Deferred results should always be deferred and be sent second

Author: JacobMountain

src/main/java/graphql/servlet/AbstractGraphQLHttpServlet.java

@@ -585,6 +585,7 @@ private static class StaticDataPublisher<T> extends SingleSubscriberPublisher<T>
  StaticDataPublisher(T data) {
  super();
  super.offer(data);
+ super.noMoreData();
  }
  }
 

src/test/groovy/graphql/servlet/AbstractGraphQLHttpServletSpec.groovy

@@ -1054,9 +1054,39 @@ class AbstractGraphQLHttpServletSpec extends Specification {
 
  def "defer query over HTTP POST"() {
  setup:
- servlet = TestUtils.createDefaultServlet()
+ request.setContent('{"query": "subscription Subscription($arg: String!) { echo(arg: $arg) }", "operationName": "Subscription", "variables": {"arg": "test"}}'.bytes)
+ request.setAsyncSupported(true)
+
+ when:
+ servlet.doPost(request, response)
+ then:
+ response.getStatus() == STATUS_OK
+ response.getContentType() == CONTENT_TYPE_SERVER_SENT_EVENTS
+
+ when:
+ subscriptionLatch.await(1, TimeUnit.SECONDS)
+ then:
+ getSubscriptionResponseContent()[0].data.echo == "First\n\ntest"
+ getSubscriptionResponseContent()[1].data.echo == "Second\n\ntest"
+ }
+
+ def "deferred query that takes longer than initial results, should still be sent second"() {
+ setup:
+ servlet = TestUtils.createDefaultServlet({ env ->
+ if (env.getField().name == "a") {
+ Thread.sleep(1000)
+ }
+ env.arguments.arg
+ })
  request.setContent(mapper.writeValueAsBytes([
- query: 'query { echo(arg:"test") @defer }'
+ query: '''
+ { 
+ object { 
+ a(arg: "Hello") 
+ b(arg: "World") @defer
+ } 
+ }
+ '''
  ]))
  request.setAsyncSupported(true)
 
@@ -1066,15 +1096,15 @@ class AbstractGraphQLHttpServletSpec extends Specification {
  then:
  response.getStatus() == STATUS_OK
  response.getContentType() == CONTENT_TYPE_SERVER_SENT_EVENTS
- getSubscriptionResponseContent()[0].data.echo == null
+ getSubscriptionResponseContent()[0].data.object.a == "Hello" // a has a Thread.sleep
 
  when:
  subscriptionLatch.await(1, TimeUnit.SECONDS)
 
  then:
  def content = getSubscriptionResponseContent()
- content[1].data == "test"
- content[1].path == ["echo"]
+ content[1].data == "World"
+ content[1].path == ["object", "b"]
  }
 
  def "errors before graphql schema execution return internal server error"() {

src/test/groovy/graphql/servlet/TestUtils.groovy

@@ -115,6 +115,32 @@ class TestUtils {
  }
  field.dataFetcher(queryDataFetcher)
  }
+ .field { GraphQLFieldDefinition.Builder field ->
+ field.name("object")
+ field.type(
+ GraphQLObjectType.newObject()
+ .name("NestedObject")
+ .field { nested ->
+ nested.name("a")
+ nested.type(Scalars.GraphQLString)
+ nested.argument { argument ->
+ argument.name("arg")
+ argument.type(Scalars.GraphQLString)
+ }
+ nested.dataFetcher(queryDataFetcher)
+ }
+ .field { nested ->
+ nested.name("b")
+ nested.type(Scalars.GraphQLString)
+ nested.argument { argument ->
+ argument.name("arg")
+ argument.type(Scalars.GraphQLString)
+ }
+ nested.dataFetcher(queryDataFetcher)
+ }
+ )
+ field.dataFetcher(new StaticDataFetcher([:]))
+ }
  .field { GraphQLFieldDefinition.Builder field ->
  field.name("returnsNullIncorrectly")
  field.type(new GraphQLNonNull(Scalars.GraphQLString))