fix bugs in the previous commit

src/QueryManager.ts

@@ -685,7 +685,7 @@ export class QueryManager {
               // this will throw an error if there are missing fields in
               // the results if returnPartialData is false.
               resultFromStore = readSelectionSetFromStore({
-                store: this.getDataWithOptimisticResults(),
+                store: this.getApolloState().data,
                 rootId: querySS.id,
                 selectionSet: querySS.selectionSet,
                 variables,

src/store.ts

@@ -135,5 +135,5 @@ export interface ApolloReducerConfig {
 
 export function getDataWithOptimisticResults(store: Store): NormalizedCache {
   const patches = store.optimistic.map(opt => opt.data);
-  return assign(store.data, ...patches) as NormalizedCache;
+  return assign({}, store.data, ...patches) as NormalizedCache;
 }

test/optimistic.ts

@@ -608,7 +608,7 @@ describe('optimistic mutation results', () => {
           optimisticResponse: optimisticResponse2,
           resultBehaviors,
         }).then((res) => {
-          checkBothMutationsAreApplied('This one was created with a mutation.', 'second mutation.');
+          checkBothMutationsAreApplied('This one was created with a mutation.', 'Second mutation.');
           const mutationsState = client.store.getState().apollo.mutations;
           assert.equal(mutationsState[2].loading, false);
           assert.equal(mutationsState[3].loading, false);
@@ -625,7 +625,7 @@ describe('optimistic mutation results', () => {
         return Promise.all([promise, promise2]);
       })
       .then(() => {
-        checkBothMutationsAreApplied('This one was created with a mutation.', 'second mutation.');
+        checkBothMutationsAreApplied('This one was created with a mutation.', 'Second mutation.');
       });
     });
   });