259b9da3e6
* make _tokenId indexed in Transfer and Approval events via: https://github.com/ethereum/EIPs/pull/1124/files * fix: make name() and symbol() external instead of public * feat: implement ERC721's ERC165 * feat: erc165 tests * fix: don't use chai-as-promised in direct await * fix: reorganize to /introspection * feat: abstract all erc165 tests to a behavior * feat: disallow registering 0xffffffff
22 lines
583 B
JavaScript
22 lines
583 B
JavaScript
import { soliditySha3 } from 'web3-utils';
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const INTERFACE_ID_LENGTH = 4;
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export default (interfaces = []) => {
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const interfaceIdBuffer = interfaces
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.map(methodSignature => soliditySha3(methodSignature)) // keccak256
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.map(h =>
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Buffer
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.from(h.substring(2), 'hex')
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.slice(0, 4) // bytes4()
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)
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.reduce((memo, bytes) => {
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for (let i = 0; i < INTERFACE_ID_LENGTH; i++) {
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memo[i] = memo[i] ^ bytes[i]; // xor
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}
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return memo;
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}, Buffer.alloc(INTERFACE_ID_LENGTH));
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return `0x${interfaceIdBuffer.toString('hex')}`;
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};
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