feat: return error for lnd bolt12

.pre-commit-config.yaml

@@ -1 +1 @@
-/nix/store/hjc1qcdcir47vpjxds5sdiiw1sw1n36q-pre-commit-config.json
+/nix/store/wrmdlcghh24lbnjwh0r42nwm54abdzsq-pre-commit-config.json

crates/cdk-lnd/src/error.rs

@@ -20,6 +20,9 @@ pub enum Error {
     /// Payment failed
     #[error("LND payment failed")]
     PaymentFailed,
+    /// Unsupported method
+    #[error("Unsupported method")]
+    UnsupportedMethod,
     /// Wrong invoice type
     #[error("Wrong invoice type")]
     WrongRequestType,

crates/cdk-lnd/src/lib.rs

@@ -403,7 +403,7 @@ impl MintLightning for Lnd {
         &self,
         _melt_quote_request: &MeltQuoteBolt12Request,
     ) -> Result<Bolt12PaymentQuoteResponse, Self::Err> {
-        todo!()
+        Err(Error::UnsupportedMethod.into())
     }
 
     /// Pay a bolt12 offer
@@ -413,7 +413,7 @@ impl MintLightning for Lnd {
         _amount: Option<Amount>,
         _max_fee_amount: Option<Amount>,
     ) -> Result<PayInvoiceResponse, Self::Err> {
-        todo!()
+        Err(Error::UnsupportedMethod.into())
     }
 
     /// Create bolt12 offer
@@ -425,6 +425,6 @@ impl MintLightning for Lnd {
         _unix_expiry: u64,
         _single_use: bool,
     ) -> Result<CreateOfferResponse, Self::Err> {
-        todo!()
+        Err(Error::UnsupportedMethod.into())
     }
 }