Document and explicitly test nested union field selections on interfaces

Author: tomhoule

graphql_client/tests/interfaces.rs

@@ -92,7 +92,7 @@ const RESPONSE_FRAGMENT: &'static str =
 #[test]
 fn fragment_in_interface() {
     use interface_with_fragment_query::*;
-    let response_data: interface_with_fragment_query::ResponseData =
+    let response_data: ResponseData =
         serde_json::from_str(RESPONSE_FRAGMENT).expect("RESPONSE_FRAGMENT did not deserialize");
 
     assert_eq!(
@@ -103,7 +103,10 @@ fn fragment_in_interface() {
                     name: "Audrey Lorde".to_string(),
                     public_status: PublicStatus {
                         display_name: false,
-                        on: PublicStatusOn::Person,
+                        on: PublicStatusOn::Person(PublicStatusOnPerson {
+                            birthday: Some("1934-02-18".to_string()),
+                            age: Some(84),
+                        }),
                     },
                     on: InterfaceWithFragmentQueryEverythingOn::Person(
                         InterfaceWithFragmentQueryEverythingOnPerson {
@@ -125,7 +128,9 @@ fn fragment_in_interface() {
                     name: "Mozilla".to_string(),
                     public_status: PublicStatus {
                         display_name: false,
-                        on: PublicStatusOn::Organization
+                        on: PublicStatusOn::Organization(PublicStatusOnOrganization {
+                            industry: Industry::CAT_FOOD,
+                        })
                     },
                     on: InterfaceWithFragmentQueryEverythingOn::Organization,
                 },

graphql_client/tests/interfaces/interface_schema.graphql

@@ -10,9 +10,11 @@ interface Named {
 type Person implements Named {
   name: String!
   birthday: String
+  age: Int
 }
 
 enum Industry {
+  CAT_FOOD
   CHOCOLATE
   OTHER
 }

graphql_client/tests/interfaces/interface_with_fragment_query.graphql

@@ -1,6 +1,13 @@
 fragment PublicStatus on Named {
   __typename
   displayName
+  ... on Person {
+    age
+    birthday
+  }
+  ... on Organization {
+    industry
+  }
 }
 
 query InterfaceWithFragmentQuery {

graphql_client/tests/interfaces/interface_with_fragment_response.json

@@ -4,7 +4,8 @@
       "__typename": "Person",
       "name": "Audrey Lorde",
       "displayName": false,
-      "birthday": "1934-02-18"
+      "birthday": "1934-02-18",
+      "age": 84
     },
     {
       "__typename": "Dog",
@@ -15,7 +16,8 @@
     {
       "__typename": "Organization",
       "name": "Mozilla",
-      "displayName": false
+      "displayName": false,
+      "industry": "CAT_FOOD"
     },
     {
       "__typename": "Dog",

graphql_client_codegen/src/interfaces.rs

@@ -9,7 +9,9 @@ use std::cell::Cell;
 use std::collections::HashSet;
 use unions::union_variants;
 
-/// Represents an Interface type extracted from the schema.
+/// A GraphQL interface (simplified schema representation).
+///
+/// In the generated code, fragments nesting is preserved, including for selection on union variants. See the tests in the graphql client crate for examples.
 #[derive(Debug, Clone, PartialEq)]
 pub struct GqlInterface<'schema> {
     /// The documentation for the interface. Extracted from the schema.

graphql_client_codegen/src/unions.rs

@@ -5,6 +5,9 @@ use selection::Selection;
 use std::cell::Cell;
 use std::collections::BTreeSet;
 
+/// A GraphQL union (simplified schema representation).
+///
+/// For code generation purposes, unions will "flatten" fragment spreads, so there is only one enum for the selection. See the tests in the graphql_client crate for examples.
 #[derive(Debug, Clone, PartialEq)]
 pub(crate) struct GqlUnion<'schema> {
     pub name: &'schema str,