Add testing exercise

exercise/testing/src/lib.rs

@@ -0,0 +1,41 @@
+pub fn sploosh(x: i32, y: i32, z: i32) -> i32 {
+    match (x, y, z) {
+        (x, _, _) if x < 0 => 99,
+        (1, 2, 3) => 4,
+        (5, 6, 7) => 3,
+        (x, y, z) => x + y - z,
+    }
+}
+
+pub fn splish(a: i32, b: i32) -> i32 {
+    -a + 3 * b
+}
+
+// 1. Use the `cfg` attribute to mark the `test` module below as a test module
+
+mod test {
+    // 2. Bring all the library items into scope with a `use` statement
+
+    // 3. Write a test function that verifies the following condition using assert_eq! or assert_ne!
+    // - sploosh(1, 2, 3) returns 4
+    // - sploosh(5, 6, 7) does not return 4
+    // - If you pass sploosh a negative number for the first argument, 99 is returned
+    //
+    // `cargo test` should run your tests AND pass
+    // Hint: Don't forget the `test` attribute for your test function!
+
+    // 4. Write a test function that verifies the following conditions using assert!
+    // - splish(100, 10) is negative
+    // - splish(40, 20) is positive
+    // - splish(9, 3) is 0
+}
+
+// 4. Create a tests/ directory and an integration test file tests/more_tests.rs
+// Inside that file, create a test function that verifies:
+// - sploosh(splish(-1, 0), splish(1, 1), splish(3, 2)) returns 4
+//
+// `cargo test` should run your more_tests.rs file and pass
+
+// Challenge: Create a benchmark that measures the speed of splish(8, 9, 10)
+// - Speed up the implementation of splish(8, 9, 10) without breaking the other tests.
+// - Hint: See Cargo.toml to get you started