print log if scheduled job fails (#82)

Author: tanner0101

.gitignore

@@ -4,5 +4,5 @@
 /*.xcodeproj
 DerivedData
 Package.resolved
-
-.swiftpm
+.swiftpm
+Tests/LinuxMain.swift

Sources/Queues/QueuesCommand.swift

@@ -133,7 +133,12 @@ public final class QueuesCommand: Command {
 
         if let task = job.schedule(context: context) {
             self.scheduledTasks[job.job.name] = task
-            task.done.whenComplete { _ in
+            task.done.whenComplete { result in
+                switch result {
+                case .failure(let error):
+                    context.logger.error("\(job.job.name) failed: \(error)")
+                case .success: break
+                }
                 self.schedule(job)
             }
         }

Tests/QueuesTests/QueueTests.swift

@@ -149,6 +149,27 @@ final class QueueTests: XCTestCase {
 
         try promise.futureResult.wait()
     }
+
+    func testFailingScheduledJob() throws {
+        let app = Application(.testing)
+        defer { app.shutdown() }
+        
+        app.queues.schedule(FailingScheduledJob()).everySecond()
+        try app.queues.startScheduledJobs()
+        
+        let promise = app.eventLoopGroup.next().makePromise(of: Void.self)
+        app.eventLoopGroup.next().scheduleTask(in: .seconds(1)) { () -> Void in
+            promise.succeed(())
+        }
+        try promise.futureResult.wait()
+    }
+}
+
+struct Failure: Error { }
+struct FailingScheduledJob: ScheduledJob {
+    func run(context: QueueContext) -> EventLoopFuture<Void> {
+        context.eventLoop.makeFailedFuture(Failure())
+    }    
 }
 
 struct TestingScheduledJob: ScheduledJob {