New partition test to cover edge case

test/src/test/kotlin/graphql/nadel/tests/hooks/batching-of-hydration-list-with-partition.kt

@@ -41,6 +41,13 @@ class `batching-of-hydration-list-with-partition` : EngineTestHook {
     }
 }
 
+@UseHook
+class `new-batching-of-hydration-list-with-partition-2` : EngineTestHook {
+    override fun makeNadel(builder: Nadel.Builder): Nadel.Builder {
+        return builder.executionHooks(BatchHydrationHooks())
+    }
+}
+
 @UseHook
 class `index-hydration-with-partitioned-inputs` : EngineTestHook {
     override fun makeExecutionHints(

test/src/test/resources/fixtures/new hydration/new-batching-of-hydration-list-with-partition-2.yml

@@ -0,0 +1,186 @@
+name: "new batching of hydration list with partition 2"
+enabled: true
+overallSchema:
+  # language=GraphQL
+  UserService: |
+    type Query {
+      usersByIds(id: [ID]): [User]
+    }
+    type User {
+      id: ID
+    }
+  # language=GraphQL
+  Issues: |
+    type Query {
+      issues: [Issue]
+    }
+    type Issue {
+      id: ID
+      authors: [User]
+      @hydrated(
+        service: "UserService"
+        field: "usersByIds"
+        arguments: [{name: "id" value: "$source.authorIds"}]
+        identifiedBy: "id"
+        batchSize: 90
+      )
+    }
+underlyingSchema:
+  # language=GraphQL
+  UserService: |
+    type Query {
+      usersByIds(id: [ID]): [User]
+    }
+
+    type User {
+      id: ID
+    }
+  # language=GraphQL
+  Issues: |
+    type Issue {
+      authorIds: [ID]
+      id: ID
+    }
+
+    type Query {
+      issues: [Issue]
+    }
+# language=GraphQL
+query: |
+  query {
+    issues {
+      id
+      authors {
+        id
+      }
+    }
+  }
+variables: { }
+serviceCalls:
+  - serviceName: "Issues"
+    request:
+      # language=GraphQL
+      query: |
+        query {
+          issues {
+            __typename__batch_hydration__authors: __typename
+            batch_hydration__authors__authorIds: authorIds
+            id
+          }
+        }
+      variables: { }
+    # language=JSON
+    response: |-
+      {
+        "data": {
+          "issues": [
+            {
+              "__typename__batch_hydration__authors": "Issue",
+              "batch_hydration__authors__authorIds": [
+                "site-1/user-1",
+                "site-2/user-2"
+              ],
+              "id": "issue-1"
+            },
+            {
+              "__typename__batch_hydration__authors": "Issue",
+              "batch_hydration__authors__authorIds": [
+              ],
+              "id": "issue-2"
+            },
+            {
+              "__typename__batch_hydration__authors": "Issue",
+              "batch_hydration__authors__authorIds": [
+                "site-2/user-4"
+              ],
+              "id": "issue-3"
+            }
+          ]
+        },
+        "extensions": {}
+      }
+  - serviceName: "UserService"
+    request:
+      # language=GraphQL
+      query: |
+        query {
+          usersByIds(id: ["site-1/user-1"]) {
+            id
+            batch_hydration__authors__id: id
+          }
+        }
+      variables: { }
+    # language=JSON
+    response: |-
+      {
+        "data": {
+          "usersByIds": [
+            {
+              "id": "site-1/user-1",
+              "batch_hydration__authors__id": "site-1/user-1"
+            }
+          ]
+        },
+        "extensions": {}
+      }
+  - serviceName: "UserService"
+    request:
+      # language=GraphQL
+      query: |
+        query {
+          usersByIds(id: ["site-2/user-2", "site-2/user-4"]) {
+            id
+            batch_hydration__authors__id: id
+          }
+        }
+      variables: { }
+    # language=JSON
+    response: |-
+      {
+        "data": {
+          "usersByIds": [
+            {
+              "id": "site-2/user-2",
+              "batch_hydration__authors__id": "site-2/user-2"
+            },
+            {
+              "id": "site-2/user-4",
+              "batch_hydration__authors__id": "site-2/user-4"
+            }
+          ]
+        },
+        "extensions": {}
+      }
+# language=JSON
+response: |-
+  {
+    "data": {
+      "issues": [
+        {
+          "id": "issue-1",
+          "authors": [
+            {
+              "id": "site-1/user-1"
+            },
+            {
+              "id": "site-2/user-2"
+            }
+          ]
+        },
+        {
+          "id": "issue-2",
+          "authors": [
+          ]
+        },
+        {
+          "id": "issue-3",
+          "authors": [
+            {
+              "id": "site-2/user-4"
+            }
+          ]
+        }
+      ]
+    },
+    "extensions": {}
+  }