### Changes:
- Created `PurchasedProductsFetcherType` to be able to mock and hold
fetchers, even on older devices
- Created `ProductEntitlementMappingFetcher` to abstract injecting
`ProductEntitlementMapping`
- Added logic to `CustomerInfoResponseHandler` to compute offline
`CustomerInfo` after a server error (see #2367). **This is used by all
`CustomerInfo` requests as well as `PostReceiptDataOperation`**.
- Wrote comprehensive `CustomerInfoResponseHandler` tests
### TODO:
- [x] Don't cache offline computed `CustomerInfo`: #2378
- [x] Integration tests: #2501.
### Changes:
- Added `Purchases.configureInCustomEntitlementsComputationMode`
- Added `Purchases.switchUser(to:)`
- Disabled parts of the SDK in this new mode
- New example app for testing `customEntitlementsComputation` mode
---------
Co-authored-by: NachoSoto <ignaciosoto90@gmail.com>
### Changes:
- Created `CacheableNetworkOperationFactory` to abstract operation and
cache key creation
- Instead of always creating an operation, we create a factory first,
which pre-computes the cache key
- This cache key is used to determine if it's a cache hit, as well as
for the subsequently created operation
I'm still investigating a leak (#2105), and I suspect it's coming from
us creating and storing completion blocks, and those staying in memory
beyond the lifetime of the operation.
This refactor and performance improvement helps us avoid get more things
in memory than we need to.
See #2138 for how this is tested.
We don't actually need to share a single queue to synchronize all the callback caches.
This new implementation also avoids using the risky `DispatchQueue.sync`.
This also fixes potential issues because `cachedCallbacksByKey` was exposed, and it could have been read without synchronizing access with the queue. This is now impossible.
Extract out various dependencies that are required to instantiate the `Backend` object.
Refactor to assist with the next few PRs that extract out other pieces
See [CSDK-82]
Resolves [CSDK-155]
Will Taylor