Automatically strip __typename for input data in variables

.changeset/cyan-insects-love.md

@@ -0,0 +1,5 @@
+---
+'@apollo/client': patch
+---
+
+Automatically strips `__typename` fields from `variables` sent to the server when using [`HttpLink`](https://www.apollographql.com/docs/react/api/link/apollo-link-http), [`BatchHttpLink`](https://www.apollographql.com/docs/react/api/link/apollo-link-batch-http), or [`GraphQLWsLink`](https://www.apollographql.com/docs/react/api/link/apollo-link-subscriptions). This allows GraphQL data returned from a query to be used as an argument to a subsequent GraphQL operation without the need to strip the `__typename` in user-space.

.prettierignore

@@ -36,6 +36,17 @@ src/react/*
 !src/utilities/
 src/utilities/*
 !src/utilities/promises/
+!src/utilities/types/
+src/utilities/types/*
+!src/utilities/types/DeepOmit.ts
+!src/utilities/common
+src/utilities/common/*
+!src/utilities/common/stripTypename.ts
+!src/utilities/common/omitDeep.ts
+!src/utilities/common/__tests__/
+src/utilities/common/__tests__/*
+!src/utilities/common/__tests__/omitDeep.ts
+!src/utilities/common/__tests__/stripTypename.ts
 
 ## Allowed React Hooks
 !src/react/hooks/

config/bundlesize.ts

@@ -3,7 +3,7 @@ import { join } from "path";
 import { gzipSync } from "zlib";
 import bytes from "bytes";
 
-const gzipBundleByteLengthLimit = bytes("34.83KB");
+const gzipBundleByteLengthLimit = bytes("34.98KB");
 const minFile = join("dist", "apollo-client.min.cjs");
 const minPath = join(__dirname, "..", minFile);
 const gzipByteLen = gzipSync(readFileSync(minPath)).byteLength;

src/__tests__/__snapshots__/exports.ts.snap

@@ -409,6 +409,7 @@ Array [
   "isNodeResponse",
   "isNonEmptyArray",
   "isNonNullObject",
+  "isPlainObject",
   "isReadableStream",
   "isReference",
   "isStatefulPromise",
@@ -423,6 +424,7 @@ Array [
   "mergeIncrementalData",
   "mergeOptions",
   "offsetLimitPagination",
+  "omitDeep",
   "relayStylePagination",
   "removeArgumentsFromDocument",
   "removeClientSetsFromDocument",
@@ -433,6 +435,7 @@ Array [
   "shouldInclude",
   "storeKeyNameFromField",
   "stringifyForDisplay",
+  "stripTypename",
   "valueToObjectRepresentation",
   "wrapPromiseWithState",
 ]

src/link/http/__tests__/HttpLink.ts

@@ -1110,7 +1110,263 @@ describe('HttpLink', () => {
       expect(errorHandler).toHaveBeenCalledWith(
         new Error('HttpLink: Trying to send a client-only query to the server. To send to the server, ensure a non-client field is added to the query or set the `transformOptions.removeClientFields` option to `true`.')
       );
-    })
+    });
+
+    it('strips __typename from object argument when sending a mutation', async () => {
+      fetchMock.mock('https://example.com/graphql', {
+        status: 200,
+        body: JSON.stringify({
+          data: {
+            __typename: 'Mutation',
+            updateTodo: { 
+              __typename: 'Todo',
+              id: 1,
+              name: 'Take out trash',
+              completed: true 
+            }
+          }
+        }),
+        headers: { 'content-type': 'application/json' }
+      });
+
+      const query = gql`
+        mutation UpdateTodo($todo: TodoInput!) {
+          updateTodo(todo: $todo) {
+            id
+            name
+            completed
+          }
+        }
+      `;
+
+      const link = createHttpLink({ uri: 'https://example.com/graphql' });
+
+      const todo = { 
+        __typename: 'Todo',
+        id: 1,
+        name: 'Take out trash',
+        completed: true,
+      }
+
+      await new Promise((resolve, reject) => {
+        execute(link, { query, variables: { todo } }).subscribe({
+          next: resolve,
+          error: reject
+        });
+      });
+
+      const [, options] = fetchMock.lastCall()!;
+      const { body } = options!
+
+      expect(JSON.parse(body!.toString())).toEqual({
+        operationName: 'UpdateTodo',
+        query: print(query),
+        variables: {
+          todo: {
+            id: 1,
+            name: 'Take out trash',
+            completed: true,
+          }
+        }
+      });
+    });
+
+    it('strips __typename from array argument when sending a mutation', async () => {
+      fetchMock.mock('https://example.com/graphql', {
+        status: 200,
+        body: JSON.stringify({
+          data: {
+            __typename: 'Mutation',
+            updateTodos: [
+              { 
+                __typename: 'Todo',
+                id: 1,
+                name: 'Take out trash',
+                completed: true 
+              },
+              { 
+                __typename: 'Todo',
+                id: 2,
+                name: 'Clean room',
+                completed: true 
+              },
+            ]
+          }
+        }),
+        headers: { 'content-type': 'application/json' }
+      });
+
+      const query = gql`
+        mutation UpdateTodos($todos: [TodoInput!]!) {
+          updateTodos(todos: $todos) {
+            id
+            name
+            completed
+          }
+        }
+      `;
+
+      const link = createHttpLink({ uri: 'https://example.com/graphql' });
+
+      const todos = [
+        { 
+          __typename: 'Todo',
+          id: 1,
+          name: 'Take out trash',
+          completed: true,
+        },
+        { 
+          __typename: 'Todo',
+          id: 2,
+          name: 'Clean room',
+          completed: true,
+        },
+      ];
+
+      await new Promise((resolve, reject) => {
+        execute(link, { query, variables: { todos } }).subscribe({
+          next: resolve,
+          error: reject
+        });
+      });
+
+      const [, options] = fetchMock.lastCall()!;
+      const { body } = options!
+
+      expect(JSON.parse(body!.toString())).toEqual({
+        operationName: 'UpdateTodos',
+        query: print(query),
+        variables: {
+          todos: [
+            {
+              id: 1,
+              name: 'Take out trash',
+              completed: true,
+            },
+            {
+              id: 2,
+              name: 'Clean room',
+              completed: true,
+            },
+          ]
+        }
+      });
+    });
+
+    it('strips __typename from mixed argument when sending a mutation', async () => {
+      fetchMock.mock('https://example.com/graphql', {
+        status: 200,
+        body: JSON.stringify({
+          data: {
+            __typename: 'Mutation',
+            updateProfile: {
+              __typename: 'Profile',
+              id: 1,
+            },
+          }
+        }),
+        headers: { 'content-type': 'application/json' }
+      });
+
+      const query = gql`
+        mutation UpdateProfile($profile: ProfileInput!) {
+          updateProfile(profile: $profile) {
+            id
+          }
+        }
+      `;
+
+      const link = createHttpLink({ uri: 'https://example.com/graphql' });
+
+      const profile = { 
+        __typename: 'Profile',
+        id: 1,
+        interests: [
+          { __typename: 'Interest', name: 'Hiking' },
+          { __typename: 'Interest', name: 'Nature' }
+        ],
+        avatar: {
+          __typename: 'Avatar',
+          url: 'https://example.com/avatar.jpg',
+        }
+      };
+
+      await new Promise((resolve, reject) => {
+        execute(link, { query, variables: { profile } }).subscribe({
+          next: resolve,
+          error: reject
+        });
+      });
+
+      const [, options] = fetchMock.lastCall()!;
+      const { body } = options!
+
+      expect(JSON.parse(body!.toString())).toEqual({
+        operationName: 'UpdateProfile',
+        query: print(query),
+        variables: {
+          profile: {
+            id: 1,
+            interests: [
+              { name: 'Hiking' },
+              { name: 'Nature' }
+            ],
+            avatar: {
+              url: 'https://example.com/avatar.jpg',
+            },
+          },
+        }
+      });
+    });
+  });
+
+  it('strips __typename when sending a query', async () => {
+    fetchMock.mock('https://example.com/graphql', {
+      status: 200,
+      body: JSON.stringify({
+        data: {
+          __typename: 'Query',
+          searchTodos: []
+        }
+      }),
+      headers: { 'content-type': 'application/json' }
+    });
+
+    const query = gql`
+      query SearchTodos($filter: TodoFilter!) {
+        searchTodos(filter: $filter) {
+          id
+          name
+        }
+      }
+    `;
+
+    const link = createHttpLink({ uri: 'https://example.com/graphql' });
+
+    const filter = { 
+      __typename: 'Filter',
+      completed: true,
+    };
+
+    await new Promise((resolve, reject) => {
+      execute(link, { query, variables: { filter } }).subscribe({
+        next: resolve,
+        error: reject
+      });
+    });
+
+    const [, options] = fetchMock.lastCall()!;
+    const { body } = options!
+
+    expect(JSON.parse(body!.toString())).toEqual({
+      operationName: 'SearchTodos',
+      query: print(query),
+      variables: {
+        filter: {
+          completed: true,
+        },
+      },
+    });
   });
 
   describe('Dev warnings', () => {

src/link/http/__tests__/selectHttpOptionsAndBody.ts

@@ -104,4 +104,25 @@ describe('selectHttpOptionsAndBody', () => {
 
     expect(body.query).toBe('query SampleQuery{stub{id}}');
   });
+
+  it('strips __typename from variables', () => {
+    const operation = createOperation(
+      {}, 
+      { 
+        query,
+        variables: { 
+          __typename: 'Test',
+          nested: { __typename: 'Nested', foo: 'bar' },
+          array: [{ __typename: 'Item', baz: 'foo' }]
+        }, 
+      }
+    );
+
+    const { body } = selectHttpOptionsAndBody(operation, {});
+
+    expect(body.variables).toEqual({ 
+      nested: { foo: 'bar' },
+      array: [{ baz: 'foo' }],
+    });
+  })
 });

src/link/http/selectHttpOptionsAndBody.ts

@@ -1,4 +1,5 @@
 import { ASTNode, print } from 'graphql';
+import { stripTypename } from '../../utilities';
 
 import { Operation } from '../core';
 
@@ -179,7 +180,7 @@ export function selectHttpOptionsAndBodyInternal(
 
   //The body depends on the http options
   const { operationName, extensions, variables, query } = operation;
-  const body: Body = { operationName, variables };
+  const body: Body = { operationName, variables: stripTypename(variables) };
 
   if (http.includeExtensions) (body as any).extensions = extensions;
 

src/link/subscriptions/index.ts

@@ -32,7 +32,7 @@ import { print } from "graphql";
 import type { Client } from "graphql-ws";
 
 import { ApolloLink, Operation, FetchResult } from "../core";
-import { isNonNullObject, Observable } from "../../utilities";
+import { isNonNullObject, stripTypename, Observable } from "../../utilities";
 import { ApolloError } from "../../errors";
 
 // https://developer.mozilla.org/en-US/docs/Web/API/WebSocket/close_event
@@ -53,7 +53,11 @@ export class GraphQLWsLink extends ApolloLink {
   public request(operation: Operation): Observable<FetchResult> {
     return new Observable((observer) => {
       return this.client.subscribe<FetchResult>(
-        { ...operation, query: print(operation.query) },
+        { 
+          ...operation,
+          query: print(operation.query),
+          variables: stripTypename(operation.variables) 
+        },
         {
           next: observer.next.bind(observer),
           complete: observer.complete.bind(observer),