ex(17): tests

.rustlings-state.txt

···
 DON'T EDIT THIS FILE!
 
-tests1
+iterators1
 
 intro1
 intro2
···
 quiz3
 lifetimes1
 lifetimes2
-lifetimes3
+lifetimes3
+tests1
+tests2
+tests3

exercises/17_tests/tests1.rs

···
 mod tests {
     // TODO: Import `is_even`. You can use a wildcard to import everything in
     // the outer module.
+    use super::*;
 
     #[test]
     fn you_can_assert() {
         // TODO: Test the function `is_even` with some values.
-        assert!();
-        assert!();
+        assert!(is_even(2));
+        assert!(!is_even(3));
     }
 }

exercises/17_tests/tests2.rs

···
     #[test]
     fn you_can_assert_eq() {
         // TODO: Test the function `power_of_2` with some values.
-        assert_eq!();
-        assert_eq!();
-        assert_eq!();
-        assert_eq!();
+        assert_eq!(power_of_2(0), 1);
+        assert_eq!(power_of_2(1), 2);
+        assert_eq!(power_of_2(2), 4);
     }
 }

exercises/17_tests/tests3.rs

···
         // TODO: This test should check if the rectangle has the size that we
         // pass to its constructor.
         let rect = Rectangle::new(10, 20);
-        assert_eq!(todo!(), 10); // Check width
-        assert_eq!(todo!(), 20); // Check height
+        assert_eq!(rect.width, 10); // Check width
+        assert_eq!(rect.height, 20); // Check height
     }
 
     // TODO: This test should check if the program panics when we try to create
     // a rectangle with negative width.
     #[test]
+    #[should_panic]
     fn negative_width() {
         let _rect = Rectangle::new(-10, 10);
     }
···
     // TODO: This test should check if the program panics when we try to create
     // a rectangle with negative height.
     #[test]
+    #[should_panic]
     fn negative_height() {
         let _rect = Rectangle::new(10, -10);
     }

solutions/17_tests/tests1.rs

···
+// Tests are important to ensure that your code does what you think it should
+// do.
+
+fn is_even(n: i64) -> bool {
+    n % 2 == 0
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    // When writing unit tests, it is common to import everything from the outer
+    // module (`super`) using a wildcard.
+    use super::*;
+
+    #[test]
+    fn you_can_assert() {
+        assert!(is_even(0));
+        assert!(!is_even(-1));
+        //      ^ You can assert `false` using the negation operator `!`.
+    }
 }

solutions/17_tests/tests2.rs

···
+// Calculates the power of 2 using a bit shift.
+// `1 << n` is equivalent to "2 to the power of n".
+fn power_of_2(n: u8) -> u64 {
+    1 << n
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn you_can_assert_eq() {
+        assert_eq!(power_of_2(0), 1);
+        assert_eq!(power_of_2(1), 2);
+        assert_eq!(power_of_2(2), 4);
+        assert_eq!(power_of_2(3), 8);
+    }
 }

solutions/17_tests/tests3.rs

···
+struct Rectangle {
+    width: i32,
+    height: i32,
+}
+
+impl Rectangle {
+    // Don't change this function.
+    fn new(width: i32, height: i32) -> Self {
+        if width <= 0 || height <= 0 {
+            // Returning a `Result` would be better here. But we want to learn
+            // how to test functions that can panic.
+            panic!("Rectangle width and height must be positive");
+        }
+
+        Rectangle { width, height }
+    }
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn correct_width_and_height() {
+        let rect = Rectangle::new(10, 20);
+        assert_eq!(rect.width, 10); // Check width
+        assert_eq!(rect.height, 20); // Check height
+    }
+
+    #[test]
+    #[should_panic] // Added this attribute to check that the test panics.
+    fn negative_width() {
+        let _rect = Rectangle::new(-10, 10);
+    }
+
+    #[test]
+    #[should_panic] // Added this attribute to check that the test panics.
+    fn negative_height() {
+        let _rect = Rectangle::new(10, -10);
+    }
 }