feat: Add double-open bug demonstration and fix toggle (EMT-2816) by wpinho-branch · Pull Request #14 · BranchMetrics/BranchLinkSimulator

wpinho-branch · 2026-01-20T21:25:58Z

Summary

This PR adds a demonstration and testing capability for the double-open bug fix (EMT-2816 / INTENG-21106) in scene-based iOS apps using Branch SDK.

The Bug

When a scene-based iOS app is cold-launched via a deep link, the OLD API pattern causes 2 OPEN requests to be sent instead of 1:

First OPEN from Branch.initSession(launchOptions: nil)
Second OPEN from scene(_:continue:) handling the Universal Link

The Fix

The NEW API (BranchScene.initSession(with: connectionOptions)) handles both initialization and deep link in a single call, sending only 1 OPEN request.

Changes

Core Implementation

SceneDelegate.swift: Implements toggle between OLD (buggy) and NEW (fixed) API modes
AppDelegate.swift: Enhanced logging and URLProtocol interceptor registration
BranchNetworkInterceptor.swift: Captures all Branch SDK network requests for debugging
RoundTripStore.swift: Improved OPEN request detection logic
HomeView.swift: UI section for EMT-2816 demo with toggle and request counter

App Architecture

BranchLinkSimulatorApp.swift: Changed to use UIApplicationMain to ensure SceneDelegate is properly invoked

E2E Tests

DoubleOpenBugUITests.swift: 15 UI tests covering toggle functionality, logs navigation, accessibility, and persistence

Test Plan

Prerequisites

Build and run the app on iOS Simulator (iPhone 16 Pro recommended)
Ensure the app is fully terminated before testing cold launch scenarios

Manual Testing: Reproducing the Bug (OLD API)

Launch the app and scroll to "EMT-2816: Double-Open Test" section
Disable the toggle "Use EMT-2816 Fix" (toggle OFF)
Tap "Clear All Logs" to reset the counter
Terminate the app completely (swipe up from app switcher)

Cold launch via Universal Link:

xcrun simctl openurl booted "https://branchlinksimulator.app.link/test"

Expected Result:
- OPEN Request counter shows 2 (RED)
- "DOUBLE-OPEN BUG DETECTED!" warning appears

Manual Testing: Verifying the Fix (NEW API)

Launch the app and scroll to "EMT-2816: Double-Open Test" section
Enable the toggle "Use EMT-2816 Fix" (toggle ON)
Tap "Clear All Logs" to reset the counter
Terminate the app completely (swipe up from app switcher)

Cold launch via Universal Link:

xcrun simctl openurl booted "https://branchlinksimulator.app.link/test"

Expected Result:
- OPEN Request counter shows 1 (GREEN)
- "Single OPEN - Working correctly!" message appears

Running E2E Tests

xcodebuild test \
  -project BranchLinkSimulator.xcodeproj \
  -scheme BranchLinkSimulatorUITests \
  -destination "platform=iOS Simulator,name=iPhone 16 Pro" \
  -only-testing:BranchLinkSimulatorUITests/DoubleOpenBugUITests

Expected: All 15 tests pass

Test Cases Covered

Test	Description
`testToggleExists`	Verify toggle is present in UI
`testToggleFunctionality`	Toggle changes state correctly
`testAPIModePersisters`	Toggle state persists across app restarts
`testModeDescriptionUpdates`	API description text updates with toggle
`testStatusIndicatorStates`	Status indicator reflects toggle state
`testOpenRequestCounterVisible`	OPEN counter is visible
`testViewLogsNavigation`	Navigate to logs screen
`testLogsScreenTabs`	Logs screen has correct tabs
`testClearLogs`	Clear logs button works
`testAllSectionsVisible`	All UI sections render correctly
`testAccessibilityElements`	Accessibility identifiers are set
`testAppLaunchPerformance`	App launch performance baseline
`testNavigateToLogsPerformance`	Navigation performance baseline
`testNewAPIColdLaunchDocumentation`	Documents NEW API behavior
`testOldAPIColdLaunchDocumentation`	Documents OLD API behavior

API Comparison

Aspect	OLD API (Bug)	NEW API (Fix)
Method	`Branch.initSession(launchOptions: nil)`	`BranchScene.initSession(with: connectionOptions)`
OPEN Requests	2	1
Deep Link Handling	Separate in `scene(_:continue:)`	Unified in single call

Implement testing UI for the double-open SDK fix: - Add SceneDelegate with toggle between old/new Branch init APIs - Add toggle in HomeView to switch between APIs (requires app restart) - Add OPEN request counter to track /v1/open and /v2/event(open) calls - Add LogsView with Timeline and OPEN Requests tabs for log visualization - Update RoundTrip model with isOpenRequest tracking - Update RoundTripStore with log entries and OPEN detection - Update Info.plist with UIApplicationSceneManifest configuration - Update BranchLinkSimulatorApp.swift for Scene lifecycle The toggle allows comparing behavior: - OLD API: Branch.initSession(launchOptions:) - may cause double OPEN - NEW API: BranchScene.initSession(with:) - prevents double OPEN Expected results when testing: - With OLD API: 2 OPEN requests on cold launch via deep link - With NEW API: 1 OPEN request on cold launch via deep link

Add more detailed logs with visual separators to make it clear: - When COLD LAUNCH happens (app was killed) - When WARM LAUNCH happens (app was in background) - Which API is being used (OLD vs NEW) - What is expected (1 vs 2 OPEN requests) - Branch callback results

Changes: - OLD API now uses Branch.handleDeepLink() instead of BranchScene methods - Cold launch with OLD API processes URL from connectionOptions manually, triggering a second OPEN request (demonstrating the bug) - NEW API skips manual URL processing since BranchScene.initSession already handles the URL internally (demonstrating the fix) Expected behavior: - OLD API (toggle OFF): 2 OPEN requests on cold launch via deep link - NEW API (toggle ON): 1 OPEN request on cold launch via deep link

Changes: - OLD API now uses Branch.application(_:open:options:) for URL schemes (the actual AppDelegate method that would cause double-open) - OLD API now uses Branch.continue(userActivity) for Universal Links - Clear step-by-step logging showing: - Step 1: initSession(launchOptions: nil) → OPEN #1 - Step 2: application(_:open:) → OPEN #2 (bug) - NEW API uses BranchScene.initSession(with:) which handles everything in a single OPEN request

Create basic Info.plist configuration for the BranchLinkSimulatorUITests target with standard bundle settings.

Add comprehensive UI test suite for verifying the double-open bug fix in scene-based iOS apps with Branch SDK. Test coverage: - testToggleExists: Verify toggle accessibility identifier - testToggleFunctionality: Test toggle state changes - testModeDescriptionUpdates: Verify API mode description updates - testViewLogsNavigation: Test navigation to logs screen - testLogsScreenTabs: Verify segmented picker tabs - testOpenRequestCounterVisible: Check OPEN request counter visibility - testClearLogs: Test clear logs functionality - testAllSectionsVisible: Verify main sections render - testAPIModePersisters: Test toggle persistence across restarts - testAccessibilityElements: Verify UI accessibility - testStatusIndicatorStates: Test status indicator text - testOldAPIColdLaunchDocumentation: Document OLD API behavior - testNewAPIColdLaunchDocumentation: Document NEW API behavior - testAppLaunchPerformance: Measure app launch time - testNavigateToLogsPerformance: Measure logs navigation Key implementation details: - Uses coordinate-based tap (dx: 0.9, dy: 0.5) for reliable SwiftUI toggle - Handles both IDFA permission and Branch SDK error alerts - Properly detects SwiftUI SegmentedPickerStyle via segmentedControls - Flexible element detection with multiple fallback checks

Configure BranchLinkSimulatorUITests target in Xcode project: - Add PBXContainerItemProxy for test dependency - Add file references for test sources and Info.plist - Configure build phases (Sources, Frameworks, Resources) - Add target dependency on BranchLinkSimulator app - Configure test host and bundle identifier settings

- Add case-insensitive matching for URL and body patterns - Detect BranchOpenRequest from SDK log messages - Handle api.branch.io URLs with open in either URL or body - Improves reliability of double-open bug detection

…h requests - Intercept all Branch SDK network requests via URLProtocol - Capture and log OPEN requests to RoundTripStore - Track request/response details for debugging - Support all Branch API domains (api.branch.io, api2.branch.io, etc.)

- Register BranchNetworkInterceptor to capture all Branch requests - Parse SDK log messages to detect OPEN requests - Log OPEN request detections to RoundTripStore - Ensure SceneDelegate is used via explicit delegateClass

- Add NEW API mode: BranchScene.initSession(with: connectionOptions) Sends only 1 OPEN request (EMT-2816 fix) - Add OLD API mode: Branch.initSession(launchOptions: nil) Demonstrates the double-open bug (2 OPEN requests) - Add debug logging to file for cold launch analysis - Log connectionOptions.urlContexts and userActivities - Support toggle via @AppStorage("useDoubleOpenFix")

@main

…gate - Replace SwiftUI @main with UIApplicationMain - Ensure SceneDelegate is properly invoked for window/scene management - Required for proper Branch SDK integration with connectionOptions

- Rename section to "EMT-2816: Double-Open Test" - Add accessibility identifiers for E2E testing - Display API mode descriptions (NEW/OLD API) - Add status indicators (fix enabled vs bug mode) - Show visual feedback for double-open bug detection - Add clear logs button for testing workflow

- Package resolution managed by SPM, no need to track

- BranchLinkSimulator.xcscheme - Main app scheme - BranchLinkSimulatorTests.xcscheme - Unit tests scheme - BranchLinkSimulatorUITests.xcscheme - UI tests scheme for E2E testing

- Automated test script for EMT-2816 / INTENG-21106 - Tests both OLD API (bug) and NEW API (fix) scenarios - Cold launch via Universal Link simulation - Validates OPEN request count for each API mode

- Package.resolved with Branch SDK dependency - Points to fix/EMT-2816-double-open-issue_without-fix branch

wpinho-branch added 19 commits January 15, 2026 18:06

chore(UITests): add Info.plist for UITests target

590815b

Create basic Info.plist configuration for the BranchLinkSimulatorUITests target with standard bundle settings.

fix(RoundTripStore): improve OPEN request detection logic

bd42e11

- Add case-insensitive matching for URL and body patterns - Detect BranchOpenRequest from SDK log messages - Handle api.branch.io URLs with open in either URL or body - Improves reliability of double-open bug detection

refactor(BranchLinkSimulatorApp): use UIApplicationMain for SceneDele…

f8b0b52

…gate - Replace SwiftUI @main with UIApplicationMain - Ensure SceneDelegate is properly invoked for window/scene management - Required for proper Branch SDK integration with connectionOptions

chore: remove Package.resolved

c5909e9

- Package resolution managed by SPM, no need to track

build(Xcode): add shared schemes for app and tests

144ebea

- BranchLinkSimulator.xcscheme - Main app scheme - BranchLinkSimulatorTests.xcscheme - Unit tests scheme - BranchLinkSimulatorUITests.xcscheme - UI tests scheme for E2E testing

test(scripts): add double-open bug test script

c0ace3d

- Automated test script for EMT-2816 / INTENG-21106 - Tests both OLD API (bug) and NEW API (fix) scenarios - Cold launch via Universal Link simulation - Validates OPEN request count for each API mode

build(SPM): add shared Swift Package Manager configuration

e3efdb9

- Package.resolved with Branch SDK dependency - Points to fix/EMT-2816-double-open-issue_without-fix branch

update script

ca4c9cc

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat: Add double-open bug demonstration and fix toggle (EMT-2816)#14

feat: Add double-open bug demonstration and fix toggle (EMT-2816)#14
wpinho-branch wants to merge 19 commits intomainfrom
feature/double-open-sdk-test

wpinho-branch commented Jan 20, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

wpinho-branch commented Jan 20, 2026

Summary

The Bug

The Fix

Changes

Core Implementation

App Architecture

E2E Tests

Test Plan

Prerequisites

Manual Testing: Reproducing the Bug (OLD API)

Manual Testing: Verifying the Fix (NEW API)

Running E2E Tests

Test Cases Covered

API Comparison

Related

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant