Finished Reviews

Idle Finance Process Quality Review

Score : 89%

This is a Process Quality Review on Idle Finance completed on 4 January 2020. It was performed using the Process Review process (version 0.6.1) and is documented here. The review was performed by ShinkaRex of DeFiSafety. Check out our Telegram.

The final score of the review is 89%, an excellent pass. The breakdown of the scoring is in Scoring Appendix.

Summary of the Process

Very simply, the review looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here are my smart contracts on the blockchain

  • Here is the documentation that explains what my smart contracts do

  • Here are the tests I ran to verify my smart contract

  • Here are the audit(s) performed on my code by third party experts

Disclaimer

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2021. Permission is given to copy in whole, retaining this copyright label.

Code and Team

This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here. This review will answer the questions;

  1. Are the executing code addresses readily available? (Y/N)

  2. Is the code actively being used? (%)

  3. Is there a public software repository? (Y/N)

  4. Is there a development history visible? (%)

  5. Is the team public (not anonymous)? (Y/N)

Are the executing code addresses readily available? (Y/N)

Answer: Yes

They are available at website https://developers.idle.finance/contracts-and-codebase as indicated in the Appendix.

How to improve this score

Make the Ethereum addresses of the smart contract utilized by your application available on either your website or your GitHub (in the README for instance). Ensure the addresses is up to date. This is a very important question wrt to the final score.

Is the code actively being used? (%)

Answer: 100%

Activity is 31 transactions a day on contract IDLE.sol , as indicated in the Appendix.

Percentage Score Guidance

100% More than 10 transactions a day 70% More than 10 transactions a week 40% More than 10 transactions a month 10% Less than 10 transactions a month 0% No activity

Is there a public software repository? (Y/N)

Answer: Yes

GitHub: https://github.com/Idle-Labs

Is there a public software repository with the code at a minimum, but normally test and scripts also (Y/N). Even if the repo was created just to hold the files and has just 1 transaction, it gets a Yes. For teams with private repos, this answer is No.

Is there a development history visible? (%)

Answer: 100%

This github has 298 commits and 1 branch, which indicates a healthy software repo.

This checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Guidance: 100% Any one of 100+ commits, 10+branches 70% Any one of 70+ commits, 7+branches 50% Any one of 50+ commits, 5+branches 30% Any one of 30+ commits, 3+branches 0% Less than 2 branches or less than 10 commits

Is the team public (not anonymous)? (Y/N)

Answer: Yes

The team can be found on LinkdIn.

For a yes in this question the real names of some team members must be public on the website or other documentation. If the team is anonymous and then this question is a No.

Documentation

This section looks at the software documentation. The document explaining these questions is here.

Required questions are;

  1. Is there a whitepaper? (Y/N)

  2. Are the basic software functions documented? (Y/N)

  3. Does the software function documentation fully (100%) cover the deployed contracts? (%)

  4. Are there sufficiently detailed comments for all functions within the deployed contract code (%)

  5. Is it possible to trace from software documentation to the implementation in codee (%)

Is there a whitepaper? (Y/N)

Answer: Yes

While there is no evident whitepaper, per se, the documentation is quite complete so we will consider their doc introduction is their whitepaper.

How to improve this score

Ensure the white paper is available for download from your website or at least the software repository. Ideally update the whitepaper to meet the capabilities of your present application.

Are the basic software functions documented? (Y/N)

Answer: Yes

The "Methods" section of their documentation gives an overview of the basic software function documentation.

How to improve this score

Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 60%

Although some functions are defined, all functions on all contracts are not defined in documentation.

Guidance:

100% All contracts and functions documented 80% Only the major functions documented 79-1% Estimate of the level of software documentation 0% No software documentation

How to improve this score

This score can improve by adding content to the requirements document such that it comprehensively covers the requirements. For guidance, refer to the SecurEth System Description Document . Using tools that aid traceability detection will help.

Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 70%

Some of the code has extremely well-commented code, explaining the functions in detail.

Code examples are in the Appendix. As per the SLOC, there is a 55% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Guidance: 100% CtC > 100 Useful comments consistently on all code 90-70% CtC > 70 Useful comment on most code 60-20% CtC > 20 Some useful commenting 0% CtC < 20 No useful commenting

How to improve this score

This score can improve by adding comments to the deployed code such that it comprehensively covers the code. For guidance, refer to the SecurEth Software Requirements.

Is it possible to trace from software documentation to the implementation in code (%)

Answer: 80%

There is clear traceability between the code and the documentation for any of the defined functions, but not all code

Guidance: 100% - Clear explicit traceability between code and documentation at a requirement level for all code 60% - Clear association between code and documents via non explicit traceability 40% - Documentation lists all the functions and describes their functions 0% - No connection between documentation and code

How to improve this score

This score can improve by adding traceability from requirements to code such that it is clear where each requirement is coded. For reference, check the SecurEth guidelines on traceability.

Testing

This section looks at the software testing available. It is explained in this document. This section answers the following questions;

  1. Full test suite (Covers all the deployed code) (%)

  2. Code coverage (Covers all the deployed lines of code, or explains misses) (%)

  3. Scripts and instructions to run the tests (Y/N)

  4. Packaged with the deployed code (Y/N)

  5. Report of the results (%)

  6. Formal Verification test done (%)

  7. Stress Testing environment (%)

Is there a Full test suite? (%)

Answer: 100%

With a TtC of 138%, there is clearly a robust series of tests.

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Guidance: 100% TtC > 120% Both unit and system test visible 80% TtC > 80% Both unit and system test visible 40% TtC < 80% Some tests visible 0% No tests obvious

How to improve this score

This score can improve by adding tests to fully cover the code. Document what is covered by traceability or test results in the software repository.

Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 50%

The code coverage is found in Idle's Audit. However the average coverage is 46%, so the default 50% is the best score we can give. It is preferable if test reports are stand-alone documents rather than an excerpt from an audit.

Guidance: 100% - Documented full coverage 99-51% - Value of test coverage from documented results 50% - No indication of code coverage but clearly there is a reasonably complete set of tests 30% - Some tests evident but not complete 0% - No test for coverage seen

How to improve this score

This score can improve by adding tests achieving full code coverage. A clear report and scripts in the software repository will guarantee a high score.

Scripts and instructions to run the tests (Y/N)

Answer: Yes

How to improve this score

Add the scripts to the repository and ensure they work. Ask an outsider to create the environment and run the tests. Improve the scripts and docs based on their feedback.

Packaged with the deployed code (Y/N)

Answer: Yes

These tests is packaged with the deployed code.

How to improve this score

Improving this score requires redeployment of the code, with the tests. This score gives credit to those who test their code before deployment and release them together. If a developer adds tests after deployment they can gain full points for all test elements except this one.

Report of the results (%)

Answer: 80%

There is a test report on page 11 of the Quantstamp audit report. It is a good report, but missing explanations for missing elements. It is preferable if test reports are stand-alone documents rather than an excerpt from an audit.

Guidance: 100% - Detailed test report as described below 70% - GitHub Code coverage report visible 0% - No test report evident

How to improve this score

Add a report with the results. The test scripts should generate the report or elements of it.

Formal Verification test done (%)

Answer: 0%

There is no evidence of formal verification testing having been done.

Stress Testing environment (%)

Answer: 100%

There is evidence of robust stress-testing on the Kovan testnet.

Audits

Answer: 90%

An audit was preformed by Quantstamp on December 10th, 2020. These are incremental audits that covered v4.

A Governance audit was preformed by Quantstamp on November 26th, 2020.

Idle v4 was released Aug 4, 2020.

Idle finance was released

Guidance:

  1. Multiple Audits performed before deployment and results public and implemented or not required (100%)

  2. Single audit performed before deployment and results public and implemented or not required (90%)

  3. Audit(s) performed after deployment and no changes required. Audit report is public. (70%)

  4. No audit performed (20%)

  5. Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address' not found, question 1 (0%)

Appendices

Author Details

The author of this review is Rex of DeFi Safety.

Email : rex@defisafety.com Twitter : @defisafety

I started with Ethereum just before the DAO and that was a wonderful education. It showed the importance of code quality. The second Parity hack also showed the importance of good process. Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.

I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development.

Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development.

Career wise I am a business development manager for an avionics supplier.

Scoring Appendix

Executing Code Appendix

Code Used Appendix

Example Code Appendix

* @title: Idle Token interface
* @author: Idle Labs Inc., idle.finance
*/
pragma solidity 0.5.16;
interface IIdleTokenV3 {
// view
/**
* IdleToken price calculation, in underlying
*
* @return : price in underlying token
*/
function tokenPrice() external view returns (uint256 price);
/**
* @return : underlying token address
*/
function token() external view returns (address);
/**
* underlying token decimals
*
* @return : decimals of underlying token
*/
function tokenDecimals() external view returns (uint256 decimals);
/**
* Get APR of every ILendingProtocol
*
* @return addresses: array of token addresses
* @return aprs: array of aprs (ordered in respect to the `addresses` array)
*/
function getAPRs() external view returns (address[] memory addresses, uint256[] memory aprs);
// external
// We should save the amount one has deposited to calc interests
/**
* Used to mint IdleTokens, given an underlying amount (eg. DAI).
* This method triggers a rebalance of the pools if needed
* NOTE: User should 'approve' _amount of tokens before calling mintIdleToken
* NOTE 2: this method can be paused
*
* @param _amount : amount of underlying token to be lended
* @param : pass []
* @return mintedTokens : amount of IdleTokens minted
*/
function mintIdleToken(uint256 _amount, uint256[] calldata) external returns (uint256 mintedTokens);
/**
* Here we calc the pool share one can withdraw given the amount of IdleToken they want to burn
* This method triggers a rebalance of the pools if needed
* NOTE: If the contract is paused or iToken price has decreased one can still redeem but no rebalance happens.
* NOTE 2: If iToken price has decresed one should not redeem (but can do it) otherwise he would capitalize the loss.
* Ideally one should wait until the black swan event is terminated
*
* @param _amount : amount of IdleTokens to be burned
* @param : pass []
* @return redeemedTokens : amount of underlying tokens redeemed
*/
function redeemIdleToken(uint256 _amount, bool _skipRebalance, uint256[] calldata)
external returns (uint256 redeemedTokens);
/**
* Here we calc the pool share one can withdraw given the amount of IdleToken they want to burn
* and send interest-bearing tokens (eg. cDAI/iDAI) directly to the user.
* Underlying (eg. DAI) is not redeemed here.
*
* @param _amount : amount of IdleTokens to be burned
*/
function redeemInterestBearingTokens(uint256 _amount) external;
/**
* @param _newAmount : amount of underlying tokens that needs to be minted with this rebalance
* @param : pass []
* @return : whether has rebalanced or not
*/
function rebalance(uint256 _newAmount, uint256[] calldata) external returns (bool);
/**
* @return : whether has rebalanced or not
*/
function rebalance() external returns (bool);
}

SLOC Appendix

Solidity Contracts

Language

Files

Lines

Blanks

Comments

Code

Complexity

Solidity

39

3405

352

1091

1962

286

Comments to Code 1091 / 1962=55%

Javascript Tests

Language

Files

Lines

Blanks

Comments

Code

Complexity

JavaScript

12

4048

436

901

2711

23

Tests to Code 2711 / 1962 = 138%