Test: Simple row populate test

src/playfield.rs

@@ -1,9 +1,10 @@
 use std::fmt;
+
 #[derive(PartialEq, Debug, Clone)]
 pub struct Playfield {
     size: usize,
     pub fields: Vec<Vec<Field>>,
-    open_fields: Vec<u32>,
+    pub open_fields: Vec<usize>,
 }
 
 impl Playfield {
@@ -11,7 +12,7 @@ impl Playfield {
         Self {
             size,
             fields: vec![vec![Field::default(); size]; size],
-            open_fields: Vec::<u32>::new(),
+            open_fields: Vec::new(),
         }
     }
     pub fn new(field: &String, size: usize) -> Playfield {
@@ -34,10 +35,12 @@ impl Playfield {
 
         for row in 0..self.size {
             for col in 0..self.size {
+                let index = row * self.size + col;
                 let field = &mut self.fields[row][col];
-                let char_field = chars.get(row * self.size + col).unwrap();
+                let char_field = chars.get(index).unwrap();
 
                 if *char_field == "0" {
+                    self.open_fields.push(index);
                     continue;
                 }
 
@@ -75,7 +78,7 @@ pub struct Field {
 impl Field {
     fn default() -> Field {
         Self {
-            possible_values: Vec::<u32>::new(),
+            possible_values: Vec::new(),
             value: None,
         }
     }
@@ -88,7 +91,7 @@ mod tests {
     impl Field {
         fn new(value: u32) -> Field {
             Self {
-                possible_values: Vec::<u32>::new(),
+                possible_values: Vec::new(),
                 value: Some(value),
             }
         }