async_taskgroup_is_empty.swift

// RUN: %target-run-simple-swift( -target %target-swift-5.1-abi-triple %import-libdispatch -parse-as-library) | %FileCheck %s

// REQUIRES: executable_test
// REQUIRES: concurrency
// REQUIRES: libdispatch

// rdar://76038845
// REQUIRES: concurrency_runtime
// UNSUPPORTED: back_deployment_runtime

import Dispatch

@available(SwiftStdlib 5.1,*)
func asyncEcho(_ value:Int)async->Int{
 value
}

@available(SwiftStdlib 5.1,*)
func test_taskGroup_isEmpty()async{
print("before all")
letresult=awaitwithTaskGroup(of:Int.self, returning:Int.self){ group in
 // CHECK: before add: isEmpty=true
print("before add: isEmpty=\(group.isEmpty)")

 group.async{
awaitTask.sleep(2_000_000_000)
returnawaitasyncEcho(1)
}

 // CHECK: while add running, outside: isEmpty=false
print("while add running, outside: isEmpty=\(group.isEmpty)")

 // CHECK: next: 1
whilelet value =try!await group.next(){
print("next: \(value)")
}

 // CHECK: after draining tasks: isEmpty=true
 print("after draining tasks: isEmpty=\(group.isEmpty)")
return42
}

 // CHECK: result: 42
print("result: \(result)")
}

@available(SwiftStdlib 5.1,*)
@mainstructMain{
staticfunc main()async{
awaittest_taskGroup_isEmpty()
}
}