Merge pull request #739 from japgolly/topic/elidableVdom

Add VdomAttr.elidable

Author: japgolly

bin/test-elision

@@ -8,6 +8,7 @@ case $# in
       COMP_NAMES_ARE_ELIDABLE
       DEVONLY
       ELIDABLE_AUTO_COMPONENT_NAME
+      ELIDABLE_VDOM_ATTR
       REUSABILITY_OVERRIDE_TEST
     )
     for t in "${terms[@]}"; do

core/src/main/scala/japgolly/scalajs/react/vdom/Attr.scala

@@ -1,7 +1,7 @@
 package japgolly.scalajs.react.vdom
 
 import org.scalajs.dom
-import scala.annotation.{implicitNotFound, nowarn}
+import scala.annotation.{elidable, implicitNotFound, nowarn}
 import scala.scalajs.LinkingInfo.developmentMode
 import scala.scalajs.js
 import japgolly.scalajs.react.internal.OptionLike
@@ -52,6 +52,16 @@ object Attr {
     else
       Dud
 
+  def elidable[A](name: => String): Attr[A] = {
+    @elidable(scala.annotation.elidable.FINEST)
+    def attempt: Attr[A] = new Generic(name)
+    val x = attempt
+    if (x eq null)
+      Dud
+    else
+      x
+  }
+
   class Generic[-U](attrName: String) extends Attr[U](attrName) {
     override def :=[A](a: A)(implicit t: ValueType[A, U]): TagMod =
       t(attrName, a)

doc/changelog/1.7.2.md

@@ -1,3 +1,4 @@
 # 1.7.2
 
 * Fix: no longer generate warnings when `-Wunused:nowarn` is enabled
+* Add `VdomAttr.elidable` which allows you to elide VDOM attributes with `scalacOptions`

test/src/test/scala/japgolly/scalajs/react/ElisionTest.scala

@@ -29,9 +29,13 @@ object ElisionTest extends TestSuite {
         .build
   }
 
+  private val attr =
+    VdomAttr.elidable("data-ELIDABLE_VDOM_ATTR")
+
   override def tests = Tests {
     "normal" - s"[${Normal.raw.displayName}]"
     "static" - s"[${Static.raw.displayName}]"
+    "attr"   - ReactDOMServer.renderToStaticMarkup(<.div(attr := 1))
 
     "reusabilityOverride" - {
       ScalaJsReactConfig.DevOnly.overrideReusability(reusabilityOverride)