Merge pull request #1113

Fix #1112: Hooks not being initialised with props children

Author: japgolly

library/coreGeneric/src/main/scala/japgolly/scalajs/react/hooks/HookComponentBuilder.scala

@@ -120,10 +120,14 @@ object HookComponentBuilder {
         step.next(init, f)
 
       override def render(f: Ctx => VdomNode)(implicit s: CtorType.Summoner[Box[P], Children.Varargs]): Component[P, s.CT] =
-        ScalaFn.withChildren((p: P, pc: PropsChildren) => f(HookCtx.withChildren(p, pc)))
+        ScalaFn.withChildren((p: P, pc: PropsChildren) => {
+          val h = HookCtx.withChildren(p, pc)
+          init(h)
+          f(h)
+        })
 
       def render(f: (P, PropsChildren) => VdomNode)(implicit s: CtorType.Summoner[Box[P], Children.Varargs]): Component[P, s.CT] =
-        ScalaFn.withChildren(f)
+        render((ctx: Ctx) => f(ctx.props, ctx.propsChildren))
 
       override def renderWithReuseBy[A](reusableInputs: Ctx => A)(f: A => VdomNode)(implicit s: CtorType.Summoner[Box[P], Children.Varargs], r: Reusability[A]): Component[P, s.CT] =
         customBy(ctx => CustomHook.shouldComponentUpdate(f).apply(() => reusableInputs(ctx)))

library/tests/src/test/scala/japgolly/scalajs/react/core/HooksTest.scala

@@ -1288,6 +1288,19 @@ object HooksTest extends TestSuite {
     }
   }
 
+  private def testOnMountWithPropsChildren(): Unit = {
+    var text = "uninitialised"
+    val comp = ScalaFnComponent.withHooks[Unit]
+      .withPropsChildren
+      .useEffectOnMount(Callback { text = "ok" })
+      .render(_.propsChildren)
+
+    test(comp(123)) { t =>
+      assertEq(text, "ok")
+      t.assertText("123")
+    }
+  }
+
   // ===================================================================================================================
 
   override def tests = Tests {
@@ -1316,6 +1329,7 @@ object HooksTest extends TestSuite {
       "depsBy" - testWithDepsBy()
       "mount" - testOnMount()
       "mountBy" - testOnMountBy()
+      "mountWithPropsChildren" - testOnMountWithPropsChildren()
     }
     "useForceUpdate" - testUseForceUpdate()
     "useLayoutEffect" - {