Fix: SessionStorage; add rawStorageValues

src/main/scala/com/raquo/airstream/web/WebStorageVar.scala

@@ -1,6 +1,6 @@
 package com.raquo.airstream.web
 
-import com.raquo.airstream.core.{BaseObservable, EventStream, Observer}
+import com.raquo.airstream.core.{BaseObservable, EventStream, Observer, Signal}
 import com.raquo.airstream.ownership.{ManualOwner, Owner}
 import com.raquo.airstream.state.SourceVar
 import org.scalajs.dom
@@ -51,7 +51,7 @@ class WebStorageVar[A] private[web] (
   /** Stream of updates of this sessionStorage/localStorage value
     * from other browser tabs and frames that have shared access to it.
     */
-  val externalUpdates: EventStream[dom.StorageEvent] =
+  lazy val externalUpdates: EventStream[dom.StorageEvent] =
     DomEventStream[dom.StorageEvent](
       eventTarget = dom.window,
       eventKey = "storage"
@@ -62,6 +62,12 @@ class WebStorageVar[A] private[web] (
       maybeStorage().contains(ev.storageArea) && ev.key == key
     }
 
+  /** Signal of raw values in the browser storage.
+    * Note: Updates are triggered only when this Var is updated.
+    */
+  lazy val rawStorageValues: Signal[Option[String]] =
+    signal.mapTo(maybeStorage().flatMap(s => Option(s.getItem(key))))
+
   // When user writes to this var, update the value in web storage
   // #Note we filter out duplicate values not here, but when we
   //  pull/sync this var. Here we only look at non-error values,
@@ -203,7 +209,7 @@ object WebStorageVar {
     key: String,
     syncOwner: Option[Owner]
   ): WebStorageBuilder = {
-    val maybeStorage = () => Try(dom.window.localStorage).toOption
+    val maybeStorage = () => Try(dom.window.sessionStorage).toOption
     new WebStorageBuilder(maybeStorage, key, syncOwner)
   }
 

src/test/scala/com/raquo/airstream/web/WebStorageVarSpec.scala

@@ -42,6 +42,8 @@ class WebStorageVarSpec extends UnitSpec with BeforeAndAfter {
 
   it("localStorage basics") {
 
+    assertEquals(WebStorageVar.localStorageIsAvailable(), true)
+
     val fooVar = WebStorageVar
       .localStorage(key = "foo", syncOwner = None)
       .withCodec[Foo](
@@ -92,6 +94,8 @@ class WebStorageVarSpec extends UnitSpec with BeforeAndAfter {
 
   it("sessionStorage basics") {
 
+    assertEquals(WebStorageVar.sessionStorageIsAvailable(), true)
+
     val fooVar = WebStorageVar
       .sessionStorage(key = "foo", syncOwner = None)
       .withCodec[Foo](
@@ -100,21 +104,21 @@ class WebStorageVarSpec extends UnitSpec with BeforeAndAfter {
         default = Success(Foo(-1))
       )
 
-    assertEquals(dom.window.localStorage.getItem("foo"), "-1")
+    assertEquals(dom.window.sessionStorage.getItem("foo"), "-1")
     assertEquals(fooVar.tryNow(), Success(Foo(-1)))
 
     // --
 
     fooVar.update(_.copy(id = 2))
 
-    assertEquals(dom.window.localStorage.getItem("foo"), "2")
+    assertEquals(dom.window.sessionStorage.getItem("foo"), "2")
     assertEquals(fooVar.tryNow(), Success(Foo(2)))
 
     // --
 
     fooVar.set(Foo(id = 3))
 
-    assertEquals(dom.window.localStorage.getItem("foo"), "3")
+    assertEquals(dom.window.sessionStorage.getItem("foo"), "3")
     assertEquals(fooVar.tryNow(), Success(Foo(3)))
 
     assertEquals(errorEffects.toList, Nil)
@@ -123,7 +127,7 @@ class WebStorageVarSpec extends UnitSpec with BeforeAndAfter {
 
     fooVar.setTry(Failure(err1))
 
-    assertEquals(dom.window.localStorage.getItem("foo"), "3")
+    assertEquals(dom.window.sessionStorage.getItem("foo"), "3")
     assertEquals(fooVar.tryNow(), Failure(err1))
 
     assertEquals(errorEffects.toList, List(
@@ -135,7 +139,7 @@ class WebStorageVarSpec extends UnitSpec with BeforeAndAfter {
 
     fooVar.pullOnce()
 
-    assertEquals(dom.window.localStorage.getItem("foo"), "3")
+    assertEquals(dom.window.sessionStorage.getItem("foo"), "3")
     assertEquals(fooVar.tryNow(), Success(Foo(3)))
 
   }