tests2 solution

exercises/17_tests/tests2.rs

@@ -1,5 +1,8 @@
-// This test has a problem with it -- make the test compile! Make the test pass!
+// Calculates the power of 2 using a bit shift.
-// Make the test fail!
+// `1 << n` is equivalent to "2 to the power of n".
+fn power_of_2(n: u8) -> u64 {
+    1 << n
+}
 
 fn main() {
     // You can optionally experiment here.
@@ -7,8 +10,14 @@ fn main() {
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn you_can_assert_eq() {
+        // TODO: Test the function `power_of_2` with some values.
+        assert_eq!();
+        assert_eq!();
+        assert_eq!();
         assert_eq!();
     }
 }

rustlings-macros/info.toml

@@ -862,13 +862,9 @@ ones pass, and which ones fail :)"""
 name = "tests2"
 dir = "17_tests"
 hint = """
-Like the previous exercise, you don't need to write any code to get this test
-to compile and run.
-
 `assert_eq!` is a macro that takes two arguments and compares them. Try giving
 it two values that are equal! Try giving it two arguments that are different!
-Try giving it two values that are of different types! Try switching which
+Try switching which argument comes first and which comes second!"""
-argument comes first and which comes second!"""
 
 [[exercises]]
 name = "tests3"

solutions/17_tests/tests2.rs

@@ -1 +1,22 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+// 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() {
+    // 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);
+    }
+}