​​Testing Smart Contracts
​​The talk: https://www.youtube.com/watch?v=fR_PXztjs-E&feature=youtu.be
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​​What to test?

​​How to test?

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​​Tools covered

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​​More: formal verification, professional auditing, bug bounties
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​​What to test

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​​Unit testing

​​Validate each unit of the code performs as designed
  • ​​Make sure the input parameters are rejecting invalid values
  • ​​Make sure the return values are within expected range and properly formatted
  • ​​Testing of smart contract state changes
  • ​​Event testing
  • ​​Error testing
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​​Prevent attacks and vulnerabilities

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​​https://github.com/sigp/solidity-security-blog
  • ​​Floating points and precision
  • ​​Arithmetic under/over flows
  • ​​Unexpected ether
  • ​​Entropy illusion
  • ​​Front-running / race conditions
  • ​​Tx.origin authentication
  • ​​Denial of service
  • ​​Re-entrancy
  • ​​Delegate call
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​​Another reference: https://consensys.github.io/smart-contract-best-practices/known_attacks/
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​​How to test