js version
This jest expect matcher detects the js version of given code
API
Either:
require('js-version-detector')
// ...
test('const', () => expect('const a = 5').toBeOfVersion(5, false))
// SyntaxError: The keyword 'const' is reserved (1:0)
test('const', () => expect('const a = 5').toBeOfVersion(5, true))
/*
> 1 | const a = 5
| ^ SyntaxError: The keyword 'const' is reserved (1:0)
*/
Or:
const check = require('js-version-detector')
// ...
console.log(check('const a = 5', 'filename.js', 5))
/*
{
message: 'The keyword \'const\' is reserved (1:0)',
loc: Position { line: 1, column: 0 }
}
(cached with filename as key)
*/
console.log(check('var a = 5', 'es5-filename.js', 5)) //true