Functional Testing

Functional Testing

bp functional-testing

Problem Description

The new direction is to move functional testing out of tempest and into the projects. This means that we need to provide guidance for how this is to be done in Keystone. This spec answers the following questons:

  1. What is considered functional tests and how are they different from unit tests?
  2. Where should the tests be located?
  3. When should these tests be run?
  4. What tooling should be used to write the tests?

We’ve also decided at the Kilo mid-cycle meeting that the Work Items will be updated in subsequent commits to reflect new functional tests scenarios that will be added. If someone decides that they would like to add tests to verify feature X, they will submit a change to this spec to add a subsection to Work Items based on the template.

This spec may lead to moving some unit tests into the functional tests, but is not advocating any substantial changes to how unit tests work today.

Proposed Change

Definitions

shared scenario tests
Tests that must pass on all Keystone configurations. (also known as ‘shared tests’)
configuration specific scenario tests
Tests that require Keystone is configured in a specific way. For example, to run the federation tests Keystone must be configured to support federation. (also known as ‘config specific tests’)

Functional or Unit Testing

From the move functional testing post:

Put the burden for a bunch of these tests back on the projects as “functional” tests. Basically a custom devstack environment that a project can create with a set of services that they minimally need to do their job. These functional tests will live in the project tree, not in Tempest, so can be atomically landed as part of the project normal development process.

What exactly is a functional test? If the answer of any of the following questions is ‘yes’, then you have a functional test.

  1. Does the test scenario need any specific components setup? (e.g. ldap, federation)
  2. Does the test need to test a Keystone instance as a black box?
  3. Does the test need to be run as a part of the test suite that runs against a variety of different configuations?

Directory structures

$ pwd
/opt/stack/keystone
keystone/tests/functional
├── federation
│   ├── __init__.py
│   └── {{test_something}}.py
└── shared
    ├── __init__.py
    └── {{test_something}}.py

2 directories, 4 files

Running Functional Tests

Functional shared tests should be run by developers before submitting changes to Gerrit. This should not be much of a barrier because those are tests that need to run on any running Keystone configuration.

When developers are working on feature for a specific configuration they should run the config specific tests.

To run all of the shared tests (unlikely that you want to do this):

tox -e functional

To run all of the federation config tests:

tox -e functional -- keystone.tests.functional.federation

How To Write Functional Tests

The tests will be written in a style that is similar to unit tests. tox will be used to run the tests. Test classes are subclasses to testtools.

The difference comes in when you start talking about the contents of the tests themselves. Functional tests should be written using the black box model. The test should have no knowledge of the backends being used. Ideally all tests can be written using primarily keystoneclient and requests to interact with Keystone.

Certain elements of the tests must be controllable via environment variables. For example, the base URL for Keystone. This allows the developer running the tests to point to any Keystone instance. Beyond the Keystone URLs there is no official list of what must be configurable.

Alternatives

I have not really investigated alternatives. This spec is intentionally a bit vague so that we can innovate a little in this space.

Security Impact

None. This is about tests and does’t directly impact production code.

Notifications Impact

None. This is about tests and does’t directly impact production code.

Other End User Impact

None. This is about tests and does’t directly impact production code.

Performance Impact

None. This is about tests and does’t directly impact production code.

Other Deployer Impact

None. This is about tests and does’t directly impact production code.

Developer Impact

  1. Developers will have to understand what functional tests are and where they go in the tree.
  2. Developers will need to know how and when to run the tests.
  3. Some existing unit tests may be moved to the functional test suite.

Implementation

Assignee(s)

Primary assignee:
dstanek

Work Items

  1. Update developer documentation.
  2. Change the tox target for unit tests to exclude functional tests.

Testing Changes

Type of tests being added (e.g. federation)

A short description of the use cases being added.

Assignee(s): <anyone>

Dependencies

Certain functional tests may require a specific environment to be available. For example, to run the federation tests your Keystone instance will have to be configured to use federation.

Documentation Impact

The developer documentation will need to be updated to explain how and when to run the functional tests. A new document will need to be created to explain how to create and extend the functional tests.

References

This is part of a bigger effort to rework the way Keystone that started in an etherpad.

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.

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