How to use module in parse-server cloud code?

Question

I have the following code which Parse has posted before on their blogs, such as this one.

    var _ = require("underscore");
Parse.Cloud.beforeSave("Post", function(request, response) {
    var post = request.object;

    var toLowerCase = function(w) { return w.toLowerCase(); };

    var words = post.get("text").split(/b/);
    words = _.map(words, toLowerCase);
    var stopWords = ["the", "in", "and"]
    words = _.filter(words, function(w) { return w.match(/^w+$/) && ! _.contains(stopWords, w); });

    var hashtags = post.get("text").match(/#.+?b/g);
    hashtags = _.map(hashtags, toLowerCase);

    post.set("words", words);
    post.set("hashtags", hashtags);
    response.success();
});

The issue is that I cannot use npm start to start my server since it crashes on the line var _ = require("underscore"); . The error is

Error: Cannot find module 'underscore'.

How could I fix this in the context of parse-server's cloud code?

Answer 1

Simply go to package.json in your parse-server and add underscore.js as a dependency, as seen below.

"dependencies": {
    "express": "~4.11.x",
    "kerberos": "~0.0.x",
    "parse-server": "^2.2.15",
    "parse": "~1.8.0",
    "nconf": "0.8.4",
    "underscore": "1.8.3"
  }

Then, if running the server locally, use:

npm install

and then

npm start

and the cloud code will now run fine.