Sample function and test re-organized.

Source code and Unit Test file splitted.

https://doc.rust-lang.org/book/ch11-03-test-organization.html

Author: Gonzalo Diaz

src/add.rs

@@ -0,0 +1,3 @@
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}

src/lib.rs

@@ -1,14 +1 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+pub mod add;

tests/add.json

@@ -0,0 +1,8 @@
+[
+  {
+    "title": "Example",
+    "a": 2,
+    "b": 2,
+    "result": 4
+  }
+]

tests/add.rs

@@ -0,0 +1,32 @@
+use exercises::add::add;
+use once_cell::sync::Lazy;
+use serde::Deserialize;
+
+mod common;
+use common::utils::load_json;
+
+#[derive(Debug, Deserialize)]
+struct AdderTestCase {
+    title: String,
+    a: u64,
+    b: u64,
+    result: u64
+}
+
+static TEST_DATA: Lazy<Vec<AdderTestCase>> =
+    Lazy::new(|| load_json("tests/add.json"));
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_adder() {
+    for test_case in TEST_DATA.iter() {
+      println!("Probando AdderTestCase : {:?}", test_case.title);
+
+      let result = add(test_case.a, test_case.b);
+      assert_eq!(result, test_case.result);
+    }
+  }
+}