fakeredis: A fake version of a redis-py
fakeredis is a pure python implementation of the redis-py python client that simulates talking to a redis server. This was created for a single purpose: to write unittests. Setting up redis is not hard, but many times you want to write unittests that do not talk to an external server (such as redis). This module now allows tests to simply use this module as a reasonable substitute for redis.
How to Use
The intent is for fakeredis to act as though you're talking to a real redis server. It does this by storing state in the fakeredis module. For example:
>>> import fakeredis >>> r = fakeredis.FakeStrictRedis() >>> r.set('foo', 'bar') True >>> r.get('foo') 'bar' >>> r.lpush('bar', 1) 1 >>> r.lpush('bar', 2) 2 >>> r.lrange('bar', 0, -1) [2, 1]
By storing state in the fakeredis module, instances can share data:
>>> import fakeredis >>> r1 = fakeredis.FakeStrictRedis() >>> r1.set('foo', 'bar') True >>> r2 = fakeredis.FakeStrictRedis() >>> r2.get('foo') 'bar' >>> r2.set('bar', 'baz') True >>> r1.get('bar') 'baz' >>> r2.get('bar') 'baz'
Fakeredis implements the same interface as redis-py, the popular redis client for python, and models the responses of redis 2.6.
All of the redis commands are implemented in fakeredis with these exceptions:
- debug object
- client list
- client kill
- config resetstat
- config get
- debug segfault
- config set
- script flush
- script kill
- script load
- script exists
Contributions are welcome. Adding support for more redis commands or fixing bugs is easy:
- Add unittests for the new command.
- Implement new command.
To ensure parity with the real redis, there are a set of integration tests that mirror the unittests. For every unittest that is written, the same test is run against a real redis instance using a real redis-py client instance. In order to run these tests you must have a redis server running on localhost, port 6379 (the default settings). The integration tests use db=10 in order to minimize collisions with an existing redis instance.
In general, new features or bug fixes will not be merged unless they have tests. This is not only to ensure the correctness of the code, but to also encourage others to expirement without wondering whether or not they are breaking things.
Running the Tests
To run all the tests, install the requirements file:
pip install -r requirements.txt
If you just want to run the unittests:
nosetests test_fakeredis.py:TestFakeStrictRedis test_fakeredis.py:TestFakeRedis
Because this module is attempting to provide the same interface as redis-py, the python bindings to redis, a reasonable way to test this to to take each unittest and run it against a real redis server. fakeredis and the real redis server should give the same result. This ensures parity between the two. You can run these "integration" tests like this:
nosetests test_fakeredis.py:TestRealStrictRedis test_fakeredis.py:TestRealRedis
In terms of implementation, TestRealRedis is a subclass of TestFakeRedis that overrides a factory method to create an instance of redis.Redis (an actual python client for redis) instead of fakeredis.FakeStrictRedis.
To run both the unittests and the "integration" tests, run:
If redis is not running and you try to run tests against a real redis server, these tests will have a result of 'S' for skipped.
There are some tests that test redis blocking operations that are somewhat slow. If you want to skip these tests during day to day development, they have all been tagged as 'slow' so you can skip them by running:
nosetests -a '!slow'