Files
letro-ios/ElementX/Sources/Other/Extensions/XCTestCase.swift
2026-01-27 12:50:57 +02:00

195 lines
9.5 KiB
Swift

//
// Copyright 2025 Element Creations Ltd.
// Copyright 2023-2025 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
// Please see LICENSE files in the repository root for full details.
//
import Combine
import XCTest
extension XCTestCase {
/// XCTest 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 custom expectation message
/// - 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: TimeInterval = 10,
message: String? = nil,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<P.Output> {
var result: Result<P.Output, Error>?
let expectation = expectation(description: message ?? "Awaiting publisher")
var hasFullfilled = false
let cancellable = publisher
.sink { completion in
switch completion {
case .failure(let error):
result = .failure(error)
expectation.fulfill()
case .finished:
break
}
} receiveValue: { value in
if condition(value), !hasFullfilled {
result = .success(value)
expectation.fulfill()
hasFullfilled = true
}
}
return DeferredFulfillment<P.Output> {
await self.fulfillment(of: [expectation], timeout: timeout)
cancellable.cancel()
let unwrappedResult = try XCTUnwrap(result, "Awaited publisher did not produce any output")
return try unwrappedResult.get()
}
}
/// XCTest 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 custom expectation message
/// - 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: TimeInterval = 10,
message: String? = nil,
until condition: @escaping (Value) -> Bool) -> DeferredFulfillment<Value> {
var result: Result<Value, Error>?
let expectation = expectation(description: message ?? "Awaiting sequence")
var hasFulfilled = false
let task = Task {
for await value in asyncSequence {
if condition(value), !hasFulfilled {
result = .success(value)
expectation.fulfill()
hasFulfilled = true
}
}
}
return DeferredFulfillment<Value> {
await self.fulfillment(of: [expectation], timeout: timeout)
task.cancel()
let unwrappedResult = try XCTUnwrap(result, "Awaited sequence did not produce any output")
return try unwrappedResult.get()
}
}
/// XCTest 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.
/// - message: An optional custom expectation message
/// - 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: TimeInterval = 10,
message: String? = nil) -> DeferredFulfillment<P.Output> {
var expectedOrder = transitionValues
return deferFulfillment(publisher, timeout: timeout, message: message) { value in
let receivedValue = value[keyPath: keyPath]
if let index = expectedOrder.firstIndex(where: { $0 == receivedValue }), index == 0 {
expectedOrder.remove(at: index)
}
return expectedOrder.isEmpty
}
}
/// XCTest 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.
/// - message: An optional custom expectation message
/// - 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: TimeInterval = 10,
message: String? = nil) -> DeferredFulfillment<Value> {
var expectedOrder = transitionValues
return deferFulfillment(asyncSequence, timeout: timeout, message: message) { value in
if let index = expectedOrder.firstIndex(where: { $0 == value }), index == 0 {
expectedOrder.remove(at: index)
}
return expectedOrder.isEmpty
}
}
/// XCTest 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 custom expectation message
/// - 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: TimeInterval,
message: String? = nil,
until condition: @escaping (P.Output) -> Bool) -> DeferredFulfillment<Void> where P.Failure == Never {
let expectation = expectation(description: message ?? "Awaiting publisher")
expectation.isInverted = true
var hasFulfilled = false
let cancellable = publisher
.sink { value in
if condition(value), !hasFulfilled {
expectation.fulfill()
hasFulfilled = true
}
}
return DeferredFulfillment<Void> {
await self.fulfillment(of: [expectation], timeout: timeout)
cancellable.cancel()
}
}
/// XCTest 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 custom expectation message
/// - 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: TimeInterval,
message: String? = nil,
until condition: @escaping (Value) -> Bool) -> DeferredFulfillment<Void> {
let expectation = expectation(description: message ?? "Awaiting sequence")
expectation.isInverted = true
var hasFulfilled = false
let task = Task {
for await value in asyncSequence {
if condition(value), !hasFulfilled {
expectation.fulfill()
hasFulfilled = true
}
}
}
return DeferredFulfillment<Void> {
await self.fulfillment(of: [expectation], timeout: timeout)
task.cancel()
}
}
struct DeferredFulfillment<T> {
let closure: () async throws -> T
@discardableResult func fulfill() async throws -> T {
try await closure()
}
}
}