NullCache isn't initialized properly

[oittaa]

Maybe I've misunderstood something, but if I try to initialize NullCache like SimpleCache is done in the README.md, something goes wrong and has method is missing.

Test 1

from flask_caching import Cache
cache = Cache(config={"CACHE_TYPE": "NullCache"})
print(cache.has("test"))

Output

Traceback (most recent call last):
  File "2.py", line 3, in <module>
    print(cache.has("test"))
AttributeError: 'Cache' object has no attribute 'has'

Test 2

If I import NullCache directly, has method works as expected and always returns False.

from flask_caching.backends.nullcache import NullCache
cache = NullCache()
print(cache.has("test"))

Output

False

[sh4nks]

There is no proxy method for has on the Cache object: https://github.com/sh4nks/flask-caching/blob/master/flask_caching/__init__.py#L261-L297

[oittaa]

Thanks, so only proxy methods are exposed from the Cache object.
Is there a "proper" way to use a cache object like SimpleCache or NullCache with an exposed has method, because I didn't really find an answer from the documentation?

from flask_caching.backends.simplecache import SimpleCache
cache = SimpleCache()
cache.set("a", 123)
print(cache.has("a"))

[sh4nks]

You can access the backend from the cache object like this:
cache.cache.has() where the first cache is the Cache object and the second the caching backend.

The reason this is not exposed on the cache object is because it is an optional method. So make sure your caching backend supports has. See https://github.com/sh4nks/flask-caching/blob/master/flask_caching/backends/base.py#L154-L167