[CMake] compare two files - testing

[Michael Wild]

On 4. Jul, 2009, at 0:56, James C. Sutherland wrote:

> I have a test that produces output files that I would like to  
> compare against a "blessed" copy.  Is there a way to do this in  
> CMake/CTest?  This is probably a very simple thing, but I have not  
> figured out how to do it.
>
> I have an
> 	add_test( ... )
> that creates the test, but I am not sure how to add the diff on the  
> output.
>
> FYI, I am running this via "make test" - I am not yet running ctest  
> directly.
>


cmake -E compare_files file1 file2
cmake -E md5sum file1 ...

where probably the former is the more appropriate for you (unless you  
store a "database" of md5 sums of your "blessed" files, so you don't  
have to store/redistribute them in case they are big). E.g put the  
following code in run_test.cmake:

# some argument checking:
# test_cmd is the command to run with all its arguments
if( NOT test_cmd )
   message( FATAL_ERROR "Variable test_cmd not defined" )
if( NOT test_cmd )
# output_blessed contains the name of the "blessed" output file
if( NOT output_blessed )
   message( FATAL_ERROR "Variable output_blessed not defined" )
if( NOT output_blessed )
# output_test contains the name of the output file the test_cmd will  
produce
if( NOT output_test )
   message( FATAL_ERROR "Variable output_test not defined" )
if( NOT output_test )

execute_command(
   COMMAND ${test_cmd}
   COMMAND ${CMAKE_COMMAND} -E compare_files ${output_blessed} $ 
{output_test}
   RESULT_VARIABLE test_not_successful
   OUTPUT_QUIET
   ERROR_QUIET
   )

if( test_not_successful )
   message( SEND_ERROR "${output_test} does not match $ 
{output_blessed}!" )
endif( test_not_successful )



and then in your CMakeLists.txt:

add_test( "someImportantTest"
   ${CMAKE_COMMAND}
   -Dtest_cmd="${CMAKE_BINARY_DIR}/tests/someImportantTestProgram -- 
with arguments"
   -Doutput_blessed="${CMAKE_SOURCE_DIR}/tests/output/ 
someImportatanTestProgram.output"
   -Doutput_test="${CMAKE_BINARY_DIR}/someImportatanTestProgram.output"
   -P ${CMAKE_SOURCE_DIR}/CMake/run_test.cmake
   )


If your test program writes to STDOUT you can use the OUTPUT_FILE  
option in the execute_command of your run_test.cmake

HTH

Michael