From 4d96cfbf6b7a8d34906150481e9d3a5543a1db38 Mon Sep 17 00:00:00 2001
From: Nepomuk Seiler <muuki88@users.noreply.github.com>
Date: Thu, 26 Jul 2018 08:44:17 +0200
Subject: [PATCH] Enable post requests for introspection (#41)

* Enable post requests for introspection

* Scalafmt
---
 README.md                                     |  6 +++
 .../muki/graphql/schema/SchemaLoader.scala    | 46 ++++++++++++++++---
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 4128154..d2dcedf 100644
--- a/README.md
+++ b/README.md
@@ -115,6 +115,12 @@ graphqlProductionSchema := GraphQLSchemaLoader
   .fromIntrospection("http://prod.your-graphql.net/graphql", streams.value.log)
   .withHeaders("X-Api-Version" -> "1", "X-Api-Key" -> "4198ab84-e992-42b0-8742-225ed15a781e")
   .loadSchema()
+  
+// from a graphql endpoint via introspection with post request
+graphqlProductionSchema := GraphQLSchemaLoader
+  .fromIntrospection("http://prod.your-graphql.net/graphql", streams.value.log)
+  .withPost()
+  .loadSchema()
 ```
 
 
diff --git a/src/main/scala/rocks/muki/graphql/schema/SchemaLoader.scala b/src/main/scala/rocks/muki/graphql/schema/SchemaLoader.scala
index 125ce06..06a1927 100644
--- a/src/main/scala/rocks/muki/graphql/schema/SchemaLoader.scala
+++ b/src/main/scala/rocks/muki/graphql/schema/SchemaLoader.scala
@@ -76,7 +76,9 @@ class FileSchemaLoader(file: File) extends SchemaLoader {
   */
 case class IntrospectSchemaLoader(url: String,
                                   log: Logger,
-                                  headers: Seq[(String, String)] = Seq.empty)
+                                  headers: Seq[(String, String)] = Seq.empty,
+                                  method: IntrospectSchemaLoader.Method =
+                                    IntrospectSchemaLoader.GET)
     extends SchemaLoader {
 
   override def loadSchema(): Schema[Any, Any] =
@@ -86,22 +88,52 @@ case class IntrospectSchemaLoader(url: String,
     copy(headers = headers.toList)
   }
 
+  /**
+    * @return a new schema loader that uses a POST requests instead of a get request
+    */
+  def withPost(): IntrospectSchemaLoader = {
+    copy(method = IntrospectSchemaLoader.POST)
+  }
+
   /**
     * @see https://github.com/graphql/graphql-js/blob/master/src/utilities/introspectionQuery.js
     * @return the introspect query result
     */
   private def introspect(): Json = {
-    log.info(s"Introspect graphql endpoint: $url")
-    val response = Http(url)
-      .headers(headers)
-      .param("query", introspectionQuery.renderCompact)
-      .asString
+    log.info(s"Introspect graphql endpoint: ${method.name} : $url")
+
+    val response = method match {
+      case IntrospectSchemaLoader.POST =>
+        val body = Json
+          .obj("query" -> Json.fromString(introspectionQuery.renderCompact))
+          .noSpaces
+        Http(url).headers(headers).method("POST").postData(body).asString
+      case IntrospectSchemaLoader.GET =>
+        Http(url)
+          .headers(headers)
+          .param("query", introspectionQuery.renderCompact)
+          .asString
+    }
+
     parse(response.body) match {
       case Right(json) => json
       case Left(error) =>
         log.error("JSON parse errors:")
         log.error(error.message)
-        sys.error(s"Invalid JSON was returned from graphql endpoint $url")
+        log.error("Body received")
+        log.error(response.body)
+        sys.error(
+          s"Invalid JSON was returned from graphql endpoint ${method.name} : $url")
     }
   }
 }
+
+object IntrospectSchemaLoader {
+
+  /**
+    * http method for introspection query
+    */
+  sealed abstract class Method(val name: String)
+  case object POST extends Method("POST")
+  case object GET extends Method("GET")
+}