GraphQL: Implement input (#2311)

src/printer-graphql.js

@@ -296,6 +296,22 @@ function genericPrint(path, options, print) {
       ]);
     }
 
+    case "InputObjectTypeDefinition": {
+      return concat([
+        "input ",
+        path.call(print, "name"),
+        printDirectives(path, print, n),
+        " {",
+        n.fields.length > 0
+          ? indent(
+              concat([hardline, join(hardline, path.map(print, "fields"))])
+            )
+          : "",
+        hardline,
+        "}"
+      ]);
+    }
+
     case "FragmentSpread": {
       return concat([
         "...",

tests/graphql_object_type_def/__snapshots__/jsfmt.spec.js.snap

@@ -20,6 +20,19 @@ type VRMConversation implements Node, Entity @foo {
 
 `;
 
+exports[`input.graphql 1`] = `
+input Params {
+  app_id: ID!
+  key_hash: String!
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+input Params {
+  app_id: ID!
+  key_hash: String!
+}
+
+`;
+
 exports[`object_type_def.graphql 1`] = `
 type FeedHomeStories {
   debug_info: String

tests/graphql_object_type_def/input.graphql

@@ -0,0 +1,4 @@
+input Params {
+  app_id: ID!
+  key_hash: String!
+}