Support multiple IOTA networks in the Resolver (#1304)

identity_iota_core/Cargo.toml

@@ -45,9 +45,11 @@ rustdoc-args = ["--cfg", "docsrs"]
 default = ["client", "iota-client", "revocation-bitmap", "send-sync-client-ext"]
 # Exposes the IotaIdentityClient and IotaIdentityClientExt traits.
 client = ["dep:async-trait", "iota-sdk"]
-# Enbales the implementation of the extension traits on the iota-sdk's Client.
+# Enables the implementation of the extension traits on the iota-sdk's Client.
 iota-client = ["client", "iota-sdk/client", "iota-sdk/tls"]
 # Enables revocation with `RevocationBitmap2022`.
 revocation-bitmap = ["identity_credential/revocation-bitmap"]
 # Adds Send bounds on the futures produces by the client extension traits.
 send-sync-client-ext = []
+# Disables the blanket implementation of `IotaIdentityClientExt`.
+test = ["client"]

identity_iota_core/src/client/identity_client.rs

@@ -1,7 +1,8 @@
 // Copyright 2020-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::block::protocol::ProtocolParameters;
+#[cfg(feature = "test")]
+use iota_sdk::client::Client;
 
 use crate::block::address::Address;
 use crate::block::output::feature::SenderFeature;
@@ -14,6 +15,7 @@ use crate::block::output::Feature;
 use crate::block::output::OutputId;
 use crate::block::output::RentStructure;
 use crate::block::output::UnlockCondition;
+use crate::block::protocol::ProtocolParameters;
 use crate::Error;
 use crate::IotaDID;
 use crate::IotaDocument;
@@ -192,7 +194,10 @@ pub trait IotaIdentityClientExt: IotaIdentityClient {
   }
 }
 
+#[cfg(not(feature = "test"))]
 impl<T> IotaIdentityClientExt for T where T: IotaIdentityClient {}
+#[cfg(feature = "test")]
+impl IotaIdentityClientExt for Client {}
 
 pub(super) async fn validate_network<T>(client: &T, did: &IotaDID) -> Result<()>
 where

identity_resolver/Cargo.toml

@@ -31,6 +31,8 @@ features = ["send-sync-client-ext", "iota-client"]
 optional = true
 
 [dev-dependencies]
+identity_iota_core = { version = "=1.1.1", path = "../identity_iota_core", features = ["test"] }
+iota-sdk = { version = "1.0.2" }
 tokio = { version = "1.29.0", default-features = false, features = ["rt-multi-thread", "macros"] }
 
 [features]

identity_resolver/src/error.rs

@@ -68,4 +68,7 @@ pub enum ErrorCause {
     /// The method that is unsupported.
     method: String,
   },
+  /// No client attached to the specific network.
+  #[error("none of the attached clients support the network {0}")]
+  UnsupportedNetwork(String),
 }

identity_resolver/src/resolution/resolver.rs

@@ -249,12 +249,14 @@ impl<DOC: 'static> Resolver<DOC, SingleThreadedCommand<DOC>> {
 
 #[cfg(feature = "iota")]
 mod iota_handler {
+  use crate::ErrorCause;
+
   use super::Resolver;
   use identity_document::document::CoreDocument;
-  use identity_iota_core::IotaClientExt;
   use identity_iota_core::IotaDID;
   use identity_iota_core::IotaDocument;
   use identity_iota_core::IotaIdentityClientExt;
+  use std::collections::HashMap;
   use std::sync::Arc;
 
   impl<DOC> Resolver<DOC>
@@ -266,7 +268,7 @@ mod iota_handler {
     /// See also [`attach_handler`](Self::attach_handler).
     pub fn attach_iota_handler<CLI>(&mut self, client: CLI)
     where
-      CLI: IotaClientExt + Send + Sync + 'static,
+      CLI: IotaIdentityClientExt + Send + Sync + 'static,
     {
       let arc_client: Arc<CLI> = Arc::new(client);
 
@@ -277,6 +279,58 @@ mod iota_handler {
 
       self.attach_handler(IotaDID::METHOD.to_owned(), handler);
     }
+
+    /// Convenience method for attaching multiple handlers responsible for resolving IOTA DIDs
+    /// on multiple networks.
+    ///
+    ///
+    /// # Arguments
+    ///
+    /// * `clients` - A collection of tuples where each tuple contains the name of the network name and its
+    ///   corresponding client.
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// // Assume `smr_client` and `iota_client` are instances IOTA clients `iota_sdk::client::Client`.
+    /// attach_multiple_iota_handlers(vec![("smr", smr_client), ("iota", iota_client)]);
+    /// ```
+    ///
+    /// # See Also
+    /// - [`attach_handler`](Self::attach_handler).
+    ///
+    /// # Note
+    ///
+    /// - Using `attach_iota_handler` or `attach_handler` for the IOTA method would override all
+    /// previously added clients.
+    /// - This function does not validate the provided configuration. Ensure that the provided
+    /// network name corresponds with the client, possibly by using `client.network_name()`.
+    pub fn attach_multiple_iota_handlers<CLI, I>(&mut self, clients: I)
+    where
+      CLI: IotaIdentityClientExt + Send + Sync + 'static,
+      I: IntoIterator<Item = (&'static str, CLI)>,
+    {
+      let arc_clients = Arc::new(clients.into_iter().collect::<HashMap<&'static str, CLI>>());
+
+      let handler = move |did: IotaDID| {
+        let future_client = arc_clients.clone();
+        async move {
+          let did_network = did.network_str();
+          let client: &CLI =
+            future_client
+              .get(did_network)
+              .ok_or(crate::Error::new(ErrorCause::UnsupportedNetwork(
+                did_network.to_string(),
+              )))?;
+          client
+            .resolve_did(&did)
+            .await
+            .map_err(|err| crate::Error::new(ErrorCause::HandlerError { source: Box::new(err) }))
+        }
+      };
+
+      self.attach_handler(IotaDID::METHOD.to_owned(), handler);
+    }
   }
 }
 
@@ -301,3 +355,63 @@ where
       .finish()
   }
 }
+
+#[cfg(test)]
+mod tests {
+  use identity_iota_core::block::output::AliasId;
+  use identity_iota_core::block::output::AliasOutput;
+  use identity_iota_core::block::output::OutputId;
+  use identity_iota_core::block::protocol::ProtocolParameters;
+  use identity_iota_core::IotaDID;
+  use identity_iota_core::IotaDocument;
+  use identity_iota_core::IotaIdentityClient;
+  use identity_iota_core::IotaIdentityClientExt;
+
+  use super::*;
+
+  struct DummyClient(IotaDocument);
+
+  #[async_trait::async_trait]
+  impl IotaIdentityClient for DummyClient {
+    async fn get_alias_output(&self, _id: AliasId) -> identity_iota_core::Result<(OutputId, AliasOutput)> {
+      unreachable!()
+    }
+    async fn get_protocol_parameters(&self) -> identity_iota_core::Result<ProtocolParameters> {
+      unreachable!()
+    }
+  }
+
+  #[async_trait::async_trait]
+  impl IotaIdentityClientExt for DummyClient {
+    async fn resolve_did(&self, did: &IotaDID) -> identity_iota_core::Result<IotaDocument> {
+      if self.0.id().as_str() == did.as_str() {
+        Ok(self.0.clone())
+      } else {
+        Err(identity_iota_core::Error::DIDResolutionError(
+          iota_sdk::client::error::Error::NoOutput(did.to_string()),
+        ))
+      }
+    }
+  }
+
+  #[tokio::test]
+  async fn test_multiple_handlers() {
+    let did1 =
+      IotaDID::parse("did:iota:smr:0x0101010101010101010101010101010101010101010101010101010101010101").unwrap();
+    let document = IotaDocument::new_with_id(did1.clone());
+    let dummy_smr_client = DummyClient(document);
+
+    let did2 = IotaDID::parse("did:iota:0x0101010101010101010101010101010101010101010101010101010101010101").unwrap();
+    let document = IotaDocument::new_with_id(did2.clone());
+    let dummy_iota_client = DummyClient(document);
+
+    let mut resolver = Resolver::<IotaDocument>::new();
+    resolver.attach_multiple_iota_handlers(vec![("iota", dummy_iota_client), ("smr", dummy_smr_client)]);
+
+    let doc = resolver.resolve(&did1).await.unwrap();
+    assert_eq!(doc.id(), &did1);
+
+    let doc = resolver.resolve(&did2).await.unwrap();
+    assert_eq!(doc.id(), &did2);
+  }
+}