cea2a85a42
* Test helpers no longer rely on Babel. * Behaviours are no longer imported. * Removed Babel dependency. * Fixed linter errors.
26 lines
636 B
JavaScript
26 lines
636 B
JavaScript
const { soliditySha3 } = require('web3-utils');
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const INTERFACE_ID_LENGTH = 4;
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function makeInterfaceId (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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module.exports = {
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makeInterfaceId,
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};
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