orval.config.ts

// example of how to run prettier from orval.config.ts

import fs from "fs/promises";
import * as prettier from "prettier";
import path from "path";

const walk = async (inputPath: string): Promise<string[]> => {
  const stats = await fs.stat(inputPath);
  if (!stats.isDirectory()) {
    return [inputPath];
  }
  const entries = await fs.readdir(inputPath, { withFileTypes: true });
  const filePaths = await Promise.all(
    entries.map(async (dirent) => walk(path.resolve(inputPath, dirent.name))),
  );
  return filePaths.flat();
};

const afterAllFilesWrite = async (paths: string[]): Promise<void> => {
  const allPaths = await Promise.all(paths.map(walk));
  for (const path of allPaths.flat()) {
    const data = await fs.readFile(path, "utf8");
    const formattedData = await prettier.format(data, { parser: "typescript" });
    await fs.writeFile(path, formattedData);
  }
};

// add as hook in your config
hooks: {
  afterAllFilesWrite,
 },