Static Metadata Validation

codegen/src/api/calls.rs

@@ -49,7 +49,7 @@ pub fn generate_calls(
         "Call",
     );
     let (call_structs, call_fns): (Vec<_>, Vec<_>) = struct_defs
-        .iter()
+        .iter_mut()
         .map(|(variant_name, struct_def)| {
             let (call_fn_args, call_args): (Vec<_>, Vec<_>) =
                 match struct_def.fields {
@@ -76,12 +76,16 @@ pub fn generate_calls(
                 };
 
             let pallet_name = &pallet.name;
-            let call_name = variant_name;
+            let call_name = &variant_name;
             let struct_name = &struct_def.name;
             let call_hash = subxt_metadata::get_call_hash(metadata, pallet_name, call_name)
                 .unwrap_or_else(|_| abort_call_site!("Metadata information for the call {}_{} could not be found", pallet_name, call_name));
 
             let fn_name = format_ident!("{}", variant_name.to_snake_case());
+            // Propagate the documentation just to `TransactionApi` methods, while
+            // draining the documentation of inner call structures.
+            let docs = struct_def.docs.take();
+            // The call structure's documentation was stripped above.
             let call_struct = quote! {
                 #struct_def
 

codegen/src/api/mod.rs

@@ -453,6 +453,7 @@ where
                     fields,
                     Some(parse_quote!(pub)),
                     type_gen,
+                    var.docs(),
                 );
                 (var.name().to_string(), struct_def)
             })

metadata/src/lib.rs

@@ -302,8 +302,11 @@ pub fn get_constant_hash(
         .find(|c| c.name == constant_name)
         .ok_or(NotFound::Item)?;
 
-    let hash = get_type_hash(&metadata.types, constant.ty.id(), &mut HashSet::new());
-    Ok(hash)
+    let mut bytes = get_type_hash(&metadata.types, constant.ty.id(), &mut HashSet::new());
+    bytes = xor(bytes, hash(constant.name.as_bytes()));
+    bytes = xor(bytes, hash(&constant.value));
+
+    Ok(bytes)
 }
 
 /// Obtain the hash for a specific call, or an error if it's not found.

subxt/Cargo.toml

@@ -25,8 +25,8 @@ log = "0.4.14"
 serde = { version = "1.0.124", features = ["derive"] }
 serde_json = "1.0.64"
 thiserror = "1.0.24"
+parking_lot = "0.12.0"
 
-subxt-codegen = { version = "0.20.0", path = "../codegen" }
 subxt-macro = { version = "0.20.0", path = "../macro" }
 subxt-metadata = { version = "0.20.0", path = "../metadata" }
 

subxt/src/client.rs

@@ -52,6 +52,7 @@ use derivative::Derivative;
 pub struct ClientBuilder {
     url: Option<String>,
     client: Option<RpcClient>,
+    metadata: Option<Metadata>,
     page_size: Option<u32>,
 }
 
@@ -61,6 +62,7 @@ impl ClientBuilder {
         Self {
             url: None,
             client: None,
+            metadata: None,
             page_size: None,
         }
     }
@@ -83,6 +85,14 @@ impl ClientBuilder {
         self
     }
 
+    /// Set the metadata.
+    ///
+    /// *Note:* Metadata will no longer be downloaded from the runtime node.
+    pub fn set_metadata(mut self, metadata: Metadata) -> Self {
+        self.metadata = Some(metadata);
+        self
+    }
+
     /// Creates a new Client.
     pub async fn build<T: Config>(self) -> Result<Client<T>, BasicError> {
         let client = if let Some(client) = self.client {
@@ -92,14 +102,19 @@ impl ClientBuilder {
             crate::rpc::ws_client(url).await?
         };
         let rpc = Rpc::new(client);
-        let (metadata, genesis_hash, runtime_version, properties) = future::join4(
-            rpc.metadata(),
+        let (genesis_hash, runtime_version, properties) = future::join3(
             rpc.genesis_hash(),
             rpc.runtime_version(None),
             rpc.system_properties(),
         )
         .await;
-        let metadata = metadata?;
+
+        let metadata = if let Some(metadata) = self.metadata {
+            metadata
+        } else {
+            let metadata = rpc.metadata().await;
+            metadata?
+        };
 
         Ok(Client {
             rpc,

subxt/src/metadata/hash_cache.rs

@@ -14,10 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with subxt.  If not, see <http://www.gnu.org/licenses/>.
 
+use parking_lot::RwLock;
 use std::{
     borrow::Cow,
     collections::HashMap,
-    sync::RwLock,
 };
 
 /// A cache with the simple goal of storing 32 byte hashes against pallet+item keys
@@ -41,7 +41,6 @@ impl HashCache {
         let maybe_hash = self
             .inner
             .read()
-            .unwrap()
             .get(&PalletItemKey::new(pallet, item))
             .copied();
 
@@ -50,7 +49,7 @@ impl HashCache {
         }
 
         let hash = f()?;
-        self.inner.write().unwrap().insert(
+        self.inner.write().insert(
             PalletItemKey::new(pallet.to_string(), item.to_string()),
             hash,
         );
@@ -96,7 +95,6 @@ mod tests {
             cache
                 .inner
                 .read()
-                .unwrap()
                 .get(&PalletItemKey::new(pallet, item))
                 .unwrap(),
             &value.unwrap()

subxt/src/metadata/metadata_type.rs

@@ -40,7 +40,7 @@ use std::{
 };
 
 /// Metadata error.
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, PartialEq)]
 pub enum MetadataError {
     /// Module is not in metadata.
     #[error("Pallet not found")]