fragment_chain: add test case

Reported in #286.

Author: cairomassimo

graphql_client/tests/fragment_chain.rs

@@ -0,0 +1,9 @@
+use graphql_client::*;
+
+#[allow(dead_code)]
+#[derive(GraphQLQuery)]
+#[graphql(
+    schema_path = "tests/fragment_chain/schema.graphql",
+    query_path = "tests/fragment_chain/query.graphql"
+)]
+struct Q;

graphql_client/tests/fragment_chain/query.graphql

@@ -0,0 +1,11 @@
+query Q {
+    ...FragmentB
+}
+
+fragment FragmentB on Query {
+    ...FragmentA
+}
+
+fragment FragmentA on Query {
+    x
+}

graphql_client/tests/fragment_chain/schema.graphql

@@ -0,0 +1,3 @@
+type Query {
+    x: String
+}