Expand BodySerializer to carry a default content type

And update circe module to use this

3 files changed, 34 insertions, 9 deletions

diff --git a/core/src/main/scala/com/softwaremill/sttp/BodySerializer.scala b/core/src/main/scala/com/softwaremill/sttp/BodySerializer.scala
new file mode 100644
index 0000000..040c563
--- /dev/null
+++ b/core/src/main/scala/com/softwaremill/sttp/BodySerializer.scala
@@ -0,0 +1,29 @@
+package com.softwaremill.sttp
+
+import com.softwaremill.sttp.model.BasicRequestBody
+
+/**
+  * Provide an implicit value of this type to serialize arbitrary classes into a request body.
+  * Handlers might also provide special logic for serializer instances which they define (e.g. to handle streaming).
+  */
+trait BodySerializer[B] {
+  def apply(body: B): BasicRequestBody
+  def defaultContentType: Option[String]
+}
+
+object BodySerializer {
+  final def apply[B](implicit instance: BodySerializer[B]): BodySerializer[B] =
+    instance
+
+  final def instance[B](f: B => BasicRequestBody) =
+    new BodySerializer[B] {
+      def apply(body: B): BasicRequestBody = f(body)
+      val defaultContentType: Option[String] = None
+    }
+
+  final def instance[B](f: B => BasicRequestBody, contentType: String) =
+    new BodySerializer[B] {
+      def apply(body: B): BasicRequestBody = f(body)
+      val defaultContentType: Option[String] = Option(contentType)
+    }
+}
diff --git a/core/src/main/scala/com/softwaremill/sttp/RequestT.scala b/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
index 4e38662..c17be59 100644
--- a/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
@@ -203,9 +203,11 @@ case class RequestT[U[_], T, +S](
     * If content type is not yet specified, will be set to
     * `application/octet-stream`.
     */
-  def body[B: BodySerializer](b: B): RequestT[U, T, S] =
-    setContentTypeIfMissing(ApplicationOctetStreamContentType).copy(
-      body = SerializableBody(implicitly[BodySerializer[B]], b))
+  def body[B](b: B)(implicit serializer: BodySerializer[B]): RequestT[U, T, S] =
+    setContentTypeIfMissing(
+      serializer.defaultContentType.getOrElse(
+        ApplicationOctetStreamContentType))
+      .copy(body = SerializableBody(serializer, b))
 
   //def multipartData(parts: MultiPart*): RequestTemplate[U] = ???
 
diff --git a/core/src/main/scala/com/softwaremill/sttp/package.scala b/core/src/main/scala/com/softwaremill/sttp/package.scala
index 884d2f9..cca86dd 100644
--- a/core/src/main/scala/com/softwaremill/sttp/package.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/package.scala
@@ -22,12 +22,6 @@ package object sttp {
       ".get(...), .post(...) etc. to obtain a non-partial request.")
   private[sttp] type IsIdInRequest[U[_]] = U[Unit] =:= Id[Unit]
 
-  /**
-    * Provide an implicit value of this type to serialize arbitrary classes into a request body.
-    * Handlers might also provide special logic for serializer instances which they define (e.g. to handle streaming).
-    */
-  type BodySerializer[B] = B => BasicRequestBody
-
   // constants
 
   private[sttp] val ContentTypeHeader = "Content-Type"