tests1 solution

exercises/17_tests/tests1.rs

@@ -1,9 +1,9 @@
 // Tests are important to ensure that your code does what you think it should
-// do. Tests can be run on this file with the following command: rustlings run
-// tests1
-//
-// This test has a problem with it -- make the test compile! Make the test pass!
-// Make the test fail!
+// do.
+
+fn is_even(n: i64) -> bool {
+    n % 2 == 0
+}
 
 fn main() {
     // You can optionally experiment here.
@@ -11,8 +11,13 @@ fn main() {
 
 #[cfg(test)]
 mod tests {
+    // TODO: Import `is_even`. You can use a wildcard to import everything in
+    // the outer module.
+
     #[test]
     fn you_can_assert() {
+        // TODO: Test the function `is_even` with some values.
+        assert!();
         assert!();
     }
 }

rustlings-macros/info.toml

@@ -851,9 +851,6 @@ hint = """Let the compiler guide you :)"""
 name = "tests1"
 dir = "17_tests"
 hint = """
-You don't even need to write any code to test -- you can just test values and
-run that, even though you wouldn't do that in real life. :)
-
 `assert!` is a macro that needs an argument. Depending on the value of the
 argument, `assert!` will do nothing (in which case the test will pass) or
 `assert!` will panic (in which case the test will fail).

solutions/17_tests/tests1.rs

@@ -1 +1,24 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+// 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() {
+    // 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 `!`.
+    }
+}