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Improved Defer Fulfillment (#5127)

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* improved defer fullfillment

* applied also for async streams

* fix xcodeproject

* better documentation

* restict deferFulfillment  only for Publisher which can never fail
This commit is contained in:
Mauro
2026-02-20 18:21:35 +01:00
committed by GitHub
parent 5e5fb19f42
commit fda19a0273
4 changed files with 149 additions and 117 deletions
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4
ElementX.xcodeproj/project.pbxproj
View File

@@ -823,6 +823,7 @@
8DF0EBD97753033C715D716E /* RoomFlowCoordinatorStateMachine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 407C8DD85179D2DB896FC0FA /* RoomFlowCoordinatorStateMachine.swift */; };
8E650379587C31D7912ED67B /* UNNotification+Creator.swift in Sources */ = {isa = PBXBuildFile; fileRef = DC0AEA686E425F86F6BA0404 /* UNNotification+Creator.swift */; };
8E7A902CA16E24928F83646C /* ElementCallServiceMock.swift in Sources */ = {isa = PBXBuildFile; fileRef = E321E840DCC63790049984F4 /* ElementCallServiceMock.swift */; };
8ECD4727BA96EF64DFCEC18F /* DeferredFulfillment.swift in Sources */ = {isa = PBXBuildFile; fileRef = C39E32F0B876B962E418B5C2 /* DeferredFulfillment.swift */; };
8ED8AF57A06F5EE9978ED23F /* AuthenticationStartScreenViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8FB89DC7F9A4A91020037001 /* AuthenticationStartScreenViewModelTests.swift */; };
8F2FAA98457750D9D664136F /* LRUCache in Frameworks */ = {isa = PBXBuildFile; productRef = 1081D3630AAD3ACEDDEC3A98 /* LRUCache */; };
8F3AD08F2E706AA60F1A1D4D /* portrait_test_image.jpg in Resources */ = {isa = PBXBuildFile; fileRef = BC51BF90469412ABDE658CDD /* portrait_test_image.jpg */; };
@@ -1413,7 +1414,6 @@
F6F49E37272AD7397CD29A01 /* HomeScreenViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 505208F28007C0FEC14E1FF0 /* HomeScreenViewModelTests.swift */; };
F71C2B24AFB566119ACCDDA1 /* Secrets.swift in Sources */ = {isa = PBXBuildFile; fileRef = D3557ACB95D0F666EF5AF0CE /* Secrets.swift */; };
F7567DD6635434E8C563BF85 /* AnalyticsClientProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = E3B97591B2D3D4D67553506D /* AnalyticsClientProtocol.swift */; };
F769F921D7823C2F1CBB5047 /* DeferredFulfillment.swift in Sources */ = {isa = PBXBuildFile; fileRef = C39E32F0B876B962E418B5C2 /* DeferredFulfillment.swift */; };
F777C6FEE7D106136E2ED2B2 /* MessageForwardingScreenViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F6E6EDC4BBF962B2ED595A4 /* MessageForwardingScreenViewModelTests.swift */; };
F78BAD28482A467287A9A5A3 /* EventBasedMessageTimelineItemProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0900BBF0A5D5D775E917C70 /* EventBasedMessageTimelineItemProtocol.swift */; };
F7932A3F075B0D3F24DEECB5 /* VoiceMessagePreviewComposer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AE807361805463F5AEDD1CA /* VoiceMessagePreviewComposer.swift */; };
@@ -7623,6 +7623,7 @@
CD0088B763CD970CF1CBF8CB /* DateTests.swift in Sources */,
80F6C8EFCA4564B67F0D34B0 /* DeactivateAccountScreenViewModelTests.swift in Sources */,
34390DAE0C574DAD30CCA7D9 /* DeclineAndBlockScreenViewModelTests.swift in Sources */,
8ECD4727BA96EF64DFCEC18F /* DeferredFulfillment.swift in Sources */,
A583B70939707197B0B21DFC /* DeferredFulfillmentTests.swift in Sources */,
EDB6915EC953BB2A44AA608E /* EditRoomAddressScreenViewModelTests.swift in Sources */,
D820B3C223E4C2E77BB2A2BF /* ElementCallServiceTests.swift in Sources */,
@@ -8010,7 +8011,6 @@
0743CF689EBDAAF1CC0B4283 /* DeclineAndBlockScreenViewModel.swift in Sources */,
F7DA19B5122AD8FA8F91B753 /* DeclineAndBlockScreenViewModelProtocol.swift in Sources */,
EE8491AD81F47DF3C192497B /* DecorationTimelineItemProtocol.swift in Sources */,
F769F921D7823C2F1CBB5047 /* DeferredFulfillment.swift in Sources */,
5780E444F405AA1304E1C23E /* DeveloperOptionsScreen.swift in Sources */,
5DD85A0FE3D85AEC3C7EFE36 /* DeveloperOptionsScreenCoordinator.swift in Sources */,
6BAE34CFA9821709CFE61E50 /* DeveloperOptionsScreenHook.swift in Sources */,

260
ElementX/Sources/Other/DeferredFulfillment.swift
View File

@@ -7,6 +7,7 @@
//
import Combine
import Testing
struct DeferredFulfillment<T> {
let closure: () async throws -> T
@@ -18,225 +19,254 @@ struct DeferredFulfillment<T> {
}
struct DeferredFulfillmentError: Error {
enum Kind {
case noOutput
case unexpectedFulfillment
static func noOutput(message: String?, sourceLocation: SourceLocation) -> Self {
defer { Issue.record(Comment(rawValue: message ?? "No Output"), sourceLocation: sourceLocation) }
return .init()
}
let kind: Kind
let message: String?
static func noOutput(message: String?) -> Self {
.init(kind: .noOutput, message: message)
static func unexpectedFulfillment(message: String?, sourceLocation: SourceLocation) -> Self {
defer { Issue.record(Comment(rawValue: message ?? "Unexpected Fulfillment"), sourceLocation: sourceLocation) }
return .init()
}
static func unexpectedFulfillment(message: String?) -> Self {
.init(kind: .unexpectedFulfillment, message: message)
static var empty: Self {
.init()
}
}
/// Utility that assists in subscribing to a publisher and deferring the fulfilment and results until some other actions have been performed.
/// Test utility that assists in subscribing to a publisher and deferring the fulfilment and results until some other actions have been performed.
/// - Parameters:
/// - publisher: The publisher to wait on.
/// - timeout: A timeout after which we give up.
/// - message: An optional message to include in the error if the condition is never met.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - until: callback that evaluates outputs until some condition is reached
/// - Returns: The deferred fulfilment to be executed after some actions and that returns the result of the publisher.
func deferFulfillment<P: Publisher>(_ publisher: P,
timeout: Duration = .seconds(10),
message: String? = nil,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<P.Output> {
var result: Result<P.Output, Error>?
var hasFulfilled = false
func deferFulfillment<P: Publisher<P.Output, Never>>(_ publisher: P,
timeout: Duration = .seconds(10),
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<P.Output> {
let (stream, continuation) = AsyncStream<P.Output>.makeStream()
let cancellable = publisher
.sink { completion in
switch completion {
case .failure(let error):
result = .failure(error)
hasFulfilled = true
case .finished:
break
}
.sink { _ in
continuation.finish()
} receiveValue: { value in
if condition(value), !hasFulfilled {
result = .success(value)
hasFulfilled = true
}
guard condition(value) else { return }
continuation.yield(value)
continuation.finish()
}
return DeferredFulfillment<P.Output> {
let startTime = ContinuousClock.now
return DeferredFulfillment {
defer { cancellable.cancel() }
while !hasFulfilled {
await Task.yield()
if ContinuousClock.now - startTime >= timeout {
break
return try await withThrowingTaskGroup(of: P.Output.self) { group in
group.addTask {
for await result in stream {
return result
}
guard !Task.isCancelled else {
// Required to avoid a double recording of the issue in the case where the task is cancelled due to timeout.
throw DeferredFulfillmentError.empty
}
throw DeferredFulfillmentError.noOutput(message: message, sourceLocation: sourceLocation)
}
group.addTask {
try await Task.sleep(for: timeout)
throw DeferredFulfillmentError.noOutput(message: message, sourceLocation: sourceLocation)
}
defer { group.cancelAll() }
return try #require(try await group.next())
}
cancellable.cancel()
guard let unwrappedResult = result else {
throw DeferredFulfillmentError.noOutput(message: message)
}
return try unwrappedResult.get()
}
}
/// Utility that assists in observing an async sequence, deferring the fulfilment and results until some condition has been met.
/// Test utility that assists in observing an async sequence, deferring the fulfilment and results until some condition has been met.
/// - Parameters:
/// - asyncSequence: The sequence to wait on.
/// - timeout: A timeout after which we give up.
/// - message: An optional message to include in the error if the condition is never met.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - until: callback that evaluates outputs until some condition is reached
/// - Returns: The deferred fulfilment to be executed after some actions and that returns the result of the sequence.
func deferFulfillment<Value>(_ asyncSequence: any AsyncSequence<Value, Never>,
timeout: Duration = .seconds(10),
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation,
until condition: @escaping (Value) -> Bool) -> DeferredFulfillment<Value> {
var result: Result<Value, Error>?
var hasFulfilled = false
let (stream, continuation) = AsyncStream<Value>.makeStream()
let task = Task {
for await value in asyncSequence {
if condition(value), !hasFulfilled {
result = .success(value)
hasFulfilled = true
}
for await value in asyncSequence where condition(value) {
continuation.yield(value)
continuation.finish()
return
}
continuation.finish()
}
return DeferredFulfillment<Value> {
let startTime = ContinuousClock.now
return DeferredFulfillment {
defer { task.cancel() }
while !hasFulfilled {
await Task.yield()
if ContinuousClock.now - startTime >= timeout {
break
return try await withThrowingTaskGroup(of: Value.self) { group in
group.addTask {
for await value in stream {
return value
}
guard !Task.isCancelled else {
// Required to avoid a double recording of the issue in the case where the task is cancelled due to timeout.
throw DeferredFulfillmentError.empty
}
throw DeferredFulfillmentError.noOutput(message: message, sourceLocation: sourceLocation)
}
group.addTask {
try await Task.sleep(for: timeout)
throw DeferredFulfillmentError.noOutput(message: message, sourceLocation: sourceLocation)
}
defer { group.cancelAll() }
return try #require(try await group.next())
}
task.cancel()
guard let unwrappedResult = result else {
throw DeferredFulfillmentError.noOutput(message: message)
}
return try unwrappedResult.get()
}
}
/// Utility that assists in subscribing to a publisher and deferring the fulfilment and results until some other actions have been performed.
/// Test utility that assists in subscribing to a publisher and deferring the fulfilment and results until some other actions have been performed.
/// - Parameters:
/// - publisher: The publisher to wait on.
/// - keyPath: the key path for the expected values
/// - transitionValues: the values through which the keypath needs to transition through
/// - timeout: A timeout after which we give up.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - Returns: The deferred fulfilment to be executed after some actions and that returns the result of the publisher.
func deferFulfillment<P: Publisher, K: KeyPath<P.Output, V>, V: Equatable>(_ publisher: P,
keyPath: K,
transitionValues: [V],
timeout: Duration = .seconds(10)) -> DeferredFulfillment<P.Output> {
func deferFulfillment<P: Publisher<P.Output, Never>, K: KeyPath<P.Output, V>, V: Equatable>(_ publisher: P,
keyPath: K,
transitionValues: [V],
timeout: Duration = .seconds(10),
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation) -> DeferredFulfillment<P.Output> {
var expectedOrder = transitionValues
return deferFulfillment(publisher, timeout: timeout) { value in
return deferFulfillment(publisher, timeout: timeout, message: message, sourceLocation: sourceLocation) { value in
let receivedValue = value[keyPath: keyPath]
if let index = expectedOrder.firstIndex(where: { $0 == receivedValue }), index == 0 {
expectedOrder.remove(at: index)
}
return expectedOrder.isEmpty
}
}
/// Utility that assists in subscribing to an async sequence and deferring the fulfilment and results until some other actions have been performed.
/// Test utility that assists in subscribing to an async sequence and deferring the fulfilment and results until some other actions have been performed.
/// - Parameters:
/// - asyncSequence: The sequence to wait on.
/// - transitionValues: the values through which the sequence needs to transition through
/// - timeout: A timeout after which we give up.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - Returns: The deferred fulfilment to be executed after some actions and that returns the result of the sequence.
func deferFulfillment<Value: Equatable>(_ asyncSequence: any AsyncSequence<Value, Never>,
transitionValues: [Value],
timeout: Duration = .seconds(10)) -> DeferredFulfillment<Value> {
timeout: Duration = .seconds(10),
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation) -> DeferredFulfillment<Value> {
var expectedOrder = transitionValues
return deferFulfillment(asyncSequence, timeout: timeout) { value in
return deferFulfillment(asyncSequence, timeout: timeout, message: message, sourceLocation: sourceLocation) { value in
if let index = expectedOrder.firstIndex(where: { $0 == value }), index == 0 {
expectedOrder.remove(at: index)
}
return expectedOrder.isEmpty
}
}
/// Utility that assists in subscribing to a publisher and deferring the failure for a particular value until some other actions have been performed.
/// Test utility that assists in subscribing to a publisher and deferring the failure for a particular value until some other actions have been performed.
/// - Parameters:
/// - publisher: The publisher to wait on.
/// - timeout: A timeout after which we give up.
/// - message: An optional message to include in the error if the condition is unexpectedly met.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - until: callback that evaluates outputs until some condition is reached
/// - Returns: The deferred fulfilment to be executed after some actions. The publisher's result is not returned from this fulfilment.
func deferFailure<P: Publisher>(_ publisher: P,
timeout: Duration,
message: String? = nil,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<Void> where P.Failure == Never {
var hasFulfilled = false
func deferFailure<P: Publisher<P.Output, Never>>(_ publisher: P,
timeout: Duration,
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<Void> where P.Failure == Never {
let (stream, continuation) = AsyncStream<Void>.makeStream()
let cancellable = publisher
.sink { value in
if condition(value), !hasFulfilled {
hasFulfilled = true
}
guard condition(value) else { return }
continuation.yield(())
continuation.finish()
}
return DeferredFulfillment<Void> {
let startTime = ContinuousClock.now
return DeferredFulfillment {
defer { cancellable.cancel() }
while !hasFulfilled {
await Task.yield()
if ContinuousClock.now - startTime >= timeout {
break
try await withThrowingTaskGroup(of: Void.self) { group in
// If the condition fires before timeout, that's the unexpected failure.
group.addTask {
for await _ in stream {
throw DeferredFulfillmentError.unexpectedFulfillment(message: message, sourceLocation: sourceLocation)
}
// Stream finished without condition firing — this shouldn't happen
// but is safe to treat as success.
}
}
cancellable.cancel()
// For deferFailure, if hasFulfilled is true, it means the condition was met (which is a failure)
if hasFulfilled {
throw DeferredFulfillmentError.unexpectedFulfillment(message: message)
// Timeout elapsing without the condition firing = success.
group.addTask {
try await Task.sleep(for: timeout)
}
defer { group.cancelAll() }
return try #require(try await group.next())
}
}
}
/// Utility that assists in subscribing to an async sequence and deferring the failure for a particular value until some other actions have been performed.
/// Test utility that assists in subscribing to an async sequence and deferring the failure for a particular value until some other actions have been performed.
/// - Parameters:
/// - asyncSequence: The sequence to wait on.
/// - timeout: A timeout after which we give up.
/// - message: An optional message to include in the error if the condition is unexpectedly met.
/// - sourceLocation: The source location to attach to any recorded issues.
/// - until: callback that evaluates outputs until some condition is reached
/// - Returns: The deferred fulfilment to be executed after some actions. The sequence's result is not returned from this fulfilment.
func deferFailure<Value>(_ asyncSequence: any AsyncSequence<Value, Never>,
timeout: Duration,
message: String? = nil,
sourceLocation: SourceLocation = #_sourceLocation,
until condition: @escaping (Value) -> Bool) -> DeferredFulfillment<Void> {
var hasFulfilled = false
let (stream, continuation) = AsyncStream<Void>.makeStream()
let task = Task {
for await value in asyncSequence {
if condition(value), !hasFulfilled {
hasFulfilled = true
}
for await value in asyncSequence where condition(value) {
continuation.yield(())
continuation.finish()
return
}
continuation.finish()
}
return DeferredFulfillment<Void> {
let startTime = ContinuousClock.now
return DeferredFulfillment {
defer { task.cancel() }
while !hasFulfilled {
await Task.yield()
if ContinuousClock.now - startTime >= timeout {
break
try await withThrowingTaskGroup(of: Void.self) { group in
// If the condition fires before timeout, that's the unexpected failure.
group.addTask {
for await _ in stream {
throw DeferredFulfillmentError.unexpectedFulfillment(message: message, sourceLocation: sourceLocation)
}
}
}
task.cancel()
// For deferFailure, if hasFulfilled is true, it means the condition was met (which is a failure)
if hasFulfilled {
throw DeferredFulfillmentError.unexpectedFulfillment(message: message)
// Timeout elapsing without the condition firing = success.
group.addTask {
try await Task.sleep(for: timeout)
}
defer { group.cancelAll() }
return try #require(try await group.next())
}
}
}

1
ElementX/SupportingFiles/target.yml
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@@ -258,6 +258,7 @@ targets:
- path: ../Sources
excludes:
- Other/Extensions/XCTestCase.swift
- Other/DeferredFulfillment.swift
- Other/Extensions/XCUIElement.swift
- path: ../../Secrets/Secrets.swift
- path: ../Resources

1
UnitTests/SupportingFiles/target.yml
View File

@@ -52,6 +52,7 @@ targets:
- path: ../../DevelopmentAssets
- path: ../../ElementX/Sources/Other/Extensions/Publisher.swift
- path: ../../ElementX/Sources/Other/Extensions/XCTestCase.swift
- path: ../../ElementX/Sources/Other/DeferredFulfillment.swift
- path: ../../ElementX/Sources/Other/InfoPlistReader.swift
- path: ../../Tools/Scripts/Templates/SimpleScreenExample/Tests/Unit