5. Testing

Components need to adhere properly to their respective interface definition to maintain compatibility in the system. To check this, we provide test cases implemented in Python (based on the Pytest framework).

Given Python’s duck-typing mechanism, it can natively test implemetations in any language, so we only need one test definition. To ‘inject’ your component, no matter the language, you simply need to subclass and provide an instance of your to-be-tested object.

5.1. Running Tests

Setting up to run the test cases requires a few steps:

1. CD into the PEPI base directory: cd pepi
2. Install the test’s Python package requirements: pip install -r test/requirements.txt

And then running the tests simply requires a single command: PYTHONPATH=$PWD:$PYTHONPATH py.test

5.2. Testing Camera Components

5.2.1. Python Cameras

Python native components are the simplest to test. We provide tests for both local Python object components, and Python components being served over Thrift. In both cases, you just need to provide an instance of your component class in the below test fixtures and the rest will be handled.

import pytest

from server.tests import AbstractCameraContract, AbstractCameraOverThrift
import MyConcreteCamera

class TestMyConcreteCamera(AbstractCameraContract):
    @pytest.fixture(scope="module")
    def camera(self):
        return MyConcreteCamera()

class TestDummyCameraOverThrift(AbstractCameraOverThrift):
    @pytest.fixture(scope="module")
    def local_camera(self):
        return MyConcreteCamera()

5.2.2. Non-Python Cameras

It is still possible to test non-Python components with the provided Python test classes, but you’ll need to launch the component’s Thrift server yourself (perhaps with some script, depending on your language).

Suppose your server is accessible at 192.168.1.10:6000, then we can utilise duck-typing to convince the Python local object test cases that they are just working with a local object. This achieved as follows:

import pytest

from server import pepi_thrift
from server.tests import AbstractCameraContract, AbstractCameraOverThrift
from thriftpy.rpc import client_context

class TestMyNonPythonConcreteCamera(AbstractCameraContract):
   @pytest.fixture(scope="module")
   def camera(self):
      with client_context(pepi_thrift.Camera, '192.168.1.10', 6000) as c:
         return c

5.3. Testing Servers

Testing servers is much the same as testing cameras – just targeting different test fixtures.

5.3.1. Python Servers

import pytest

from server import pepi_thrift
from server.tests import MetaCameraServerContract
from thriftpy.rpc import client_context

import MyPythonServer

class TestMyNonPythonServer(MetaCameraServerContract):
   @pytest.fixture(scope="module")
   def server(self):
      return MyPythonServer()

class TestMyPythonServerOverThrift(MetaCameraServerContractOverThrift):
   @pytest.fixture(scope="module")
   def local_server(self):
      return MyPythonServer()

5.3.2. Non-Python Servers

Again, non-Python servers can still be tested, but you’ll need to launch the launch the component’s Thrift server yourself. Suppose your sever is accessible at 192.168.1.10:6000:

import pytest

from server import pepi_thrift
from server.tests import MetaCameraServerContract
from thriftpy.rpc import client_context

class TestMyNonPythonServer(MetaCameraServerContract):
   @pytest.fixture(scope="module")
   def server(self):
      with client_context(pepi_thrift.CameraServer, '192.168.1.10', 6000) as c:
         return c