Add tests.

Cargo.toml

@@ -94,7 +94,7 @@ test = false # no unit tests
 [[bin]]
 name = "rustup-init"
 path = "src/cli/main.rs"
-test = false # no unit tests
+test = true
 
 [profile.release]
 lto = true

src/cli/download_tracker.rs

@@ -118,6 +118,15 @@ impl DownloadTracker {
         }
         self.prepare_for_new_download();
     }
+    // we're doing modular arithmetic, treat as integer
+    pub fn from_seconds(sec: u32) -> (u32, u32, u32, u32) {
+        let d = sec / (24 * 3600);
+        let h = sec % (24 * 3600) / 3600;
+        let min = sec % 3600 / 60;
+        let sec = sec % 60;
+
+        (d, h, min, sec)
+    }
     /// Resets the state to be ready for a new download.
     fn prepare_for_new_download(&mut self) {
         self.content_len = None;
@@ -186,27 +195,16 @@ impl fmt::Display for Duration {
         let sec = self.0;
 
         if sec.is_infinite() {
-            write!(f, "Unknown");
+            write!(f, "Unknown")
         } else {
-            match from_seconds(sec as u32) {
+            match DownloadTracker::from_seconds(sec as u32) {
                 (d, h, m, s) if d > 0 => write!(f, "{:3.0}d {:2.0}h {:2.0}m {:2.0}s", d, h, m, s),
                 (0, h, m, s) if h > 0 => write!(f, "{:2.0}h {:2.0}m {:2.0}s", h, m, s),
                 (0, 0, m, s) if m > 0 => write!(f, "{:2.0}m {:2.0}s", m, s),
                 (_, _, _, s) => write!(f, "{:2.0}s", s),
             }
         }
     }
-
-    fn from_seconds(sec: u32) -> (u32, u32, u32, u32) {
-        // we're doing modular arithmetic, treat as integer
-        let d = sec / (24 * 3600);
-        let h = sec % (24 * 3600) / 3600;
-        let min = sec % 3600 / 60;
-        let sec = sec % 60;
-
-        (d, h, min, sec)
-    }
-
 }
 
 /// Human readable size (bytes)
@@ -227,3 +225,24 @@ impl fmt::Display for Size {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn download_tracker_from_seconds_test() {
+        use crate::download_tracker::DownloadTracker;
+        assert_eq!(DownloadTracker::from_seconds(2), (0, 0, 0, 2));
+
+        assert_eq!(DownloadTracker::from_seconds(60), (0, 0, 1, 0));
+
+        assert_eq!(DownloadTracker::from_seconds(3600), (0, 1, 0, 0));
+
+        assert_eq!(DownloadTracker::from_seconds(3600 * 24), (1, 0, 0, 0));
+
+        assert_eq!(DownloadTracker::from_seconds(52292), (0, 14, 31, 32));
+
+        assert_eq!(DownloadTracker::from_seconds(222292), (2, 13, 44, 52));
+    }
+
+}