Merge branch 'master' of github.com:apollographql/apollo-link-rest

src/__tests__/restLink.ts

@@ -3579,6 +3579,91 @@ describe('export directive', () => {
     expect(data.post.tag).toEqual({ ...tag, __typename: 'Tag' });
     expect(data.post.author).toEqual({ ...author, __typename: 'User' });
   });
+
+  it('can handle nested exports with deeply structured response data', async () => {
+    expect.assertions(3);
+
+    const link = new RestLink({ uri: '/api' });
+
+    const user = {
+      id: 'user-a',
+      posts: [
+        {
+          id: 'post-a',
+          tags: [
+            {
+              id: 'tag-a',
+            },
+            {
+              id: 'tag-b',
+            },
+          ],
+        },
+        {
+          id: 'post-b',
+          tags: [
+            {
+              id: 'tag-c',
+            },
+          ],
+        },
+      ],
+    };
+    fetchMock.get('/api/user', user);
+    const postATagA = {
+      id: 'tag-a-details',
+      message: 'this is tag details a',
+    };
+    fetchMock.get('/api/posts/post-a/tags/tag-a', postATagA);
+    const postATagB = {
+      id: 'tag-b-details',
+      message: 'this is tag details b',
+    };
+    fetchMock.get('/api/posts/post-a/tags/tag-b', postATagB);
+    const postBTagC = {
+      id: 'tag-c-details',
+      message: 'this is tag details c',
+    };
+    fetchMock.get('/api/posts/post-b/tags/tag-c', postBTagC);
+
+    const userPostsWithTagDetails = gql`
+      query userPostsWithTagDetails {
+        user @rest(path: "/user") {
+          id
+          posts {
+            id @export(as: "postId")
+            tags {
+              id @export(as: "tagId")
+              details
+                @rest(
+                  path: "/posts/{exportVariables.postId}/tags/{exportVariables.tagId}"
+                ) {
+                id
+                message
+              }
+            }
+          }
+        }
+      }
+    `;
+
+    const { data } = await makePromise<Result>(
+      execute(link, {
+        operationName: 'userPostsWithTagDetails',
+        query: userPostsWithTagDetails,
+      }),
+    );
+
+    expect(data.user.posts[0].tags[0].details.message).toEqual(
+      'this is tag details a',
+    );
+    expect(data.user.posts[0].tags[1].details.message).toEqual(
+      'this is tag details b',
+    );
+    expect(data.user.posts[1].tags[0].details.message).toEqual(
+      'this is tag details c',
+    );
+  });
 });
 
 describe('Apollo client integration', () => {

src/restLink.ts

@@ -791,8 +791,8 @@ interface RequestContext {
   /** Credentials Policy for Fetch */
   credentials?: RequestCredentials | null;
 
-  /** Exported variables fulfilled in this request, using @export(as:) */
-  exportVariables: { [key: string]: any };
+  /** Exported variables fulfilled in this request, using @export(as:). They are stored keyed by node to support deeply nested structures with exports at multiple levels */
+  exportVariablesByNode: Map<any, { [key: string]: any }>;
 
   endpoints: RestLink.Endpoints;
   customFetch: RestLink.CustomFetch;
@@ -832,7 +832,21 @@ const resolver: Resolver = async (
   info: ExecInfo,
 ) => {
   const { directives, isLeaf, resultKey } = info;
-  const { exportVariables } = context;
+  const { exportVariablesByNode } = context;
+
+  const exportVariables = exportVariablesByNode.get(root) || {};
+
+  /** creates a copy of this node's export variables for its child nodes. iterates over array results to provide for each child. returns the passed result. */
+  const copyExportVariables = <T>(result: T): T => {
+    if (result instanceof Array) {
+      result.forEach(copyExportVariables);
+    } else {
+      // export variables are stored keyed on the node they are for
+      exportVariablesByNode.set(result, { ...exportVariables });
+    }
+
+    return result;
+  };
 
   // Support GraphQL Aliases!
   const aliasedNode = (root || {})[resultKey];
@@ -862,7 +876,7 @@ const resolver: Resolver = async (
   if (isNotARestCall) {
     // This is not tagged with @rest()
     // This might not belong to us so return the aliasNode version preferentially
-    return aliasedNode || preAliasingNode;
+    return copyExportVariables(aliasedNode || preAliasingNode);
   }
   const {
     credentials,
@@ -1078,7 +1092,8 @@ const resolver: Resolver = async (
     mainDefinition.selectionSet,
   );
 
-  return addTypeNameToResult(result, type, typePatcher);
+  result = addTypeNameToResult(result, type, typePatcher);
+  return copyExportVariables(result);
 };
 
 /**
@@ -1265,8 +1280,8 @@ export class RestLink extends ApolloLink {
     const requestContext: RequestContext = {
       headers,
       endpoints: this.endpoints,
-      // Provide an empty hash for this request's exports to be stuffed into
-      exportVariables: {},
+      // Provide an empty map for this request's exports to be stuffed into
+      exportVariablesByNode: new Map(),
       credentials,
       customFetch: this.customFetch,
       operationType,