fn get_opt(a int) ?string {
    if a < 0 {
        return none
    }
    return 'success'
}

fn get_opt_int(a int) ?int {
    if a < 0 {
        return none
    }
    return 12
}

struct TestResult {
    cols map[string]int
    rows []TestRow
}

struct TestRow {
    vals []?string
}

struct TestDb {}

struct TestPgConnection {
    db TestDb
}

fn (db TestDb) exec_result(_ string) !TestResult {
    return TestResult{
        cols: {
            'present': 0
            'empty':   1
            'none':    2
        }
        rows: [TestRow{
            vals: [?string('hello'), ?string(''), ?string(none)]
        }]
    }
}

fn (c &TestPgConnection) query(q string) ![]map[string]string {
    res := c.db.exec_result(q)!
    mut rows := []map[string]string{}

    for row in res.rows {
        mut values := map[string]string{}
        for col, idx in res.cols {
            values[col] = row.vals[idx] or { '' } as string
        }
        rows << values
    }
    return rows
}

fn test_option_unwrap_as_cast() {
    x := get_opt(1)
    d := get_opt_int(12)
    dump(d? as int == 12)
    dump('${x? as string}' == 'success')

    assert d? as int == 12
    assert x? as string == 'success'
}

fn test_option_array_index_or_block_followed_by_as_cast() {
    conn := &TestPgConnection{
        db: TestDb{}
    }
    rows := conn.query('select') or { panic(err) }

    assert rows.len == 1
    assert rows[0]['present'] == 'hello'
    assert rows[0]['empty'] == ''
    assert rows[0]['none'] == ''
}