Info about session #05

What you need to know about our 5th session!

DApps Dev Club is holding its 5th session, about testing smart contracts, on Tuesday, 23rd April Tuesday, 30th April. Note that this event has been postponed by a week from the originally scheduled date.

RSVP now!

Here's what you need to know!


The session will be held at BitTemple's office in Raffles Place.

Thanks Solomon for helping us run the event!


In our previous session, we wrote smart contracts in Solidity, and used truffle to deploy them to a local blockchain. In this session we will be continuing to use truffle, but this time using its test runner capabilities.

We will learn how to write tests in Mocha (which truffle's test runner wraps around), specifically to:

  • test state machines
  • test data storage
  • test events
  • mock smart contracts

As with the previous session, there will be hands on parts, so please bring along your laptops!


A basic level of Javascript will be required for this session, as we will be using it during the session. Here are some recommendations on where to learn Javascript.

(arranged in order, from lowest to highest time commitment required.)

The reason for this is that we will be writing tests for our smart contracts in Javascript, not Solidity.

So if you're not familiar with Javascript, or need a refresher, please make use of one of the resources above, and get up to speed. You need not feel daunted though, as we have enlisted the help of some volunteers from the SingaporeJS community, as well as the broader developer community here, who are familiar with Javascript, in order to help you all out during the session.

I can haz Javascript?

Once (re)acquainted with Javascript, the next thing to do as preparation would be to get acquainted with Mocha. We will be using truffle's test runner, which is a wrapper around Mocha with some additional stuff that is specific to smart contracts. That additional stuff will be the focus of the session, so it would be beneficial to get familiar to the base layer of Mocha before getting deeper into it.

The Mocha getting started guide is excellent, and should not take longer than ten minutes to get through, so give that a whir!

Next session

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… it helps us plan for seating, ordering F&B, et cetera.

See you all again soon!