How to rerun the failed tests with ctest?

Question

I'm using CTest to launch the tests of my project. I would like to launch only the tests that have failed at the last execution.

Is there a simple way to do that with CTest ?

Answer 1

The --rerun-failed option was added to CTest in CMake 3.0:

 --rerun-failed
    Run only the tests that failed previously

    This  option  tells  ctest to perform only the tests that failed
    during its previous run.  When this option is  specified,  ctest
    ignores  all  other options intended to modify the list of tests
    to run (-L, -R, -E, -LE, -I, etc).  In the event that CTest runs
    and   no   tests  fail,  subsequent  calls  to  ctest  with  the
    --rerun-failed option will  run  the  set  of  tests  that  most
    recently failed (if any).

References:

• CTest documentation

• GitHub commit

Answer 2

The short answer is no, I think.

However, you can use a simple CMake script to convert the list of last failed tests to a format suitable for CTest's -I option.

CTest writes a file called something like <your build dir>/Testing/Temporary/LastTestsFailed.log which contains a list of failed tests. This list is not cleared if all tests pass on a subsequent run. Also, if CTest is running in dashboard mode (as a dart client), the log file name will include the timestamp as detailed in the file <your build dir>/Testing/TAG.

The script below doesn't take into account the file name including the timestamp, but it should be easy to extend it to do this. It reads the list of failed tests and writes a file called FailedTests.log to the current build dir.

set(FailedFileName FailedTests.log)
if(EXISTS "Testing/Temporary/LastTestsFailed.log")
  file(STRINGS "Testing/Temporary/LastTestsFailed.log" FailedTests)
  string(REGEX REPLACE "([0-9]+):[^;]*" "\\1" FailedTests "${FailedTests}")
  list(SORT FailedTests)
  list(GET FailedTests 0 FirstTest)
  set(FailedTests "${FirstTest};${FirstTest};;${FailedTests};")
  string(REPLACE ";" "," FailedTests "${FailedTests}")
  file(WRITE ${FailedFileName} ${FailedTests})
else()
  file(WRITE ${FailedFileName} "")
endif()

You should then be able to run just the failing tests by doing:

cmake -P <path to this script>
ctest -I FailedTests.log