add easier async to future conversion (#2334)

apple · Dec 19, 2022 · 86e8b5f · 86e8b5f
1 parent 0760383
commit 86e8b5f
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Showing 3 changed files with 43 additions and 0 deletions.
diff --git a/Sources/NIOCore/AsyncAwaitSupport.swift b/Sources/NIOCore/AsyncAwaitSupport.swift
@@ -330,3 +330,13 @@ struct AsyncSequenceFromIterator<AsyncIterator: AsyncIteratorProtocol>: AsyncSeq
         self.iterator
     }
 }
+
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
+extension EventLoop {
+    @inlinable
+    public func makeFutureWithTask<Return>(_ body: @Sendable @escaping () async throws -> Return) -> EventLoopFuture<Return> {
+        let promise = self.makePromise(of: Return.self)
+        promise.completeWithTask(body)
+        return promise.futureResult
+    }
+}
diff --git a/Tests/NIOPosixTests/EventLoopTest+XCTest.swift b/Tests/NIOPosixTests/EventLoopTest+XCTest.swift
@@ -89,6 +89,8 @@ extension EventLoopTest {
                 ("testEventLoopGroupsWithoutAnyImplementationAreValid", testEventLoopGroupsWithoutAnyImplementationAreValid),
                 ("testCallingAnyOnAnMTELGThatIsNotSelfDoesNotReturnItself", testCallingAnyOnAnMTELGThatIsNotSelfDoesNotReturnItself),
                 ("testMultiThreadedEventLoopGroupSupportsStickyAnyImplementation", testMultiThreadedEventLoopGroupSupportsStickyAnyImplementation),
+                ("testAsyncToFutureConversionSuccess", testAsyncToFutureConversionSuccess),
+                ("testAsyncToFutureConversionFailure", testAsyncToFutureConversionFailure),
            ]
    }
 }

diff --git a/Tests/NIOPosixTests/EventLoopTest.swift b/Tests/NIOPosixTests/EventLoopTest.swift
@@ -1479,6 +1479,7 @@ public final class EventLoopTest : XCTestCase {
         }.wait())
     }
 
+    @available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
     func testMultiThreadedEventLoopGroupSupportsStickyAnyImplementation() {
         let group = MultiThreadedEventLoopGroup(numberOfThreads: 3)
         defer {
@@ -1492,6 +1493,36 @@ public final class EventLoopTest : XCTestCase {
             XCTAssert(el1 === MultiThreadedEventLoopGroup.currentEventLoop!)
         }.wait())
     }
+
+    @available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
+    func testAsyncToFutureConversionSuccess() {
+        let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+        defer {
+            XCTAssertNoThrow(try group.syncShutdownGracefully())
+        }
+
+        XCTAssertEqual("hello from async",
+                       try group.next().makeFutureWithTask {
+            try await Task.sleep(nanoseconds: 37)
+            return "hello from async"
+        }.wait())
+    }
+
+    func testAsyncToFutureConversionFailure() {
+        let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+        defer {
+            XCTAssertNoThrow(try group.syncShutdownGracefully())
+        }
+
+        struct DummyError: Error {}
+
+        XCTAssertThrowsError(try group.next().makeFutureWithTask {
+            try await Task.sleep(nanoseconds: 37)
+            throw DummyError()
+        }.wait()) { error in
+            XCTAssert(error is DummyError)
+        }
+    }
 }
 
 fileprivate class EventLoopWithPreSucceededFuture: EventLoop {