[Async Refactoring] Add @discardableResult for defaulted completion

If the completion handler parameter has a default
argument, mark the resulting async function as
`@discardableResult`, as the caller may not care
about the result.

rdar://79190170
This commit is contained in:
Hamish Knight
2021-06-11 11:39:16 +01:00
parent 38c544aa0e
commit e97c781ca1
2 changed files with 35 additions and 0 deletions

View File

@@ -1,3 +1,5 @@
// RUN: %empty-directory(%t)
enum CustomError : Error {
case Bad
}
@@ -309,3 +311,21 @@ func rdar78693050(_ completion: () -> Void) {
// RDAR78693050-NEXT: }
// RDAR78693050-NEXT: return
// RDAR78693050-NEXT: }
// RUN: %refactor-check-compiles -convert-to-async -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=DISCARDABLE-RESULT %s
func withDefaultedCompletion(arg: String, completion: @escaping (String) -> Void = {_ in}) {
completion(arg)
}
// DISCARDABLE-RESULT: @discardableResult
// DISCARDABLE-RESULT-NEXT: func withDefaultedCompletion(arg: String) async -> String {
// DISCARDABLE-RESULT-NEXT: return arg
// DISCARDABLE-RESULT-NEXT: }
// RUN: %refactor-check-compiles -convert-to-async -dump-text -source-filename %s -pos=%(line+1):1 | %FileCheck -check-prefix=DEFAULT-ARG %s
func withDefaultArg(x: String = "") {
}
// DEFAULT-ARG: convert_function.swift [[# @LINE-3]]:1 -> [[# @LINE-2]]:2
// DEFAULT-ARG-NOT: @discardableResult
// DEFAULT-ARG-NEXT: {{^}}func withDefaultArg(x: String = "") async