Automatic Global Object Identification

.changeset/@graphql-tools_federation-1232-dependencies.md

@@ -0,0 +1,8 @@
+---
+'@graphql-tools/federation': patch
+---
+
+dependencies updates: 
+
+- Added dependency [`@graphql-tools/batch-delegate@workspace:^` ↗︎](https://www.npmjs.com/package/@graphql-tools/batch-delegate/v/workspace:^) (to `dependencies`)
+- Added dependency [`graphql-relay@^0.10.2` ↗︎](https://www.npmjs.com/package/graphql-relay/v/0.10.2) (to `dependencies`)

.changeset/rare-pants-develop.md

@@ -0,0 +1,37 @@
+---
+'@graphql-mesh/fusion-runtime': minor
+'@graphql-tools/federation': minor
+'@graphql-hive/gateway-runtime': minor
+---
+
+Automatic Global Object Identification
+
+Setting the `globalObjectIdentification` option to true will automatically implement the
+GraphQL Global Object Identification Specification by adding a `Node` interface and `node(id: ID!): Node` field to the `Query` type.
+
+The `Node` interface will have a `nodeId` (not `id`!) field used as the global identifier. It
+is intentionally not `id` to avoid collisions with existing `id` fields in subgraphs.
+
+```graphql
+"""
+An object with a globally unique `ID`.
+"""
+interface Node {
+  """
+  A globally unique identifier. Can be used in various places throughout the system to identify this single value.
+  """
+  nodeId: ID!
+}
+
+extend type Query {
+  """
+  Fetches an object given its globally unique `ID`.
+  """
+  node(
+    """
+    The globally unique `ID`.
+    """
+    nodeId: ID!
+  ): Node
+}
+```

e2e/global-object-identification/gateway.config.ts

@@ -0,0 +1,5 @@
+import { defineConfig } from '@graphql-hive/gateway';
+
+export const gatewayConfig = defineConfig({
+  globalObjectIdentification: true,
+});

e2e/global-object-identification/global-object-identification.e2e.ts

@@ -0,0 +1,55 @@
+import { createExampleSetup, createTenv } from '@internal/e2e';
+import { toGlobalId } from 'graphql-relay';
+import { expect, it } from 'vitest';
+
+const { gateway } = createTenv(__dirname);
+const { supergraph, query, result } = createExampleSetup(__dirname);
+
+it('should execute as usual', async () => {
+  const { execute } = await gateway({
+    supergraph: await supergraph(),
+  });
+  await expect(
+    execute({
+      query,
+    }),
+  ).resolves.toEqual(result);
+});
+
+it('should find objects through node', async () => {
+  const { execute } = await gateway({
+    supergraph: await supergraph(),
+  });
+  await expect(
+    execute({
+      query: /* GraphQL */ `
+        query ($nodeId: ID!) {
+          node(nodeId: $nodeId) {
+            ... on Product {
+              nodeId
+              upc
+              name
+              price
+              weight
+            }
+          }
+        }
+      `,
+      variables: {
+        nodeId: toGlobalId('Product', '2'),
+      },
+    }),
+  ).resolves.toMatchInlineSnapshot(`
+    {
+      "data": {
+        "node": {
+          "name": "Couch",
+          "nodeId": "UHJvZHVjdDoy",
+          "price": 1299,
+          "upc": "2",
+          "weight": 1000,
+        },
+      },
+    }
+  `);
+});

e2e/global-object-identification/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@e2e/global-object-identification",
+  "private": true,
+  "dependencies": {
+    "graphql": "^16.11.0",
+    "graphql-relay": "^0.10.2"
+  }
+}

packages/batch-delegate/src/getLoader.ts

@@ -21,7 +21,10 @@ function createBatchFn<K = any>(options: BatchDelegateOptions) {
       .then(() =>
         delegateToSchema({
           returnType: new GraphQLList(
-            getNamedType(options.returnType || options.info.returnType),
+            getNamedType(
+              // options.returnType || // if the returnType is provided by options, it'll override this property because of the spread below. it was like this since forever, so lets keep it for backwards compatibility
+              options.info.returnType,
+            ),
           ),
           onLocatedError: (originalError) => {
             if (originalError.path == null) {

packages/federation/package.json

@@ -38,6 +38,7 @@
     "graphql": "^14.0.0 || ^15.0.0 || ^16.0.0 || ^17.0.0"
   },
   "dependencies": {
+    "@graphql-tools/batch-delegate": "workspace:^",
     "@graphql-tools/delegate": "workspace:^",
     "@graphql-tools/executor": "^1.4.7",
     "@graphql-tools/executor-http": "workspace:^",
@@ -51,6 +52,7 @@
     "@whatwg-node/events": "^0.1.2",
     "@whatwg-node/fetch": "^0.10.8",
     "@whatwg-node/promise-helpers": "^1.3.0",
+    "graphql-relay": "^0.10.2",
     "tslib": "^2.8.1"
   },
   "devDependencies": {