Skip to main content

Simple testing of RESTful APIs

Project description

pypi docs workflow

Easier API testing

Tavern is a pytest plugin, command-line tool and Python library for automated testing of APIs, with a simple, concise and flexible YAML-based syntax. It's very simple to get started, and highly customisable for complex tests. Tavern supports testing RESTful APIs as well as MQTT based APIs.

The best way to use Tavern is with pytest. Tavern comes with a pytest plugin so that literally all you have to do is install pytest and Tavern, write your tests in .tavern.yaml files and run pytest. This means you get access to all of the pytest ecosystem and allows you to do all sorts of things like regularly run your tests against a test server and report failures or generate HTML reports.

You can also integrate Tavern into your own test framework or continuous integration setup using the Python library, or use the command line tool, tavern-ci with bash scripts and cron jobs.

To learn more, check out the examples or the complete documentation. If you're interested in contributing to the project take a look at the GitHub repo.

Quickstart

First up run pip install tavern.

Then, let's create a basic test, test_minimal.tavern.yaml:

---
# Every test file has one or more tests...
test_name: Get some fake data from the JSON placeholder API

# ...and each test has one or more stages (e.g. an HTTP request)
stages:
  - name: Make sure we have the right ID

    # Define the request to be made...
    request:
      url: https://jsonplaceholder.typicode.com/posts/1
      method: GET

    # ...and the expected response code and body
    response:
      status_code: 200
      json:
        id: 1
        userId: 1
        title: "sunt aut facere repellat provident occaecati excepturi optio reprehenderit"
        body: "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"

This file can have any name, but if you intend to use Pytest with Tavern, it will only pick up files called test_*.tavern.yaml.

This can then be run like so:

$ pip install tavern[pytest]
$ py.test test_minimal.tavern.yaml  -v
=================================== test session starts ===================================
platform linux -- Python 3.5.2, pytest-3.4.2, py-1.5.2, pluggy-0.6.0 -- /home/taverntester/.virtualenvs/tavernexample/bin/python3
cachedir: .pytest_cache
rootdir: /home/taverntester/myproject, inifile:
plugins: tavern-0.7.2
collected 1 item

test_minimal.tavern.yaml::Get some fake data from the JSON placeholder API PASSED   [100%]

================================ 1 passed in 0.14 seconds =================================

It is strongly advised that you use Tavern with Pytest - not only does it have a lot of utility to control discovery and execution of tests, there are a huge amount of plugins to improve your development experience. If you absolutely can't use Pytest for some reason, use the tavern-ci command line interface:

$ pip install tavern
$ tavern-ci --stdout test_minimal.tavern.yaml
2017-11-08 16:17:00,152 [INFO]: (tavern.core:55) Running test : Get some fake data from the JSON placeholder API
2017-11-08 16:17:00,153 [INFO]: (tavern.core:69) Running stage : Make sure we have the right ID
2017-11-08 16:17:00,239 [INFO]: (tavern.core:73) Response: '<Response [200]>' ({
  "userId": 1,
  "id": 1,
  "title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
  "json": "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
})
2017-11-08 16:17:00,239 [INFO]: (tavern.printer:9) PASSED: Make sure we have the right ID [200]

Why not Postman, Insomnia or pyresttest etc?

Tavern is a focused tool which does one thing well: automated testing of APIs.

Postman and Insomnia are excellent tools which cover a wide range of use-cases for RESTful APIs, and indeed we use Tavern alongside Postman. However, specifically with regards to automated testing, Tavern has several advantages over Postman:

  • A full-featured Python environment for writing easily reusable custom validation functions
  • Testing of MQTT based systems in tandem with RESTful APIS.
  • Seamless integration with pytest to keep all your tests in one place
  • A simpler, less verbose and clearer testing language

Tavern does not do many of the things Postman and Insomnia do. For example, Tavern does not have a GUI nor does it do API monitoring or mock servers. On the other hand, Tavern is free and open-source and is a more powerful tool for developers to automate tests.

pyresttest is a similar tool to Tavern for testing RESTful APIs, but is no longer actively developed. On top of MQTT testing, Tavern has several other advantages over PyRestTest which overall add up to a better developer experience:

  • Cleaner test syntax which is more intuitive, especially for non-developers
  • Validation function are more flexible and easier to use
  • Better explanations of why a test failed

Hacking on Tavern

If you want to add a feature to Tavern or just play around with it locally, it's a good plan to first create a local development environment (this page has a good primer for working with development environments with Python). After you've created your development environment, just pip install tox and run tox to run the unit tests. If you want to run the integration tests, make sure you have docker installed and run tox -c tox-integration.ini (bear in mind this might take a while.) It's that simple!

If you want to develop things in tavern, enter your virtualenv and run pip install -r requirements.txt to install the library, any requirements, and other useful development options.

Tavern uses ruff to keep all of the code formatted consistently. There is a pre-commit hook to run ruff format which can be enabled by running pre-commit install.

If you want to add a feature to get merged back into mainline Tavern:

  • Add the feature you want
  • Add some tests for your feature:
    • If you are adding some utility functionality such as improving verification of responses, adding some unit tests might be best. These are in the tests/unit/ folder and are written using Pytest.
    • If you are adding more advanced functionality like extra validation functions, or some functionality that directly depends on the format of the input YAML, it might also be useful to add some integration tests. At the time of writing, this is done by adding an example flask endpoint in tests/integration/server.py and a corresponding Tavern YAML test file in the same directory. This will be cleaned up a bit once we have a proper plugin system implemented.
  • Open a pull request.

See CONTRIBUTING.md for more details.

Acknowledgements

Tavern makes use of several excellent open-source projects:

Maintenance

Tavern is currently maintained by

  • @michaelboulton

Project details


Release history Release notifications | RSS feed

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

tavern-2.15.0.tar.gz (249.4 kB view details)

Uploaded Source

Built Distribution

tavern-2.15.0-py3-none-any.whl (106.7 kB view details)

Uploaded Python 3

File details

Details for the file tavern-2.15.0.tar.gz.

File metadata

  • Download URL: tavern-2.15.0.tar.gz
  • Upload date:
  • Size: 249.4 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: python-requests/2.32.3

File hashes

Hashes for tavern-2.15.0.tar.gz
Algorithm Hash digest
SHA256 f18b5e9ffd8e0fe4b99a19f4b0051f5e86ff97e2584b053c0719c935b40bdbbd
MD5 ed79dd67c18876fb06aad74dc0391a66
BLAKE2b-256 deb9d487a66d01845ca61cb738bee4d25b93264088218164a63c45470ea81eb0

See more details on using hashes here.

File details

Details for the file tavern-2.15.0-py3-none-any.whl.

File metadata

  • Download URL: tavern-2.15.0-py3-none-any.whl
  • Upload date:
  • Size: 106.7 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? No
  • Uploaded via: python-requests/2.32.3

File hashes

Hashes for tavern-2.15.0-py3-none-any.whl
Algorithm Hash digest
SHA256 17bc9698db8e33534075cd9389f6684bf2b07fee597a7585357aef433b824f58
MD5 25902c5abda685ca8454d401007bd3ba
BLAKE2b-256 13c9da0c14863c28a91cef5583449ed655e994276afc4f69edf11a487131c2c8

See more details on using hashes here.

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Pingdom Monitoring Sentry Error logging StatusPage Status page