You could write a macro to factor out the common code (here and above):

```rust
macro_rules! t {
    ($input: expr, $expected: expr) => {
        assert_eq!($input.nfkc_chars().collect::<~str>(), $expected.to_owned());
    }
}

t!("abc", "abc");
t!("\u1e0b\u01c4", "\u1e0bD\u017d");
// ...
```

(Could also be a function, but the macro will print more useful information on failure.)