Fixture module

fixture.js

// Loads fixtures using given data, and executes callback
//
// The fixutres are loaded in recursive callbacks from the documents' save 
// methods, therefore the loadFixtures call is asynchronous itself, even though
// it will load documents serially.
//
// When using loadFixtues in testing, you need to keep above in mind. Running
// multiple tests that use loadFixtures one after another _will_ cause trouble.
//
// The callback function is passed data that has been entered into the 
// database, and a callback function that will wipe the database if it is 
// called. You do not need to call this function if you do not wish the tear
// down the fixtures after the test. This callback will also accept a single
// argument, which is a post-tear-down callback.
//
// The ``done`` parameter is used internally to keep track of state between
// recursions. You should not pass anything as ``done`` unless you know what
// you are doing.
//
// @param Model, mongoose model object (or object that implements same API)
// @param data, array of objects to pass to Model's constructor
// @param callback(data, next), callback function, expects data and next
// @param done, list of document instances that were processed
// @api public
function loadFixtures(Model, data, callback, done) {
  var currentItem, itemsLeft, document;

  function worker() {
    // Done is passed by ref always, it maintains state between recursions.
    // We only initialize it if it's not passed.
    done = done || [];

    if (!(data && data.length)) {
      // No more left
      return callback(done, function(next) {
        Model.remove({}, function(err) {
          if (typeof next === 'function') {
            next(err);
          }
        });
      });
    } else {
      // There's still to go
      currentItem = data[0];
      itemsLeft = data.slice(1);
      // Create a document from the current item
      document = new Model(currentItem);
      document.save(function(err, doc) {
        // This is called later, when document is saved
        // Let's assume there were no errors

        // Let's add the freshly baked doc to done array
        done.push(doc);

        // Let's recurse
        loadFixtures(Model, itemsLeft, callback, done);
      });
    }
  }

  if (done && done.length) {
    // If this is not the first iteration, don't wipe the database
    worker();
  } else {
    // Clean up the database if this is the first iteration
    Model.remove(function() {
      worker();
    });
  }
}

exports.load = exports.withFixtures = loadFixtures;