image module; mocks module

src/image.rs

@@ -0,0 +1,67 @@
+use crate::mocks;
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Image {
+    pub(crate) pixels: Vec<u8>, // 64 for SD, 256 for HD
+}
+
+impl From<String> for Image {
+    #[inline]
+    fn from(string: String) -> Image {
+        let string = string.replace("\n", "");
+        let pixels: Vec<&str> = string.split("").collect();
+        // the above seems to add an extra "" at the start and end of the vec, so strip them below
+        let pixels = &pixels[1..(pixels.len() - 1)];
+        let pixels: Vec<u8> = pixels.iter().map(|&pixel| {
+            pixel.parse::<u8>().unwrap()
+        }).collect();
+
+        Image { pixels }
+    }
+}
+
+impl ToString for Image {
+    #[inline]
+    fn to_string(&self) -> String {
+        let mut string = String::new();
+
+        let sqrt = (self.pixels.len() as f64).sqrt() as usize; // 8 for SD, 16 for HD
+        for line in self.pixels.chunks(sqrt) {
+            for pixel in line {
+                string.push_str(&format!("{}", *pixel));
+            }
+            string.push('\n');
+        }
+
+        string.pop(); // remove trailing newline
+
+        string
+    }
+}
+
+#[test]
+fn test_image_from_string() {
+    let output = Image::from(include_str!("../test/resources/image").to_string());
+
+    let expected = Image {
+        pixels: vec![
+            1,1,1,1,1,1,1,1,
+            1,1,0,0,1,1,1,1,
+            1,0,1,1,1,1,1,1,
+            1,1,1,1,1,1,1,1,
+            1,1,1,1,1,1,1,1,
+            1,1,1,1,1,1,1,1,
+            1,1,1,1,1,1,1,1,
+            1,1,1,1,1,1,1,1,
+        ]
+    };
+
+    assert_eq!(output, expected)
+}
+
+#[test]
+fn test_image_to_string() {
+    let output = mocks::image::chequers_1().to_string();
+    let expected = include_str!("../test/resources/image-chequers-1").to_string();
+    assert_eq!(output, expected);
+}