Add __typename removal for mutations

src/app/graphql.module.ts

@@ -1,13 +1,33 @@
 import { NgModule } from '@angular/core';
 import { APOLLO_OPTIONS } from 'apollo-angular';
-import {ApolloClientOptions, ApolloLink, InMemoryCache} from '@apollo/client/core';
+import {
+  ApolloClientOptions,
+  ApolloLink,
+  concat,
+  InMemoryCache,
+} from '@apollo/client/core';
 import { HttpLink } from 'apollo-angular/http';
 import { environment } from '../environments/environment';
 
 const uri = environment.apiUrl + '/graphql'; // <-- add the URL of the GraphQL server here
+
+const cleanTypeName = new ApolloLink((operation, forward) => {
+  if (operation.variables) {
+    const omitTypename = (key: string, value: any) =>
+      key === '__typename' ? undefined : value;
+    operation.variables = JSON.parse(
+      JSON.stringify(operation.variables),
+      omitTypename
+    );
+  }
+  return forward(operation).map((data) => {
+    return data;
+  });
+});
+
 export function createApollo(httpLink: HttpLink): ApolloClientOptions<any> {
   return {
-    link: httpLink.create({uri}),
+    link: concat(cleanTypeName, httpLink.create({ uri })),
     cache: new InMemoryCache({}),
   };
 }
@@ -21,5 +41,4 @@ export function createApollo(httpLink: HttpLink): ApolloClientOptions<any> {
     },
   ],
 })
-export class GraphQLModule {
-}
+export class GraphQLModule {}