Support appending header ranges to CorsSettings.

http-cors/src/main/java/org/apache/pekko/http/cors/javadsl/model/HttpHeaderRange.java

@@ -24,6 +24,13 @@
 public abstract class HttpHeaderRange {
   public abstract boolean matches(String header);
 
+  /**
+   * Produces a new range that matches the headers of this range and the given range.
+   *
+   * @since 2.0.0
+   */
+  public abstract HttpHeaderRange concat(HttpHeaderRange range);
+
   public static HttpHeaderRange create(String... headers) {
     return HttpHeaderRange$.MODULE$.apply(Util.convertArray(headers));
   }

http-cors/src/main/mima-filters/2.0.x.backwards.excludes/new-methods.excludes

@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# New methods added in 2.0.x
+ProblemFilters.exclude[ReversedMissingMethodProblem]("org.apache.pekko.http.cors.javadsl.model.HttpHeaderRange.concat")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("org.apache.pekko.http.cors.scaladsl.model.HttpHeaderRange.concat")

http-cors/src/main/scala/org/apache/pekko/http/cors/CorsJavaMapping.scala

@@ -27,5 +27,8 @@ private[pekko] object CorsJavaMapping {
   object Implicits {
     implicit object CorsSettingsMapping
         extends JavaMapping.Inherited[javadsl.settings.CorsSettings, scaladsl.settings.CorsSettings]
+
+    implicit object HttpHeaderRangeMapping
+        extends JavaMapping.Inherited[javadsl.model.HttpHeaderRange, scaladsl.model.HttpHeaderRange]
   }
 }

http-cors/src/main/scala/org/apache/pekko/http/cors/scaladsl/model/HttpHeaderRange.scala

@@ -20,19 +20,39 @@ package org.apache.pekko.http.cors.scaladsl.model
 import scala.collection.immutable.Seq
 
 import org.apache.pekko
+import pekko.http.cors.CorsJavaMapping.Implicits._
 import pekko.http.cors.javadsl
+import pekko.http.impl.util.JavaMapping
 import pekko.util.Helpers
 
-abstract class HttpHeaderRange extends javadsl.model.HttpHeaderRange
+sealed abstract class HttpHeaderRange extends javadsl.model.HttpHeaderRange {
+  override def concat(range: javadsl.model.HttpHeaderRange): HttpHeaderRange
+
+  /**
+   * Operator alias for [[concat]].
+   *
+   * @since 2.0.0
+   */
+  def ++(range: javadsl.model.HttpHeaderRange): HttpHeaderRange = concat(range)
+}
 
 object HttpHeaderRange {
   case object `*` extends HttpHeaderRange {
     def matches(header: String) = true
+
+    override def concat(range: javadsl.model.HttpHeaderRange): HttpHeaderRange = this
   }
 
   final case class Default(headers: Seq[String]) extends HttpHeaderRange {
     private val lowercaseHeaders: Seq[String] = headers.map(Helpers.toRootLowerCase)
     def matches(header: String): Boolean = lowercaseHeaders.contains(Helpers.toRootLowerCase(header))
+
+    override def concat(range: javadsl.model.HttpHeaderRange): HttpHeaderRange = {
+      JavaMapping.toScala(range) match {
+        case `*`              => `*`
+        case Default(headers) => Default(this.headers ++ headers)
+      }
+    }
   }
 
   def apply(headers: String*): Default = Default(Seq(headers: _*))

http-cors/src/test/scala/org/apache/pekko/http/cors/scaladsl/model/HttpHeaderRangeSpec.scala

@@ -0,0 +1,107 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.pekko.http.cors.scaladsl.model
+
+import org.apache.pekko.http.scaladsl.model.headers.{ `Content-Type`, Accept }
+import org.scalatest.Inspectors
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpec
+
+class HttpHeaderRangeSpec extends AnyWordSpec with Matchers with Inspectors {
+
+  "The `*` range" should {
+    "match any Header" in {
+      val headers = Seq(
+        `Content-Type`.name,
+        "conTent-tyPe",
+        Accept.name,
+        "x-any-random-header-name")
+
+      forAll(headers) { o => HttpHeaderRange.*.matches(o) shouldBe true }
+    }
+
+    "be printed as `*`" in {
+      HttpHeaderRange.*.toString shouldBe "*"
+    }
+  }
+
+  "The default range" should {
+    val range = HttpHeaderRange(`Content-Type`.name, Accept.name)
+
+    "match headers ignoring case" in {
+      val headers = Seq(
+        `Content-Type`.name,
+        `Content-Type`.name.toUpperCase(),
+        `Content-Type`.name.toLowerCase(),
+        "conTent-tyPe",
+        Accept.name,
+        Accept.name.toUpperCase(),
+        Accept.name.toLowerCase(),
+        "aCcepT")
+
+      forAll(headers) { o => range.matches(o) shouldBe true }
+    }
+
+    "not match other headers" in {
+      val headers = Seq(
+        "Content-Type2",
+        "Content-Typ",
+        "x-any-random-header-name")
+
+      forAll(headers) { o => range.matches(o) shouldBe false }
+    }
+  }
+
+  "Concatenation of ranges" should {
+    "match both ranges" in {
+      val range1 = HttpHeaderRange(`Content-Type`.name)
+      val range2 = HttpHeaderRange(Accept.name)
+
+      val combined = range1 ++ range2
+
+      val headers = Seq(
+        `Content-Type`.name,
+        Accept.name)
+      val notHeaders = Seq(
+        "Content-Type2",
+        "Content-Typ",
+        "x-any-random-header-name")
+
+      forAll(headers) { o => combined.matches(o) shouldBe true }
+      forAll(notHeaders) { o => combined.matches(o) shouldBe false }
+    }
+
+    "combine with the `*` range" in {
+      val range1 = HttpHeaderRange(`Content-Type`.name)
+      val starRange = HttpHeaderRange.*
+
+      val combinedBefore = starRange ++ range1
+      val combinedAfter = range1 ++ starRange
+
+      val headers = Seq(
+        `Content-Type`.name,
+        "conTent-tyPe",
+        Accept.name,
+        "x-any-random-header-name")
+
+      forAll(headers) { o => combinedBefore.matches(o) shouldBe true }
+      forAll(headers) { o => combinedAfter.matches(o) shouldBe true }
+    }
+  }
+
+}