Convert flow typed JS files to Typescript using @khanacademy/flow-to-ts.

README.md

Usage: npx https://gist.github.com/gnbaron/48d417e54fb9527a24422546b3ef763c src/folder

index.js

#!/usr/bin/env node
const { readFile, rename, writeFileSync } = require("fs");
const { basename, dirname, join } = require("path");
const glob = require("glob");
const convert = require("@khanacademy/flow-to-ts");

const cwd = process.argv[2];

function convertFile(filePath, cb) {
  readFile(filePath, "utf8", (err, src) => {
    writeFileSync(filePath, convert(src), "utf8");
    cb();
  });
}

glob("**/*.js", { cwd, ignore: ["**/*.test.js"] }, (err, files) => {
  files.forEach(file => {
    const filePath = join(cwd, file);
    const destinationPath = join(
      dirname(filePath),
      basename(filePath, ".js") + ".tsx"
    );

    rename(filePath, destinationPath, err => {
      if (err) throw err;
      convertFile(destinationPath, () => {
        console.log(`Converted ${file} to Typescript`);
      });
    });
  });
});

package.json

{
  "name": "convert-flow-to-ts",
  "version": "1.0.0",
  "bin": "./index.js",
  "dependencies": {
    "@khanacademy/flow-to-ts": "^0.1.4",
    "glob": "^7.1.3"
  }
}