Writing-a-Feature-Test-Case.md

Writing Automated Feature Test Cases

Writing test cases

A test suite is a Python file whose name begins with test, like: test_name_of_the_test_suite.py

Topology definition

Suites must have only one topology definition, a string that defines a test topology. The following is an example:

TOPOLOGY = """
+-------+                                       +-------+
|       |       +-------+       +-------+       |       |
| hs1   <------->  sw1  <------->  sw2  <------->  hs2  |
|       |       +-------+       +-------+       |       |
+-------+                                       +-------+

# Nodes
[type=openswitch name=“Switch 1”] sw1
[type=openswitch name=“Switch 2”] sw2
[type=host name=“Host 1”] hs1 hs2

# Ports
[up=True] hs1:1

# Links
[category=5e] hs1:1 – sw1:3
sw1:4 – sw2:3 sw2:4 – hs2:1
"""

The topology definition must be assigned to a variable named TOPOLOGY.

This syntax supports comments, any line that begins with # will be ignored by the parser.

There are three elements in a topology definition:

1. Nodes represented by a simple string: sw1
2. Ports represented by a colon and the name of the port: hs1:1
3. Links represented by a double dash between 2 ports: hs1: -- sw1:3

Each element in a topology definition can have attributes, a list of key=value pairs that define their properties. These attributes are passed to the specific topology platform plugin that handles them adequately or ignores them.

Test case functions

A suite may have several test case functions. These functions must begin with test and may receive fixtures. This framework provides the topology fixture that handles topology setup and teardown automatically. To use it, define a test case like this:

def test_name_of_the_test_case(topology):
     """
     Description of the test case.
     """

     hs1 = topology.get('hs1')

     ...

As you can see from the example above, topology can be used to access the nodes in the topology.

You can add input in the test logs by calling the step function in your test case like this:

def test_name_of_the_test_case(topology, step):
     """
     Description of the test case.
     """
     step('Getting the devices')
     hs1 = topology.get('hs1')

     ...

The arguments for the step function will show up inside the .tox/py34/tmp/tests.xml file.