chore: add the overrides from scala-js/scala-js (scala-js/scala-js@d6d6a37)

Author: hamzaremmal

library-js/src/scala/App.scala

@@ -0,0 +1,85 @@
+/*
+ * Scala (https://www.scala-lang.org)
+ *
+ * Copyright EPFL and Lightbend, Inc.
+ *
+ * Licensed under Apache License 2.0
+ * (http://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package scala
+
+import java.lang.System.{currentTimeMillis => currentTime}
+import scala.collection.mutable.ListBuffer
+
+/** The `App` trait can be used to quickly turn objects
+ *  into executable programs. Here is an example:
+ *  {{{
+ *  object Main extends App {
+ *    Console.println("Hello World: " + (args mkString ", "))
+ *  }
+ *  }}}
+ *
+ *  No explicit `main` method is needed.  Instead,
+ *  the whole class body becomes the “main method”.
+ *
+ *  `args` returns the current command line arguments as an array.
+ *
+ *  ==Caveats==
+ *
+ *  '''''It should be noted that this trait is implemented using the [[DelayedInit]]
+ *  functionality, which means that fields of the object will not have been initialized
+ *  before the main method has been executed.'''''
+ *
+ *  Future versions of this trait will no longer extend `DelayedInit`.
+ *
+ *  @author  Martin Odersky
+ *  @since   2.1
+ */
+trait App extends DelayedInit {
+
+  /** The time when the execution of this program started, in milliseconds since 1
+    * January 1970 UTC. */
+  final val executionStart: Long = currentTime
+
+  /** The command line arguments passed to the application's `main` method.
+   */
+  protected final def args: Array[String] = _args
+
+  private[this] var _args: Array[String] = _
+
+  private[this] val initCode = new ListBuffer[() => Unit]
+
+  /** The init hook. This saves all initialization code for execution within `main`.
+   *  This method is normally never called directly from user code.
+   *  Instead it is called as compiler-generated code for those classes and objects
+   *  (but not traits) that inherit from the `DelayedInit` trait and that do not
+   *  themselves define a `delayedInit` method.
+   *  @param body the initialization code to be stored for later execution
+   */
+  @deprecated("the delayedInit mechanism will disappear", "2.11.0")
+  override def delayedInit(body: => Unit): Unit = {
+    initCode += (() => body)
+  }
+
+  /** The main method.
+   *  This stores all arguments so that they can be retrieved with `args`
+   *  and then executes all initialization code segments in the order in which
+   *  they were passed to `delayedInit`.
+   *  @param args the arguments passed to the main method
+   */
+  final def main(args: Array[String]) = {
+    this._args = args
+    for (proc <- initCode) proc()
+
+    /* DELETED for Scala.js
+    if (util.Properties.propIsSet("scala.time")) {
+      val total = currentTime - executionStart
+      Console.println("[total " + total + "ms]")
+    }
+    */
+  }
+}