Exercism Rust Minesweeper

lib.rs

pub fn annotate(minefield: &[&str]) -> Vec<String> {
	let row_count = minefield.len();
	if row_count == 0 {
		return vec![];
	}
	let col_count = minefield[0].len();
	if col_count == 0 {
		return vec![String::new()];
	}
	// 2d u8 vector, 0 is space, 9 is a mine, 1-8 is number of mines
	let mut two_d_array: Vec<Vec<u8>> = vec![vec![0; col_count]; row_count];
	let mut result: Vec<String> = vec![String::new(); row_count];

	for (row_index, row) in minefield.iter().enumerate() {
		row.as_bytes().iter().enumerate().for_each(|(col_index, cell)| {
			if *cell == b'*' {
				two_d_array[row_index][col_index] = 9;
				// increment all surrounding cells
				for i in -1..=1 {
					for j in -1..=1 {
						if i == 0 && j == 0 {
							// ...unless it's the origin
							continue;
						}
						let row = row_index as i32 + i;
						let col = col_index as i32 + j;
						if row >= 0 && row < row_count as i32 && col >= 0 && col < col_count as i32 {
							let cell_val = two_d_array[row as usize][col as usize];
							match cell_val {
								9 => continue, // don't increment mines
								_ => two_d_array[row as usize][col as usize] += 1,
							}
						}
					}
				}
			}
		});
	};
	result = two_d_array.iter().map(|row| {
		row.iter().map(|cell| {
			// convert back to char
			match cell {
				9 => '*',
				0 => ' ',
				_ => (cell + 48) as char,
			}
		}).collect()
	}).collect();

	result
}

enum Option {
	Some(i32),
	None,
}

enum Result {
	Ok(i32),
	Err(String),
}

minesweeper.rs

use minesweeper::annotate;

fn remove_annotations(board: &[&str]) -> Vec<String> {
    board.iter().map(|r| remove_annotations_in_row(r)).collect()
}

fn remove_annotations_in_row(row: &str) -> String {
    row.chars()
        .map(|ch| match ch {
            '*' => '*',
            _ => ' ',
        })
        .collect()
}

fn run_test(test_case: &[&str]) {
    let cleaned = remove_annotations(test_case);
    let cleaned_strs = cleaned.iter().map(|r| &r[..]).collect::<Vec<_>>();
    let expected = test_case.iter().map(|&r| r.to_string()).collect::<Vec<_>>();
    assert_eq!(expected, annotate(&cleaned_strs));
}

#[test]
fn no_rows() {
    #[rustfmt::skip]
    run_test(&[
    ]);
}

#[test]
#[ignore]
fn no_columns() {
    #[rustfmt::skip]
    run_test(&[
        "",
    ]);
}

#[test]
#[ignore]
fn no_mines() {
    #[rustfmt::skip]
    run_test(&[
        "   ",
        "   ",
        "   ",
    ]);
}

#[test]
#[ignore]
fn board_with_only_mines() {
    #[rustfmt::skip]
    run_test(&[
        "***",
        "***",
        "***",
    ]);
}

#[test]
#[ignore]
fn mine_surrounded_by_spaces() {
    #[rustfmt::skip]
    run_test(&[
        "111",
        "1*1",
        "111",
    ]);
}

#[test]
#[ignore]
fn space_surrounded_by_mines() {
    #[rustfmt::skip]
    run_test(&[
        "***",
        "*8*",
        "***",
    ]);
}

#[test]
#[ignore]
fn horizontal_line() {
    #[rustfmt::skip]
    run_test(&[
        "1*2*1",
    ]);
}

#[test]
#[ignore]
fn horizontal_line_mines_at_edges() {
    #[rustfmt::skip]
    run_test(&[
        "*1 1*",
    ]);
}

#[test]
#[ignore]
fn vertical_line() {
    #[rustfmt::skip]
    run_test(&[
        "1",
        "*",
        "2",
        "*",
        "1",
    ]);
}

#[test]
#[ignore]
fn vertical_line_mines_at_edges() {
    #[rustfmt::skip]
    run_test(&[
        "*",
        "1",
        " ",
        "1",
        "*",
    ]);
}

#[test]
#[ignore]
fn cross() {
    #[rustfmt::skip]
    run_test(&[
        " 2*2 ",
        "25*52",
        "*****",
        "25*52",
        " 2*2 ",
    ]);
}

#[test]
#[ignore]
fn large_board() {
    #[rustfmt::skip]
    run_test(&[
        "1*22*1",
        "12*322",
        " 123*2",
        "112*4*",
        "1*22*2",
        "111111",
    ]);
}