chore: Update after review

contracts/ibc-callbacks/schema/ibc-callbacks.json

@@ -43,7 +43,11 @@
               },
               "channel_version": {
                 "description": "IBC channel version",
-                "type": "string"
+                "allOf": [
+                  {
+                    "$ref": "#/definitions/ChannelVersion"
+                  }
+                ]
               },
               "timeout_seconds": {
                 "description": "The amount of seconds from now the transfer should timeout at",
@@ -87,6 +91,13 @@
             ]
           }
         ]
+      },
+      "ChannelVersion": {
+        "type": "string",
+        "enum": [
+          "v1",
+          "v2"
+        ]
       }
     }
   },

contracts/ibc-callbacks/schema/raw/execute.json

@@ -32,7 +32,11 @@
             },
             "channel_version": {
               "description": "IBC channel version",
-              "type": "string"
+              "allOf": [
+                {
+                  "$ref": "#/definitions/ChannelVersion"
+                }
+              ]
             },
             "timeout_seconds": {
               "description": "The amount of seconds from now the transfer should timeout at",
@@ -76,6 +80,13 @@
           ]
         }
       ]
+    },
+    "ChannelVersion": {
+      "type": "string",
+      "enum": [
+        "v1",
+        "v2"
+      ]
     }
   }
 }

contracts/ibc-callbacks/src/contract.rs

@@ -4,7 +4,7 @@ use cosmwasm_std::{
     MessageInfo, Response, StdError, StdResult, TransferMsgBuilder, TransferMsgBuilderV2,
 };
 
-use crate::msg::{CallbackType, ExecuteMsg, QueryMsg};
+use crate::msg::{CallbackType, ChannelVersion, ExecuteMsg, QueryMsg};
 use crate::state::{load_stats, save_stats, CallbackStats};
 
 #[entry_point]
@@ -55,7 +55,7 @@ fn execute_transfer(
     channel_id: String,
     timeout_seconds: u32,
     callback_type: CallbackType,
-    channel_version: String,
+    channel_version: ChannelVersion,
 ) -> StdResult<Response> {
     let src_callback = IbcSrcCallback {
         address: env.contract.address,
@@ -66,8 +66,8 @@ fn execute_transfer(
         gas_limit: None,
     };
 
-    let transfer_msg = match channel_version.as_str() {
-        "V1" => {
+    let transfer_msg = match channel_version {
+        ChannelVersion::V1 => {
             let coin = match &*info.funds {
                 [coin] if !coin.amount.is_zero() => coin,
                 _ => {
@@ -91,7 +91,7 @@ fn execute_transfer(
                 CallbackType::Dst => builder.with_dst_callback(dst_callback).build(),
             }
         }
-        "V2" => {
+        ChannelVersion::V2 => {
             let builder = TransferMsgBuilderV2::new(
                 channel_id,
                 to_address.clone(),
@@ -107,11 +107,6 @@ fn execute_transfer(
                 CallbackType::Dst => builder.with_dst_callback(dst_callback).build(),
             }
         }
-        _ => {
-            return Err(StdError::generic_err(
-                "Must specify \"V1\" or \"V2\" channel version",
-            ))
-        }
     };
 
     Ok(Response::new()

contracts/ibc-callbacks/src/msg.rs

@@ -8,6 +8,12 @@ pub enum QueryMsg {
     CallbackStats {},
 }
 
+#[cw_serde]
+pub enum ChannelVersion {
+    V1,
+    V2,
+}
+
 #[cw_serde]
 pub enum ExecuteMsg {
     Transfer {
@@ -21,7 +27,7 @@ pub enum ExecuteMsg {
         #[serde(default)]
         callback_type: CallbackType,
         /// IBC channel version
-        channel_version: String,
+        channel_version: ChannelVersion,
     },
 }
 

packages/go-gen/tests/cosmwasm_std__IbcMsg.go

@@ -21,8 +21,6 @@ type TransferV2Msg struct {
 	// An optional memo. See the blog post ["Moving Beyond Simple Token Transfers"](https://medium.com/the-interchain-foundation/moving-beyond-simple-token-transfers-d42b2b1dc29b) for more information.
 	//
 	// There is no difference between setting this to `None` or an empty string.
-	//
-	// This field is only supported on chains with CosmWasm >= 2.0 and silently ignored on older chains. If you need support for both 1.x and 2.x chain with the same codebase, it is recommended to use `CosmosMsg::Stargate` with a custom MsgTransfer protobuf encoder instead.
 	Memo string `json:"memo,omitempty"`
 	// when packet times out, measured on remote chain
 	Timeout IBCTimeout `json:"timeout"`

packages/std/src/ibc.rs

@@ -4,7 +4,6 @@
 use core::cmp::{Ord, Ordering, PartialOrd};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
-use std::vec;
 
 use crate::coin::Coin;
 use crate::prelude::*;
@@ -84,12 +83,6 @@ pub enum IbcMsg {
         /// for more information.
         ///
         /// There is no difference between setting this to `None` or an empty string.
-        ///
-        /// This field is only supported on chains with CosmWasm >= 2.0 and silently
-        /// ignored on older chains.
-        /// If you need support for both 1.x and 2.x chain with the same codebase,
-        /// it is recommended to use `CosmosMsg::Stargate` with a custom MsgTransfer
-        /// protobuf encoder instead.
         memo: Option<String>,
         // A struct containing the list of next hops,
         // determining where the tokens must be forwarded next.

packages/std/src/ibc/transfer_msg_builder.rs

@@ -9,23 +9,23 @@ pub struct EmptyMemo;
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[non_exhaustive]
 pub struct WithMemo {
-    pub memo: String,
+    pub(crate) memo: String,
 }
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[non_exhaustive]
 pub struct WithSrcCallback {
-    pub src_callback: IbcSrcCallback,
+    pub(crate) src_callback: IbcSrcCallback,
 }
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[non_exhaustive]
 pub struct WithDstCallback {
-    pub dst_callback: IbcDstCallback,
+    pub(crate) dst_callback: IbcDstCallback,
 }
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[non_exhaustive]
 pub struct WithCallbacks {
-    pub src_callback: IbcSrcCallback,
-    pub dst_callback: IbcDstCallback,
+    pub(crate) src_callback: IbcSrcCallback,
+    pub(crate) dst_callback: IbcDstCallback,
 }
 
 pub trait MemoSource {

packages/std/src/ibc/transfer_msg_builder_v2.rs

@@ -4,40 +4,52 @@ use super::{
     EmptyMemo, Hop, MemoSource, WithCallbacks, WithDstCallback, WithMemo, WithSrcCallback,
 };
 
-impl<M: MemoSource> TransferMsgBuilderV2<M> {
+impl<M: MemoSource, F: Into<Vec<Hop>>> TransferMsgBuilderV2<M, F> {
     pub fn build(self) -> IbcMsg {
         IbcMsg::TransferV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
             tokens: self.tokens,
             timeout: self.timeout,
             memo: self.memo.into_memo(),
-            forwarding: self.forwarding,
+            forwarding: self.forwarding.into(),
         }
     }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct TransferMsgBuilderV2<MemoData> {
+pub struct TransferMsgBuilderV2<MemoData, ForwardingData> {
     channel_id: String,
     to_address: String,
     tokens: Vec<Coin>,
     timeout: IbcTimeout,
     memo: MemoData,
-    forwarding: Vec<Hop>,
+    forwarding: ForwardingData,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[non_exhaustive]
-pub struct WithForwarding;
+pub struct WithoutForwarding;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[non_exhaustive]
+pub struct WithForwarding {
+    pub(crate) forwarding: Vec<Hop>,
+}
 
-impl MemoSource for WithForwarding {
-    fn into_memo(self) -> Option<String> {
-        None
+impl From<WithoutForwarding> for Vec<Hop> {
+    fn from(_val: WithoutForwarding) -> Self {
+        vec![]
     }
 }
 
-impl TransferMsgBuilderV2<EmptyMemo> {
+impl From<WithForwarding> for Vec<Hop> {
+    fn from(val: WithForwarding) -> Self {
+        val.forwarding
+    }
+}
+
+impl TransferMsgBuilderV2<EmptyMemo, WithoutForwarding> {
     /// Creates a new transfer message with the given parameters and no memo.
     pub fn new(
         channel_id: impl Into<String>,
@@ -51,12 +63,15 @@ impl TransferMsgBuilderV2<EmptyMemo> {
             tokens,
             timeout: timeout.into(),
             memo: EmptyMemo,
-            forwarding: vec![],
+            forwarding: WithoutForwarding,
         }
     }
 
     /// Adds a memo text to the transfer message.
-    pub fn with_memo(self, memo: impl Into<String>) -> TransferMsgBuilderV2<WithMemo> {
+    pub fn with_memo(
+        self,
+        memo: impl Into<String>,
+    ) -> TransferMsgBuilderV2<WithMemo, WithoutForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
@@ -74,7 +89,7 @@ impl TransferMsgBuilderV2<EmptyMemo> {
     pub fn with_src_callback(
         self,
         src_callback: IbcSrcCallback,
-    ) -> TransferMsgBuilderV2<WithSrcCallback> {
+    ) -> TransferMsgBuilderV2<WithSrcCallback, WithoutForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
@@ -92,7 +107,7 @@ impl TransferMsgBuilderV2<EmptyMemo> {
     pub fn with_dst_callback(
         self,
         dst_callback: IbcDstCallback,
-    ) -> TransferMsgBuilderV2<WithDstCallback> {
+    ) -> TransferMsgBuilderV2<WithDstCallback, WithoutForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
@@ -105,29 +120,32 @@ impl TransferMsgBuilderV2<EmptyMemo> {
 
     /// Adds forwarding data.
     /// It is worth to notice that the builder does not allow to add forwarding data along with
-    /// callbacks. It is discouraged in the IBC docs:
-    /// https://github.com/cosmos/ibc-go/blob/main/docs/docs/04-middleware/02-callbacks/01-overview.md#known-limitations
-    pub fn with_forwarding(self, forwarding: Vec<Hop>) -> TransferMsgBuilderV2<WithForwarding> {
+    /// source callback. It is discouraged in the IBC docs:
+    /// https://ibc.cosmos.network/v9/middleware/callbacks/overview/#known-limitations
+    pub fn with_forwarding(
+        self,
+        forwarding: Vec<Hop>,
+    ) -> TransferMsgBuilderV2<EmptyMemo, WithForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
             tokens: self.tokens,
             timeout: self.timeout,
-            memo: WithForwarding,
-            forwarding,
+            memo: self.memo,
+            forwarding: WithForwarding { forwarding },
         }
     }
 }
 
-impl TransferMsgBuilderV2<WithSrcCallback> {
+impl TransferMsgBuilderV2<WithSrcCallback, WithoutForwarding> {
     /// Adds an IBC destination callback entry to the memo field.
     /// Use this if you want to receive IBC callbacks on the destination chain.
     ///
     /// For more info check out [`crate::IbcDestinationCallbackMsg`].
     pub fn with_dst_callback(
         self,
         dst_callback: IbcDstCallback,
-    ) -> TransferMsgBuilderV2<WithCallbacks> {
+    ) -> TransferMsgBuilderV2<WithCallbacks, WithoutForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
@@ -142,15 +160,15 @@ impl TransferMsgBuilderV2<WithSrcCallback> {
     }
 }
 
-impl TransferMsgBuilderV2<WithDstCallback> {
+impl TransferMsgBuilderV2<WithDstCallback, WithoutForwarding> {
     /// Adds an IBC source callback entry to the memo field.
     /// Use this if you want to receive IBC callbacks on the source chain.
     ///
     /// For more info check out [`crate::IbcSourceCallbackMsg`].
     pub fn with_src_callback(
         self,
         src_callback: IbcSrcCallback,
-    ) -> TransferMsgBuilderV2<WithCallbacks> {
+    ) -> TransferMsgBuilderV2<WithCallbacks, WithoutForwarding> {
         TransferMsgBuilderV2 {
             channel_id: self.channel_id,
             to_address: self.to_address,
@@ -163,6 +181,24 @@ impl TransferMsgBuilderV2<WithDstCallback> {
             forwarding: self.forwarding,
         }
     }
+
+    /// Adds forwarding data.
+    /// It is worth to notice that the builder does not allow to add forwarding data along with
+    /// source callback. It is discouraged in the IBC docs:
+    /// https://ibc.cosmos.network/v9/middleware/callbacks/overview/#known-limitations
+    pub fn with_forwarding(
+        self,
+        forwarding: Vec<Hop>,
+    ) -> TransferMsgBuilderV2<WithDstCallback, WithForwarding> {
+        TransferMsgBuilderV2 {
+            channel_id: self.channel_id,
+            to_address: self.to_address,
+            tokens: self.tokens,
+            timeout: self.timeout,
+            memo: self.memo,
+            forwarding: WithForwarding { forwarding },
+        }
+    }
 }
 
 #[cfg(test)]