5. Tools

fsmt already comes with a few handy tools. In the following, we will list and explain all of them. For instance, “rx” stands for ROS example component, “ex” for example execution component. Tools can be found in the fsmt/bin/ folder.

  • fsmt_exchild This component only spawns child processes. It takes one argument: number of child processes to spawn. After execution, you should see fsmt killing 6 children in console the output:

    fsmt_exchild 6
  • fsmt_exout This component just writes output to the console, you might use it to test your stdout criteria. You will find FINDME, while DONOTFINDME will not be found. It takes one argument, defining the runtime duration of the component in seconds. If none is given, it will run forever (or until fsmt closes it), e.g.:

    fsmt_exout 10
  • fsmt_exsilent This component runs silently for a given amount of time (in seconds). If no argument given, it runs forever (or until fsmt (closes it)

  • fsmt_exouttimed Basically the same as fsmt_exout, but you can decide when it should start delivering output. Additionally, you can set the run duration. The first argument defines the runtime in seconds, the second argument defines the time in seconds after which the component should start its output:

    fsmt_exouttimed 10 2
  • fsmt_exlockouttimed This component holds the same functionality as fsmt_exouttimed and adds the use of a lockfile, which exists during the component runtime. In the regular mode, the lockfile is removed at the end. However, if you are using endless mode, the lockfile will not be removed. As this component is mainly designed for testing purposes, it removes previously existing lockfiles on startup and creates its own to avoid collisions and unittest breaks. The additional last argument (optional) is the path to the lockfile which should be used, if non is given, /tmp/.lockfile_$USERNAME is used:

    fsmt_exlockouttimed 10 2 /path/of/lockfile/to/use/.lockfile_name

5.1. State Machine execution Result in xUnit

If you want to include the results of the execution of a FSMT run in your CI system/testing environment, you can simply use the provided xUnit feature. fsmt is therefore creating a separated XML file in the data log folder, which is called:


The result of an erroneous run could for example look like this:

$ cat /tmp/nkoester/fsmt/01-09_160010/data/state_component_run_test.xml

<?xml version="1.0" ?>
<testsuite failures="0" name="FSMT run on /tmp/abc.scxml" tests="3">
        <testcase name="roscore"/>
        <testcase name="morse">
                <failure>57The defined component morse is faulty. The  path/command does not exist: /opt/fsmt-experiments/bin//morse -- The current working directory is: /home/nkoester/workspace</failure>
        <testcase name="ERROR">

5.2. Verification of Execution Order, Timing and General Functionality

If you want to verify the correctness of your state machine in terms of execution order, component start/end/duration timing, and general long-term stability/functionality, you may use the component:

$ fsmt_validation

For a test, one can use any SCXML by giving it as an argument. On default, 50 runs are done to test the SCMXL.

A typical call will look like this:

$ fsmt_validation /tmp/stdout_example.scxml -r 5

Writing verification log files to /tmp/nkoester/fsmt_validation/03-18_171714

Running and observing FSMT (run 1 of 5)
  L__ Finished - FSMT ran for 10.569s
Running and observing FSMT (run 2 of 5)
  L__ Finished - FSMT ran for 10.583s
Running and observing FSMT (run 3 of 5)
  L__ Finished - FSMT ran for 10.577s
Running and observing FSMT (run 4 of 5)
  L__ Finished - FSMT ran for 10.537s
Running and observing FSMT (run 5 of 5)
  L__ Finished - FSMT ran for 10.571s


All output of the called fsmt instance is hidden! So make sure your SCXML is actually working before using the functionality tester. However, the output/logging files of each fsmt run are also written to the logging directory as described below.

The results of the fsmt_validation component are by default written to


The usual structure of the logging folder is:

$ /tmp/nkoester/tree -L 4
└── [4.0K]  fsmt_validation
    └── [4.0K]  03-18_171714
(4)     ├── [4.0K]  fsmt_runs
        │   ├── [4.0K]  03-18_171715
        │   ├── [ 14K]  03-18_171715.zip
        │   ├── [4.0K]  03-18_171725
        │   ├── [ 14K]  03-18_171725.zip
        │   ├── [...]
(1)     ├── [1.9K]  functionality_verification_result.csv
(2)     ├── [1.3K]  functionality_verification_process_order.csv
(3)     └── [ 673]  functionality_verification_result_intervalls.csv

While (1) holds all information in one file, (2) only lists the order of execution of components within each fsmtest run, and (3) lists the time before, between and after of components (as well as their durations). Lastly, the fsmt_runs folder (4) contains the logging files of each fsmtest run for your convenience.