[Electric-Coin-Company#1179] Handle false positive getSubtreeRoots wh…

…en connectivity is down

- when getSubtreeRoots call fails on timeout, the connectivity is not present and the action must be terminated (throw) an error, this way when the connectivity is back, the State Machine starts over and getSubtreeRoots get a chance to properly decide if SBS is supported

[Electric-Coin-Company#1179] Handle false positive getSubtreeRoots when connectivity is down

- unit test for the timeout getSubtreeRoot added

[Electric-Coin-Company#1179] Handle false positive getSubtreeRoots when connectivity is down (Electric-Coin-Company#1222)

- warning fixed

Sources/ZcashLightClientKit/Block/Actions/UpdateSubtreeRootsAction.swift

@@ -39,6 +39,8 @@ extension UpdateSubtreeRootsAction: Action {
             for try await subtreeRoot in stream {
                 roots.append(subtreeRoot)
             }
+        } catch ZcashError.serviceSubtreeRootsStreamFailed(LightWalletServiceError.timeOut) {
+            throw ZcashError.serviceSubtreeRootsStreamFailed(LightWalletServiceError.timeOut)
         } catch {
             logger.debug("getSubtreeRoots failed with error \(error.localizedDescription)")
             err = error

Tests/OfflineTests/CompactBlockProcessorActions/UpdateSubtreeRootsActionTests.swift

@@ -68,6 +68,36 @@ final class UpdateSubtreeRootsActionTests: ZcashTestCase {
         }
     }
 
+    func testUpdateSubtreeRootsAction_getSubtreeRootsTimeout() async throws {
+        let loggerMock = LoggerMock()
+
+        loggerMock.infoFileFunctionLineClosure = { _, _, _, _ in  }
+
+        let tupple = setupAction(loggerMock)
+        let updateSubtreeRootsActionAction = tupple.action
+        tupple.serviceMock.getSubtreeRootsClosure = { _ in
+            AsyncThrowingStream { continuation in continuation.finish(throwing: ZcashError.serviceSubtreeRootsStreamFailed(LightWalletServiceError.timeOut)) }
+        }
+
+        do {
+            let context = ActionContextMock.default()
+            context.updateSupportedSyncAlgorithmClosure = { _ in }
+
+            _ = try await updateSubtreeRootsActionAction.run(with: context) { _ in }
+            XCTFail("The test is expected to fail but continued.")
+        } catch ZcashError.serviceSubtreeRootsStreamFailed(LightWalletServiceError.timeOut) {
+            // this is expected, the action must be terminated as there is no connectivity
+        } catch {
+            XCTFail(
+                """
+                testUpdateSubtreeRootsAction_getSubtreeRootsTimeout is expected to fail with
+                ZcashError.serviceSubtreeRootsStreamFailed(LightWalletServiceError.timeOut)
+                but received \(error)".
+                """
+            )
+        }
+    }
+
     func testUpdateSubtreeRootsAction_getSubtreeRootsEmpty() async throws {
         let loggerMock = LoggerMock()