package creates variable names starting with numbers

[RobertSandiford]

• Version: 2.1.2
• TypeScript Version:
• Operating System and version (if applicable): Win
• Node Version (if applicable): 14

Description

cjstoesm creates invalid variable names beginning with numbers

// input

'use strict'
var low = require('./lib/core.js')
module.exports = low
low.registerLanguage('1c', require('highlight.js/lib/languages/1c'))
low.registerLanguage('abnf', require('highlight.js/lib/languages/abnf'))

Actual Behavior

// output

import * as low from "./lib/core.js";
import 1c from "highlight.js/lib/languages/1c";
import abnf from "highlight.js/lib/languages/abnf";
'use strict';
low.registerLanguage('1c', 1c);
low.registerLanguage('abnf', abnf);
export default low;

Expected Behavior

// output

import * as low from "./lib/core.js";
import _1c from "highlight.js/lib/languages/1c"; // use underscore for valid var name
import abnf from "highlight.js/lib/languages/abnf";
'use strict';
low.registerLanguage('1c', _1c);
low.registerLanguage('abnf', abnf);
export default low;