watcher-ts/packages/solidity-mapper

solidity-mapper

Get value of state variable from storage for a solidity contract.

Pre-requisites

• NodeJS and NPM

  https://nodejs.org/en/ or use https://github.com/nvm-sh/nvm

Instructions

• Create environment variable file

  $ cp .env.example .env
  

• Run the tests using the following command

  $ yarn test
  
  # For testing on private network using RPC getStorageAt.
  # Set ETH_RPC_URL in .env
  $ yarn test:geth-rpc
  
  # For testing on private network using ipld-eth-client getStorageAt.
  # Set GQL_ENDPOINT in .env
  $ yarn test:ipld-gql
  

Different Types

• Value Types
  • Booleans
  • Integers
  • Fixed Point Numbers
  • Address
  • Contract Types
  • Fixed-size byte arrays
  • Enums
  • Function Types
• Reference Types
  • Arrays
    • Get all elements in array
    • Get element in array by index
    • Fixed size arrays
      • Integer Type
      • Boolean Type
      • Address Type
      • Fixed-size byte arrays
      • Enum type
      • Dynamically-sized byte array
      • Struct Type
      • Mapping Type
    • Dynamically-sized arrays
      • Integer Type
      • Boolean Type
      • Address Type
      • Fixed-size byte arrays
      • Enum Type
      • Dynamically-sized byte array
      • Struct Type
      • Mapping Type
    • Nested Arrays
      • Fixed size arrays
      • Dynamically-sized arrays
  • Dynamically-sized byte array
    • Bytes
    • String
  • Structs
    • Get struct value with all members
    • Value Types
    • Get value of a single member in struct
    • Reference Types
      • Struct type members (nested)
      • Fixed size Array members
      • Dynamically sized Array members
      • Bytes and string type members
      • Mapping type members
  • Mapping Types
    • Value Type keys
    • Fixed-size byte array keys
    • Dynamically-sized byte array keys
    • Reference Type Mapping values
      • Struct type values
      • Array type values
      • Dynamically sized Bytes and string type values
    • Nested Mapping

Observations

• The storage layouts are formed according to the rules in https://docs.soliditylang.org/en/latest/internals/layout_in_storage.html#layout-of-state-variables-in-storage

• Structs can occupy multiple slots depending on the size required by its members.

• Fixed arrays can occupy multiple slots according to the size of the array and the type of array.