fix: call iterateObserversSafely if variables change

package.json

@@ -58,7 +58,7 @@
     {
       "name": "apollo-client",
       "path": "./dist/apollo-client.min.cjs",
-      "maxSize": "31.71kB"
+      "maxSize": "31.74kB"
     }
   ],
   "engines": {

src/__tests__/local-state/general.ts

@@ -1,5 +1,16 @@
 import gql from 'graphql-tag';
-import { DocumentNode, GraphQLError, getIntrospectionQuery } from 'graphql';
+import {
+  graphql,
+  GraphQLInt,
+  print,
+  DocumentNode,
+  GraphQLError,
+  getIntrospectionQuery,
+  GraphQLSchema,
+  GraphQLObjectType,
+  GraphQLID,
+  GraphQLString
+} from 'graphql';
 
 import { Observable } from '../../utilities';
 import { ApolloLink } from '../../link/core';
@@ -819,6 +830,102 @@ describe('Combining client and server state/operations', () => {
     }, 10);
   });
 
+  itAsync('query resolves with loading: false if subsequent responses contain the same data', (resolve, reject) => {
+    const request = {
+      query: gql`
+        query people($id: Int) {
+          people(id: $id) {
+            id
+            name
+          }
+        }
+      `,
+      variables: {
+        id: 1,
+      },
+      notifyOnNetworkStatusChange: true
+    };
+
+    const PersonType = new GraphQLObjectType({
+      name: "Person",
+      fields: {
+        id: { type: GraphQLID },
+        name: { type: GraphQLString }
+      }
+    });
+
+    const peopleData = [
+      { id: 1, name: "John Smith" },
+      { id: 2, name: "Sara Smith" },
+      { id: 3, name: "Budd Deey" }
+    ];
+
+    const QueryType = new GraphQLObjectType({
+      name: "Query",
+      fields: {
+        people: {
+          type: PersonType,
+          args: {
+            id: {
+              type: GraphQLInt
+            }
+          },
+          resolve: (_, { id }) => {
+            return peopleData;
+          }
+        }
+      }
+    });
+
+    const schema = new GraphQLSchema({ query: QueryType });
+
+    const link = new ApolloLink(operation => {
+      // @ts-ignore
+      return new Observable(async observer => {
+        const { query, operationName, variables } = operation;
+        try {
+          const result = await graphql({
+            schema,
+            source: print(query),
+            variableValues: variables,
+            operationName,
+          });
+          observer.next(result);
+          observer.complete();
+        } catch (err) {
+          observer.error(err);
+        }
+      });
+    });
+
+    const client = new ApolloClient({
+      cache: new InMemoryCache(),
+      link,
+    });
+
+    const observer = client.watchQuery(request);
+
+    let count = 0;
+    observer.subscribe({
+      next: ({ loading, data }) => {
+        if (count === 0) expect(loading).toBe(false);
+        if (count === 1) expect(loading).toBe(true);
+        if (count === 2) {
+          expect(loading).toBe(false)
+          resolve();
+        };
+        count++;
+      },
+      error: reject,
+    });
+
+    setTimeout(() => {
+      observer.refetch({
+        id: 2
+      });
+    }, 1);
+  });
+
   itAsync('should correctly propagate an error from a client resolver', async (resolve, reject) => {
     const data = {
       list: {

src/core/ObservableQuery.ts

@@ -307,6 +307,12 @@ export class ObservableQuery<
     return !this.last || !equal(this.last.result, newResult);
   }
 
+  // Compares variables to the variables in the snapshot we took of
+  // this.lastResult when it was first received.
+  public hasDifferentVariablesFromLastResult(variables?: TVariables) {
+    return !this.last || !equal(this.last.variables, variables)
+  }
+
   private getLast<K extends keyof Last<TData, TVariables>>(
     key: K,
     variablesMustMatch?: boolean,
@@ -872,7 +878,9 @@ Did you mean to call refetch(variables) instead of refetch({ variables })?`);
     variables: TVariables | undefined,
   ) {
     const lastError = this.getLastError();
-    if (lastError || this.isDifferentFromLastResult(result)) {
+    if (lastError
+      || this.isDifferentFromLastResult(result)
+      || this.hasDifferentVariablesFromLastResult(variables)) {
       if (lastError || !result.partial || this.options.returnPartialData) {
         this.updateLastResult(result, variables);
       }

src/core/__tests__/fetchPolicies.ts

@@ -1163,7 +1163,17 @@ describe("nextFetchPolicy", () => {
       // resets the fetchPolicy to context.initialPolicy), so cache-first is
       // still what we see here.
       expect(observable.options.fetchPolicy).toBe("cache-first");
+    } else if (count === 3) {
+      expect(result.loading).toBe(false);
+      expect(result.data).toEqual({
+        linkCounter: 2,
+        opName: "EchoQuery",
+        opVars: {
+          refetching: true,
+        },
+      });
 
+      expect(observable.options.fetchPolicy).toBe("cache-first");
       setTimeout(resolve, 20);
     } else {
       reject(`Too many results (${count})`);