tbot can keep record of test-runs in a log-file. For this, entries detailing a number of events will be stored:

  • Testcase begin and end, their duration and success state.

  • All commands which are run, their output, return-code, and on which machine they were run.

  • Custom messages and events emitted by testcases (for example by using tbot.log.message()).

To enable logging, set either the --log=<file.json> or the --log-auto parameter. The latter will automatically create a log-file in log/<lab>-<board>-NNNN.json, NNNN incrementing so old files are not overwritten.

The log format is a stream of json objects. To read it, you can use the generators/logparser.py module.


A json stream is not just a json file. This means trying to parse the log-file as plain json will fail! Use the provided log-parser instead.


One use of the log is generating visualizations and statistics of a test run. There are a few so called generators already included with tbot:

  • generators/dot.py: Generate a graphviz dot graph of the testcase hirarchy that was run.

  • generators/htmllog.py: Generate a html representation of the log that gives an overview of the occurences that happened during the run.

  • generators/junit.py: Convert the log to a JUnit xml file which can be displayed by CI tools like Jenkins.

  • generators/messages.py: A simple demo generator that just prints all message events.

Log Events

Log events are json objects. Each one has at least the following fields:

  • "type": An array that identifies the event type. Events for similar occurences have a common prefix in the type array.

  • "time": Time in seconds since the test run began.

  • "data": An object with event specific elements.

The following events are emitted by tbot (possibly incomplete):

  • ["tc", "begin"] - Testcase being called, data contains the "name".

  • ["tc", "end"] - Testcase ending, data holds the "name", "duration", and "success" state.

  • ["cmd", "<machine-name>"] - A command was issued on the specified machine. data is filled with the "cmd" that was sent and its "stdout".

  • ["msg", "<LEVEL>"] - A log message at the specified level, data contains the "text".

  • ["tbot", "end"] - Emitted once after all testcases completed (or failed). data knows about the total "duration" and overall "success".

More might be added in the future.