test-repo/.yarn/plugins/plugin-prepare.cjs

const fs = require("node:fs");
const path = require("node:path");

const root = path.join(__dirname, "../../");

async function setupVscode() {
  const vscodeDirectory = path.join(root, ".vscode/");
  const settingsFile = path.join(vscodeDirectory, "settings.json");
  const settingsExampleFile = path.join(
    vscodeDirectory,
    "settings.example.json",
  );

  if (fs.existsSync(settingsFile) || !fs.existsSync(settingsExampleFile)) {
    return;
  }

  await fs.promises.copyFile(settingsExampleFile, settingsFile);
}

module.exports = {
  name: "plugin-prepare",
  factory: () => ({
    hooks: {
      async afterAllInstalled({ cwd: rawCwd }) {
        console.log(`Yarn plugin "prepare" running in "${rawCwd}".`);

        let cwd = rawCwd;

        if (process.platform === "win32" && cwd.startsWith("/")) {
          cwd = cwd.slice(1);
        }

        if (path.join(cwd, "./") !== root) {
          console.log(
            `Yarn plugin "prepare" skipped, yarn command not running in "${root}".`,
          );
          return;
        }

        await Promise.allSettled([
          setupVscode(),
          import("../../scripts/build-babel-code-frame-for-test.js"),
          import("../../scripts/generate-flow-estree-type-definition.js"),
        ]);
      },
    },
  }),
};