form5.vue

<script>
  import { GET_NAMES, ADD_NAME } from "../queries";
  export default {
    name: "Form",
    data() {
      return {
        person: ""
      };
    },
    methods: {
      onSubmit() {
        const name = this.person;
        this.person = "";
        this.$apollo.mutate({
          mutation: ADD_NAME,
          variables: {
            name
          },
          update: (cache, { data: { createNames } }) => {
            const { allNameses } = cache.readQuery({ query: GET_NAMES });

            cache.writeQuery({
              query: GET_NAMES,
              data: {
                allNameses: allNameses.concat(createNames)
              }
            });
          }
        })
      }
    }
  };
</script>