Only return union members which have fragments in the selection set (#…

…289)

* Missing copyright headers

* Point to prerelease documentation for 2.0.0 branch

* General housekeeping before release

* Update code comment

* Fix TCK tests broken from merge

* Add scalars earlier in schema augmentation for use in types and interfaces without throwing Error (fixes DateTime relationship properties)

* Changes to accomodate merge from master

* Only return union members of which a fragment is present in the selection set

* Fix test broken from merge

packages/graphql/src/translate/connection/create-connection-and-params.ts

@@ -85,6 +85,10 @@ function createConnectionAndParams({
         const unionSubqueries: string[] = [];
 
         unionNodes.forEach((n) => {
+            if (!node?.fieldsByTypeName[n.name]) {
+                return;
+            }
+
             const relatedNodeVariable = `${nodeVariable}_${n.name}`;
             const nodeOutStr = `(${relatedNodeVariable}:${n.name})`;
 

packages/graphql/tests/integration/connections/unions.int.test.ts

@@ -186,10 +186,6 @@ describe("Connections -> Unions", () => {
                                     title: "Oliver Twist",
                                 },
                             },
-                            {
-                                words: 3413,
-                                node: {},
-                            },
                         ],
                     },
                 },

packages/graphql/tests/tck/tck-test-files/cypher/connections/unions.md

@@ -166,3 +166,51 @@ RETURN this { .name, publicationsConnection } as this
 ```
 
 ---
+
+### Projecting only one member of union node and relationship properties with no arguments
+
+**GraphQL input**
+
+```graphql
+query {
+    authors {
+        name
+        publicationsConnection {
+            edges {
+                words
+                node {
+                    ... on Book {
+                        title
+                    }
+                }
+            }
+        }
+    }
+}
+```
+
+**Expected Cypher output**
+
+```cypher
+MATCH (this:Author)
+CALL {
+    WITH this
+    CALL {
+        WITH this
+        OPTIONAL MATCH (this)-[this_wrote:WROTE]->(this_Book:Book)
+        WITH { words: this_wrote.words, node: { __resolveType: "Book", title: this_Book.title } } AS edge
+        RETURN edge
+    }
+    WITH collect(edge) as edges, count(edge) as totalCount
+    RETURN { edges: edges, totalCount: totalCount } AS publicationsConnection
+}
+RETURN this { .name, publicationsConnection } as this
+```
+
+**Expected Cypher params**
+
+```cypher-params
+{}
+```
+
+---