feat: automatic detection of ros backend for package.xml files (#4782)

Author: ruben-arts

crates/pixi_build_discovery/src/backend_spec.rs

@@ -168,4 +168,25 @@ impl JsonRpcBackendSpec {
             })),
         }
     }
+
+    /// Constructs a new default instance for spawning a ROS build backend.
+    pub fn default_ros_build(channel_config: &ChannelConfig) -> Self {
+        const DEFAULT_BUILD_TOOL: &str = "pixi-build-ros";
+
+        let conda_forge_channel = Channel::from_name("conda-forge", channel_config).base_url;
+        let backends_channel = Url::from_str("https://prefix.dev/pixi-build-backends")
+            .unwrap()
+            .into();
+
+        Self {
+            name: DEFAULT_BUILD_TOOL.to_string(),
+            command: CommandSpec::EnvironmentSpec(Box::new(EnvironmentSpec {
+                requirement: (DEFAULT_BUILD_TOOL.parse().unwrap(), PixiSpec::any()),
+                additional_requirements: Default::default(),
+                constraints: Default::default(),
+                channels: vec![conda_forge_channel, backends_channel],
+                command: None,
+            })),
+        }
+    }
 }

crates/pixi_build_discovery/src/discovery.rs

@@ -24,6 +24,7 @@ use crate::{
 
 const VALID_RECIPE_NAMES: [&str; 2] = ["recipe.yaml", "recipe.yml"];
 const VALID_RECIPE_DIRS: [&str; 2] = ["", "recipe"];
+const VALID_ROS_BACKEND_NAMES: [&str; 1] = ["package.xml"];
 
 /// Describes a backend discovered for a given source location.
 #[derive(Debug, Clone)]
@@ -72,6 +73,8 @@ pub struct BackendInitializationParams {
 pub struct EnabledProtocols {
     /// Enable the rattler-build protocol.
     pub enable_rattler_build: bool,
+    /// Enable the ROS protocol.
+    pub enable_ros: bool,
     /// Enable the pixi protocol.
     pub enable_pixi: bool,
 }
@@ -81,6 +84,7 @@ impl Default for EnabledProtocols {
     fn default() -> Self {
         Self {
             enable_rattler_build: true,
+            enable_ros: true,
             enable_pixi: true,
         }
     }
@@ -95,6 +99,9 @@ pub enum DiscoveryError {
     #[error("depending on a `{0}` file but the rattler-build protocol is not enabled")]
     UnsupportedRecipeYaml(String),
 
+    #[error("depending on a `{0}` file but the ros protocol is not enabled")]
+    UnsupportedPackageXml(String),
+
     #[error(transparent)]
     #[diagnostic(transparent)]
     FailedToDiscoverPackage(#[from] WorkspaceDiscoveryError),
@@ -140,6 +147,23 @@ impl DiscoveredBackend {
                     .expect("the recipe must live somewhere");
                 return Self::from_recipe(source_dir.to_path_buf(), source_path, channel_config);
             }
+
+            // If the user explicitly asked for a package.xml file
+            if VALID_ROS_BACKEND_NAMES.contains(&source_file_name) {
+                if !enabled_protocols.enable_ros {
+                    return Err(DiscoveryError::UnsupportedPackageXml(
+                        source_file_name.to_string(),
+                    ));
+                }
+                let source_dir = source_path
+                    .parent()
+                    .expect("the package.xml must live somewhere");
+                return Self::from_ros_package(
+                    source_dir.to_path_buf(),
+                    source_path,
+                    channel_config,
+                );
+            }
         }
 
         // Try to discover a pixi project.
@@ -156,6 +180,13 @@ impl DiscoveredBackend {
             }
         }
 
+        // Try to discover as a ROS package.
+        if enabled_protocols.enable_ros {
+            if let Some(ros) = Self::discover_ros(source_path.clone(), channel_config)? {
+                return Ok(ros);
+            }
+        }
+
         Err(DiscoveryError::FailedToDiscover(
             source_path.to_string_lossy().to_string(),
         ))
@@ -331,4 +362,47 @@ impl DiscoveredBackend {
         }
         Ok(None)
     }
+
+    /// Construct a new instance based on a specific `package.xml` file in the
+    /// source directory.
+    fn from_ros_package(
+        source_dir: PathBuf,
+        package_xml_absolute_path: PathBuf,
+        channel_config: &ChannelConfig,
+    ) -> Result<Self, DiscoveryError> {
+        debug_assert!(source_dir.is_absolute());
+        debug_assert!(package_xml_absolute_path.is_absolute());
+        Ok(Self {
+            backend_spec: BackendSpec::JsonRpc(JsonRpcBackendSpec::default_ros_build(
+                channel_config,
+            )),
+            init_params: BackendInitializationParams {
+                workspace_root: source_dir.clone(),
+                source: None,
+                source_anchor: source_dir,
+                manifest_path: package_xml_absolute_path,
+                project_model: Some(ProjectModelV1::default()),
+                configuration: None,
+                target_configuration: None,
+            },
+        })
+    }
+
+    /// Try to discover a ROS package.xml file in the repository.
+    fn discover_ros(
+        source_dir: PathBuf,
+        channel_config: &ChannelConfig,
+    ) -> Result<Option<Self>, DiscoveryError> {
+        for &package_file in VALID_ROS_BACKEND_NAMES.iter() {
+            let package_path = source_dir.join(package_file);
+            if package_path.is_file() {
+                return Ok(Some(Self::from_ros_package(
+                    source_dir,
+                    package_path,
+                    channel_config,
+                )?));
+            }
+        }
+        Ok(None)
+    }
 }

crates/pixi_build_discovery/tests/discovery.rs

@@ -104,3 +104,21 @@ fn test_direct_recipe() {
         assert_discover_snapshot ! ( & path);
     });
 }
+
+#[test]
+fn test_direct_package_xml() {
+    let path = dunce::canonicalize(discovery_directory().join("ros-package/package.xml")).unwrap();
+    let source_path_regex = path
+        .parent()
+        .unwrap()
+        .to_string_lossy()
+        .replace(r"\", r"\\\\");
+    insta::with_settings!({
+        filters => vec![
+            (source_path_regex.as_str(), "file://<ROOT>"),
+            (r"\\", r"/"),
+        ],
+    }, {
+        assert_discover_snapshot ! ( & path);
+    });
+}

crates/pixi_build_discovery/tests/snapshots/discovery__direct_package_xml.snap

@@ -0,0 +1,34 @@
+---
+source: crates/pixi_build_discovery/tests/discovery.rs
+expression: backend
+---
+backend-spec:
+  type: json-rpc
+  name: pixi-build-ros
+  command:
+    type: environment-spec
+    requirement:
+      - pixi-build-ros
+      - "*"
+    channels:
+      - "https://conda.anaconda.org/conda-forge"
+      - "https://prefix.dev/pixi-build-backends"
+init-params:
+  workspace-root: "file://<ROOT>/ros-package"
+  source: ~
+  source-anchor: "file://<ROOT>/ros-package"
+  manifest-path: "file://<ROOT>/ros-package/package.xml"
+  project-model:
+    name: ~
+    version: ~
+    description: ~
+    authors: ~
+    license: ~
+    licenseFile: ~
+    readme: ~
+    homepage: ~
+    repository: ~
+    documentation: ~
+    targets: ~
+  configuration: ~
+  target-configuration: ~

crates/pixi_build_discovery/tests/snapshots/[email protected]

@@ -0,0 +1,35 @@
+---
+source: crates/pixi_build_discovery/tests/discovery.rs
+expression: backend
+input_file: tests/data/discovery/ros-package/TEST-CASE
+---
+backend-spec:
+  type: json-rpc
+  name: pixi-build-ros
+  command:
+    type: environment-spec
+    requirement:
+      - pixi-build-ros
+      - "*"
+    channels:
+      - "https://conda.anaconda.org/conda-forge"
+      - "https://prefix.dev/pixi-build-backends"
+init-params:
+  workspace-root: "file://<ROOT>/ros-package"
+  source: ~
+  source-anchor: "file://<ROOT>/ros-package"
+  manifest-path: "file://<ROOT>/ros-package/package.xml"
+  project-model:
+    name: ~
+    version: ~
+    description: ~
+    authors: ~
+    license: ~
+    licenseFile: ~
+    readme: ~
+    homepage: ~
+    repository: ~
+    documentation: ~
+    targets: ~
+  configuration: ~
+  target-configuration: ~