Variable declared after use in generated code

[tsvetomir]

TypeScript Version: 2.2.2

Code

function foo() {
    const key = 'bar';

    return {
        [key || 'baz']: true
    }
}

Expected behavior:

function foo() {
    var key = 'bar';
    var _a;
    return _a = {},
        _a[key || 'baz'] = true,
        _a;
}

Actual behavior:

function foo() {
    var key = 'bar';
    return _a = {},
        _a[key || 'baz'] = true,
        _a;
    var _a;
}

[tsvetomir]

Note that the generated code is actually correct as _a is hoisted to the function scope.
The problem is that minifiers such as UglifyJS will complain about it as it follows a return statement.

Dropping unreachable code
Declarations in unreachable code!

[fatcerberus]

This is a known issue - see #4138.

[tsvetomir]

Thanks! The original issue is closed, should we keep this one or reopen it instead?

[mhegazy]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.