Remove the `*Features::known` constructor

As we move towards specify supported/required feature bits in the
module(s) where they are supported, the global `known` feature set
constructors no longer make sense.

Here we (finally) remove the `known` constructor entirely,
modifying tests in the `features` module as required.

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 9509f0f23bf6e1c5e7a5d0c66da2a7e3c8bdc58b..0566a80b3daf5b8c0b613fc3a486629deaf88c83 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -666,14 +666,6 @@ impl<T: sealed::Context> Features<T> {
                }
        }
 
-       /// Creates a Features with the bits set which are known by the implementation
-       pub fn known() -> Self {
-               Self {
-                       flags: T::KNOWN_FEATURE_FLAGS.to_vec(),
-                       mark: PhantomData,
-               }
-       }
-
        /// Converts `Features<T>` to `Features<C>`. Only known `T` features relevant to context `C` are
        /// included in the result.
        fn to_context_internal<C: sealed::Context>(&self) -> Features<C> {
@@ -765,24 +757,6 @@ impl<T: sealed::UpfrontShutdownScript> Features<T> {
        }
 }
 
-
-impl<T: sealed::GossipQueries> Features<T> {
-       #[cfg(test)]
-       pub(crate) fn clear_gossip_queries(mut self) -> Self {
-               <T as sealed::GossipQueries>::clear_bits(&mut self.flags);
-               self
-       }
-}
-
-impl<T: sealed::InitialRoutingSync> Features<T> {
-       // Note that initial_routing_sync is ignored if gossip_queries is set.
-       #[cfg(test)]
-       pub(crate) fn clear_initial_routing_sync(mut self) -> Self {
-               <T as sealed::InitialRoutingSync>::clear_bits(&mut self.flags);
-               self
-       }
-}
-
 impl<T: sealed::ShutdownAnySegwit> Features<T> {
        #[cfg(test)]
        pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
@@ -836,97 +810,9 @@ impl Readable for ChannelTypeFeatures {
 
 #[cfg(test)]
 mod tests {
-       use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
+       use super::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, InvoiceFeatures, NodeFeatures, sealed};
        use bitcoin::bech32::{Base32Len, FromBase32, ToBase32, u5};
 
-       #[test]
-       fn sanity_test_known_features() {
-               assert!(!ChannelFeatures::known().requires_unknown_bits());
-               assert!(!ChannelFeatures::known().supports_unknown_bits());
-               assert!(!InitFeatures::known().requires_unknown_bits());
-               assert!(!InitFeatures::known().supports_unknown_bits());
-               assert!(!NodeFeatures::known().requires_unknown_bits());
-               assert!(!NodeFeatures::known().supports_unknown_bits());
-
-               assert!(InitFeatures::known().supports_upfront_shutdown_script());
-               assert!(NodeFeatures::known().supports_upfront_shutdown_script());
-               assert!(!InitFeatures::known().requires_upfront_shutdown_script());
-               assert!(!NodeFeatures::known().requires_upfront_shutdown_script());
-
-               assert!(InitFeatures::known().supports_gossip_queries());
-               assert!(NodeFeatures::known().supports_gossip_queries());
-               assert!(!InitFeatures::known().requires_gossip_queries());
-               assert!(!NodeFeatures::known().requires_gossip_queries());
-
-               assert!(InitFeatures::known().supports_data_loss_protect());
-               assert!(NodeFeatures::known().supports_data_loss_protect());
-               assert!(!InitFeatures::known().requires_data_loss_protect());
-               assert!(!NodeFeatures::known().requires_data_loss_protect());
-
-               assert!(InitFeatures::known().supports_variable_length_onion());
-               assert!(NodeFeatures::known().supports_variable_length_onion());
-               assert!(InvoiceFeatures::known().supports_variable_length_onion());
-               assert!(InitFeatures::known().requires_variable_length_onion());
-               assert!(NodeFeatures::known().requires_variable_length_onion());
-               assert!(InvoiceFeatures::known().requires_variable_length_onion());
-
-               assert!(InitFeatures::known().supports_static_remote_key());
-               assert!(NodeFeatures::known().supports_static_remote_key());
-               assert!(InitFeatures::known().requires_static_remote_key());
-               assert!(NodeFeatures::known().requires_static_remote_key());
-
-               assert!(InitFeatures::known().supports_payment_secret());
-               assert!(NodeFeatures::known().supports_payment_secret());
-               assert!(InvoiceFeatures::known().supports_payment_secret());
-               assert!(InitFeatures::known().requires_payment_secret());
-               assert!(NodeFeatures::known().requires_payment_secret());
-               assert!(InvoiceFeatures::known().requires_payment_secret());
-
-               assert!(InitFeatures::known().supports_basic_mpp());
-               assert!(NodeFeatures::known().supports_basic_mpp());
-               assert!(InvoiceFeatures::known().supports_basic_mpp());
-               assert!(!InitFeatures::known().requires_basic_mpp());
-               assert!(!NodeFeatures::known().requires_basic_mpp());
-               assert!(!InvoiceFeatures::known().requires_basic_mpp());
-
-               assert!(InitFeatures::known().supports_channel_type());
-               assert!(NodeFeatures::known().supports_channel_type());
-               assert!(!InitFeatures::known().requires_channel_type());
-               assert!(!NodeFeatures::known().requires_channel_type());
-
-               assert!(InitFeatures::known().supports_shutdown_anysegwit());
-               assert!(NodeFeatures::known().supports_shutdown_anysegwit());
-
-               assert!(InitFeatures::known().supports_scid_privacy());
-               assert!(NodeFeatures::known().supports_scid_privacy());
-               assert!(ChannelTypeFeatures::known().supports_scid_privacy());
-               assert!(!InitFeatures::known().requires_scid_privacy());
-               assert!(!NodeFeatures::known().requires_scid_privacy());
-               assert!(ChannelTypeFeatures::known().requires_scid_privacy());
-
-               assert!(InitFeatures::known().supports_wumbo());
-               assert!(NodeFeatures::known().supports_wumbo());
-               assert!(!InitFeatures::known().requires_wumbo());
-               assert!(!NodeFeatures::known().requires_wumbo());
-
-               assert!(InitFeatures::known().supports_onion_messages());
-               assert!(NodeFeatures::known().supports_onion_messages());
-               assert!(!InitFeatures::known().requires_onion_messages());
-               assert!(!NodeFeatures::known().requires_onion_messages());
-
-               assert!(InitFeatures::known().supports_zero_conf());
-               assert!(!InitFeatures::known().requires_zero_conf());
-               assert!(NodeFeatures::known().supports_zero_conf());
-               assert!(!NodeFeatures::known().requires_zero_conf());
-               assert!(ChannelTypeFeatures::known().supports_zero_conf());
-               assert!(ChannelTypeFeatures::known().requires_zero_conf());
-
-               let mut init_features = InitFeatures::known();
-               assert!(init_features.initial_routing_sync());
-               init_features = init_features.clear_initial_routing_sync();
-               assert!(!init_features.initial_routing_sync());
-       }
-
        #[test]
        fn sanity_test_unknown_bits() {
                let features = ChannelFeatures::empty();
@@ -946,7 +832,22 @@ mod tests {
 
        #[test]
        fn convert_to_context_with_relevant_flags() {
-               let init_features = InitFeatures::known().clear_upfront_shutdown_script().clear_gossip_queries();
+               let mut init_features = InitFeatures::empty();
+               // Set a bunch of features we use, plus initial_routing_sync_required (which shouldn't get
+               // converted as it's only relevant in an init context).
+               init_features.set_initial_routing_sync_required();
+               init_features.set_data_loss_protect_optional();
+               init_features.set_variable_length_onion_required();
+               init_features.set_static_remote_key_required();
+               init_features.set_payment_secret_required();
+               init_features.set_basic_mpp_optional();
+               init_features.set_wumbo_optional();
+               init_features.set_shutdown_any_segwit_optional();
+               init_features.set_onion_messages_optional();
+               init_features.set_channel_type_optional();
+               init_features.set_scid_privacy_optional();
+               init_features.set_zero_conf_optional();
+
                assert!(init_features.initial_routing_sync());
                assert!(!init_features.supports_upfront_shutdown_script());
                assert!(!init_features.supports_gossip_queries());
@@ -984,8 +885,9 @@ mod tests {
        #[test]
        fn convert_to_context_with_unknown_flags() {
                // Ensure the `from` context has fewer known feature bytes than the `to` context.
-               assert!(InvoiceFeatures::known().flags.len() < NodeFeatures::known().flags.len());
-               let mut invoice_features = InvoiceFeatures::known();
+               assert!(<sealed::InvoiceContext as sealed::Context>::KNOWN_FEATURE_MASK.len() <
+                       <sealed::NodeContext as sealed::Context>::KNOWN_FEATURE_MASK.len());
+               let mut invoice_features = InvoiceFeatures::empty();
                invoice_features.set_unknown_feature_optional();
                assert!(invoice_features.supports_unknown_bits());
                let node_features: NodeFeatures = invoice_features.to_context();