subgraph-generator.js

const pTap = require('p-tap');
const { pools } = require('vesper-metadata');
const {
  readFile,
  writeFile,
  rmdir,
  mkdir,
  pathExists,
  copy,
} = require('fs-extra');
const Mustache = require('mustache');
const { exec } = require('child_process');

const TypesFolder = './types';
const GeneratedCodeFolder = './generated';

const poolsToWatch = pools
  .filter((pool) => pool.chainId === 1 && pool.stage === 'prod')
  .map(({ version = 2, address, name, birthblock }) => ({
    version,
    address,
    name,
    birthblock,
    interestFeeEvent:
      version === 2
        ? 'Deposit(indexed address,uint256,uint256)'
        : 'Transfer(indexed address,indexed address,uint256)',
  }));

function promisifyChildProcess(fn) {
  return function (...args) {
    const child = fn(...args);
    // forward the output of the child process to the parent one
    child.stdout.pipe(process.stdout);
    child.stderr.pipe(process.stderr);
    return new Promise(function (resolve, reject) {
      child.addListener('error', reject);
      child.addListener('exit', resolve);
    });
  };
}

async function copyGeneratedFiles(pool) {
  if (!pool) {
    return;
  }
  const folderName = `${GeneratedCodeFolder}/poolV${pool.version}_${pool.name}_${pool.address}`;
  return copy(folderName, TypesFolder, { overwrite: true }).then(
    pTap(() => console.log(`Copied classes for V${pool.version} pools.`))
  );
}

// node-graph generates a class for each pool, but we just need a class for v2 and v3 pools (so far)
function cleanUpdatedFiles() {
  return pathExists(TypesFolder)
    .then(
      pTap((exists) =>
        console.log(`Types folder ${exists ? '' : 'does not '}exists`)
      )
    )
    .then((exists) =>
      exists ? rmdir(TypesFolder, { recursive: true }) : Promise.resolve()
    )
    .then(pTap(() => console.log('Starting to run codegen.')))
    .then(() => promisifyChildProcess(exec)('npm run codegen'))
    .then(
      pTap(() =>
        console.log(
          'Generation of classes and schema succeded! Proceeding now to clean up the generated files.'
        )
      )
    )
    .then(() => mkdir(TypesFolder))
    .then(pTap(() => console.log('Types folder created!')))
    .then(function () {
      // take a v2 pool, a v3pool, calculate the folder name and move the files into ./types
      const v2Pool = poolsToWatch.find(({ version }) => version === 2);
      const v3Pool = poolsToWatch.find(({ version }) => version === 3);
      return copyGeneratedFiles(v2Pool)
        .then(() => copyGeneratedFiles(v3Pool))
        .then(() =>
          copy(`${GeneratedCodeFolder}/schema.ts`, `${TypesFolder}/schema.ts`, {
            overwrite: true,
          })
        );
    })
    .then(() => rmdir(GeneratedCodeFolder, { recursive: true }));
}

console.log('Reading the template file');
readFile('./subgraph.template.yaml', 'utf8')
  .then((templateFile) =>
    writeFile(
      './subgraph.yaml',
      Mustache.render(templateFile, { pools: poolsToWatch })
    )
  )
  .then(pTap(() => console.log('subgraph.yaml generated successfully')))
  .then(cleanUpdatedFiles)
  .then(pTap(() => console.log('All file and code generation succeeded!')))
  .catch((e) => console.error(e));