Change code in directory to typescript

tsify.js

// this script is used to:
// - rename .js files to .tsx and .ts
// - remove "// @flow" from top of files
// script is unsafe
// run from root of project

const fs = require('fs');
const path = require('path');

const dirPath = 'components';

/**
 * Find all files inside a dir, recursively.
 * @function getAllFiles
 * @param  {string} dir Dir path string.
 * @return {string[]} Array with all file names that are inside the directory.
 * from https://gist.github.com/kethinov/6658166
 */
const getAllFiles = dir =>
    fs.readdirSync(dir).reduce((files, file) => {
        const name = path.join(dir, file);
        const isDirectory = fs.statSync(name).isDirectory();
        const isJs = path.extname(file) === '.js';
        if (isDirectory) {
            return [...files, ...getAllFiles(name)]
        } else if (isJs) {
            return [...files, name];
        } else {
            return [...files];
        }
    }, []);

let fileCount = 0;
//iterates through each file in the components directory with .js extension
getAllFiles(dirPath).forEach((file) => {
    console.log(`Processing file ${file}`);
    // If filename has Styles.js at the end, rename it (not checked for "// @flow")
    if (/Styles\.js$/.test(file) || /^index\.js$/.test(file)) {
        fs.renameSync(file, file.replace(/\.js$/, '.ts'));
        console.log(`${file}\t=>\t${file.replace(/.js$/, '.ts')}`);
    } else {
        console.log(file);
        let fileContent = fs.readFileSync(file, 'utf8');
        if (/^\/\/ @flow\n/.test(fileContent)) {
            const newFileContent = fileContent.substr(fileContent.indexOf('\n') + 1);
            fs.writeFileSync(file, newFileContent);
            console.log('\tRemoved first line from file');
            fileContent = fs.readFileSync(file, 'utf8');
        }
        if (/Styles\.js'/.test(fileContent)) {
            const newFileContent = fileContent.replace(/Styles\.js'/, 'Styles\'');
            fs.writeFileSync(file, newFileContent);
            console.log('\tRemoved .js from import');
            fileContent = fs.readFileSync(file, 'utf8');
        }
        // (file is not explicitly checked if it has JSX)
        fs.renameSync(file, file.replace(/\.js$/, '.tsx'));
        console.log(`${file}\t=>\t${file.replace(/.js$/, '.tsx')}`);
    }
    fileCount++;
});

console.log('.js files read: ', fileCount);