### Purpose:
This is a prerequisite for #2288. The new grace period means that if we
didn't update the date from the cached responses, entitlements would
become stale and expired after 3 days.
### Changes:
- Added `HTTPResponseBody.copy(with newRequestDate:)` to be able to
modify responses from the header request date
- `CustomerInfo` implements this method to modify its request date
- Added `HTTPResponse.requestDate` to be able to keep track of the
request date from the server
- Added `VerificationResult.from(cache:response:)` to determine the most
restrictive verification result based on what's cached or checked from a
response
- Added `HTTPResponse.copy(with:)` to modify the verification result of
a response using the previous method
- `HTTPClient` now uses the most restrictive verification result
- `HTTPClient` updates request date from server responses or cached
responses (unless verification failed). This was the missing piece for
#2288.
### Tests:
- Verify that `ETagManager` does not use an ETag if verification was
previously not enabled
- Verify that `ETagManager` returns the request date from the server
when returning a cached response
- Verify that `HTTPClient` updates the request date from the server or
from a cached response
- Verify that `HTTPClient` does not update request date if verification
failed
- Tests for `HTTPResponse` request date parsing
- Test for `CustomerInfoResponseHandler` updating request date
- Tests for `CustomerInfo.copy(with newRequestDate:)`
### Other smaller changes:
- Moved `CustomerInfo.asData()` into `Encodable.asJSONEncodedData()`
- Renamed `requestTime` to `requestDate` everywhere for consistency
Fixes [CSDK-629].
Depends on #2274 and #2267.
Entitlement verification is accomplished by preventing MiTM attacks
between the SDK and the RevenueCat server.
With verification enabled, the SDK ensures that the response created by
the server was not modified by a third-party, and the entitlements
received are exactly what was sent.
Entitlements are only verified if enabled using
`Configuration.Builder.with(entitlementVerificationMode:)`, which is
disabled by default.
### Changes:
- Added new `VerificationResult`, which replaces
`HTTPResponseVerificationResult`
- Renamed `Configuration.EntitlementVerificationLevel` to
`Configuration.EntitlementVerificationMode`
- `Configuration.with(entitlementVerificationMode:)` is now `public`
- Added `CustomerInfo.entitlementVerification`
- Added `EntitlementInfos.verification` and
`EntitlementInfo.verification`
- Added tests to cover serialization of these new values
- `CustomerInfoResponseHandler` copies the `ValidationResult` to
`CustomerInfo` (all operations that fetch `CustomerInfo` use this)
- Renamed "validation" to "verification" everywhere for consistency
- Finalized documentation
### TODO:
- [x] Figure out whether to use a separate type from
`HTTPResponseValidationResult` or rename that one
- [x] Figure out final API type and property names
- [x] Add tests for `CustomerInfo.copy(with:)`
- [x] Ensure validation result is encoded and decoded (for caching)
- [x] Add missing snapshots
[CSDK-629]:
https://revenuecats.atlassian.net/browse/CSDK-629?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
Fixes [CSDK-634].
## Changes:
- Created `HTTPResponseValidationResult`
- Added `HTTPResponseValidationResult` and `HTTPClient.ResponseHeaders`
to `HTTPResponse`
- Added new `ErrorCode.signatureVerificationFailed`
- Extracted `SigningType` to create `MockSigning` to test `HTTPClient`
without bothering with signatures
- Refactored `ETagManager` to use `HTTPResponse`, making it easier to
pass through response headers and verification results
- Stored `HTTPResponseValidationResult` in `ETagManager` cache
- `HTTPClient` handles signatures from response based on
`SystemInfo.responseVerificationLevel`
- Renamed `HTTPRequest.createIntegrityEnforcedRequestRequest` to
`HTTPRequest.createWithResponseVerification`
- Added lots of tests for this new behavior in `HTTPClient`
- Added lots of new tests for `ETagManager`
[CSDK-634]:
https://revenuecats.atlassian.net/browse/CSDK-634?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
This is the last change from what was started with #1437. That PR introduced a few private error types, but for the errors returned in the public `APIs` we were still passing around `Error`s everywhere, which didn't provide any compile-time guarantees.
### Goals:
- Ensure that public APIs *only* return `ErrorCode`s wrapped with the additional `userInfo`, and not accidentally return other types like `SKError`, `BackendError`, `ErrorCode` directly, etc.
- Guarantee type-safety when passing errors around within our internal implementations instead of assuming certain thrown errors are of a particular type.
### Changes:
- Created `PurchasesError` for wrapping an `ErrorCode` with the additional `userInfo`.
- Changed returned errors from `Error` to `NSError`. This is a change in the API, but the new type is a more specific `Error` so it shouldn't lead to any changes in client apps.
- Because `PurchasesError` isn't implicitly convertible to `NSError`, this ensures that we don't return those values directly, and instead use `PurchasesError.asPublicError`.
- Changed `ErrorCodeConvertible` to a now more precise `PurchasesErrorConvertible`.
Thanks to this new type-safety this PR fixes at least 3 bugs where we were returning private errors instead of `ErrorCode`s.
### Testing:
Thanks to #1871 we know that the returned errors are still convertible to `ErrorCode` so users can `switch` over them.
Follow up to #1776. That PR added a lot of tests to cover error logging, and #1778 introduced a small error that wasn't covered: if attribute errors are empty, the `localizedDescription` could end up becoming `"[:]"`. This fixes that.
## Examples:
This was the underlying error returned (the output of `error.localizedDescription`):
#### Before:
> [:]
#### After:
> There was a credentials issue. Check the underlying error for more details.
And this is what was logged (notice that I also fixed `ErrorCode.invalidCredentialsError` to not log as an "Apple Error"):
#### Before:
> 🍎‼️There was a credentials issue. Check the underlying error for more details. [:]
#### After:
> 😿‼️ There was a credentials issue. Check the underlying error for more details.