Adding headers to an Akka HTTP HttpRequest

Question

I have an existing Akka HTTP HttpRequest and I want to add two headers to it.

val req: HttpRequest = ???
val hs: Seq[HttpHeader] = Seq(RawHeader("a", "b"))
req.addHeaders(hs)

Expected:

• a new HttpRequest object with the additional headers

Actual:

• .addHeaders expects a java.lang.Iterable and does not compile.

What is the recommended way of doing this in Scala?

There is a workaround, but it's a bit cludgy:

req.withHeaders(req.headers ++ hs)

Running Scala 2.12.8 and Akka HTTP 10.1.7.

Answer 1

Another workaround that is maybe a tiny sliver less cludgy. This is approximately how addHeaders is defined in the source. I unfortunately have no clue why addHeaders is not exposed in the scala api.

req.mapHeaders(_ ++ hs)