Cleanup for 2022 days 11 through 21: Turned into a lib and introduced parse errors

2022/day20-grove_positioning_system/src/lib.rs

@@ -1,14 +1,9 @@
-use std::fs;
-
-fn read_file(path: &str) -> String {
-    fs::read_to_string(path)
-        .expect("File not Found")
-}
+use std::num::ParseIntError;
 
 fn get_coordinates(encrypted: &[isize], key: isize, rounds: u8) -> (isize, isize, isize) {
     let decrypted = shuffle_with_key(encrypted, key, rounds);
 
-    let offset = decrypted.iter().position(|&x| x == 0).unwrap() as usize;
+    let offset = decrypted.iter().position(|&x| x == 0).unwrap();
     let c1 = decrypted[(1000 + offset) % decrypted.len()];
     let c2 = decrypted[(2000 + offset) % decrypted.len()];
     let c3 = decrypted[(3000 + offset) % decrypted.len()];
@@ -43,38 +38,33 @@ fn shuffle_with_key(old: &[isize], key: isize, rounds: u8) -> Vec<isize> {
         .collect()
 }
 
-fn main() {
-    let contents = read_file("input");
-    
-    let encrypted: Vec<isize> = contents.lines().map(|i| i.parse().unwrap()).collect();
-    
-    let (c1, c2, c3) = get_coordinates(&encrypted, 1, 1);
-    println!("The relevant numbers are {}, {} and {}, totalling {}.", c1, c2, c3, c1+c2+c3);
-
-    let (d1, d2, d3) = get_coordinates(&encrypted, 811589153, 10);
-    println!("With Key, the relevant numbers are {}, {} and {}, totalling {}.", d1, d2, d3, d1+d2+d3);
-}
-
-#[test]
-fn sample_input() {
-    let contents = read_file("tests/sample_input");
-    let encrypted: Vec<isize> = contents.lines().map(|i| i.parse().unwrap()).collect();
-
+pub fn run(input: &str) -> Result<(isize, isize), ParseIntError> {
+    let encrypted: Vec<isize> = input.lines().map(|i| i.parse()).collect::<Result<Vec<_>, _>>()?;
     let (c1, c2, c3) = get_coordinates(&encrypted, 1, 1);
     let (d1, d2, d3) = get_coordinates(&encrypted, 811589153, 10);
-
-    assert_eq!((c1, c2, c3), (4, -3, 2));
-    assert_eq!((d1, d2, d3), (811589153, 2434767459, -1623178306));
+    let first = c1+c2+c3;
+    let second = d1+d2+d3;
+    Ok((first, second))
 }
 
-#[test]
-fn challenge_input() {
-    let contents = read_file("tests/input");
-    let encrypted: Vec<isize> = contents.lines().map(|i| i.parse().unwrap()).collect();
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs::read_to_string;
 
-    let (c1, c2, c3) = get_coordinates(&encrypted, 1, 1);
-    let (d1, d2, d3) = get_coordinates(&encrypted, 811589153, 10);
+    fn read_file(name: &str) -> String {
+        read_to_string(name).expect(&format!("Unable to read file: {name}")[..]).trim().to_string()
+    }
 
-    assert_eq!((c1, c2, c3), (6790, 9749, -8511));
-    assert_eq!((d1, d2, d3), (6447264231432, 3708150840057, -1356977063816));
+    #[test]
+    fn test_sample() {
+        let sample_input = read_file("tests/sample_input");
+        assert_eq!(run(&sample_input), Ok((3, 1623178306)));
+    }
+
+    #[test]
+    fn test_challenge() {
+        let challenge_input = read_file("tests/challenge_input");
+        assert_eq!(run(&challenge_input), Ok((8028, 8798438007673)));
+    }
 }