# OpenStack

# ostestr

The ostestr command provides a wrapper around the testr command included in the testrepository package. It’s designed to build on the functionality included in testr and workaround several UI bugs in the short term. By default it also has output that is much more useful for OpenStack’s test suites which are lengthy in both runtime and number of tests. Please note that the CLI semantics are still a work in progress as the project is quite young, so default behavior might change in future version.

## Summary

> ostestr [-b|–blacklist_file <blacklist_file>] [-r|–regex REGEX]
>   [-p|–pretty] [–no-pretty] [-s|–subunit] [-l|–list] [-n|–no-discover <test_id>] [–slowest] [–no-slowest] [–pdb <test_id>] [–parallel] [–serial] [-c|–concurrency <workers>] [–until-failure] [–print-exclude]

## Options

> `--blacklist_file BLACKLIST_FILE, -b BLACKLIST_FILE`
> | Path to a blacklist file, this file contains a separate regex exclude on each newline
> `--regex REGEX, -r REGEX`
> | A normal testr selection regex. If a blacklist file is specified, the regex will be appended to the end of the generated regex from that file
> `--pretty, -p` | Print pretty output from subunit-trace. This is mutually exclusive with –subunit
> `--no-pretty` | Disable the pretty output with subunit-trace
> `--subunit, -s` | output the raw subunit v2 from the test run this is mutuall exclusive with –pretty
> `--list, -l` | List all the tests which will be run.
> `--no-discover TEST_ID, -n TEST_ID`
> | Takes in a single test to bypasses test discover and just excute the test specified
> `--slowest` | After the test run print the slowest tests
> `--no-slowest` | After the test run don’t print the slowest tests
> `--pdb TEST_ID` | Run a single test that has pdb traces added
> `--parallel` | Run tests in parallel (this is the default)
> `--serial` | Run tests serially
> `--concurrency WORKERS, -c WORKERS`
> | The number of workers to use when running in parallel. By default this is the number of cpus
> `--until-failure`
> | Run the tests in a loop until a failure is encountered. Running with subunit or prettyoutput enable will force the loop to run testsserially
> `--print-exclude`
> | If an exclude file is used this option will prints the comment from the same line and all skipped tests before the test run

## Running Tests

os-testr is primarily for running tests at it’s basic level you just invoke ostestr to run a test suite for a project. (assuming it’s setup to run tests using testr already) For example:

    $ ostestr

This will run tests in parallel (with the number of workers matching the number of CPUs) and with subunit-trace output. If you need to run tests in serial you can use the serial option:

    $ ostestr --serial

Or if you need to adjust the concurrency but still run in parallel you can use -c/–concurrency:

    $ ostestr --concurrency 2

If you only want to run an individual test module or more specific (a single class, or test) and parallel execution doesn’t matter, you can use the -n/–no-discover to skip test discovery and just directly calls subunit.run on the tests under the covers. Bypassing discovery is desirable when running a small subset of tests in a larger test suite because the discovery time can often far exceed the total run time of the tests.

For example:

    $ ostestr --no-discover test.test_thing.TestThing.test_thing_method

Additionally, if you need to run a single test module, class, or single test with pdb enabled you can use –pdb to directly call testtools.run under the covers which works with pdb. For example:

    $ ostestr --pdb tests.test_thing.TestThing.test_thing_method

## Test Selection

ostestr is designed to build on top of the test selection in testr. testr only exposed a regex option to select tests. This equivalent is functionality is exposed via the –regex option. For example:

    $ ostestr --regex 'magic\.regex'

This will do a straight passthrough of the provided regex to testr. Additionally, ostestr allows you to specify a blacklist file to define a set of regexes to exclude. You can specify a blacklist file with the –blacklist-file/-b option, for example:

    $ ostestr --blacklist_file $path_to_file

The format for the file is line separated regex, with ‘#’ used to signify the start of a comment on a line. For example:

    # Blacklist File
    ^regex1 # Excludes these tests
    .*regex2 # exclude those tests

Will generate a regex to pass to testr which will exclude both any tests matching ‘^regex1’ and ‘.*regex2’. If a blacklist file is used in conjunction with the –regex option the regex specified with –regex will be appended to the generated output from the –blacklist_file. Also it’s worth noting that the regex test selection options can not be used in conjunction with the –no-discover or –pdb options described in the previous section. This is because the regex selection requires using testr under the covers to actually do the filtering, and those 2 options do not use testr.

It’s also worth noting that you can use the test list option to dry run any selection arguments you are using. You just need to use –list/-l with your selection options to do this, for example:

    $ ostestr --regex 'regex3.*' --blacklist_file blacklist.txt --list

This will list all the tests which will be run by ostestr using that combination of arguments.

Please not that all of this selection functionality will be expanded on in the future and a default grammar for selecting multiple tests will be chosen in a future release. However as of right now all current arguments (which have guarantees on always remaining in place) are still required to perform any selection logic while this functionality is still under development.

## Output Options

By default ostestr will use subunit-trace as the output filter on the test run. It will also print the slowest tests from the run after the run is concluded. You can disable the printing the slowest tests with the –no-slowest flag, for example:

    $ ostestr --no-slowest

If you’d like to disable the subunit-trace output you can do this using –no-pretty:

    $ ostestr --no-pretty

ostestr also provides the option to just output the raw subunit stream on STDOUT with –subunit/-s. Note if you want to use this you also have to specify –no-pretty as the subunit-trace output and the raw subunit output are mutually exclusive. For example, to get raw subunit output the arguments would be:

    $ ostestr --no-pretty --subunit

An additional option on top of the blacklist file is –print-exclude option. When this option is specified when using a blacklist file before the tests are run ostestr will print all the tests it will be excluding from the blacklist file. If a line in the blacklist file has a comment that will be printed before listing the tests which will be excluded by that line’s regex. If no comment is present on a line the regex from that line will be used instead. For example, if you were using the example blacklist file from the previous section the output before the regular test run output would be:

    $ ostestr -b blacklist-file blacklist.txt --print-exclude
    Excludes these tests
    regex1_match
    regex1_exclude

    exclude those tests
    regex2_match
    regex2_exclude

    ...

## Notes for running with tox

If you use `tox`_ for running your tests and call ostestr as the test command .. _tox: https://tox.readthedocs.org/en/latest/ it’s recommended that you set a posargs following ostestr on the commands

> stanza. For example:

>     [testenv]
>     commands = ostestr {posargs}

this will enable end users to pass args to configure the output, use the selection logic, or any other options directly from the tox cli. This will let tox take care of the venv management and the environment separation but enable direct access to all of the ostestr options to easily customize your test run. For example, assuming the above posargs usage you would be to do:

    $ tox -epy34 -- --regex ^regex1

or to skip discovery:

    $ tox -epy34 -- -n test.test_thing.TestThing.test_thing_method