ERC1155 implementation by Yul + Foundry Forge tests

Yul tips

• array, bytes and string are treated as following way

// if there is uint256[] memory ids = new uint256[](3);
// ids[0] = 1;
// ids[1] = 2;
// ids[2] = 3;
0x0000000000000000000000000000000000000000000000000000000000000020  // 0x00 : where the array starts
0x0000000000000000000000000000000000000000000000000000000000000003  // 0x20 : length of 'ids'
0x0000000000000000000000000000000000000000000000000000000000000001  // 0x40 : ids 1st item
0x0000000000000000000000000000000000000000000000000000000000000002  // 0x80 : ids 2nd item
0x0000000000000000000000000000000000000000000000000000000000000003  // 0xa0 : ids 3rd item

• But in case of bytes and string are slightly different.

// if there is bytes memory txt = "abc";
0x0000000000000000000000000000000000000000000000000000000000000020  // 0x00 : where the string starts
0x0000000000000000000000000000000000000000000000000000000000000003  // 0x20 : length of 'txt'
0x6162630000000000000000000000000000000000000000000000000000000001  // 0x40 : there is "abc" which is 61 62 63 and it's left aligned

• mapping is a function. Check balanceOf.

Repository installation

1. Install Foundry

curl -L https://foundry.paradigm.xyz | bash
foundryup

2. Install solidity compiler https://docs.soliditylang.org/en/latest/installing-solidity.html#installing-the-solidity-compiler

3. Build Yul contracts and check tests pass

forge test

Running tests

Run tests (compiles yul then fetch resulting bytecode in test)

forge test

To see the console logs during tests

forge test -vvv