implements new Storage API for handleEventsForBackgroundURLSession

[brennanMKE]

Issue #, if available:

N/A

Description of changes:

Check points: (check or cross out if not relevant)

• Added new tests to cover change, if needed
• Build succeeds with all target using Swift Package Manager
• All unit tests pass
• All integration tests pass
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[royjit]

This notification was setup just for unit test? Looks like this will be fired in the production app as well. We should think about a better way to make this class testable?

[brennanMKE]

What other options do you suggest?

[royjit]

The test worked without the notification expectation:

    func testRegisteringAndUnregister() async throws {
        let identifier = UUID().uuidString
        let otherIdentifier = UUID().uuidString
        await StorageBackgroundEventsRegistry.shared.register(identifier: identifier)

        let done = asyncExpectation(description: "done")
        Task {
            let handled = await StorageBackgroundEventsRegistry.shared.handleEventsForBackgroundURLSession(identifier: identifier)
            await done.fulfill()
            XCTAssertTrue(handled)
        }

        let didContinue = await handleEvents(for: identifier)
        XCTAssertTrue(didContinue)
        await waitForExpectations([done])

        let otherDone = asyncExpectation(description: "other done")

        Task {
            let otherHandled = await StorageBackgroundEventsRegistry.shared.handleEventsForBackgroundURLSession(identifier: otherIdentifier)
            await otherDone.fulfill()
            XCTAssertFalse(otherHandled)
        }

        let didNotContinue = await handleEvents(for: otherIdentifier)
        XCTAssertFalse(didNotContinue)
        await waitForExpectations([otherDone])
    }

[brennanMKE]

You have to run it on macOS many times repeatedly to get it to fail. Without the notification it is a flaky test which will fail based on timing.

[royjit]

This issue can then happen in the real app as well right? What if the URLSession call back reach before we setup the continuation?

[royjit]

Another option could be to create an overloaded function just for test:

    func handleEventsForBackgroundURLSession(identifier: String) async -> Bool {
        return await handleEventsForBackgroundURLSession(identifier: identifier, notifyTest: nil)
    }

    func handleEventsForBackgroundURLSession(identifier: String, notifyTest: ((String) -> Void)? ) async -> Bool {
        guard self.identifier == identifier else { return false }
        return await withCheckedContinuation { (continuation: CheckedContinuation<Bool, Never>) in
            self.continuation = continuation
            if let notifyTest = notifyTest {
                notifyTest(identifier)
            }
        }
    }

[akshaaatt]

When can we expect this to be released?