support @defer on inline fragments

- add inline fragment test case
- rename rest to initial

Author: lilianammmatos

src/__tests__/starWarsDeferredQuery-test.js

@@ -106,8 +106,8 @@ describe('Star Wars Query Deferred Tests', () => {
       `;
 
       const result = await graphql(StarWarsSchemaDeferStreamEnabled, query);
-      const { patches: patchesIterable, ...rest } = result;
-      expect(rest).to.deep.equal({
+      const { patches: patchesIterable, ...initial } = result;
+      expect(initial).to.deep.equal({
         data: {
           hero: {
             id: '2001',
@@ -149,6 +149,49 @@ describe('Star Wars Query Deferred Tests', () => {
   // TODO
   // describe('Using aliases to change the key in the response', () => {});
 
+  describe('Inline Fragments', () => {
+    it('Allows us to defer an inline fragment', async () => {
+      const query = `
+        query UserFragment {
+          human(id: "1003") {
+            id
+            ... on Human @defer(label: "InlineDeferred"){
+              name
+              homePlanet
+            }
+          }
+        }
+
+      `;
+      const result = await graphql(StarWarsSchemaDeferStreamEnabled, query);
+      const { patches: patchesIterable, ...initial } = result;
+      expect(initial).to.deep.equal({
+        data: {
+          human: {
+            id: '1003',
+          },
+        },
+      });
+
+      const patches = [];
+
+      if (patchesIterable) {
+        await forAwaitEach(patchesIterable, patch => {
+          patches.push(patch);
+        });
+      }
+      expect(patches).to.have.lengthOf(1);
+      expect(patches[0]).to.deep.equal({
+        label: 'InlineDeferred',
+        path: ['human'],
+        data: {
+          name: 'Leia Organa',
+          homePlanet: 'Alderaan',
+        },
+      });
+    });
+  });
+
   describe('Uses fragments to express more complex queries', () => {
     it('Allows us to use a fragment to avoid duplicating content', async () => {
       const query = `
@@ -183,9 +226,9 @@ describe('Star Wars Query Deferred Tests', () => {
         }
       `;
       const result = await graphql(StarWarsSchemaDeferStreamEnabled, query);
-      const { patches: patchesIterable, ...rest } = result;
+      const { patches: patchesIterable, ...initial } = result;
 
-      expect(rest).to.deep.equal({
+      expect(initial).to.deep.equal({
         data: {
           han: {
             __typename: 'Human',

src/execution/execute.js

@@ -548,26 +548,47 @@ export function collectFields(
         ) {
           continue;
         }
-        collectFields(
-          exeContext,
-          runtimeType,
-          selection.selectionSet,
-          fields,
-          patches,
-          visitedFragmentNames,
-        );
+
+        const patchLabel = exeContext.schema.__experimentalDeferFragmentSpreads
+          ? getDeferredNodeLabel(exeContext, selection)
+          : '';
+
+        if (patchLabel) {
+          const { fields: patchFields } = collectFields(
+            exeContext,
+            runtimeType,
+            selection.selectionSet,
+            Object.create(null),
+            patches,
+            visitedFragmentNames,
+          );
+          patches.push({
+            label: patchLabel,
+            fields: patchFields,
+          });
+        } else {
+          collectFields(
+            exeContext,
+            runtimeType,
+            selection.selectionSet,
+            fields,
+            patches,
+            visitedFragmentNames,
+          );
+        }
         break;
       }
       case Kind.FRAGMENT_SPREAD: {
         const fragName = selection.name.value;
 
+        if (!shouldIncludeNode(exeContext, selection)) {
+          continue;
+        }
+
         const patchLabel = exeContext.schema.__experimentalDeferFragmentSpreads
           ? getDeferredNodeLabel(exeContext, selection)
           : '';
 
-        if (!shouldIncludeNode(exeContext, selection)) {
-          continue;
-        }
         if (
           visitedFragmentNames[fragName] &&
           // Cannot continue in this case because fields must be recollected for patch

src/type/directives.js

@@ -176,7 +176,6 @@ export const GraphQLDeferDirective = new GraphQLDirective({
     'Directs the executor to defer this fragment when the `if` argument is true or undefined.',
   locations: [
     DirectiveLocation.FRAGMENT_SPREAD,
-    // TODO: Do we want to support on inline fragments? (Can we? How would you make label unique?)
     DirectiveLocation.INLINE_FRAGMENT,
   ],
   args: {