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petejkim/testing-storage-slot-9.js

Created December 21, 2020 20:40
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USDC v2: Upgrading a $1.4B Token - Testing Storage Slot 9
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testing-storage-slot-9.js
// Storage slot 9 contains "balances" (mapping(address => uint256))
// Derive slot position for the key k
const k = holderAddr.slice(2).toLowerCase().padStart(64, "0");
const p = "9".padStart(64, "0");
const valueSlotPos = web3.utils.keccak256("0x" + k + p);
const data = await web3.eth.getStorageAt(contract.address, valueSlotPos);
expect(new BN(data.slice(2), 16).eq(expectedBalance)).to.be.true;
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