baldertest 0.1.0b7

balder: reusable scenario based test framework

Balder is a very powerful, universal and flexible python test system that allows you to reuse a once written testcode as efficiently as possible for different but similar platforms/devices/applications. Balder's goal is being a platform for combining the single steps of defining, developing and documenting the entire test process while using test scenarios which can be reused across different projects.

You can share your own testcode by creating a new BalderHub project, or you use an existing BalderHub project, by simply installing and using it. This makes the test development for your project much faster, since it is often times enough to only provide the user-specific code.

Be part of the progress and share your tests with others, your company or the whole world.

Installation

You can install the latest release with pip:

python -m pip install baldertest

Run Balder

After you've installed it, you can run Balder inside a Balder environment with the following command:

balder

You can also provide a specific path to the balder environment directory by using this console argument:

balder --working-dir /path/to/working/dir

How does it work?

Balder allows you to reuse previously written test code by dividing it into the components that are needed for a test (Scenario) and the components that we have (Setup).

Scenario classes define a test. Only describe the most important aspects you need for the execution of the corresponding test (method of the scenario class) inside Scenario classes. Often it is enough to define abstract methods in the scenario-level features.

In contrast, Setup classes describe exactly what you have. This is where you define all the devices and their features. Balder will then automatically search for mappings and run your test with them.

Define the Scenario class

Inside Scenario or Setup classes, inner Device classes describe your environment. For example, if you want to test the process of sending a message between two devices, you can create a Scenario like shown below:

import balder
from .features import SendMessageFeature, RecvMessageFeature


class ScenarioMessaging(balder.Scenario):
    
    class Sender(balder.Device):
        send = SendMessageFeature()
    
    @balder.connect(Sender, over_connection=balder.Connection())
    class Receiver(balder.Device):
        recv = RecvMessageFeature()
        
    

You have now defined, that the Sender device must be able to send messages (has SendMessageFeature()), while the Receiver device must be able to receive messages (has RecvMessageFeature()). Both devices are connected with each other. For this we use the general connection balder.Connection(), which allows every type of connection.

You can implement your test, by adding a new method that starts with test_*():

import balder
from .features import SendMessageFeature, RecvMessageFeature


class ScenarioMessaging(balder.Scenario):
    
    class Sender(balder.Device):
        send = SendMessageFeature()
    
    @balder.connect(Sender, over_connection=balder.Connection())
    class Receiver(balder.Device):
        recv = RecvMessageFeature()
        
    def test_send_msg(self):
        MESSAGE_TXT = "Hello World"
        self.Sender.send.send_msg(MESSAGE_TXT)
        received_msg = self.Receiver.recv.get_last_received_msg()
        assert received_msg == MESSAGE_TXT

Define the Setup class

The next step is defining a Setup class, which describes what we have. For a Scenario to match a Setup, all of your scenario-devices must be able to map to a sub selection of some setup-devices.

For example, if you want to verify if your DUT is able to receive messages from your computer (both are connected over USB), just create a Setup class with the both devices Computer and Dut and add an implementation (subclasses) of our previously defined feature classes SendMessageFeature and RecvMessageFeature to them:

import balder
from balder import connections as cnns
from .setup_features import SendUsbMessageFeature, RecvUsbMessageFeature


class SetupOverUsb(balder.Setup):
    
    class Computer(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendUsbMessageFeature()
    
    @balder.connect(Computer, over_connection=cnns.UsbConnection())
    class Dut(balder.Device):
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()

With the features SendUsbMessageFeature and RecvUsbMessageFeature, both devices hold an implementation of our previous scenario-level features SendMessageFeature and RecvMessageFeature. They are the child classes of our scenario-level features and hold the full implementation for sending/receiving data over USB.

As soon as you run Balder, Balder will automatically detect that our scenario ScenarioMessaging can be mapped to the SetupOverUsb. This will cause Balder to run the test test_send_msg() with the implemented setup-level version of the features.

The big advantage of Balder is the reusability. If you want to test if the communication also works in the other direction, just add the features inverted:

import balder
from balder import connections as cnns
from .setup_features import SendUsbMessageFeature, RecvUsbMessageFeature


class SetupOverUsb(balder.Setup):
    
    class Computer(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendUsbMessageFeature()
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()
    
    @balder.connect(Computer, over_connection=cnns.UsbConnection())
    class Dut(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendUsbMessageFeature()
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()

Balder will now run the test once with the Computer being the sender and once with the Dut being the Sender, even though you didn't implement anything new.

	ScenarioMessaging.Sender	ScenarioMessaging.Sender
VARIATION 1	SetupOverUsb.Computer	SetupOverUsb.Dut
VARIATION 2	SetupOverUsb.Dut	SetupOverUsb.Computer

Do you have another device, that should be tested too? Just add it to your setup:

import balder
from balder import connections as cnns
from .setup_features import SendUsbMessageFeature, RecvUsbMessageFeature


class SetupOverUsb(balder.Setup):
    
    class Computer(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendUsbMessageFeature()
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()
    
    @balder.connect(Computer, over_connection=cnns.UsbConnection())
    class Dut(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendUsbMessageFeature()
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()
        
    @balder.connect(Computer, over_connection=cnns.UsbConnection())
    class AnotherDut(balder.Device):
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvUsbMessageFeature()

Now balder will run our scenario once each with the following mappings:

	ScenarioMessaging.Sender	ScenarioMessaging.Sender
VARIATION 1	SetupOverUsb.Computer	SetupOverUsb.Dut
VARIATION 2	SetupOverUsb.Dut	SetupOverUsb.Computer
VARIATION 3	SetupOverUsb.Computer	SetupOverUsb.AnotherDut

If you want to test a Dut device that does not use USB for communication, you can also add other feature implementations of SendMessageFeature and RecvMessageFeature in your setup devices. For this we just add a new setup:

import balder
from balder import connections as cnns
from .setup_features import SendUsbMessageFeature, RecvUsbMessageFeature, SendBluetoothMessageFeature, RecvBluetoothMessageFeature


class SetupOverUsb(balder.Setup):
    
    ...

class SetupOverBluetooth(balder.Setup):
    class Computer(balder.Device):
        # non-abstract subclass of `SendMessageFeature`
        send = SendBluetoothMessageFeature()
    
    @balder.connect(Computer, over_connection=cnns.BluetoothConnection)
    class Dut(balder.Device):
        # non-abstract subclass of `RecvMessageFeature`
        recv = RecvBluetoothMessageFeature()

If you now execute Balder, it will run the scenario with all possible device constellations of the SetupOverUsb and the SetupOverBluetooth.

	ScenarioMessaging.Sender	ScenarioMessaging.Sender
VARIATION 1	SetupOverUsb.Computer	SetupOverUsb.Dut
VARIATION 2	SetupOverUsb.Dut	SetupOverUsb.Computer
VARIATION 3	SetupOverUsb.Computer	SetupOverUsb.AnotherDut
VARIATION 4	SetupOverBluetooth.Computer	SetupOverBluetooth.Dut

NOTE: You could also add all of these devices in a shared setup and use one common feature for both protocols, but for this you would need to use VDevices. You can read more about this in the documentation section about VDevices

Example: Use an installable BalderHub package

With Balder you can create custom test environments or install open source available test packages, so called BalderHub packages. If you want to test a SNMP client device for example, you can use the package balderhub-snmpagent. Just install it with:

$ pip install balderhub-snmpagent

You only need to provide two things: The configuration of your DUT as subclass of SnmpSystemConfig and your environment (the Setup class):

# file `features.py`
from balderhub.snmpagent.lib import features

class MySnmpSystemConfig(features.SnmpSystemConfig):

    host = "192.168.178.28"
    sys_descr = "my fancy sysDescr"
    sys_object_id = "1.3.6.1.4.1.1234.2.3.9.1"
    read_community = "public"
    write_community = "public"

# file `setup_example.py`
import balder
from balderhub.snmpagent.lib.connections import SnmpConnection
from balderhub.snmpagent.lib.features import HasSnmpSystemGroupFeature
from balderhub.snmpagent.lib.setup_features import SendSnmpGetRequestPysnmpFeature, SendSnmpSetRequestPysnmpFeature
from . import features as setup_features


class SetupPrinter(balder.Setup):

    class Printer(balder.Device):
        _snmp_sys = HasSnmpSystemGroupFeature()
        config = setup_features.SnmpSystemConfig()

    @balder.connect(Printer, over_connection=SnmpConnection())
    class HostPc(balder.Device):
        get_request_snmp = SendSnmpGetRequestPysnmpFeature()
        set_request_snmp = SendSnmpSetRequestPysnmpFeature()

Call Balder in your project:

$ balder

And all existing and matching tests in balderhub-snmpagent will then be executed for you:

+----------------------------------------------------------------------------------------------------------------------+
| BALDER Testsystem                                                                                                    |
|  python version 3.10.6 (main, Mar 10 2023, 10:55:28) [GCC 11.3.0] | balder version 0.1.0b6                           |
+----------------------------------------------------------------------------------------------------------------------+
Collect 1 Setups and 3 Scenarios
  resolve them to 3 mapping candidates

================================================== START TESTSESSION ===================================================
SETUP SetupPrinter
  SCENARIO ScenarioMibSysDescr
    VARIATION ScenarioMibSysDescr.SnmpAgent:SetupPrinter.Printer | ScenarioMibSysDescr.SnmpManager:SetupPrinter.HostPc
      TEST ScenarioMibSysDescr.test_get_sys_descr [.]
      TEST ScenarioMibSysDescr.test_get_sys_descr_ascii_check [.]
      TEST ScenarioMibSysDescr.test_set_sys_descr [.]
  SCENARIO ScenarioMibSysObjectId
    VARIATION ScenarioMibSysObjectId.SnmpAgent:SetupPrinter.Printer | ScenarioMibSysObjectId.SnmpManager:SetupPrinter.HostPc
      TEST ScenarioMibSysObjectId.test_get_sys_object_id [.]
      TEST ScenarioMibSysObjectId.test_set_sys_object_id [.]
  SCENARIO ScenarioMibSysUpTime
    VARIATION ScenarioMibSysUpTime.SnmpAgent:SetupPrinter.Printer | ScenarioMibSysUpTime.SnmpManager:SetupPrinter.HostPc
      TEST ScenarioMibSysUpTime.test_get_sys_up_time [.]
      TEST ScenarioMibSysUpTime.test_get_sys_up_time_changed_check [.]
      TEST ScenarioMibSysUpTime.test_set_sys_up_time [.]
================================================== FINISH TESTSESSION ==================================================
TOTAL NOT_RUN: 0 | TOTAL FAILURE: 0 | TOTAL ERROR: 0 | TOTAL SUCCESS: 8 | TOTAL SKIP: 0 | TOTAL COVERED_BY: 0

Contribution guidelines

Any help is appreciated. If you want to contribute to balder, take a look into the contribution guidelines.

Balder is still in its early steps. Unfortunately, this also means that we don't have a broad variety of BalderHub projects at the moment.

Are you an expert in your field? Do you enjoy the concept of balder? How about you create your own BalderHub project? Take a look into our Balder GitHub Group and feel free to share your ideas. You can contribute to an existing project or create your own. If you are not sure, a project for your idea already exists or if you want to discuss your ideas with others, feel free to create an issue in the BalderHub main entry project or start a new discussion.

License

Balder is free and Open-Source

Copyright (c) 2022 Max Stahlschmidt and others

Distributed under the terms of the MIT license