add in tests for the totp time_until functions

Author: tmthecoder

src/totp.rs

@@ -167,7 +167,11 @@ impl TOTP {
     /// specified start time in case an offset is desired. Both values must be
     /// in seconds.
     pub fn time_until_refresh_with_start(&self, time: u64, time_start: u64) -> u64 {
-        (time - time_start) % period
+        let time_until = (time - time_start) % self.period;
+        if time_until == 0 {
+            return self.period;
+        }
+        time_until
     }
 }
 

tests/totp.rs

@@ -215,3 +215,28 @@ fn rfc_test_6_sha512() {
         47863826
     )
 }
+
+// Tests to check the time_until_refresh methods.
+#[test]
+fn test_time_until() {
+    let totp = TOTP::default_from_base32("SecretKey");
+    assert_eq!(totp.time_until_refresh(15), 15);
+}
+
+#[test]
+fn test_time_until_at_edge() {
+    let totp = TOTP::default_from_base32("SecretKey");
+    assert_eq!(totp.time_until_refresh(30), 30)
+}
+
+#[test]
+fn test_time_until_with_start() {
+    let totp = TOTP::default_from_base32("SecretKey");
+    assert_eq!(totp.time_until_refresh_with_start(30, 15), 15)
+}
+
+#[test]
+fn test_time_until_with_start_at_edge() {
+    let totp = TOTP::default_from_base32("SecretKey");
+    assert_eq!(totp.time_until_refresh_with_start(45, 15), 30)
+}