Remove WeakMap usage

Author: japgolly

core/src/main/scala/japgolly/scalajs/react/AsyncCallback.scala

@@ -113,11 +113,6 @@ object AsyncCallback {
 
   @inline implicit def asynCallbackCovariance[A, B >: A](c: AsyncCallback[A]): AsyncCallback[B] =
     c.widen
-
-  private[AsyncCallback] val memoMap = {
-    type Fn[A] = (Try[A] => Callback) => Callback
-    internal.WeakMap().castK[Fn, AsyncCallback]
-  }
 }
 
 /** Pure asynchronous callback.
@@ -289,19 +284,17 @@ final class AsyncCallback[A] private[AsyncCallback] (val completeWith: (Try[A] =
   /** Return a version of this callback that will only execute once, and reuse the result for all
     * other invocations.
     */
-  def memo: AsyncCallback[A] =
-    AsyncCallback.memoMap.getOrSet(completeWith) {
-      var result: Option[AsyncCallback[A]] = None
-      def set(r: AsyncCallback[A]) = {result = Some(r); r}
-
-      AsyncCallback.byName {
-        result.getOrElse {
-          val first = attemptTry.flatMap(t => AsyncCallback.byName(set(AsyncCallback.const(t))))
-          val promise = first.unsafeToJsPromise()
-          result getOrElse set(AsyncCallback.fromJsPromise(promise))
-        }
+  def memo(): AsyncCallback[A] = {
+    var result: Option[AsyncCallback[A]] = None
+    def set(r: AsyncCallback[A]) = {result = Some(r); r}
+    AsyncCallback.byName {
+      result.getOrElse {
+        val first = attemptTry.flatMap(t => AsyncCallback.byName(set(AsyncCallback.const(t))))
+        val promise = first.unsafeToJsPromise()
+        result getOrElse set(AsyncCallback.fromJsPromise(promise))
       }
     }
+  }
 
   /** Conditional execution of this callback.
     *

core/src/main/scala/japgolly/scalajs/react/Callback.scala

@@ -372,9 +372,6 @@ object CallbackTo {
 
   @inline implicit def MapGuard[A]: MapGuard[A] =
     null.asInstanceOf[MapGuard[A]]
-
-  private[CallbackTo] val memoMap =
-    internal.WeakMap().castK[Function0, CallbackTo]
 }
 
 // =====================================================================================================================
@@ -536,11 +533,19 @@ final class CallbackTo[A] private[react] (private[CallbackTo] val f: () => A) ex
   /** Return a version of this callback that will only execute once, and reuse the result for all
     * other invocations.
     */
-  def memo: CallbackTo[A] =
-    CallbackTo.memoMap.getOrSet(f) {
-      lazy val t = attemptTry.runNow()
-      CallbackTo(t.get)
+  def memo(): CallbackTo[A] = {
+    var result: Option[Try[A]] = None
+    val self = attemptTry
+    CallbackTo {
+      val t: Try[A] =
+        result.getOrElse {
+          val t = self.runNow()
+          result = Some(t)
+          t
+        }
+      t.get
     }
+  }
 
   /** Conditional execution of this callback.
     *

core/src/main/scala/japgolly/scalajs/react/internal/WeakMap.scala

@@ -124,14 +124,14 @@ object AsyncTest {
         var count = 0
         val getCount = AsyncCallback.point(count)
         val incCount = AsyncCallback.point(count += 1).delayMs(400)
-        def m = incCount.memo
+        val m = incCount.memo()
         // start 1
         // start 2
         // complete 1
         // complete 2
         // start 3
         // complete 3
-        val t = (m *> m) >> m.memo >> getCount
+        val t = (m *> m) >> m.memo() >> getCount
         t -> 1
       })
 

gh-pages/src/main/scala/ghpages/secret/tests/AsyncTest.scala

@@ -10,7 +10,7 @@ object CallbackTest extends TestSuite {
     'memo {
       var count = 0
       val inc = Callback(count += 1)
-      def c = inc.memo
+      val c = inc.memo()
       (c >> c.memo >> c).runNow()
       assert(count == 1)
     }