fix(from_str): test for error instead of unwrap/should_panic

exercises/conversions/from_str.rs

@@ -11,15 +11,17 @@ struct Person {
 }
 
 // I AM NOT DONE
+
 // Steps:
-// 1. If the length of the provided string is 0, then return an error
+// 1. If the length of the provided string is 0 an error should be returned
 // 2. Split the given string on the commas present in it
-// 3. Extract the first element from the split operation and use it as the name
+// 3. Only 2 elements should returned from the split, otherwise return an error
-// 4. If the name is empty, then return an error
+// 4. Extract the first element from the split operation and use it as the name
 // 5. Extract the other element from the split operation and parse it into a `usize` as the age
 //    with something like `"4".parse::<usize>()`.
-// If while parsing the age, something goes wrong, then return an error
+// 5. If while extracting the name and the age something goes wrong an error should be returned
-// Otherwise, then return a Result of a Person object
+// If everything goes well, then return a Result of a Person object
+
 impl FromStr for Person {
     type Err = String;
     fn from_str(s: &str) -> Result<Person, Self::Err> {
@@ -48,50 +50,42 @@ mod tests {
         assert_eq!(p.age, 32);
     }
     #[test]
-    #[should_panic]
     fn missing_age() {
-        "John,".parse::<Person>().unwrap();
+        assert!("John,".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn invalid_age() {
-        "John,twenty".parse::<Person>().unwrap();
+        assert!("John,twenty".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_comma_and_age() {
-        "John".parse::<Person>().unwrap();
+        assert!("John".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name() {
-        ",1".parse::<Person>().unwrap();
+        assert!(",1".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name_and_age() {
-        ",".parse::<Person>().unwrap();
+        assert!(",".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name_and_invalid_age() {
-        ",one".parse::<Person>().unwrap();
+        assert!(",one".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn trailing_comma() {
-        "John,32,".parse::<Person>().unwrap();
+        assert!("John,32,".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn trailing_comma_and_some_string() {
-        "John,32,man".parse::<Person>().unwrap();
+        assert!("John,32,man".parse::<Person>().is_err());
     }
 }