Feathers hook for including seqeulize models

model-includes.hook.js

'use strict';

// Feathers hook to do `/thing?includes=other`

// before : {
//   find: [modelIncludes()],
//   get: [modelIncludes()]
// },
// after : {
//   find: [modelIncludes()],
//   get: [modelIncludes()]
// }

// This is an efficient way to include associations using sequelize.
// Shame sequelize has a bug that means its findAndCount doesn't include a
// count once `raw:false` is included, which we need to get 1:m array.
// https://github.com/sequelize/sequelize/issues/7931

// Ensure you also include this both before to set up the include,
// and after to reset the count.

module.exports = () => {
  return hook => {
    if (hook.type === 'before') {
      let includes;
      if (hook.params.query.includes) {
        includes = hook.params.query.includes;
        hook.params.includes = includes;
        delete hook.params.query.includes;

        if (!Array.isArray(includes)) includes = [includes];

        let models = includes
          .filter(include => hook.app.services[include])
          .map(include =>
            hook.app.services[include].Model.schema(
              hook.params.agencyConfig.pg_schema
            )
          );

        if (!hook.params.sequelize) hook.params.sequelize = {};
        Object.assign(hook.params.sequelize, {
          raw: false,
          include: models
        });
      }
    }

    //
    if (hook.type === 'after' && hook.method === 'find') {
      if (hook.params.includes) {
        return hook.service.Model.count().then(count => {
          hook.result.total = count;
          return hook;
        });
      }
    }

    return hook;
  };
};