我在单元测试中有一个辅助方法:
func expect(_ sut: CompanyStore, toRetrieve expectedResult: RetrieveCacheResult, when action: @escaping (() -> Void), file: StaticString = #file, line: UInt = #line) {
let exp = expectation(description: "await completion")
sut.retrieve { retrievedResult in
switch (expectedResult, retrievedResult) {
case (.empty, .empty), (.failure, .failure):
break
case let (.found(retrieved), .found(expected)):
XCTAssertEqual(retrieved.item, expected.item, file: file, line: line)
XCTAssertEqual(retrieved.timestamp, expected.timestamp, file: file, line: line)
default:
XCTFail("Expected to retrieve \(expectedResult), got \(retrievedResult) instead", file: file, line: line)
}
exp.fulfill()
}
action()
wait(for: [exp], timeout: 1.0)
}
它允许我创建测试,例如:
func test_retrieve_delivers_empty_on_empty_cache() {
let sut = makeSUT()
expect(sut, toRetrieve: .empty, when: {
// some action to perform
})
}
自升级到Swift 5.1后,我收到以下警告:
无法一次匹配多个关联的值,因此会隐式地将关联值并尝试匹配该值
在下一行
case let (.found(retrieved), .found(expected)):
这些值是一个元组(item: LocalCompany, timestamp: Date)
我无法确定如何清除此警告。
编辑:
.found
是一个枚举:
public enum RetrieveCacheResult {
case empty
case found(item: LocalCompany, timestamp: Date)
case failure(Error)
}
您有两个选择:
case found( (item: Int, timestamp: Bool) )
case let (
.found(retrievedItem, retrievedTimestamp),
.found(expectedItem, expectedTimestamp)
):