add-import-extensions.js

// npx jscodeshift --parser=ts add-import-extensions.js src/

module.exports = function(fileInfo, api) {
    const j = api.jscodeshift;
    const root = j(fileInfo.source);

    root.find(j.ImportDeclaration).forEach(path => {
        const source = path.value.source;
        if (source.value.startsWith('.') && !source.value.endsWith('.js')) {
            source.value += '.js';
        }
    });

    return root.toSource();
};