trufflesuite/truffle

import type { LinkReference, CompiledContract } from "../types";

export function forContract(contract: CompiledContract): any {
  const {
    contractName,
    sourcePath,
    source,
    sourceMap,
    deployedSourceMap,
    legacyAST,
    ast,
    abi,
    metadata,
    bytecode,
    deployedBytecode,
    compiler,
    devdoc,
    userdoc,
    immutableReferences,
    generatedSources,
    deployedGeneratedSources,
    db
  } = contract;

  return {
    contract_name: contractName,
    sourcePath,
    source,
    sourceMap,
    deployedSourceMap,
    legacyAST,
    ast,
    abi,
    metadata,
    bytecode: forBytecode(bytecode),
    deployedBytecode: forBytecode(deployedBytecode),
    unlinked_binary: forBytecode(bytecode),
    compiler,
    devdoc,
    userdoc,
    immutableReferences,
    generatedSources,
    deployedGeneratedSources,
    db
  };
}

export function forBytecode(bytecode: any): any {
  if (!bytecode) {
    return bytecode;
  }
  if (typeof bytecode === "string") {
    return bytecode;
  }

  let { bytes, linkReferences } = bytecode;

  linkReferences = linkReferences || [];

  // inline link references - start by flattening the offsets
  const flattenedLinkReferences = linkReferences
    // map each link ref to array of link refs with only one offset
    .map(({ offsets, length, name }: LinkReference) =>
      offsets.map(offset => ({ offset, length, name }))
    )
    // flatten
    .reduce((a: object[], b: object[]) => [...a, ...b], []);

  // then overwite bytes with link reference
  bytes = flattenedLinkReferences.reduce(
    (
      bytes: string,
      { offset, name, length }: { offset: number; name: string; length: number }
    ) => {
      // length is a byte offset
      const characterLength = length * 2;

      let linkId = `__${name.slice(0, characterLength - 2)}`;
      while (linkId.length < characterLength) {
        linkId += "_";
      }

      const start = offset * 2;

      return `${bytes.substring(0, start)}${linkId}${bytes.substring(
        start + characterLength
      )}`;
    },
    bytes
  );

  return `0x${bytes}`;
}