Implement TransferMsgBuilder

CHANGELOG.md

@@ -48,6 +48,9 @@ and this project adheres to
   `ibc_source_callback` and `ibc_destination_callback`, as well as the
   `IbcCallbackRequest` type. ([#2025])
 - cosmwasm-vm: Add support for the two new IBC Callbacks entrypoints. ([#2025])
+- cosmwasm-std: Add `TransferMsgBuilder` to more easily create an
+  `IbcMsg::Transfer` with different kinds of memo values, including IBC
+  Callbacks memo values. ([#2167])
 
 [#1983]: https://github.com/CosmWasm/cosmwasm/pull/1983
 [#2025]: https://github.com/CosmWasm/cosmwasm/pull/2025
@@ -64,6 +67,7 @@ and this project adheres to
 [#2124]: https://github.com/CosmWasm/cosmwasm/pull/2124
 [#2129]: https://github.com/CosmWasm/cosmwasm/pull/2129
 [#2166]: https://github.com/CosmWasm/cosmwasm/pull/2166
+[#2167]: https://github.com/CosmWasm/cosmwasm/pull/2167
 
 ### Changed
 

contracts/ibc-callbacks/src/contract.rs

@@ -1,7 +1,7 @@
 use cosmwasm_std::{
-    entry_point, to_json_binary, to_json_string, Binary, Deps, DepsMut, Empty, Env,
-    IbcBasicResponse, IbcCallbackRequest, IbcDestinationCallbackMsg, IbcDstCallback, IbcMsg,
-    IbcSourceCallbackMsg, IbcSrcCallback, IbcTimeout, MessageInfo, Response, StdError, StdResult,
+    entry_point, to_json_binary, Binary, Deps, DepsMut, Empty, Env, IbcBasicResponse,
+    IbcDestinationCallbackMsg, IbcDstCallback, IbcSourceCallbackMsg, IbcSrcCallback, IbcTimeout,
+    MessageInfo, Response, StdError, StdResult, TransferMsgBuilder,
 };
 
 use crate::msg::{CallbackType, ExecuteMsg, QueryMsg};
@@ -71,16 +71,19 @@ fn execute_transfer(
         }
     };
 
-    let transfer_msg = IbcMsg::Transfer {
-        to_address,
-        timeout: IbcTimeout::with_timestamp(env.block.time.plus_seconds(timeout_seconds as u64)),
+    let builder = TransferMsgBuilder::new(
         channel_id,
-        amount: coin.clone(),
-        memo: Some(to_json_string(&match callback_type {
-            CallbackType::Both => IbcCallbackRequest::both(src_callback, dst_callback),
-            CallbackType::Src => IbcCallbackRequest::source(src_callback),
-            CallbackType::Dst => IbcCallbackRequest::destination(dst_callback),
-        })?),
+        to_address.clone(),
+        coin.clone(),
+        IbcTimeout::with_timestamp(env.block.time.plus_seconds(timeout_seconds as u64)),
+    );
+    let transfer_msg = match callback_type {
+        CallbackType::Both => builder
+            .with_src_callback(src_callback)
+            .with_dst_callback(dst_callback)
+            .build(),
+        CallbackType::Src => builder.with_src_callback(src_callback).build(),
+        CallbackType::Dst => builder.with_dst_callback(dst_callback).build(),
     };
 
     Ok(Response::new()

packages/std/src/ibc.rs

@@ -13,7 +13,10 @@ use crate::StdResult;
 use crate::{to_json_binary, Binary};
 
 mod callbacks;
+mod transfer_msg_builder;
+
 pub use callbacks::*;
+pub use transfer_msg_builder::*;
 
 /// These are messages in the IBC lifecycle. Only usable by IBC-enabled contracts
 /// (contracts that directly speak the IBC protocol via 6 entry points)

packages/std/src/ibc/callbacks.rs

@@ -15,12 +15,34 @@ use crate::{Addr, IbcAcknowledgement, IbcPacket, Uint64};
 ///
 /// # Example
 ///
+/// Using [`TransferMsgBuilder`](crate::TransferMsgBuilder):
 /// ```rust
 /// use cosmwasm_std::{
-///     to_json_string, Coin, IbcCallbackRequest, IbcMsg, IbcSrcCallback, IbcTimeout, Response,
+///     to_json_string, Coin, IbcCallbackRequest, TransferMsgBuilder, IbcSrcCallback, IbcTimeout, Response,
 ///     Timestamp,
 /// };
+/// # use cosmwasm_std::testing::mock_env;
+/// # let env = mock_env();
+///
+/// let _msg = TransferMsgBuilder::new(
+///     "channel-0".to_string(),
+///     "cosmos1example".to_string(),
+///     Coin::new(10u32, "ucoin"),
+///     Timestamp::from_seconds(12345),
+/// )
+/// .with_src_callback(IbcSrcCallback {
+///     address: env.contract.address,
+///     gas_limit: None,
+/// })
+/// .build();
+/// ```
 ///
+/// Manual serialization:
+/// ```rust
+/// use cosmwasm_std::{
+///     to_json_string, Coin, IbcCallbackRequest, IbcMsg, IbcSrcCallback, IbcTimeout, Response,
+///     Timestamp,
+/// };
 /// # use cosmwasm_std::testing::mock_env;
 /// # let env = mock_env();
 ///