packages/node_modules/pouchdb-find/src/adapters/http/index.js

import { generateErrorFromResponse } from 'pouchdb-errors';
import { Headers } from 'pouchdb-fetch';
import massageCreateIndexRequest from '../../massageCreateIndexRequest';

function dbFetch(db, path, opts, callback) {
  var status, ok;
  opts.headers = new Headers({'Content-type': 'application/json'});
  db.fetch(path, opts).then(function (response) {
    status = response.status;
    ok = response.ok;
    return response.json();
  }).then(function (json) {
    if (!ok) {
      json.status = status;
      var err = generateErrorFromResponse(json);
      callback(err);
    } else {
      callback(null, json);
    }
  }).catch(callback);
}

function createIndex(db, requestDef, callback) {
  requestDef = massageCreateIndexRequest(requestDef);
  dbFetch(db, '_index', {
    method: 'POST',
    body: JSON.stringify(requestDef)
  }, callback);
}

function find(db, requestDef, callback) {
  dbFetch(db, '_find', {
    method: 'POST',
    body: JSON.stringify(requestDef)
  }, callback);
}

function explain(db, requestDef, callback) {
  dbFetch(db, '_explain', {
    method: 'POST',
    body: JSON.stringify(requestDef)
  }, callback);
}

function getIndexes(db, callback) {
  dbFetch(db, '_index', {
    method: 'GET'
  }, callback);
}

function deleteIndex(db, indexDef, callback) {


  var ddoc = indexDef.ddoc;
  var type = indexDef.type || 'json';
  var name = indexDef.name;

  if (!ddoc) {
    return callback(new Error('you must provide an index\'s ddoc'));
  }

  if (!name) {
    return callback(new Error('you must provide an index\'s name'));
  }

  var url = '_index/' + [ddoc, type, name].map(encodeURIComponent).join('/');

  dbFetch(db, url, {method: 'DELETE'}, callback);
}

export {
  createIndex,
  find,
  getIndexes,
  deleteIndex,
  explain
};