refactor

- expect says what it expects to be true (but isn't).
- avoid unwraps

Author: Byron

gitoxide-core/src/hours/core.rs

@@ -28,7 +28,7 @@ pub fn estimate_hours(
         let mut hours = 0.0;
 
         let mut commits = commits.iter().map(|t| &t.1).rev();
-        let mut cur = commits.next().expect("not a single commit found");
+        let mut cur = commits.next().expect("at least one commit if we are here");
 
         for next in commits {
             let change_in_minutes = (next.time.seconds.saturating_sub(cur.time.seconds)) as f32 / MINUTES_PER_HOUR;
@@ -37,7 +37,6 @@ pub fn estimate_hours(
             } else {
                 hours += FIRST_COMMIT_ADDITION_IN_MINUTES / MINUTES_PER_HOUR
             }
-
             cur = next;
         }
 

gitoxide-core/src/hours/util.rs

@@ -55,10 +55,10 @@ where
             // estimate lower bound of capacity needed
             let (lower, _) = iter.size_hint();
             let mut result = String::with_capacity(sep.len() * lower);
-            write!(&mut result, "{first_elt}").unwrap();
+            write!(&mut result, "{first_elt}").expect("enough memory");
             iter.for_each(|elt| {
                 result.push_str(sep);
-                write!(&mut result, "{elt}").unwrap();
+                write!(&mut result, "{elt}").expect("enough memory");
             });
             result
         }