StreamedResponse headers map is now case insensitive (backport #909) by @mkurz

play-ahc-ws-standalone/src/main/java/play/libs/ws/ahc/StreamedResponse.java

@@ -17,9 +17,11 @@
 import scala.jdk.javaapi.StreamConverters;
 
 import java.net.URI;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.TreeMap;
 import java.util.function.Predicate;
 
 import static java.util.stream.Collectors.toMap;
@@ -121,7 +123,16 @@ public URI getUri() {
     }
 
     private static java.util.Map<String, List<String>> asJava(scala.collection.Map<String, Seq<String>> scalaMap) {
-        return StreamConverters.asJavaSeqStream(scalaMap).collect(toMap(f -> f._1(), f -> CollectionConverters.asJava(f._2())));
+        return StreamConverters.asJavaSeqStream(scalaMap).collect(toMap(f -> f._1(), f -> CollectionConverters.asJava(f._2()),
+                (l, r) -> {
+                    final List<String> merged = new ArrayList<>(l.size() + r.size());
+                    merged.addAll(l);
+                    merged.addAll(r);
+                    return merged;
+                },
+                () -> new TreeMap<>(String.CASE_INSENSITIVE_ORDER)
+            )
+        );
     }
 
 }

play-ahc-ws-standalone/src/main/scala/play/api/libs/ws/ahc/StreamedResponse.scala

@@ -11,6 +11,9 @@ import play.api.libs.ws.StandaloneWSResponse
 import play.api.libs.ws.WSCookie
 import play.shaded.ahc.org.asynchttpclient.HttpResponseBodyPart
 
+import scala.collection.immutable.TreeMap
+import scala.collection.mutable
+
 /**
  * A streamed response containing a response header and a streamable body.
  *
@@ -39,17 +42,49 @@ class StreamedResponse(
     val status: Int,
     val statusText: String,
     val uri: java.net.URI,
-    val headers: Map[String, scala.collection.Seq[String]],
     publisher: Publisher[HttpResponseBodyPart],
     val useLaxCookieEncoder: Boolean
 ) extends StandaloneWSResponse
     with CookieBuilder {
 
+  def this(
+      client: StandaloneAhcWSClient,
+      status: Int,
+      statusText: String,
+      uri: java.net.URI,
+      headers: Map[String, scala.collection.Seq[String]],
+      publisher: Publisher[HttpResponseBodyPart],
+      useLaxCookieEncoder: Boolean
+  ) = {
+    this(
+      client,
+      status,
+      statusText,
+      uri,
+      publisher,
+      useLaxCookieEncoder
+    )
+    origHeaders = headers
+  }
+
+  private var origHeaders: Map[String, scala.collection.Seq[String]] = Map.empty
+
   /**
    * Get the underlying response object.
    */
   override def underlying[T]: T = publisher.asInstanceOf[T]
 
+  override lazy val headers: Map[String, scala.collection.Seq[String]] = {
+    val mutableMap = mutable.TreeMap[String, scala.collection.Seq[String]]()(CaseInsensitiveOrdered)
+    origHeaders.keys.foreach { name =>
+      mutableMap.updateWith(name) {
+        case Some(value) => Some(value ++ origHeaders.getOrElse(name, Seq.empty))
+        case None        => Some(origHeaders.getOrElse(name, Seq.empty))
+      }
+    }
+    TreeMap[String, scala.collection.Seq[String]]()(CaseInsensitiveOrdered) ++ mutableMap
+  }
+
   /**
    * Get all the cookies.
    */

play-ahc-ws-standalone/src/test/scala/play/api/libs/ws/ahc/AhcWSResponseSpec.scala

@@ -128,6 +128,14 @@ class AhcWSResponseSpec extends Specification with DefaultBodyReadables with Def
       headers.contains("Bar") must beTrue
     }
 
+    "get headers map which retrieves headers case insensitively (for streamed responses)" in {
+      val srcHeaders = Map("Foo" -> Seq("a"), "foo" -> Seq("b"), "FOO" -> Seq("b"), "Bar" -> Seq("baz"))
+      val response   = new StreamedResponse(null, 200, "", null, srcHeaders, null, true)
+      val headers    = response.headers
+      headers("foo") must_== Seq("a", "b", "b")
+      headers("BAR") must_== Seq("baz")
+    }
+
     "get a single header" in {
       val ahcResponse: AHCResponse = mock[AHCResponse]
       val ahcHeaders               = new DefaultHttpHeaders(true)

play-ahc-ws-standalone/src/test/scala/play/libs/ws/ahc/AhcWSResponseSpec.scala

@@ -46,6 +46,14 @@ class AhcWSResponseSpec extends Specification with DefaultBodyReadables with Def
       headers.get("BAR").asScala must_== Seq("baz")
     }
 
+    "get headers map which retrieves headers case insensitively (for streamed responses)" in {
+      val srcHeaders = Map("Foo" -> Seq("a"), "foo" -> Seq("b"), "FOO" -> Seq("b"), "Bar" -> Seq("baz"))
+      val response   = new StreamedResponse(null, 200, "", null, srcHeaders, null, true)
+      val headers    = response.getHeaders
+      headers.get("foo").asScala must_== Seq("a", "b", "b")
+      headers.get("BAR").asScala must_== Seq("baz")
+    }
+
     "get a single header" in {
       val srcResponse = mock[Response]
       val srcHeaders = new DefaultHttpHeaders()