Parse errors with ES6 export {} declaration

[gustavderdrache]

Both of these lines cause an error about an expected identifier, but the grammar indicates they should be allowed:

/* jshint esnext:true */

export {};
export {x,};

[nicolo-ribaudo]

I think JSHint should warn at line 3: it is valid, but it is probably a mistake.

[lukeapage]

I think you could argue that both are possibly mistakes.. the 2nd case could be covered by elision but then possibly so should

/* jshint elision: false */
var [a,] = [a];
var {x,} = a;

neither of which give warnings.

[lukeapage]

you could argue that both are possibly mistakes.

(but to clarify they shouldn't error, they should possibly warn)

[nicolo-ribaudo]

the 2nd case could be covered by elision but then possibly so should

JSHint doesn't warn about trailing commas, as they are ignored. I think this is more JSCS territory.

var a = [ 1, ]; // No warnings
var b = [ 1, , 2]; // Empty array elements require elision=true.

[lukeapage]

JSHint doesn't warn about trailing commas, as they are ignored. I think this is more JSCS territory.

You're right, it didn't occur to me it could be a style choice.

I agree on a warning for line 3.

[gustavderdrache]

It'd probably be good to warn on the equivalent import statement, too:

import {} from 'module';

It's more likely that the user messed up since there's the syntax import "module" for including a module only for its side-effects.

[lukeapage]

@gustavderdrache, @nicolo-ribaudo already did this on the pr ;) but its a breaking change so likely one for v3