Thanks to @aboedo for the suggestion.
### Changes
- Moved signature verification files and tests to new `Security` folder
- Moved `CacheFetchPolicy` inside `Caching`
- Split files inside `Misc` into subfolders
### 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.
See also #2135.
I'm looking into the leak in #2105, and I have a theory that it's due to
callbacks being stored in this cache, but sometimes not being dequeued,
so leaking all references in them.
This assertion will only run in RC tests, and will ensure that this
doesn't happen.
Fixes [CSDK-419].
This is an improvement over the fix in #1292. In there, we avoided
appending on an existing `CustomerInfoOperation` if there were any
`PostReceiptDataOperation`s in progress, because those might come back
with outdated entitlements.
This fix removes that cache key hack, and instead *reuses* the entire
response to that `PostReceiptDataOperation` by "stealing" that request's
cache key.
This is perfectly captured by the existing test
`BackendPostReceiptDataTests.testGetsUpdatedSubscriberInfoAfterPost`,
added in #1292. Amazingly enough, that test still passes with one minor
change: the entire process requires one fewer API call 🎉🐼
[CSDK-419]:
https://revenuecats.atlassian.net/browse/CSDK-419?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
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.
Closes#695 and finishes [CF-195].
Depends on ~~#1431, #1432, #1433, #1437~~.
## Goals:
- [x] Handle all requests / response / deserialization errors in `HTTPClient`. Clients of `HTTPClient` will only have to handle the "happy" path: #1431
- [x] `HTTPClient` shouldn't return `Result.success` with failed responses, forcing clients to verify the response is actually a failure: https://github.com/RevenueCat/purchases-ios/pull/1431
- [x] Abstract error response deserialization / error creation: #1427
- [x] Abstract attribute error parsing: #1427
- [x] Move response deserialization to `HTTPClient` based on a `ResponseType: Decodable` type, so the completion block will simply return a `Result<HTTPResponse<ResponseType>, Error>`
- [x] `ETagManager` should store response `Data` instead of a deserialized `[String: Any]`
- [x] Improved error types in `HTTPClient` to fix tests: #1437
- [x] Dealt with non-backwards compatible `ETagManager: #1438
## Changes:
- Replaced `HTTPResponse`'s body from `[String: Any]` to a generic `HTTPResponseBody`.
- Created `HTTPResponseBody` to abstract `Decodable` and provide some default implementations for types like `Data,` `[String: Any]` (for backwards compatibility to types that aren't `Decodable` yet), and `Decodable` itself.
- New `HTTPResponse.Result` typealias (`Result<HTTPResponse<HTTPResponseBody>, Error>`) used everywhere. This will allow replacing `Error` with a more specific `Error` so we can forward known typed errors, and make sure that we don't end up with the wrong error type, or with a very complex error hierarchy and the details buried in `underlyingError`.
- Each layer (only a few for now) has its own error type: `NetworkError`, `BackendError`, `OfferingsManager.Error`.
- `HTTPClient` for example has to produce `NetworkError`, operations produce `BackendError`
- The parent `BackendError` can have specific errors like `.missingAppUserID`, but also be simply a child error `case networkError(NetworkError)`
- All of these conform to a `ErrorCodeConvertible`, so there is a single point of code that converts from simple and readable errors (like `BackendError.emptySubscriberAttributes`, `.unexpectedBackendResponse(.loginResponseDecoding)`) into errors with all the context using `ErrorUtils`
- Converted `DNSError` into `NetworkError.dnsError`. Its functionality remains unchanged.
- Removed `Backend.RCSuccessfullySyncedKey` and `ErrorDetails.finishableKey` in favor of tested properties on `NetworkError`
### Leftovers
There's a few things I've decided to not finish for now:
- [ ] `CustomerInfo` still does't conform to `Decodable` (manual deserialization is still supported by the current system): #1496
- `SubscriberAttributeDict` could also be `Codable`
- [x] Replace `OfferingsFactory` with `Decodable`: #1435
[CF-195]: https://revenuecats.atlassian.net/browse/CF-195?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
