Lab 6 Details for MPCS 56605

Each lab will consist of a small problem and details of how to proceed. Each lab is intended to give every student hands-on experience with the core concepts and technologies covered during the course.  A student may concentrate, as a team member, on one technology over another for the final project, but labs are designed to give each and every student exposure to all the technologies that come into play.  You need to submit labs to the TAs for grading--see submission instructions below.  Generally, unless otherwise specified, you will have one week to complete each assigned lab.

See the syllabus for information on grading.  Turning in lab assignments on time is required, without exception, and all late deliveries will be penalized, regardless of cause.  Submit your assignments to the subversion repository according to the directions on the syllabus page.

Lab 6   Due: 4:00 pm, Monday, July 31, 2023

Problem 1:  Smart Contracts:  Testing Smart Contracts: 

BACKGROUND:

Like all programming problems, learning a new technology is not an exercise in reading but rather an exercise in thinking and typing.  In this lab, you will continue programming smart contracts on Ethereum.  This lab is designed to give you more hands-on experience in some fundamental skills involved in smart contract development and testing.  In this lab, you will create from scratch a smart contract using Visual Studio Code that implements a new ERC-20 Token in solidity with truffle and ganache.  You will write tests to confirm that your functions are executing properly.  You will then deploy your smart contract on Ganache and run the tests to confirm correct execution.

WHAT YOU NEED TO DO:

Like all programming problems, learning a new technology is not an exercise in reading but rather an exercise in thinking and typing.  In this lab, you will continue programming smart contracts on Ethereum.  This lab is designed to give you more hands-on experience in some fundamental skills involved in smart contract development and testing.  In this lab, you will create from scratch a smart contract using Visual Studio Code that implements a new ERC-20 Token in solidity with truffle and ganache to run a basic ...???.  Whenever you ..., you get a token.  You will write tests to confirm that your math functions are executing properly.  You will then deploy your smart contract on Ganache and run the tests to confirm correct execution.

STEP 1:

Since we are developing a new smart contract that manages a new token according to the ERC-20 specification, it would behoove you to become familiar with it!  Before beginning this lab, read through the ERC-20 token standard on ethereum.org:

ERC-20: Token Standard (ethereum.org)

Also read through the background information at the ERC20 wiki here:

ERC20 Token Standard - IndexUniverse Crypto

and the ERC-20 FAQs here:

What is the ERC-20 Ethereum Token Standard? - CoinDesk

Also, make sure you are very familiar with Section 7.6 of Infante's Building Ethereum Dapps.  You will find it helpful as you work on this lab.  You may examine the sample implementations referenced from ConsenSys and OpenZepplin for clarification of the implementation ideas (only).  Now that you've got a clue where we're going, let's get started.

STEP 2:

First, let's create a lab workspace.  Create a Lab.6/metacoin directory wherever you want (e.g., under ~/56605/src/LABS) and initialize the truffle framework by unboxing a truffle boilerplate that will help us along with this lab.  You can see a listing of the current truffle boxes available here:  Truffle Boxes - Truffle Suite.  You can initialize tutorial boilerplates for a pet shop, a React project, a bazaar, an Angular-based Truffle Daap, a room thermostat hosted in Azure, etc.  Some of the boxes are deprecated, including (alas) tutorialtoken.  We're just going to use the following command (from your Lab.6/metacoin (or wherever you want it) directory):

$ truffle unbox

When you get your prompt back, here's what you have in your directories:

$ find .
.
./migrations
./migrations/1_initial_migration.js
./migrations/2_deploy_contracts.js
./.DS_Store
./test
./test/metacoin.js
./test/TestMetacoin.sol
./contracts
./contracts/MetaCoin.sol
./contracts/ConvertLib.sol
./contracts/Migrations.sol
./truffle-config.js

Replace the truffle-config.js file that was created by truffle with this version here which uncomments the development network section and changes the port to ganache listening on port 7545 and sets the default compiler version to our default of 0.5.16. 

Next, open ganache and create a new workspace, and call it Metacoin and link the project .../Lab.6/metacoin to it (remember?  by selecting "truffle-config.js"...).  If your memory fails you, look back to labs 4 and 5 for detailed instructions on this.  You should have a new ganache workspace that looks something like this (again, account numbers and mnemonic will of course differ...):



Once you've done the above, let's run truffle deploy (the details of the output will of course vary in your case):

$ truffle deploy

Compiling your contracts...
===========================
> Compiling ./contracts/ConvertLib.sol
> Compiling ./contracts/MetaCoin.sol
> Compiling ./contracts/Migrations.sol
> Artifacts written to /Users/mark/Dropbox/UofC/56605/src/LABS/Lab.6/metacoin/build/contracts
> Compiled successfully using:
   - solc: 0.5.16+commit.9c3226ce.Emscripten.clang


Starting migrations...
======================
> Network name:    'development'
> Network id:      5777
> Block gas limit: 6721975 (0x6691b7)


1_initial_migration.js
======================

   Deploying 'Migrations'
   ----------------------
   > transaction hash:    0x899b45fbf934ca5b605484b25bfb8f78e08ab5c150e2121ab8f6b2f86c1928d3
   > Blocks: 0            Seconds: 0
   > contract address:    0x1723D88C9A83Bb464Ba17c41B60F3eBf9A52Ba7f
   > block number:        189
   > block timestamp:     1685482211
   > account:             0xa4208DA857fF1Bf784B7b80E48f5d0Cd764d0369
   > balance:             98.81432088
   > gas used:            225237 (0x36fd5)
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.00450474 ETH

   > Saving migration to chain.
   > Saving artifacts
   -------------------------------------
   > Total cost:          0.00450474 ETH


2_deploy_contracts.js
=====================

   Deploying 'ConvertLib'
   ----------------------
   > transaction hash:    0x2ec53a834bbb14b0d903b60b1ea614b24bb2681c2d294ac321dacf8e20c72054
   > Blocks: 0            Seconds: 0
   > contract address:    0xFAC37BDDeC2d99a7f6f6C1FD611A592780C110D0
   > block number:        191
   > block timestamp:     1685482212
   > account:             0xa4208DA857fF1Bf784B7b80E48f5d0Cd764d0369
   > balance:             98.81156422
   > gas used:            95470 (0x174ee)
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.0019094 ETH


   Linking
   -------
   * Contract: MetaCoin <--> Library: ConvertLib (at address: 0xFAC37BDDeC2d99a7f6f6C1FD611A592780C110D0)

   Deploying 'MetaCoin'
   --------------------
   > transaction hash:    0x3947361f616862c3ae83d043acbe509ed137a06498f23819e89434df0385237e
   > Blocks: 0            Seconds: 0
   > contract address:    0xF1d5612365CcE12C17880616f1BB98D9bCa126f0
   > block number:        192
   > block timestamp:     1685482212
   > account:             0xa4208DA857fF1Bf784B7b80E48f5d0Cd764d0369
   > balance:             98.80583292
   > gas used:            286565 (0x45f65)
   > gas price:           20 gwei
   > value sent:          0 ETH
   > total cost:          0.0057313 ETH

   > Saving migration to chain.
   > Saving artifacts
   -------------------------------------
   > Total cost:           0.0076407 ETH

Summary
=======
> Total deployments:   3
> Final cost:          0.01214544 ETH

Now, let's run the default tests:

$ truffle test
Using network 'development'.


Compiling your contracts...
===========================
> Compiling ./test/TestMetacoin.sol
> Artifacts written to /var/folders/mt/2wzh5nb144g44l496xrdkf3r0000gn/T/test--18374-YY5N6DoU07zS
> Compiled successfully using:
   - solc: 0.5.16+commit.9c3226ce.Emscripten.clang


  TestMetacoin
    ✔ testInitialBalanceUsingDeployedContract (177ms)
    ✔ testInitialBalanceWithNewMetaCoin (116ms)

  Contract: MetaCoin
    ✔ should put 10000 MetaCoin in the first account (67ms)
    ✔ should call a function that depends on a linked library (86ms)
    ✔ should send coin correctly (221ms)


  5 passing (7s)

STEP 2:

Next, let's create a new lab workspace.  Create a Lab.6/MPCS20Token directory wherever you want (e.g., under ~/56605/src/LABS) and initialize the truffle framework using the following command (from your Lab.6/MPCS20Token directory):

$ truffle init

After running init, open the blank project in MS Code.  Open a terminal window, and make the usual edits, you know the drill by now, uncomment the development network section and change the port to ganache listening on port 7545 and set the default compiler version to our default of 0.5.16.  Then save your changes.

STEP 3:

Next, download this solidity interface file and place it in your contracts subdirectory (e.g., in Lab.6/MPCS20Token/contracts).  Then, copy this migrations file and place it in your migrations subdirectory.  This file will set up an initial deployment of your new token with 10,000 "Uchicago Tokens" with symbol "UCT".  Also, copy over the Migrations.sol file from the metacoin/contracts directory and the 1_initial_migration.js file from the metacoin/migrations directory into your MPCS20Token project.

Your next task is to implement the ERC-20 interface in solidity inside a file called ERC20MPCSToken.sol.  You should use some require statements to make sure parameter values are within range, and your implementation of TransferFrom() should emit the Transfer event and your implementation of Approve() should emit the Approval event.

When you've got all the right files in your project, your MS Code Explorer window should look like this:

STEP 4:

Next, let's add a test for our contract.  In our MPCS20Token directory, issue this command:

$ truffle create test ERC20MPCSToken

After running create test, a new test file with a JavaScript test frame that truffle created is under the test directory in your project in MS Code. Rename it to "erc20mpcsToken.js" if necessary.  Now, run the base test frame:

$ truffle test
Using network 'development'.


Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.


  Contract: ERC20MPCSToken
    ✔ should assert true


  1 passing (111ms)

Ok, that initial test (just of deployment) ran just fine.  Let's build some real tests.

STEP 5:

Next, let's create some new tests that test out our new coin.  Inside your test file erc20mpcsToken.js, create several new tests that test account balances and transfers, etc.  Specifically, and at a minimum, you should verify that:

$ truffle test
Using network 'development'.

Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.


  Contract: ERC20MPCSToken
    ✔ should assert true as deployed
    ✔ should have put 10000 ERC20MPCSTokens in the first account
    ✔ should send 10 coins correctly from accounts[0] to accounts[1] (224ms)


  3 passing (369ms)

You might find the following helpful in your testing (you'll have to convert it from metacoin to your ERC20MPCSToken interface):   Write JavaScript tests - Truffle Suite  (Note you can skip the implementation of the test described as "should call a function that depends on a linked library", as we're not carrying that over).

References:

You may find the following references helpful (in addition to the links from previous labs):

Submitting:

Each assignment will have an invitation to create a Github repository. You will use the lab[1-7]-YOUR_GITHUB_USERID to submit your homework.