Add query_grpc and document gRPC querying

CHANGELOG.md

@@ -27,6 +27,8 @@ and this project adheres to
   are like the `Add`/`Sub` implementations but `const`. ([#2098], [#2107])
 - cosmwasm-std: Let `Timestamp::plus_nanos`/`::minus_nanos` use
   `Uint64::strict_add`/`::strict_sub` and document overflows. ([#2098], [#2107])
+- cosmwasm-std: Add `QuerierWrapper::query_grpc` helper for gRPC queries.
+  ([#2120])
 
 [#1983]: https://github.com/CosmWasm/cosmwasm/pull/1983
 [#2057]: https://github.com/CosmWasm/cosmwasm/pull/2057
@@ -37,6 +39,7 @@ and this project adheres to
 [#2098]: https://github.com/CosmWasm/cosmwasm/pull/2098
 [#2099]: https://github.com/CosmWasm/cosmwasm/pull/2099
 [#2107]: https://github.com/CosmWasm/cosmwasm/pull/2107
+[#2120]: https://github.com/CosmWasm/cosmwasm/pull/2120
 
 ### Changed
 

contracts/reflect/schema/raw/query.json

@@ -334,7 +334,7 @@
       ]
     },
     "GrpcQuery": {
-      "description": "Queries the chain using a grpc query. This allows to query information that is not exposed in our API. The chain needs to allowlist the supported queries. The drawback of this query is that you have to handle the protobuf encoding and decoding yourself.\n\nThe returned data is protobuf encoded. The protobuf type depends on the query.\n\nTo find the path, as well as the request and response types, you can query the chain's gRPC endpoint using a tool like [grpcurl](https://github.com/fullstorydev/grpcurl).",
+      "description": "Queries the chain using a grpc query. This allows to query information that is not exposed in our API. The chain needs to allowlist the supported queries. The drawback of this query is that you have to handle the protobuf encoding and decoding yourself.\n\nThe returned data is protobuf encoded. The protobuf type depends on the query. Because of this, using it with the [`query`](crate::QuerierWrapper::query) function will result in a deserialization error. Use [`raw_query`](crate::Querier::raw_query) or [`query_grpc`](crate::QuerierWrapper::query_grpc) instead.\n\nTo find the path, as well as the request and response types, you can query the chain's gRPC endpoint using a tool like [grpcurl](https://github.com/fullstorydev/grpcurl).",
       "type": "object",
       "required": [
         "data",

contracts/reflect/schema/reflect.json

@@ -1427,7 +1427,7 @@
         ]
       },
       "GrpcQuery": {
-        "description": "Queries the chain using a grpc query. This allows to query information that is not exposed in our API. The chain needs to allowlist the supported queries. The drawback of this query is that you have to handle the protobuf encoding and decoding yourself.\n\nThe returned data is protobuf encoded. The protobuf type depends on the query.\n\nTo find the path, as well as the request and response types, you can query the chain's gRPC endpoint using a tool like [grpcurl](https://github.com/fullstorydev/grpcurl).",
+        "description": "Queries the chain using a grpc query. This allows to query information that is not exposed in our API. The chain needs to allowlist the supported queries. The drawback of this query is that you have to handle the protobuf encoding and decoding yourself.\n\nThe returned data is protobuf encoded. The protobuf type depends on the query. Because of this, using it with the [`query`](crate::QuerierWrapper::query) function will result in a deserialization error. Use [`raw_query`](crate::Querier::raw_query) or [`query_grpc`](crate::QuerierWrapper::query_grpc) instead.\n\nTo find the path, as well as the request and response types, you can query the chain's gRPC endpoint using a tool like [grpcurl](https://github.com/fullstorydev/grpcurl).",
         "type": "object",
         "required": [
           "data",

packages/std/src/query/mod.rs

@@ -76,6 +76,10 @@ pub enum QueryRequest<C> {
 /// The drawback of this query is that you have to handle the protobuf encoding and decoding yourself.
 ///
 /// The returned data is protobuf encoded. The protobuf type depends on the query.
+/// Because of this, using it with the [`query`](crate::QuerierWrapper::query) function will result
+/// in a deserialization error.
+/// Use [`raw_query`](crate::Querier::raw_query) or [`query_grpc`](crate::QuerierWrapper::query_grpc)
+/// instead.
 ///
 /// To find the path, as well as the request and response types,
 /// you can query the chain's gRPC endpoint using a tool like

packages/std/src/traits.rs

@@ -268,6 +268,13 @@ impl<'a, C: CustomQuery> QuerierWrapper<'a, C> {
     /// one level. Only use this if you don't need to check the SystemError
     /// eg. If you don't differentiate between contract missing and contract returned error
     pub fn query<U: DeserializeOwned>(&self, request: &QueryRequest<C>) -> StdResult<U> {
+        self.query_raw(request).and_then(|raw| from_json(raw))
+    }
+
+    /// Internal helper to avoid code duplication.
+    /// Performs a query and returns the binary result without deserializing it,
+    /// wrapping any errors that may occur into `StdError`.
+    fn query_raw(&self, request: &QueryRequest<C>) -> StdResult<Binary> {
         let raw = to_json_vec(request).map_err(|serialize_err| {
             StdError::generic_err(format!("Serializing QueryRequest: {serialize_err}"))
         })?;
@@ -278,7 +285,7 @@ impl<'a, C: CustomQuery> QuerierWrapper<'a, C> {
             SystemResult::Ok(ContractResult::Err(contract_err)) => Err(StdError::generic_err(
                 format!("Querier contract error: {contract_err}"),
             )),
-            SystemResult::Ok(ContractResult::Ok(value)) => from_json(value),
+            SystemResult::Ok(ContractResult::Ok(value)) => Ok(value),
         }
     }
 
@@ -395,6 +402,13 @@ impl<'a, C: CustomQuery> QuerierWrapper<'a, C> {
         Ok(res.validators)
     }
 
+    /// See [`GrpcQuery`](crate::GrpcQuery) for more information.
+    #[cfg(feature = "cosmwasm_2_0")]
+    pub fn query_grpc(&self, path: String, data: Binary) -> StdResult<Binary> {
+        use crate::GrpcQuery;
+        self.query_raw(&QueryRequest::Grpc(GrpcQuery { path, data }))
+    }
+
     /// Queries another wasm contract. You should know a priori the proper types for T and U
     /// (response and request) based on the contract API
     pub fn query_wasm_smart<T: DeserializeOwned>(