Wrap Sink.create in IO

src/main/scala/outwatch/SideEffects.scala

@@ -4,7 +4,7 @@ import monix.execution.Ack.Continue
 import monix.execution.Scheduler
 
 trait SideEffects {
-  def sideEffect[T](f: T => Unit)(implicit s: Scheduler): Sink[T] = Sink.create[T] { e => f(e); Continue }(s)
-  def sideEffect[S, T](f: (S, T) => Unit)(implicit s: Scheduler): Sink[(S, T)] = Sink.create[(S, T)] { e => f(e._1, e._2); Continue }(s)
-  def sideEffect(f: => Unit)(implicit s: Scheduler): Sink[Any] = Sink.create[Any] { e => f; Continue }(s)
+  def sideEffect[T](f: T => Unit)(implicit s: Scheduler): Sink[T] = Sink.create[T] { e => f(e); Continue }(s).unsafeRunSync()
+  def sideEffect[S, T](f: (S, T) => Unit)(implicit s: Scheduler): Sink[(S, T)] = Sink.create[(S, T)] { e => f(e._1, e._2); Continue }(s).unsafeRunSync()
+  def sideEffect(f: => Unit)(implicit s: Scheduler): Sink[Any] = Sink.create[Any] { e => f; Continue }(s).unsafeRunSync()
 }

src/main/scala/outwatch/Sink.scala

@@ -79,15 +79,16 @@ object Sink {
   def create[T](next: T => Future[Ack],
                 error: Throwable => Unit = _ => (),
                 complete: () => Unit = () => ()
-               )(implicit s: Scheduler): Sink[T] = {
-    val sink = ObserverSink(
-      new Observer[T] {
-        override def onNext(t: T): Future[Ack] = next(t)
-        override def onError(ex: Throwable): Unit = error(ex)
-        override def onComplete(): Unit = complete()
-      }
-    )
-    sink
+               )(implicit s: Scheduler): IO[Sink[T]] = {
+    IO{
+      ObserverSink(
+        new Observer[T] {
+          override def onNext(t: T): Future[Ack] = next(t)
+          override def onError(ex: Throwable): Unit = error(ex)
+          override def onComplete(): Unit = complete()
+        }
+      )
+    }
   }
 
 

src/main/scala/outwatch/dom/ManagedSubscriptions.scala

@@ -4,27 +4,28 @@ import cats.effect.IO
 import monix.execution.Ack.Continue
 import monix.execution.cancelables.CompositeCancelable
 import monix.execution.{Cancelable, Scheduler}
+import org.scalajs.dom
 import outwatch.dom.dsl.attributes.lifecycle
 
 trait ManagedSubscriptions {
 
   def managed(subscription: IO[Cancelable])(implicit s: Scheduler): VDomModifier = {
     subscription.flatMap { sub: Cancelable =>
-      lifecycle.onDestroy --> Sink.create{_ =>
+      Sink.create[dom.Element] { _ =>
         sub.cancel()
         Continue
-      }
+      }.flatMap( sink => lifecycle.onDestroy --> sink)
     }
   }
 
   def managed(sub1: IO[Cancelable], sub2: IO[Cancelable], subscriptions: IO[Cancelable]*)(implicit s: Scheduler): VDomModifier = {
 
     (sub1 :: sub2 :: subscriptions.toList).sequence.flatMap { subs: Seq[Cancelable] =>
       val composite = CompositeCancelable(subs: _*)
-      lifecycle.onDestroy --> Sink.create{_ =>
+      Sink.create[dom.Element]{ _ =>
         composite.cancel()
         Continue
-      }
+      }.flatMap(sink => lifecycle.onDestroy --> sink)
     }
   }
 

src/main/scala/outwatch/util/WebSocket.scala

@@ -1,5 +1,6 @@
 package outwatch.util
 
+import cats.effect.IO
 import monix.execution.Ack.Continue
 import monix.execution.{Cancelable, Scheduler}
 import monix.reactive.OverflowStrategy.Unbounded
@@ -8,7 +9,7 @@ import outwatch.Sink
 import outwatch.dom.Observable
 
 object WebSocket {
-  implicit def toSink(socket: WebSocket): Sink[String] = socket.sink
+  implicit def toSink(socket: WebSocket): IO[Sink[String]] = socket.sink
   implicit def toSource(socket: WebSocket): Observable[MessageEvent] = socket.source
 }
 

src/test/scala/outwatch/LifecycleHookSpec.scala

@@ -19,7 +19,9 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(onInsert --> sink)
+    val node = sink.flatMap { sink =>
+      div(onInsert --> sink)
+    }
 
     switch shouldBe false
 
@@ -41,7 +43,11 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(onInsert --> sink)(onInsert --> sink2)
+    val node = for {
+      sink <- sink
+      sink2 <- sink2
+      node <- div(onInsert --> sink)(onInsert --> sink2)
+    } yield node
 
     switch shouldBe false
     switch2 shouldBe false
@@ -62,7 +68,9 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(child <-- Observable(span(onDestroy --> sink), div("Hasdasd")))
+    val node = sink.flatMap { sink =>
+      div(child <-- Observable(span(onDestroy --> sink), div("Hasdasd")))
+    }
 
     switch shouldBe false
 
@@ -85,7 +93,11 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(child <-- Observable(span(onDestroy --> sink)(onDestroy --> sink2), div("Hasdasd")))
+    val node = for {
+      sink <- sink
+      sink2 <- sink2
+      node <- div(child <-- Observable(span(onDestroy --> sink)(onDestroy --> sink2), div("Hasdasd")))
+    } yield node
 
     switch shouldBe false
     switch2 shouldBe false
@@ -109,7 +121,11 @@ class LifecycleHookSpec extends JSDomSpec {
     }
 
     val message = PublishSubject[String]
-    val node = div(child <-- message, onUpdate --> sink1)(onUpdate --> sink2)
+    val node = for {
+      sink1 <- sink1
+      sink2 <- sink2
+      node <- div(child <-- message, onUpdate --> sink1)(onUpdate --> sink2)
+    } yield node
 
     OutWatch.renderInto("#app", node).unsafeRunSync()
     switch1 shouldBe false
@@ -129,7 +145,9 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(child <-- Observable(span(onUpdate --> sink, "Hello"), span(onUpdate --> sink, "Hey")))
+    val node = sink.flatMap { sink =>
+      div(child <-- Observable(span(onUpdate --> sink, "Hello"), span(onUpdate --> sink, "Hey")))
+    }
 
     switch shouldBe false
 
@@ -147,7 +165,9 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(child <-- Observable(span("Hello")), span(attributes.key := "1", onPrePatch --> sink, "Hey"))
+    val node = sink.flatMap { sink =>
+      div(child <-- Observable(span("Hello")), span(attributes.key := "1", onPrePatch --> sink, "Hey"))
+    }
 
     switch shouldBe false
 
@@ -168,7 +188,11 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
     val message = PublishSubject[String]()
-    val node = div(child <-- message, onPrePatch --> sink1)(onPrePatch --> sink2)
+    val node =  for {
+      sink1 <- sink1
+      sink2 <- sink2
+      node <- div(child <-- message, onPrePatch --> sink1)(onPrePatch --> sink2)
+    } yield node
 
     OutWatch.renderInto("#app", node).unsafeRunSync()
     switch1 shouldBe false
@@ -188,7 +212,9 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
 
-    val node = div(child <-- Observable("message"), onPostPatch --> sink, "Hey")
+    val node = sink.flatMap { sink =>
+      div(child <-- Observable("message"), onPostPatch --> sink, "Hey")
+    }
 
     switch shouldBe false
 
@@ -210,7 +236,11 @@ class LifecycleHookSpec extends JSDomSpec {
       Continue
     }
     val message = PublishSubject[String]()
-    val node = div(child <-- message, onPostPatch --> sink1)(onPostPatch --> sink2)
+    val node = for {
+      sink1 <- sink1
+      sink2 <- sink2
+      node <- div(child <-- message, onPostPatch --> sink1)(onPostPatch --> sink2)
+    } yield node
 
     OutWatch.renderInto("#app", node).unsafeRunSync()
     switch1 shouldBe false
@@ -248,13 +278,20 @@ class LifecycleHookSpec extends JSDomSpec {
     }
 
     val message = PublishSubject[String]()
-    val node = div(child <-- message,
-      onInsert --> insertSink,
-      onPrePatch --> prepatchSink,
-      onUpdate --> updateSink,
-      onPostPatch --> postpatchSink,
-      onDestroy --> destroySink
-    )
+    val node = for {
+      insertSink <- insertSink
+      updateSink <- updateSink
+      destroySink <- destroySink
+      prepatchSink <- prepatchSink
+      postpatchSink <- postpatchSink
+      node <- div(child <-- message,
+        onInsert --> insertSink,
+        onPrePatch --> prepatchSink,
+        onUpdate --> updateSink,
+        onPostPatch --> postpatchSink,
+        onDestroy --> destroySink
+      )
+    } yield node
 
     hooks shouldBe empty
 
@@ -279,10 +316,14 @@ class LifecycleHookSpec extends JSDomSpec {
     }
 
     val messageList = PublishSubject[Seq[String]]()
-    val node = div("Hello",  children <-- messageList.map(_.map(span(_))),
-      onInsert --> insertSink,
-      onUpdate --> updateSink
-    )
+    val node = for {
+      insertSink <- insertSink
+      updateSink <- updateSink
+      node <- div("Hello", children <-- messageList.map(_.map(span(_))),
+        onInsert --> insertSink,
+        onUpdate --> updateSink
+      )
+    } yield node
 
     hooks shouldBe empty
 
@@ -307,9 +348,14 @@ class LifecycleHookSpec extends JSDomSpec {
     }
 
     val message = PublishSubject[String]()
-    val node = div(span("Hello", onInsert --> insertSink, onUpdate --> updateSink, onDestroy --> destroySink),
-      child <-- message.map(span(_))
-    )
+    val node = for {
+      insertSink <- insertSink
+      updateSink <- updateSink
+      destroySink <- destroySink
+      node <- div(span("Hello", onInsert --> insertSink, onUpdate --> updateSink, onDestroy --> destroySink),
+        child <-- message.map(span(_))
+      )
+    } yield node
 
     hooks shouldBe empty
 
@@ -336,9 +382,14 @@ class LifecycleHookSpec extends JSDomSpec {
     }
 
     val messageList = PublishSubject[Seq[String]]()
-    val node = div(children <-- messageList.map(_.map(span(_))),
-      span("Hello", onInsert --> insertSink, onUpdate --> updateSink, onDestroy --> destroySink)
-    )
+    val node = for {
+      insertSink <- insertSink
+      updateSink <- updateSink
+      destroySink <- destroySink
+      node <- div(children <-- messageList.map(_.map(span(_))),
+        span("Hello", onInsert --> insertSink, onUpdate --> updateSink, onDestroy --> destroySink)
+      )
+    } yield node
 
     hooks shouldBe empty
 
@@ -364,9 +415,11 @@ class LifecycleHookSpec extends JSDomSpec {
 
     val sub = PublishSubject[String]
 
-    val node = div(child <-- nodes.startWith(Seq(
-      span(managed(sink <-- sub))
-    )))
+    val node = sink.flatMap { sink =>
+      div(child <-- nodes.startWith(Seq(
+        span(managed(sink <-- sub))
+      )))
+    }
 
     OutWatch.renderInto("#app", node).unsafeRunSync()
 
@@ -393,10 +446,12 @@ class LifecycleHookSpec extends JSDomSpec {
 
     val divTagName = onInsert.map(_.tagName.toLowerCase).filter(_ == "div")
 
-    val node = div(onInsert("insert") --> sink,
-      div(divTagName --> sink),
-      span(divTagName --> sink)
-    )
+    val node = sink.flatMap { sink =>
+      div(onInsert("insert") --> sink,
+        div(divTagName --> sink),
+        span(divTagName --> sink)
+      )
+    }
 
     OutWatch.renderInto("#app", node).unsafeRunSync()
 

src/test/scala/outwatch/OutWatchDomSpec.scala

@@ -51,7 +51,7 @@ class OutWatchDomSpec extends JSDomSpec {
         Seq(
           div(),
           attributes.`class` := "blue",
-          attributes.onClick(1) --> Sink.create[Int](_ => Continue),
+          attributes.onClick(1) --> Sink.create[Int](_ => Continue).unsafeRunSync(),
           attributes.hidden <-- Observable(false)
         ).map(_.unsafeRunSync())
       ),