option(
-  ITK_REMOVE_TEST_FILES_ON_SUCCESS
-  "Remove large test output files after test completion. Set OFF to retain files for debugging."
+  ITK_REMOVE_TEMPORARY_TEST_FILES
+  "Remove transient test outputs after each test (default ON; removed even on failure). Set OFF to retain all outputs for debugging."
   ON
 )
-mark_as_advanced(ITK_REMOVE_TEST_FILES_ON_SUCCESS)
+mark_as_advanced(ITK_REMOVE_TEMPORARY_TEST_FILES)
 
 #-----------------------------------------------------------------------------
 # itk_add_file_test_cleanup(<test_name> <output_file> [<output_file2> ...])
@@ -363,19 +382,19 @@ mark_as_advanced(ITK_REMOVE_TEST_FILES_ON_SUCCESS)
 # NOTE: Per CMake documentation, FIXTURES_CLEANUP tests execute
 # unconditionally after their fixture — they run regardless of whether the
 # SETUP test passed, failed, or was skipped.  To retain output files for
-# debugging after a failure, set ITK_REMOVE_TEST_FILES_ON_SUCCESS=OFF.
+# debugging after a failure, set ITK_REMOVE_TEMPORARY_TEST_FILES=OFF.
 #
 # NOTE: In a full unfiltered run all tests (including *_cleanup variants)
 # are in the active set and fixture ordering is respected.  When rerunning
 # a single test with a strict filter (e.g. ctest -R "^<test_name>$"),
 # the *_cleanup test does not match; omit the anchors (ctest -R <test_name>)
 # so both the main test and its cleanup are selected.
 #
-# When ITK_REMOVE_TEST_FILES_ON_SUCCESS is OFF, no cleanup test is added
+# When ITK_REMOVE_TEMPORARY_TEST_FILES is OFF, no cleanup test is added
 # and the output files are retained for manual inspection.
 #
 function(itk_add_file_test_cleanup TEST_NAME)
-  if(NOT ITK_REMOVE_TEST_FILES_ON_SUCCESS)
+  if(NOT ITK_REMOVE_TEMPORARY_TEST_FILES)
     return()
   endif()
 
@@ -389,31 +408,24 @@ function(itk_add_file_test_cleanup TEST_NAME)
         ${FIXTURE_NAME}
   )
 
-  # Build the removal command for all output files
-  set(RM_ARGS "")
-  foreach(OUTPUT_FILE ${ARGN})
-    # For .mhd files, also remove the companion .raw/.zraw
-    get_filename_component(EXT "${OUTPUT_FILE}" LAST_EXT)
-    get_filename_component(BASE_NAME "${OUTPUT_FILE}" NAME_WLE)
-    get_filename_component(DIR "${OUTPUT_FILE}" DIRECTORY)
-    list(APPEND RM_ARGS "${OUTPUT_FILE}")
-    if("${EXT}" STREQUAL ".mhd")
-      list(APPEND RM_ARGS "${DIR}/${BASE_NAME}.raw")
-      list(APPEND RM_ARGS "${DIR}/${BASE_NAME}.zraw")
-    endif()
-  endforeach()
+  # The developer supplies the exact files and glob patterns to remove.  Each
+  # entry is forwarded verbatim; itkRemoveTestFiles.cmake expands patterns at
+  # test time and removes only the matching files (never directories).
+  set(RM_ARGS ${ARGN})
 
-  add_test(
-    NAME ${TEST_NAME}_cleanup
-    COMMAND
-      ${CMAKE_COMMAND} -E rm -f ${RM_ARGS}
-  )
-  set_tests_properties(
-    ${TEST_NAME}_cleanup
-    PROPERTIES
-      FIXTURES_CLEANUP
-        ${FIXTURE_NAME}
-      LABELS
-        "CLEANUP"
-  )
+  if(RM_ARGS)
+    add_test(
+      NAME ${TEST_NAME}_cleanup
+      COMMAND
+        ${CMAKE_COMMAND} -P ${ITK_CMAKE_DIR}/itkRemoveTestFiles.cmake ${RM_ARGS}
+    )
+    set_tests_properties(
+      ${TEST_NAME}_cleanup
+      PROPERTIES
+        FIXTURES_CLEANUP
+          ${FIXTURE_NAME}
+        LABELS
+          "CLEANUP"
+    )
+  endif()
 endfunction()

CMake/itkRemoveTestFiles.cmake

@@ -0,0 +1,50 @@
+# Remove transient test output files matching the given path patterns.
+#
+# Invoked as a fixture cleanup command:
+#   cmake -P itkRemoveTestFiles.cmake <pattern> [<pattern> ...]
+#
+# Each pattern is expanded with file(GLOB) at test time and only the matching
+# regular files are removed.  Directories are never removed, so an unintended
+# pattern can delete individual files but can never recurse into a tree.
+#
+# A pattern may contain a single brace set "{a,b,c}" listing the extensions a
+# test actually writes for a shared stem, e.g. "foo.{mhd,raw}" expands to
+# "foo.mhd" and "foo.raw" before globbing.
+if(CMAKE_ARGC LESS 4)
+  return()
+endif()
+
+# Expand one "{a,b,c}" brace set in PATTERN into OUT_VAR (a list).
+function(_itk_expand_braces PATTERN OUT_VAR)
+  string(FIND "${PATTERN}" "{" _open)
+  string(FIND "${PATTERN}" "}" _close)
+  if(_open EQUAL -1 OR _close EQUAL -1 OR _close LESS _open)
+    set(${OUT_VAR} "${PATTERN}" PARENT_SCOPE)
+    return()
+  endif()
+  string(SUBSTRING "${PATTERN}" 0 ${_open} _prefix)
+  math(EXPR _glen "${_close} - ${_open} - 1")
+  math(EXPR _gstart "${_open} + 1")
+  string(SUBSTRING "${PATTERN}" ${_gstart} ${_glen} _group)
+  math(EXPR _sstart "${_close} + 1")
+  string(SUBSTRING "${PATTERN}" ${_sstart} -1 _suffix)
+  string(REPLACE "," ";" _opts "${_group}")
+  set(_result "")
+  foreach(_o IN LISTS _opts)
+    list(APPEND _result "${_prefix}${_o}${_suffix}")
+  endforeach()
+  set(${OUT_VAR} "${_result}" PARENT_SCOPE)
+endfunction()
+
+math(EXPR _last "${CMAKE_ARGC} - 1")
+foreach(_i RANGE 3 ${_last})
+  _itk_expand_braces("${CMAKE_ARGV${_i}}" _patterns)
+  foreach(_pat IN LISTS _patterns)
+    file(GLOB _matches "${_pat}")
+    foreach(_match IN LISTS _matches)
+      if(NOT IS_DIRECTORY "${_match}")
+        file(REMOVE "${_match}")
+      endif()
+    endforeach()
+  endforeach()
+endforeach()

CMake/stubs/itk_add_test.cmake

@@ -12,7 +12,7 @@ function(itk_add_test)
     ARG
     "COMMAND_EXPAND_LISTS"
     "NAME;WORKING_DIRECTORY"
-    "COMMAND;CONFIGURATIONS"
+    "COMMAND;CONFIGURATIONS;ITK_REMOVE_TEMPORARY_TEST_FILES"
   )
 
   # This is a stub function to assist code formatting

Modules/Bridge/VtkGlue/test/CMakeLists.txt

@@ -82,6 +82,8 @@ if(NOT VTK_RENDERING_BACKEND STREQUAL "None")
       QuickViewTest
       DATA{${ITK_DATA_ROOT}/Input/peppers.png}
       ${ITK_TEST_OUTPUT_DIR}
+    ITK_REMOVE_TEMPORARY_TEST_FILES
+      ${ITK_TEST_OUTPUT_DIR}/QuickViewTest0.png
   )
   set_property(
     TEST