Make HTMLCollection covariant in E

Author: armanbilge

api-reports/2_12.txt

@@ -25826,7 +25826,7 @@ html[SO] type Base = HTMLBaseElement
 html[SO] type Body = HTMLBodyElement
 html[SO] type Button = HTMLButtonElement
 html[SO] type Canvas = HTMLCanvasElement
-html[SO] type Collection[E] = HTMLCollection[E]
+html[SO] type Collection[+E] = HTMLCollection[E]
 html[SO] type DList = HTMLDListElement
 html[SO] type DataList = HTMLDataListElement
 html[SO] type Div = HTMLDivElement

api-reports/2_13.txt

@@ -25826,7 +25826,7 @@ html[SO] type Base = HTMLBaseElement
 html[SO] type Body = HTMLBodyElement
 html[SO] type Button = HTMLButtonElement
 html[SO] type Canvas = HTMLCanvasElement
-html[SO] type Collection[E] = HTMLCollection[E]
+html[SO] type Collection[+E] = HTMLCollection[E]
 html[SO] type DList = HTMLDListElement
 html[SO] type DataList = HTMLDataListElement
 html[SO] type Div = HTMLDivElement

src/main/scala/org/scalajs/dom/HTMLCollection.scala

@@ -14,7 +14,7 @@ import scala.scalajs.js.annotation._
   */
 @js.native
 @JSGlobal
-abstract class HTMLCollection[E] extends DOMList[E] {
+abstract class HTMLCollection[+E] extends DOMList[E] {
   def item(index: Int): E = js.native
 
   /** Returns the specific node whose ID or, as a fallback, name matches the string specified by name. Matching by name

src/main/scala/org/scalajs/dom/html.scala

@@ -10,7 +10,7 @@ object html {
   type Button = HTMLButtonElement
   type BR = HTMLBRElement
   type Canvas = HTMLCanvasElement
-  type Collection[E] = HTMLCollection[E]
+  type Collection[+E] = HTMLCollection[E]
   type DataList = HTMLDataListElement
   type Div = HTMLDivElement
   type DList = HTMLDListElement