flowcoordinator: navigate on main thread

Author: twittemb

CHANGELOG.md

@@ -1,3 +1,7 @@
+** Version 2.12.2 **:
+
+- ensure the navigate function is called on the main thread (regression introduced in 2.12.1)
+
 ** Version 2.12.1 **:
 
 - fix a possible memory leak when the Coordinator's lifecycle was unexpectedly longer than the flow ones (thanks to @asiliuk)

RxFlow.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name = "RxFlow"
-  s.version = "2.12.1"
+  s.version = "2.12.2"
   s.swift_version = '5.3'
   s.summary = "RxFlow is a navigation framework for iOS applications, based on a Reactive Coordinator pattern."
 

RxFlow.xcodeproj/project.pbxproj

@@ -604,7 +604,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.12.1;
+				MARKETING_VERSION = 2.12.2;
 				PRODUCT_BUNDLE_IDENTIFIER = io.warpfactor.RxFlow;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
@@ -639,7 +639,7 @@
 					"@executable_path/Frameworks",
 					"@loader_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.12.1;
+				MARKETING_VERSION = 2.12.2;
 				PRODUCT_BUNDLE_IDENTIFIER = io.warpfactor.RxFlow;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				PROVISIONING_PROFILE_SPECIFIER = "";

RxFlow/FlowCoordinator.swift

@@ -50,7 +50,8 @@ public final class FlowCoordinator: NSObject {
                 self?.childFlowCoordinators.removeAll()
                 self?.parentFlowCoordinator?.childFlowCoordinators.removeValue(forKey: self?.identifier ?? "")
             })
-            .flatMapLatest { flow.adapt(step: $0) }
+            .asSignal(onErrorJustReturn: NoneStep())
+            .flatMapLatest { flow.adapt(step: $0).asSignal(onErrorJustReturn: NoneStep()) }
             .do(onNext: { [weak self] in self?.willNavigateRelay.accept((flow, $0)) })
             .map { return (flowContributors: flow.navigate(to: $0), step: $0) }
             .do(onNext: { [weak self] in self?.didNavigateRelay.accept((flow, $0.step)) })
@@ -77,8 +78,9 @@ public final class FlowCoordinator: NSObject {
             .do(onNext: { [weak self] presentableAndSteppers in
                 self?.setReadiness(for: flow, basedOn: presentableAndSteppers.map { $0.presentable })
             })
-            // transforms a FlowContributors in a sequence of individual FlowContributor
+
             .flatMap { Signal.from($0) }
+            // transforms a FlowContributors in a sequence of individual FlowContributor
             // the FlowContributor is related to a new Flow, we coordinate this new Flow
             .do(onNext: { [weak self] presentableAndStepper in
                 if let childFlow = presentableAndStepper.presentable as? Flow {
@@ -96,6 +98,7 @@ public final class FlowCoordinator: NSObject {
             .flatMap { [weak self] in
                 self?.steps(from: $0, within: flow, allowStepWhenDismissed: allowStepWhenDismissed) ?? Signal.empty()
             }
+            .asObservable()
             .take(until: allowStepWhenDismissed ? .empty() : flow.rxDismissed.asObservable())
             .asSignal(onErrorJustReturn: NoneStep())
             .emit(to: self.stepsRelay)

RxFlowTests/FlowCoordinatorTests.swift

@@ -8,6 +8,7 @@
 
 #if canImport(UIKit)
 
+import Dispatch
 @testable import RxFlow
 import XCTest
 import RxBlocking
@@ -367,6 +368,51 @@ final class FlowCoordinatorTests: XCTestCase {
 
         XCTAssertNil(leakingFlowReference)
     }
+
+    func testNavigate_executes_on_mainThread() {
+        class ThreadRecorderFlow: Flow {
+            let rootViewController = UINavigationController()
+            var root: Presentable {
+                return rootViewController
+            }
+
+            var recordedThreadName: String?
+
+            func adapt(step: Step) -> Single<Step> {
+                return Single.just(step).observe(on: SerialDispatchQueueScheduler(internalSerialQueueName: UUID().uuidString))
+            }
+
+            func navigate(to step: Step) -> FlowContributors {
+                self.recordedThreadName = DispatchQueue.currentLabel
+                return .none
+            }
+        }
+
+        let exp = expectation(description: "Navigates on main thread")
+
+        // Given: a Flow that records its navigation thread (and adapt on a background thread)
+        let recorderFlow = ThreadRecorderFlow()
+        let sut = FlowCoordinator()
+
+        Flows.use(recorderFlow, when: .ready) { (_) in
+            exp.fulfill()
+        }
+
+        // When: coordinating that flow
+        sut.coordinate(flow: recorderFlow,
+                       with: OneStepper(withSingleStep: TestSteps.one))
+
+        waitForExpectations(timeout: 0.5)
+
+        // Then: the flow navigates on the main thread
+        XCTAssertEqual(recorderFlow.recordedThreadName, "com.apple.main-thread")
+    }
+}
+
+extension DispatchQueue {
+    class var currentLabel: String {
+        return String(validatingUTF8: __dispatch_queue_get_label(nil))!
+    }
 }
 
 #endif

xcarthage-archive.sh

@@ -0,0 +1,19 @@
+# carthage-update.sh
+# Usage example: ./carthage-archive.sh
+
+set -euo pipefail
+
+xcconfig=$(mktemp /tmp/static.xcconfig.XXXXXX)
+trap 'rm -f "$xcconfig"' INT TERM HUP EXIT
+
+# For Xcode 12 make sure EXCLUDED_ARCHS is set to arm architectures otherwise
+# the build will fail on lipo due to duplicate architectures.
+
+CURRENT_XCODE_VERSION=$(xcodebuild -version | grep "Build version" | cut -d' ' -f3)
+echo "EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_simulator__NATIVE_ARCH_64_BIT_x86_64__XCODE_1200__BUILD_$CURRENT_XCODE_VERSION = arm64 arm64e armv7 armv7s armv6 armv8" >> $xcconfig
+
+echo 'EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_simulator__NATIVE_ARCH_64_BIT_x86_64__XCODE_1200 = $(EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_simulator__NATIVE_ARCH_64_BIT_x86_64__XCODE_1200__BUILD_$(XCODE_PRODUCT_BUILD_VERSION))' >> $xcconfig
+echo 'EXCLUDED_ARCHS = $(inherited) $(EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_$(EFFECTIVE_PLATFORM_SUFFIX)__NATIVE_ARCH_64_BIT_$(NATIVE_ARCH_64_BIT)__XCODE_$(XCODE_VERSION_MAJOR))' >> $xcconfig
+
+export XCODE_XCCONFIG_FILE="$xcconfig"
+carthage build --archive

xcarthage-bootstrap.sh

@@ -16,4 +16,4 @@ echo 'EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_simulator__NATIVE_ARCH_64_BIT_x8
 echo 'EXCLUDED_ARCHS = $(inherited) $(EXCLUDED_ARCHS__EFFECTIVE_PLATFORM_SUFFIX_$(EFFECTIVE_PLATFORM_SUFFIX)__NATIVE_ARCH_64_BIT_$(NATIVE_ARCH_64_BIT)__XCODE_$(XCODE_VERSION_MAJOR))' >> $xcconfig
 
 export XCODE_XCCONFIG_FILE="$xcconfig"
-carthage bootstrap "$@"
+carthage bootstrap "$@" --cache-builds