Add support for ros2 wsting

.github/workflows/ros2.yml

@@ -58,6 +58,11 @@ jobs:
       - name: Lint
         run: source /root/.cargo/env && cargo fmt --all -- --check
 
+      - name: Install wstring interoperability test messages
+        run: |
+          apt-get update
+          apt-get install -y ros-${{ matrix.distro }}-test-msgs
+
       - name: Start rosbridge services
         run: |
           source /opt/ros/${{ matrix.distro }}/setup.bash

README.md

@@ -82,6 +82,32 @@ If you want to see what the generated code looks like checkout [our generated me
 While the macro is useful for getting started, we recommend using `roslibrust_codegen` with a `build.rs` as shown in [example_package](https://github.com/RosLibRust/roslibrust/tree/master/example_package).
 This allows cargo to know when message files are edited and automatically re-generate the code.
 
+## ROS 2 `wstring` compatibility
+
+ROS 2 `wstring` fields are generated as `roslibrust::codegen::WString`. The
+Rust value contains a normal UTF-8 `String` and supports conversion from `&str`
+and `String` with `.into()`.
+
+The wire representation is selected automatically by the backend:
+
+- Native ROS 2 CDR backends, including ros-z, convert the Rust string to a DDS
+  `wstring`: a sequence of UTF-16 code units. Received UTF-16 is validated and
+  converted back to UTF-8; invalid UTF-16 produces a serialization error.
+- Rosbridge represents `wstring` as a normal JSON string. JSON handles scalar,
+  array, and sequence fields without a special wrapper representation.
+- ROS 1 has no native `wstring` type. The TCPROS and ROS 1 Zenoh backends
+  therefore encode each `WString` as an ordinary ROS 1 UTF-8 `string` and
+  convert it back automatically when receiving. This compatibility conversion
+  also applies to `wstring` arrays and sequences.
+
+The ROS 1 conversion does not add `wstring` to the ROS 1 type system. For topic
+connections, the TCPROS and ROS 1 Zenoh backends automatically advertise a
+compatible definition and MD5 using `string`, `string[N]`, or `string[]` in the
+corresponding fields. The ROS 1 peer must have that compatible definition under
+the same package and message name. String and sequence bounds remain in the
+generated ROS 2 metadata but, like the existing bounded collection support,
+are not enforced at runtime.
+
 ## Getting Started / Examples
 
 - Checkout the [Quick Getting Started Guide](https://roslibrust.github.io/roslibrust/quick_getting_started.html) for a brief guide on how to get started with RosLibRust.

assets/ros2_test_msgs/msg/WStrings.msg

@@ -0,0 +1,10 @@
+wstring wstring_value
+wstring wstring_value_default1 "Hello world!"
+wstring wstring_value_default2 "Hellö wörld!"
+wstring wstring_value_default3 "ハローワールド"
+#wstring WSTRING_CONST="Hello world!"
+#wstring<=22 bounded_wstring_value
+#wstring<=22 bounded_wstring_value_default1 "Hello world!"
+wstring[3] array_of_wstrings
+wstring[<=3] bounded_sequence_of_wstrings
+wstring[] unbounded_sequence_of_wstrings

assets/ros2_wstring_test_msgs/test_msgs/msg/WStrings.msg

@@ -0,0 +1,10 @@
+wstring wstring_value
+wstring wstring_value_default1 "Hello world!"
+wstring wstring_value_default2 "Hellö wörld!"
+wstring wstring_value_default3 "ハローワールド"
+#wstring WSTRING_CONST="Hello world!"
+#wstring<=22 bounded_wstring_value
+#wstring<=22 bounded_wstring_value_default1 "Hello world!"
+wstring[3] array_of_wstrings
+wstring[<=3] bounded_sequence_of_wstrings
+wstring[] unbounded_sequence_of_wstrings

assets/ros2_wstring_test_msgs/test_msgs/package.xml

@@ -0,0 +1,10 @@
+<package format="3">
+  <name>test_msgs</name>
+  <version>2.0.0</version>
+  <description>Minimal ROS 2 test_msgs fixture for wstring interoperability tests.</description>
+  <maintainer email="roslibrust@example.com">RosLibRust</maintainer>
+  <license>Apache-2.0</license>
+  <buildtool_depend>ament_cmake</buildtool_depend>
+  <build_depend>rosidl_default_generators</build_depend>
+  <member_of_group>rosidl_interface_packages</member_of_group>
+</package>

docker/galactic/Dockerfile

@@ -4,7 +4,7 @@ LABEL maintainer="Carter Schultz <carterjschultz@gmail.com>"
 # Required by github CI for submodule support
 RUN apt update && apt install -y git
 
-RUN apt update && apt install -y ros-galactic-rosbridge-suite
+RUN apt update && apt install -y ros-galactic-rosbridge-suite ros-galactic-test-msgs
 
 # Install rosbag2 and MCAP storage plugin for MCAP integration testing
 # Note: MCAP is not the default storage format in Galactic, so we need the plugin

docker/humble/Dockerfile

@@ -4,7 +4,7 @@ LABEL maintainer="Carter Schultz <carterjschultz@gmail.com>"
 # Required by github CI for submodule support
 RUN apt update && apt install -y git
 
-RUN apt update && apt install -y ros-humble-rosbridge-suite
+RUN apt update && apt install -y ros-humble-rosbridge-suite ros-humble-test-msgs
 
 # Install rosbag2 and MCAP storage plugin for MCAP integration testing
 # Note: MCAP is not the default storage format in Humble, so we need the plugin

docker/iron/Dockerfile

@@ -4,7 +4,7 @@ LABEL maintainer="Carter Schultz <carterjschultz@gmail.com>"
 # Required by github CI for submodule support
 RUN apt update && apt install -y git
 
-RUN apt update && apt install -y ros-iron-rosbridge-suite
+RUN apt update && apt install -y ros-iron-rosbridge-suite ros-iron-test-msgs
 
 # Install rosbag2 and MCAP storage plugin for MCAP integration testing
 # Note: MCAP is not the default storage format in Iron, so we need the plugin

docker/kilted/Dockerfile

@@ -5,7 +5,7 @@ LABEL maintainer="Carter Schultz <carterjschultz@gmail.com>"
 RUN apt update && apt install -y git
 
 # Install rosbridge suite for rosbridge backend testing
-RUN apt update && apt install -y ros-kilted-rosbridge-suite
+RUN apt update && apt install -y ros-kilted-rosbridge-suite ros-kilted-test-msgs
 
 # Install rosbag2 for MCAP integration testing
 RUN apt update && apt install -y ros-kilted-rosbag2

docker/rolling/Dockerfile

@@ -5,7 +5,7 @@ LABEL maintainer="Carter Schultz <carterjschultz@gmail.com>"
 RUN apt update && apt install -y git
 
 # Install rosbridge suite for rosbridge backend testing
-RUN apt update && apt install -y ros-rolling-rosbridge-suite
+RUN apt update && apt install -y ros-rolling-rosbridge-suite ros-rolling-test-msgs
 
 # Install rosbag2 for MCAP integration testing
 RUN apt update && apt install -y ros-rolling-rosbag2
@@ -24,4 +24,3 @@ WORKDIR /
 COPY entrypoint.sh .
 RUN chmod +x entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]
-

roslibrust_codegen/Cargo.toml

@@ -43,6 +43,7 @@ anyhow = "1.0"
 tokio = { workspace = true }
 env_logger = "0.10"
 test-log = { workspace = true }
+cdr = "0.2"
 
 [features]
 # For use with CI environment or any environment with ROS1 installed

roslibrust_codegen/src/gen.rs

@@ -351,7 +351,10 @@ fn convert_ros_constant_type_to_rust_type(
 
     convert_ros_type_to_rust_type(version, &constant.constant_type)
         .map(|rust_type| {
-            if rust_type == "::std::string::String" {
+            if matches!(
+                rust_type,
+                "::std::string::String" | "::roslibrust::codegen::WString"
+            ) {
                 "&'static str"
             } else {
                 rust_type
@@ -457,14 +460,20 @@ fn parse_ros_value(
         "int32" => generic_parse_value::<i32>(value, is_list),
         "uint64" => generic_parse_value::<u64>(value, is_list),
         "int64" => generic_parse_value::<i64>(value, is_list),
-        "string" => {
+        "string" | "wstring" => {
             // String is a special case because of quotes and to_string()
             if is_list {
                 // TODO there is a bug here, no idea how I should be attempting to convert / escape single quotes here...
                 let parsed: Vec<String> = serde_json::from_str(value).map_err(|e|
                     Error::with(format!("Failed to parse a literal value in a message file to the corresponding rust type: {value} to Vec<String>").as_str(), e)
                 )?;
-                let vec_str = format!("{parsed:?}.iter().map(|x| x.to_string()).collect()");
+                let vec_str = if ros_type == "wstring" {
+                    format!(
+                        "{parsed:?}.iter().map(|x| ::roslibrust::codegen::WString::from(*x)).collect()"
+                    )
+                } else {
+                    format!("{parsed:?}.iter().map(|x| x.to_string()).collect()")
+                };
                 Ok(quote! { #vec_str })
             } else {
                 match version {

roslibrust_codegen/src/lib.rs

@@ -34,6 +34,8 @@ mod ros2_builtin_interfaces;
 
 pub mod integral_types;
 pub use integral_types::*;
+mod wstring;
+pub use wstring::WString;
 
 // Custom serde module for Vec<u8> that handles both base64 (rosbridge) and arrays (other formats)
 pub mod serde_rosmsg_bytes;

roslibrust_codegen/src/parse/mod.rs

@@ -52,9 +52,9 @@ lazy_static::lazy_static! {
         ("float32", "f32"),
         ("float64", "f64"),
         ("string", "::std::string::String"),
+        ("wstring", "::roslibrust::codegen::WString"),
         ("builtin_interfaces/Time", "::roslibrust::codegen::integral_types::Time"),
         ("builtin_interfaces/Duration", "::roslibrust::codegen::integral_types::Duration"),
-        // ("wstring", TODO),
     ].into_iter().collect();
 }
 
@@ -216,17 +216,26 @@ fn parse_field_type(
     }
 }
 
-/// Specifically handles bounded string types, e.g. "string<=10"
+/// Specifically handles bounded string types, e.g. "string<=10" or "wstring<=10".
 /// Returns the field_type and the string_capacity if it is a bounded string
 /// Otherwise returns the original type and None for the capacity
 fn parse_bounded_string(type_str: &str) -> Result<(String, Option<usize>), Error> {
-    if let Some(stripped) = type_str.strip_prefix("string<=") {
-        let capacity = stripped.parse::<usize>().map_err(|err| {
+    let bounded_type = type_str
+        .strip_prefix("string<=")
+        .map(|capacity| ("string", capacity))
+        .or_else(|| {
+            type_str
+                .strip_prefix("wstring<=")
+                .map(|capacity| ("wstring", capacity))
+        });
+
+    if let Some((field_type, capacity)) = bounded_type {
+        let capacity = capacity.parse::<usize>().map_err(|err| {
             Error::new(format!(
                 "Unable to parse capacity of bounded string: {type_str}: {err}"
             ))
         })?;
-        Ok(("string".to_string(), Some(capacity)))
+        Ok((field_type.to_string(), Some(capacity)))
     } else {
         Ok((type_str.to_string(), None))
     }
@@ -326,6 +335,21 @@ mod test {
         assert_eq!(parsed.array_info, ArrayType::Unbounded);
     }
 
+    #[test_log::test]
+    fn parse_type_handles_bounded_wstring_correctly() {
+        let pkg = Package {
+            name: "test_pkg".to_string(),
+            path: "./not_a_path".into(),
+            version: Some(RosVersion::ROS2),
+        };
+        let parsed = parse_type("wstring<=32[<=4]", &pkg).unwrap();
+
+        assert_eq!(parsed.field_type, "wstring");
+        assert_eq!(parsed.string_capacity, Some(32));
+        assert_eq!(parsed.array_info, ArrayType::Bounded(4));
+        assert_eq!(parsed.package_name, None);
+    }
+
     #[test_log::test]
     fn parse_constant_with_hash_in_value() {
         use crate::parse::parse_constant_field;