fn test_slice_string()

in starlark/src/values/types/string/mod.rs [491:539]

• 47 lines of code
• 6 McCabe index (conditional complexity)

    fn test_slice_string() {
        let heap = Heap::new();
        for example in EXAMPLES {
            let s = heap.alloc_str(example).to_value();
            for i in -5..=6 {
                for j in -5..=6 {
                    let start = if i == 6 {
                        None
                    } else {
                        Some(Value::new_int(i))
                    };
                    let stop = if j == 6 {
                        None
                    } else {
                        Some(Value::new_int(j))
                    };
                    // Compare list slicing (comparatively simple) to string slicing (complex unicode)
                    let res1 = apply_slice(&example.chars().collect::<Vec<_>>(), start, stop, None)
                        .unwrap()
                        .iter()
                        .collect::<String>();
                    let res2 = s
                        .slice(start, stop, None, &heap)
                        .unwrap()
                        .unpack_str()
                        .unwrap();
                    assert_eq!(
                        &res1,
                        res2,
                        "{:?}[{}:{}]",
                        example,
                        start.map_or("".to_owned(), |x| x.to_string()),
                        stop.map_or("".to_owned(), |x| x.to_string())
                    );
                }
            }
        }

        assert::all_true(
            r#"
"abc"[1:] == "bc" # Remove the first element
"abc"[:-1] == "ab" # Remove the last element
"abc"[1:-1] == "b" # Remove the first and the last element
"banana"[1::2] == "aaa" # Select one element out of 2, skipping the first
"banana"[4::-2] == "nnb" # Select one element out of 2 in reverse order, starting at index 4
"242"[ -0:-2:-1] == "" # From https://github.com/facebookexperimental/starlark-rust/issues/35
"#,
        );
    }