# XCTExpectFailure(_:options:failingBlock:) Instructs the test to expect a failure in an assertion in the provided block of code, with options to customize expected failure checking and handling. ``` func XCTExpectFailure(_ failureReason: String? = nil, options: XCTExpectedFailure.Options = .init(), failingBlock: () throws -> R) rethrows -> R ``` ## Parameters `failureReason` An optional string that describes why the test expects a failure. `options` Options that determine how the test matches the expected failure to an actual test failure, and whether an unfulfilled expected failure results in a test failure. `failingBlock` A block of test code and assertions where the test expects a failure. ## Return Value If the `failingBlock` you provide returns a value or throws an error, the function returns that value or rethrows the error. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)