JSON serialize Vec<u8> fields as hex

serde_json has no simple way to serialize specific field types as hex,
until specialization is merged. This commit contains a hack to serialize
all Vec<u8> fields as hex anyway. It is impossible to check the type of
a generic type parameter at runtime. So all values are first serialized,
then attempted to deserialize into a Vec<u8>. If that works, the found
vector will be serialized as a hex string, rather than an array of
numbers. This is not a performant machanism, but it gets the job done.
As long as it is only used for dev commands and diagnostic data it
should be fine. At least all those number arrays in the diagnostic data
are now gone, without having to duplicate every struct definition just
for serialization.

Note that the 'Value' serialization is a copy of the real one.

libs/sdk-core/Cargo.toml

@@ -51,6 +51,7 @@ miniz_oxide = "0.7.1"
 tokio-stream = "0.1.14"
 serde_with = "3.3.0"
 regex = { workspace = true }
+ryu = "1.0.18"
 
 [dev-dependencies]
 mockito = { workspace = true }

libs/sdk-core/src/breez_services.rs

@@ -1149,7 +1149,7 @@ impl BreezServices {
             Ok(dev_cmd) => match dev_cmd {
                 DevCommand::GenerateDiagnosticData => self.generate_diagnostic_data().await,
             },
-            Err(_) => Ok(serde_json::to_string_pretty(
+            Err(_) => Ok(crate::serializer::to_string_pretty(
                 &self.node_api.execute_command(command).await?,
             )?),
         }
@@ -1176,7 +1176,7 @@ impl BreezServices {
             "node": node_data,
             "sdk": sdk_data
         });
-        Ok(serde_json::to_string_pretty(&result)?)
+        Ok(crate::serializer::to_string_pretty(&result)?)
     }
 
     /// This method sync the local state with the remote node state.
@@ -2171,18 +2171,20 @@ impl BreezServices {
     }
 
     async fn generate_sdk_diagnostic_data(&self) -> SdkResult<Value> {
-        let state = serde_json::to_value(&self.persister.get_node_state()?)?;
-        let payments = serde_json::to_value(
+        let state = crate::serializer::value::to_value(&self.persister.get_node_state()?)?;
+        let payments = crate::serializer::value::to_value(
             &self
                 .persister
                 .list_payments(ListPaymentsRequest::default())?,
         )?;
-        let channels = serde_json::to_value(&self.persister.list_channels()?)?;
-        let settings = serde_json::to_value(&self.persister.list_settings()?)?;
-        let reverse_swaps =
-            serde_json::to_value(self.persister.list_reverse_swaps().map(sanitize_vec)?)?;
-        let swaps = serde_json::to_value(self.persister.list_swaps().map(sanitize_vec)?)?;
-        let lsp_id = serde_json::to_value(&self.persister.get_lsp_id()?)?;
+        let channels = crate::serializer::value::to_value(&self.persister.list_channels()?)?;
+        let settings = crate::serializer::value::to_value(&self.persister.list_settings()?)?;
+        let reverse_swaps = crate::serializer::value::to_value(
+            self.persister.list_reverse_swaps().map(sanitize_vec)?,
+        )?;
+        let swaps =
+            crate::serializer::value::to_value(self.persister.list_swaps().map(sanitize_vec)?)?;
+        let lsp_id = crate::serializer::value::to_value(&self.persister.get_lsp_id()?)?;
 
         let res = json!({
             "node_state": state,

libs/sdk-core/src/greenlight/node_api.rs

@@ -1765,7 +1765,7 @@ impl NodeAPI for Greenlight {
                     .await?
                     .into_inner();
 
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::ListPeerChannels => {
                 let resp = self
@@ -1774,7 +1774,7 @@ impl NodeAPI for Greenlight {
                     .list_peer_channels(cln::ListpeerchannelsRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::ListFunds => {
                 let resp = self
@@ -1783,7 +1783,7 @@ impl NodeAPI for Greenlight {
                     .list_funds(cln::ListfundsRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::ListPayments => {
                 let resp = self
@@ -1792,7 +1792,7 @@ impl NodeAPI for Greenlight {
                     .list_pays(cln::ListpaysRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::ListInvoices => {
                 let resp = self
@@ -1801,7 +1801,7 @@ impl NodeAPI for Greenlight {
                     .list_invoices(cln::ListinvoicesRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::CloseAllChannels => {
                 let peers_res = self
@@ -1823,7 +1823,7 @@ impl NodeAPI for Greenlight {
                     .getinfo(cln::GetinfoRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
             NodeCommand::Stop => {
                 let resp = self
@@ -1832,7 +1832,7 @@ impl NodeAPI for Greenlight {
                     .stop(cln::StopRequest::default())
                     .await?
                     .into_inner();
-                Ok(serde_json::to_value(&resp)?)
+                Ok(crate::serializer::value::to_value(&resp)?)
             }
         }
     }

libs/sdk-core/src/lib.rs

@@ -178,6 +178,7 @@ mod lsps0;
 mod lsps2;
 mod models;
 mod persist;
+mod serializer;
 mod support;
 mod swap_in;
 mod swap_out;