Use constant for invoice's default expiry value

diff --git a/lightning-invoice/src/lib.rs b/lightning-invoice/src/lib.rs
index b33b1b374d85b1bea79e5d38a984b7be36e8b0d0..0e469ff1e8600745cd97648cf7f9739524f18377 100644 (file)
--- a/lightning-invoice/src/lib.rs
+++ b/lightning-invoice/src/lib.rs
@@ -54,6 +54,11 @@ const SYSTEM_TIME_MAX_UNIX_TIMESTAMP: u64 = std::i32::MAX as u64;
 /// it should be rather low as long as we still have to support 32bit time representations
 const MAX_EXPIRY_TIME: u64 = 60 * 60 * 24 * 356;
 
+/// Default expiry time as defined by [BOLT 11].
+///
+/// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
+const DEFAULT_EXPIRY_TIME: u64 = 3600;
+
 /// This function is used as a static assert for the size of `SystemTime`. If the crate fails to
 /// compile due to it this indicates that your system uses unexpected bounds for `SystemTime`. You
 /// can remove this functions and run the test `test_system_time_bounds_assumptions`. In any case,
@@ -1041,11 +1046,11 @@ impl Invoice {
                self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
        }
 
-       /// Returns the invoice's expiry time if present
+       /// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
        pub fn expiry_time(&self) -> Duration {
                self.signed_invoice.expiry_time()
                        .map(|x| x.0)
-                       .unwrap_or(Duration::from_secs(3600))
+                       .unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
        }
 
        /// Returns the invoice's `min_cltv_expiry` time if present