Add methods to set features in Features objects.

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 488d6d70f5768ffde2d0af6afd80707a595625c9..549663c90d080c6eaae1111fce74909bc8d1dc18 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -32,6 +32,8 @@ use ln::msgs::DecodeError;
 use util::ser::{Readable, Writeable, Writer};
 
 mod sealed {
+       use ln::features::Features;
+
        /// The context in which [`Features`] are applicable. Defines which features are required and
        /// which are optional for the context.
        ///
@@ -157,7 +159,8 @@ mod sealed {
        ///
        /// [`Context`]: trait.Context.html
        macro_rules! define_feature {
-               ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr) => {
+               ($odd_bit: expr, $feature: ident, [$($context: ty),+], $doc: expr, $optional_setter: ident,
+                $required_setter: ident) => {
                        #[doc = $doc]
                        ///
                        /// See [BOLT #9] for details.
@@ -242,6 +245,20 @@ mod sealed {
                                }
                        }
 
+                       impl <T: $feature> Features<T> {
+                               /// Set this feature as optional.
+                               pub fn $optional_setter(mut self) -> Self {
+                                       <T as $feature>::set_optional_bit(&mut self.flags);
+                                       self
+                               }
+
+                               /// Set this feature as required.
+                               pub fn $required_setter(mut self) -> Self {
+                                       <T as $feature>::set_required_bit(&mut self.flags);
+                                       self
+                               }
+                       }
+
                        $(
                                impl $feature for $context {
                                        // EVEN_BIT % 2 == 0
@@ -251,28 +268,34 @@ mod sealed {
                                        const ASSERT_ODD_BIT_PARITY: usize = (<Self as $feature>::ODD_BIT % 2) - 1;
                                }
                        )*
+
                }
        }
 
        define_feature!(1, DataLossProtect, [InitContext, NodeContext],
-               "Feature flags for `option_data_loss_protect`.");
+               "Feature flags for `option_data_loss_protect`.", set_data_loss_protect_optional,
+               set_data_loss_protect_required);
        // NOTE: Per Bolt #9, initial_routing_sync has no even bit.
-       define_feature!(3, InitialRoutingSync, [InitContext],
-               "Feature flags for `initial_routing_sync`.");
+       define_feature!(3, InitialRoutingSync, [InitContext], "Feature flags for `initial_routing_sync`.",
+               set_initial_routing_sync_optional, set_initial_routing_sync_required);
        define_feature!(5, UpfrontShutdownScript, [InitContext, NodeContext],
-               "Feature flags for `option_upfront_shutdown_script`.");
+               "Feature flags for `option_upfront_shutdown_script`.", set_upfront_shutdown_script_optional,
+               set_upfront_shutdown_script_required);
        define_feature!(7, GossipQueries, [InitContext, NodeContext],
-               "Feature flags for `gossip_queries`.");
+               "Feature flags for `gossip_queries`.", set_gossip_queries_optional, set_gossip_queries_required);
        define_feature!(9, VariableLengthOnion, [InitContext, NodeContext, InvoiceContext],
-               "Feature flags for `var_onion_optin`.");
+               "Feature flags for `var_onion_optin`.", set_variable_length_onion_optional,
+               set_variable_length_onion_required);
        define_feature!(13, StaticRemoteKey, [InitContext, NodeContext],
-               "Feature flags for `option_static_remotekey`.");
+               "Feature flags for `option_static_remotekey`.", set_static_remote_key_optional,
+               set_static_remote_key_required);
        define_feature!(15, PaymentSecret, [InitContext, NodeContext, InvoiceContext],
-               "Feature flags for `payment_secret`.");
+               "Feature flags for `payment_secret`.", set_payment_secret_optional, set_payment_secret_required);
        define_feature!(17, BasicMPP, [InitContext, NodeContext, InvoiceContext],
-               "Feature flags for `basic_mpp`.");
+               "Feature flags for `basic_mpp`.", set_basic_mpp_optional, set_basic_mpp_required);
        define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
-               "Feature flags for `opt_shutdown_anysegwit`.");
+               "Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
+               set_shutdown_any_segwit_required);
 
        #[cfg(test)]
        define_context!(TestingContext {
@@ -296,7 +319,8 @@ mod sealed {
 
        #[cfg(test)]
        define_feature!(23, UnknownFeature, [TestingContext],
-               "Feature flags for an unknown feature used in testing.");
+               "Feature flags for an unknown feature used in testing.", set_unknown_feature_optional,
+               set_unknown_feature_required);
 }
 
 /// Tracks the set of features which a node implements, templated by the context in which it
@@ -614,7 +638,7 @@ impl<T: sealed::Context> Readable for Features<T> {
 
 #[cfg(test)]
 mod tests {
-       use super::{ChannelFeatures, InitFeatures, NodeFeatures};
+       use super::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
 
        #[test]
        fn sanity_test_known_features() {
@@ -718,4 +742,15 @@ mod tests {
                assert!(!features.supports_upfront_shutdown_script());
                assert!(!init_features.supports_gossip_queries());
        }
+
+       #[test]
+       fn set_feature_bits() {
+               let features = InvoiceFeatures::empty()
+                       .set_basic_mpp_optional()
+                       .set_payment_secret_required();
+               assert!(features.supports_basic_mpp());
+               assert!(!features.requires_basic_mpp());
+               assert!(features.requires_payment_secret());
+               assert!(features.supports_payment_secret());
+       }
 }