[fix] durations can be <= 0 when using '--end'

src/commands/time_entries.rs

@@ -197,7 +197,7 @@ pub(super) fn calculate_duration(
     let duration = end - start;
 
     if time_entry.lunch_break {
-      Ok(duration - launch_break())
+      calculate_duration_with_lunch_break(duration)
     } else {
       Ok(duration)
     }
@@ -208,6 +208,18 @@ pub(super) fn calculate_duration(
   }
 }
 
+fn calculate_duration_with_lunch_break(
+  duration: Duration,
+) -> anyhow::Result<Duration> {
+  let duration_with_lunch_break = duration - launch_break();
+
+  if duration_with_lunch_break <= Duration::zero() {
+    Err(anyhow!("Duration minus lunch break is <= 0"))
+  } else {
+    Ok(duration_with_lunch_break)
+  }
+}
+
 pub fn start(
   format: &Format,
   time_entry: &StartTimeEntry,

src/commands/time_entries_tests.rs

@@ -118,7 +118,7 @@ fn test_calculate_duration() -> anyhow::Result<()> {
     project: "fkbr".to_string(),
     start: DateTime::<Local>::from_str("2021-11-21T22:58:09Z")?,
     end: Some(DateTime::<Local>::from_str("2021-11-21T22:58:09Z")?),
-    duration: Some(Duration::hours(2)),
+    duration: None,
     non_billable: false,
     lunch_break: false,
     description: None,
@@ -138,22 +138,38 @@ fn test_calculate_duration() -> anyhow::Result<()> {
     project: "fkbr".to_string(),
     start: DateTime::<Local>::from_str("2021-11-21T23:58:09Z")?,
     end: Some(DateTime::<Local>::from_str("2021-11-21T22:58:09Z")?),
-    duration: Some(Duration::hours(2)),
+    duration: None,
     non_billable: false,
     lunch_break: false,
     description: None,
     tags: None,
   };
 
   assert_eq!(
-    calculate_duration(
-      &time_entry_with_start_is_after_end
-    )
-    .unwrap_err()
-    .to_string(),
+    calculate_duration(&time_entry_with_start_is_after_end)
+      .unwrap_err()
+      .to_string(),
     "start='2021-11-22 00:58:09 +01:00' is greater or equal than end='2021-11-21 23:58:09 +01:00'".to_string()
   );
 
+  let time_entry_where_lunch_break_is_longer_than_duration = CreateTimeEntry {
+    project: "fkbr".to_string(),
+    start: DateTime::<Local>::from_str("2021-11-21T10:58:09Z")?,
+    end: Some(DateTime::<Local>::from_str("2021-11-21T11:58:09Z")?),
+    duration: None,
+    non_billable: false,
+    lunch_break: true,
+    description: None,
+    tags: None,
+  };
+
+  assert_eq!(
+    calculate_duration(&time_entry_where_lunch_break_is_longer_than_duration)
+      .unwrap_err()
+      .to_string(),
+    "Duration minus lunch break is <= 0".to_string()
+  );
+
   Ok(())
 }