Update listings in ch 11-01 to reflect current output from cargo new

listings/ch11-writing-automated-tests/listing-11-01/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

listings/ch11-writing-automated-tests/listing-11-03/src/lib.rs

@@ -1,11 +1,18 @@
 // ANCHOR: here
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn exploration() {
-        assert_eq!(2 + 2, 4);
+        let result = add(2, 2);
+        assert_eq!(result, 4);
     }
-
+    
     #[test]
     fn another() {
         panic!("Make this test fail");

listings/ch11-writing-automated-tests/no-listing-01-changing-test-name/src/lib.rs

@@ -1,7 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn exploration() {
-        assert_eq!(2 + 2, 4);
+        let result = add(2, 2);
+        assert_eq!(result, 4);
     }
 }

src/ch11-01-writing-tests.md

@@ -62,7 +62,7 @@ cd ../../..
 <span class="caption">Listing 11-1: The test module and function generated
 automatically by `cargo new`</span>
 
-For now, let’s ignore the top two lines and focus on the function. Note the
+For now, let’s focus solely on the `it_works()` function. Note the
 `#[test]` annotation: this attribute indicates this is a test function, so the
 test runner knows to treat this function as a test. We might also have non-test
 functions in the `tests` module to help set up common scenarios or perform