FF ONLY Merge 0.6.x into master, July 8

DEVELOPING.md

@@ -78,6 +78,15 @@ The JUnit tests from scala/scala can be run with
 
     > scalaTestSuite/test
 
+## Metals-based IDEs
+
+We recommend [Metals](https://scalameta.org/metals/)-based IDEs such as VS Code
+to develop Scala.js itself. It can import the Scala.js build out-of-the-box.
+
+After importing the build in Metals, you will need to run `clean` in sbt before
+normal sbt commands can correctly work. Metals will continue to provide all its
+features after cleaning.
+
 ## Eclipse
 
 If you want to develop in Eclipse, use

compiler/src/main/scala/org/scalajs/nscplugin/PrepJSExports.scala

@@ -366,6 +366,17 @@ trait PrepJSExports[G <: Global with Singleton] { this: PrepJSInterop[G] =>
       ExportInfo(name, destination)(annot.pos)
     }
 
+    allExportInfos.filter(_.destination == ExportDestination.Normal)
+      .groupBy(_.jsName)
+      .filter { case (jsName, group) =>
+        if (jsName == "apply" && group.size == 2)
+          // @JSExportAll and single @JSExport("apply") should not be warned.
+          !unitAnnots.exists(_.symbol == JSExportAllAnnotation)
+        else
+          group.size > 1
+      }
+      .foreach(_ => reporter.warning(sym.pos, s"Found duplicate @JSExport"))
+
     /* Filter out static exports of accessors (as they are not actually
      * exported, their fields are). The above is only used to uniformly perform
      * checks.

compiler/src/test/scala/org/scalajs/nscplugin/test/JSExportTest.scala

@@ -28,6 +28,88 @@ class JSExportTest extends DirectTest with TestHelpers {
     """import scala.scalajs.js, js.annotation._
     """
 
+  @Test
+  def warnOnDuplicateExport: Unit = {
+    """
+    class A {
+      @JSExport
+      @JSExport
+      def a = 1
+    }
+    """ hasWarns
+    """
+      |newSource1.scala:6: warning: Found duplicate @JSExport
+      |      def a = 1
+      |          ^
+    """
+
+    """
+    class A {
+      @JSExport
+      @JSExport("a")
+      def a = 1
+    }
+    """ hasWarns
+    """
+      |newSource1.scala:6: warning: Found duplicate @JSExport
+      |      def a = 1
+      |          ^
+    """
+
+    """
+    class A {
+      @JSExport("a")
+      @JSExport("a")
+      def a = 1
+    }
+    """ hasWarns
+    """
+      |newSource1.scala:6: warning: Found duplicate @JSExport
+      |      def a = 1
+      |          ^
+    """
+
+    // special case for @JSExportAll and 2 or more @JSExport("apply")
+    // since @JSExportAll and single @JSExport("apply") should not be warned (see other tests)
+    """
+    @JSExportAll
+    class A {
+      @JSExport("apply")
+      @JSExport("apply")
+      def apply(): Int = 1
+    }
+    """ hasWarns
+    """
+      |newSource1.scala:7: warning: Found duplicate @JSExport
+      |      def apply(): Int = 1
+      |          ^
+    """
+
+    """
+    @JSExportAll
+    class A {
+      @JSExport
+      def a = 1
+    }
+    """ hasWarns
+    """
+      |newSource1.scala:6: warning: Found duplicate @JSExport
+      |      def a = 1
+      |          ^
+    """
+  }
+
+  @Test
+  def noWarnOnUniqueExplicitName: Unit = {
+    """
+    class A {
+      @JSExport("a")
+      @JSExport("b")
+      def c = 1
+    }
+    """.hasNoWarns
+  }
+
   @Test
   def noJSExportClass: Unit = {
     """

javalib/src/main/scala/java/io/OutputStreamWriter.scala

@@ -44,8 +44,14 @@ class OutputStreamWriter(private[this] var out: OutputStream,
   def this(out: OutputStream) =
     this(out, Charset.defaultCharset)
 
-  def this(out: OutputStream, charsetName: String) =
-    this(out, Charset.forName(charsetName))
+  def this(out: OutputStream, charsetName: String) = {
+    this(out, try {
+      Charset.forName(charsetName)
+    } catch {
+      case _: UnsupportedCharsetException =>
+        throw new UnsupportedEncodingException(charsetName)
+    })
+  }
 
   def getEncoding(): String =
     if (closed) null else enc.charset.name

javalib/src/main/scala/java/util/Collection.scala

@@ -12,6 +12,10 @@
 
 package java.util
 
+import java.util.function.Predicate
+
+import scala.scalajs.js.annotation.JavaDefaultMethod
+
 trait Collection[E] extends java.lang.Iterable[E] {
   def size(): Int
   def isEmpty(): Boolean
@@ -24,6 +28,20 @@ trait Collection[E] extends java.lang.Iterable[E] {
   def containsAll(c: Collection[_]): Boolean
   def addAll(c: Collection[_ <: E]): Boolean
   def removeAll(c: Collection[_]): Boolean
+
+  @JavaDefaultMethod
+  def removeIf(filter: Predicate[_ >: E]): Boolean = {
+    var result = false
+    val iter = iterator()
+    while (iter.hasNext()) {
+      if (filter.test(iter.next())) {
+        iter.remove()
+        result = true
+      }
+    }
+    result
+  }
+
   def retainAll(c: Collection[_]): Boolean
   def clear(): Unit
   def equals(o: Any): Boolean

javalib/src/main/scala/java/util/Objects.scala

@@ -17,13 +17,13 @@ import scala.reflect.ClassTag
 object Objects {
 
   @inline
-  def equals(a: AnyRef, b: AnyRef): Boolean =
+  def equals(a: Any, b: Any): Boolean =
     if (a == null) b == null
     else a.equals(b)
 
   @inline
-  def deepEquals(a: AnyRef, b: AnyRef): Boolean = {
-    if (a eq b) true
+  def deepEquals(a: Any, b: Any): Boolean = {
+    if (a.asInstanceOf[AnyRef] eq b.asInstanceOf[AnyRef]) true
     else if (a == null || b == null) false
     else {
       (a, b) match {
@@ -42,7 +42,7 @@ object Objects {
   }
 
   @inline
-  def hashCode(o: AnyRef): Int =
+  def hashCode(o: Any): Int =
     if (o == null) 0
     else o.hashCode()
 
@@ -51,11 +51,11 @@ object Objects {
     Arrays.hashCode(values)
 
   @inline
-  def toString(o: AnyRef): String =
+  def toString(o: Any): String =
     String.valueOf(o)
 
   @inline
-  def toString(o: AnyRef, nullDefault: String): String =
+  def toString(o: Any, nullDefault: String): String =
     if (o == null) nullDefault
     else o.toString
 
@@ -75,11 +75,11 @@ object Objects {
     else obj
 
   @inline
-  def isNull(obj: AnyRef): Boolean =
+  def isNull(obj: Any): Boolean =
     obj == null
 
   @inline
-  def nonNull(obj: AnyRef): Boolean =
+  def nonNull(obj: Any): Boolean =
     obj != null
 
   // Requires the implementation of java.util.function

javalib/src/main/scala/java/util/concurrent/CopyOnWriteArrayList.scala

@@ -14,6 +14,7 @@ package java.util.concurrent
 
 import java.lang.{reflect => jlr}
 import java.util._
+import java.util.function.Predicate
 
 import scala.annotation.tailrec
 
@@ -185,6 +186,39 @@ class CopyOnWriteArrayList[E <: AnyRef] private (private var inner: js.Array[E])
     !c.isEmpty
   }
 
+  /* Override Collection.removeIf() because our iterators do not support
+   * the `remove()` method.
+   */
+  override def removeIf(filter: Predicate[_ >: E]): Boolean = {
+    // scalastyle:off return
+    /* The outer loop iterates as long as no element passes the filter (and
+     * hence no modification is required).
+     */
+    val iter = iterator()
+    var index = 0
+    while (iter.hasNext()) {
+      if (filter.test(iter.next())) {
+        /* We found the first element that needs to be removed: copy and
+         * truncate at the current index.
+         */
+        copyIfNeeded()
+        innerSplice(index, size() - index)
+        /* Now keep iterating, but push elements that do not pass the test.
+         * `index` is useless from now on, so do not keep updating it.
+         */
+        while (iter.hasNext()) {
+          val elem = iter.next()
+          if (!filter.test(elem))
+            innerPush(elem)
+        }
+        return true
+      }
+      index += 1
+    }
+    false // the outer loop finished without entering the inner one
+    // scalastyle:on return
+  }
+
   override def toString: String =
     iterator().scalaOps.mkString("[", ",", "]")
 

javalib/src/main/scala/java/util/function/Predicate.scala

@@ -0,0 +1,55 @@
+/*
+ * Scala.js (https://www.scala-js.org/)
+ *
+ * Copyright EPFL.
+ *
+ * Licensed under Apache License 2.0
+ * (https://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package java.util.function
+
+import java.{util => ju}
+
+import scala.scalajs.js.annotation.JavaDefaultMethod
+
+@FunctionalInterface
+trait Predicate[T] { self =>
+  def test(t: T): Boolean
+
+  @JavaDefaultMethod
+  def and(other: Predicate[_ >: T]): Predicate[T] = {
+    new Predicate[T] {
+      def test(t: T): Boolean =
+        self.test(t) && other.test(t) // the order and short-circuit are by-spec
+    }
+  }
+
+  @JavaDefaultMethod
+  def negate(): Predicate[T] = {
+    new Predicate[T] {
+      def test(t: T): Boolean =
+        !self.test(t)
+    }
+  }
+
+  @JavaDefaultMethod
+  def or(other: Predicate[_ >: T]): Predicate[T] = {
+    new Predicate[T] {
+      def test(t: T): Boolean =
+        self.test(t) || other.test(t) // the order and short-circuit are by-spec
+    }
+  }
+}
+
+object Predicate {
+  def isEqual[T](targetRef: Any): Predicate[T] = {
+    new Predicate[T] {
+      def test(t: T): Boolean =
+        ju.Objects.equals(targetRef, t)
+    }
+  }
+}

library/src/main/scala/scala/scalajs/js/typedarray/Float32Array.scala

@@ -44,4 +44,4 @@ class Float32Array private[this] () extends TypedArray[Float, Float32Array] {
  */
 @js.native
 @JSGlobal
-object Float32Array extends TypedArrayStatic
+object Float32Array extends TypedArrayStatic[Float, Float32Array]

library/src/main/scala/scala/scalajs/js/typedarray/Float64Array.scala

@@ -44,4 +44,4 @@ class Float64Array private[this] () extends TypedArray[Double, Float64Array] {
  */
 @js.native
 @JSGlobal
-object Float64Array extends TypedArrayStatic
+object Float64Array extends TypedArrayStatic[Double, Float64Array]

library/src/main/scala/scala/scalajs/js/typedarray/Int16Array.scala

@@ -44,4 +44,4 @@ class Int16Array private[this] () extends TypedArray[Short, Int16Array] {
  */
 @js.native
 @JSGlobal
-object Int16Array extends TypedArrayStatic
+object Int16Array extends TypedArrayStatic[Short, Int16Array]

library/src/main/scala/scala/scalajs/js/typedarray/Int32Array.scala

@@ -44,4 +44,4 @@ class Int32Array private[this] () extends TypedArray[Int, Int32Array] {
  */
 @js.native
 @JSGlobal
-object Int32Array extends TypedArrayStatic
+object Int32Array extends TypedArrayStatic[Int, Int32Array]

library/src/main/scala/scala/scalajs/js/typedarray/Int8Array.scala

@@ -44,4 +44,4 @@ class Int8Array private[this] () extends TypedArray[Byte, Int8Array] {
  */
 @js.native
 @JSGlobal
-object Int8Array extends TypedArrayStatic
+object Int8Array extends TypedArrayStatic[Byte, Int8Array]

library/src/main/scala/scala/scalajs/js/typedarray/TypedArray.scala

@@ -65,6 +65,20 @@ trait TypedArray[T, Repr] extends ArrayBufferView with js.Iterable[T] {
  *  Static information that exists for any concrete TypedArray
  */
 @js.native
-trait TypedArrayStatic extends js.Object {
+trait TypedArrayStatic[T, Repr] extends js.Object {
   val BYTES_PER_ELEMENT: Int = js.native
+
+  /** Returns a new array from a set of elements. */
+  def of(items: T*): Repr = js.native
+
+  /** Creates an array from an `iterable` object. */
+  def from(iterable: js.Iterable[T]): Repr = js.native
+
+  /** Creates an array from an `iterable` object. */
+  def from[E](iterable: js.Iterable[E],
+      mapFn: js.Function1[E, T]): Repr = js.native
+
+  /** Creates an array from an `iterable` object. */
+  def from[D, E](iterable: js.Iterable[E], mapFn: js.ThisFunction1[D, E, T],
+      thisArg: D): Repr = js.native
 }

library/src/main/scala/scala/scalajs/js/typedarray/Uint16Array.scala

@@ -44,4 +44,4 @@ class Uint16Array private[this] () extends TypedArray[Int, Uint16Array] {
  */
 @js.native
 @JSGlobal
-object Uint16Array extends TypedArrayStatic
+object Uint16Array extends TypedArrayStatic[Int, Uint16Array]

library/src/main/scala/scala/scalajs/js/typedarray/Uint32Array.scala

@@ -44,4 +44,4 @@ class Uint32Array private[this] () extends TypedArray[Double, Uint32Array] {
  */
 @js.native
 @JSGlobal
-object Uint32Array extends TypedArrayStatic
+object Uint32Array extends TypedArrayStatic[Double, Uint32Array]

library/src/main/scala/scala/scalajs/js/typedarray/Uint8Array.scala

@@ -44,4 +44,4 @@ class Uint8Array private[this] () extends TypedArray[Short, Uint8Array] {
  */
 @js.native
 @JSGlobal
-object Uint8Array extends TypedArrayStatic
+object Uint8Array extends TypedArrayStatic[Short, Uint8Array]