element-ios/RiotSwiftUI/Modules/Common/Test/XCTestPublisherExtensions.s...

71 lines
2.6 KiB
Swift

//
// Copyright 2021-2024 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
//
import Combine
import XCTest
extension XCTestCase {
/// XCTest utility to wait for results from publishers, so that the output can be used for assertions.
///
/// ```
/// let collectedEvents = somePublisher.collect(3).first()
/// XCTAssertEqual(try xcAwait(collectedEvents), [expected, values, here])
/// ```
/// - Parameters:
/// - publisher: The publisher to wait on.
/// - timeout: A timeout after which we give up.
/// - Throws: If it can't get the unwrapped result.
/// - Returns: The unwrapped result.
func xcAwait<T: Publisher>(_ publisher: T,
timeout: TimeInterval = 10) throws -> T.Output {
try xcAwaitDeferred(publisher, timeout: timeout)()
}
/// XCTest utility that allows for a deferred wait of results from publishers, so that the output can be used for assertions.
///
/// ```
/// let collectedEvents = somePublisher.collect(3).first()
/// let awaitDeferred = xcAwaitDeferred(collectedEvents)
/// // Do some other work that publishes to somePublisher
/// XCTAssertEqual(try awaitDeferred(), [expected, values, here])
/// ```
/// - Parameters:
/// - publisher: The publisher to wait on.
/// - timeout: A timeout after which we give up.
/// - Returns: A closure that starts the waiting of results when called. The closure will return the unwrapped result.
func xcAwaitDeferred<T: Publisher>(_ publisher: T,
timeout: TimeInterval = 10) -> (() throws -> (T.Output)) {
var result: Result<T.Output, Error>?
let expectation = expectation(description: "Awaiting publisher")
let cancellable = publisher.sink(
receiveCompletion: { completion in
switch completion {
case .failure(let error):
result = .failure(error)
case .finished:
break
}
expectation.fulfill()
},
receiveValue: { value in
result = .success(value)
}
)
return {
self.waitForExpectations(timeout: timeout)
cancellable.cancel()
let unwrappedResult = try XCTUnwrap(
result,
"Awaited publisher did not produce any output"
)
return try unwrappedResult.get()
}
}
}