Another example

mutations.js

function mapMutationsToProps({ ownProps, state }) {
  return {
    postReply: (raw) => ({
      mutation: gql`
        mutation postReply(
          $topic_id: ID!
          $category_id: ID!
          $raw: String!
        ) {
          ...
        }
      `,
      variables: {
        // Use the container component's props
        topic_id: ownProps.topic_id,

        // Use the redux state
        category_id: state.selectedCategory,

        // Use an argument passed from the triggering of the mutation
        raw,
      },
    }),
  };
};