graphql apollo cache setup

handle_cache.ts

try {
              const cacheData = cloneDeep(client.cache.readQuery<PostsQuery, PostsQueryVariables>({
                query: Posts,
                variables: args.postsVariables
              }));
              if (!cacheData) {
                throw new Error('no cache data found');
              }
              const postCache = cacheData.posts.results.find(elem => elem.id === args.data.id);

              const addReactionRes = await client.mutate<AddReactionMutation, AddReactionMutationVariables>({
                mutation: AddReaction,
                variables: {
                  parent: args.data.id,
                  parentType: ReactionParentType.Post,
                  reaction: emoji
                }
              });
              if (addReactionRes.errors) {
                throw new Error(addReactionRes.errors.join(', '));
              }
              postCache.userReactions.push({
                id: addReactionRes.data.addReaction,
                type: emoji
              });
              postCache.reactionCount++;

              if (args.data.userReactions.length > 0) {
                const reactionID = args.data.userReactions[0].id;
                const deleteReactionRes = await client.mutate<DeleteReactionMutation, DeleteReactionMutationVariables>({
                  mutation: DeleteReaction,
                  variables: {
                    id: reactionID
                  }
                });
                if (deleteReactionRes.errors) {
                  throw new Error(deleteReactionRes.errors.join(', '));
                }
                postCache.userReactions = postCache.userReactions.filter(elem => elem.id !== reactionID);
                postCache.reactionCount--;
              }

              client.cache.writeQuery<PostsQuery, PostsQueryVariables>({
                query: Posts,
                variables: args.postsVariables,
                data: cacheData
              });
              await args.updateData(false);
            } catch (err) {
              toast(err.message, {
                type: 'error',
              });
            }