Add support for reading PEP 735 dependency groups

crates/uv-workspace/src/pyproject.rs

@@ -43,6 +43,8 @@ pub struct PyProjectToml {
     pub project: Option<Project>,
     /// Tool-specific metadata.
     pub tool: Option<Tool>,
+    /// Non-project dependency groups, as defined in PEP 735.
+    pub dependency_groups: Option<BTreeMap<ExtraName, Vec<String>>>,
     /// The raw unserialized document.
     #[serde(skip)]
     pub raw: String,
@@ -1053,6 +1055,8 @@ pub enum DependencyType {
     Dev,
     /// A dependency in `project.optional-dependencies.{0}`.
     Optional(ExtraName),
+    /// A dependency in `project.dependency-groups.{0}`.
+    Group(ExtraName),
 }
 
 /// <https://github.com/serde-rs/serde/issues/1316#issue-332908452>
@@ -1081,3 +1085,30 @@ mod serde_from_and_to_string {
             .map_err(de::Error::custom)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::str::FromStr;
+
+    use uv_pep508::ExtraName;
+
+    use crate::pyproject::PyProjectToml;
+
+    #[test]
+    fn test_read_dependency_groups() {
+        let toml = r#"
+[dependency-groups]
+test = ["a"]
+"#;
+
+        let result =
+            PyProjectToml::from_string(toml.to_string()).expect("Deserialization should succeed");
+        let groups = result
+            .dependency_groups
+            .expect("`dependency-groups` should be present");
+        let test = groups
+            .get(&ExtraName::from_str("test").unwrap())
+            .expect("Group `test` should be present");
+        assert_eq!(test, &["a".to_string()]);
+    }
+}

crates/uv-workspace/src/pyproject_mut.rs

@@ -495,14 +495,30 @@ impl PyProjectTomlMut {
             }
         }
 
+        // Check `tool.uv.dev-dependencies`.
+        if let Some(groups) = self.doc.get("dependency-groups").and_then(Item::as_table) {
+            for (group, dependencies) in groups {
+                let Some(dependencies) = dependencies.as_array() else {
+                    continue;
+                };
+                let Ok(group) = ExtraName::new(group.to_string()) else {
+                    continue;
+                };
+
+                if !find_dependencies(name, marker, dependencies).is_empty() {
+                    types.push(DependencyType::Group(group));
+                }
+            }
+        }
+
         // Check `tool.uv.dev-dependencies`.
         if let Some(dev_dependencies) = self
             .doc
             .get("tool")
             .and_then(Item::as_table)
             .and_then(|tool| tool.get("uv"))
             .and_then(Item::as_table)
-            .and_then(|tool| tool.get("dev-dependencies"))
+            .and_then(|uv| uv.get("dev-dependencies"))
             .and_then(Item::as_array)
         {
             if !find_dependencies(name, marker, dev_dependencies).is_empty() {

crates/uv/src/commands/project/add.rs

@@ -202,6 +202,7 @@ pub(crate) async fn add(
                     bail!("Project is missing a `[project]` table; add a `[project]` table to use optional dependencies, or run `{}` instead", "uv add --dev".green())
                 }
                 DependencyType::Dev => (),
+                DependencyType::Group(_) => (),
             }
         }
 
@@ -449,6 +450,7 @@ pub(crate) async fn add(
             DependencyType::Optional(ref group) => {
                 toml.add_optional_dependency(group, &requirement, source.as_ref())?
             }
+            DependencyType::Group(_) => todo!("adding dependencies to groups is not yet supported"),
         };
 
         // If the edit was inserted before the end of the list, update the existing edits.
@@ -707,6 +709,9 @@ async fn lock_and_sync(
                 DependencyType::Optional(ref group) => {
                     toml.set_optional_dependency_minimum_version(group, *index, minimum)?;
                 }
+                DependencyType::Group(_) => {
+                    todo!("adding dependencies to groups is not yet supported")
+                }
             }
 
             modified = true;
@@ -767,6 +772,7 @@ async fn lock_and_sync(
             let dev = DevMode::Exclude;
             (extras, dev)
         }
+        DependencyType::Group(_) => todo!("adding dependencies to groups is not yet supported"),
     };
 
     project::sync::do_sync(

crates/uv/src/commands/project/remove.rs

@@ -120,6 +120,9 @@ pub(crate) async fn remove(
                     );
                 }
             }
+            DependencyType::Group(_) => {
+                todo!("removing dependencies from groups is not yet supported")
+            }
         }
     }
 
@@ -246,6 +249,9 @@ fn warn_if_present(name: &PackageName, pyproject: &PyProjectTomlMut) {
                     "`{name}` is an optional dependency; try calling `uv remove --optional {group}`",
                 );
             }
+            DependencyType::Group(_) => {
+                // TODO(zanieb): Once we support `remove --group`, add a warning here.
+            }
         }
     }
 }

crates/uv/src/settings.rs

@@ -838,8 +838,8 @@ impl AddSettings {
             python,
         } = args;
 
-        let dependency_type = if let Some(group) = optional {
-            DependencyType::Optional(group)
+        let dependency_type = if let Some(extra) = optional {
+            DependencyType::Optional(extra)
         } else if dev {
             DependencyType::Dev
         } else {