Add support for reading PEP 735 dependency groups (#8104)

Part of #8090

As a basic first step, we parse these groups defined in `pyproject.toml`
files.

crates/uv-workspace/src/pyproject.rs

@@ -44,6 +44,8 @@ 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,
@@ -1141,6 +1143,8 @@ pub enum DependencyType {
     Dev,
     /// A dependency in `project.optional-dependencies.{0}`.
     Optional(ExtraName),
+    /// A dependency in `dependency-groups.{0}`.
+    Group(ExtraName),
 }
 
 /// <https://github.com/serde-rs/serde/issues/1316#issue-332908452>

crates/uv-workspace/src/pyproject_mut.rs

@@ -712,6 +712,22 @@ impl PyProjectTomlMut {
             }
         }
 
+        // Check `dependency-groups`.
+        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
@@ -719,7 +735,7 @@ impl PyProjectTomlMut {
             .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-workspace/src/workspace/tests.rs

@@ -1,12 +1,15 @@
 use std::env;
-
 use std::path::Path;
+use std::str::FromStr;
 
 use anyhow::Result;
 use assert_fs::fixture::ChildPath;
 use assert_fs::prelude::*;
 use insta::assert_json_snapshot;
 
+use uv_pep508::ExtraName;
+
+use crate::pyproject::PyProjectToml;
 use crate::workspace::{DiscoveryOptions, ProjectWorkspace};
 
 async fn workspace_test(folder: &str) -> (ProjectWorkspace, String) {
@@ -76,7 +79,8 @@ async fn albatross_in_example() {
             ],
             "optional-dependencies": null
           },
-          "tool": null
+          "tool": null,
+          "dependency-groups": null
         }
       }
     }
@@ -128,7 +132,8 @@ async fn albatross_project_in_excluded() {
                 ],
                 "optional-dependencies": null
               },
-              "tool": null
+              "tool": null,
+              "dependency-groups": null
             }
           }
         }
@@ -237,7 +242,8 @@ async fn albatross_root_workspace() {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -326,7 +332,8 @@ async fn albatross_virtual_workspace() {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -377,7 +384,8 @@ async fn albatross_just_project() {
                 ],
                 "optional-dependencies": null
               },
-              "tool": null
+              "tool": null,
+              "dependency-groups": null
             }
           }
         }
@@ -528,7 +536,8 @@ async fn exclude_package() -> Result<()> {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -629,7 +638,8 @@ async fn exclude_package() -> Result<()> {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -743,7 +753,8 @@ async fn exclude_package() -> Result<()> {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -831,7 +842,8 @@ async fn exclude_package() -> Result<()> {
                   "override-dependencies": null,
                   "constraint-dependencies": null
                 }
-              }
+              },
+              "dependency-groups": null
             }
           }
         }
@@ -840,3 +852,21 @@ async fn exclude_package() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn 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/src/commands/project/add.rs

@@ -204,6 +204,7 @@ 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(_) => (),
             }
         }
 
@@ -469,6 +470,7 @@ 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.
@@ -743,6 +745,9 @@ 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;
@@ -817,6 +822,7 @@ 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

@@ -122,6 +122,9 @@ pub(crate) async fn remove(
                     );
                 }
             }
+            DependencyType::Group(_) => {
+                todo!("removing dependencies from groups is not yet supported")
+            }
         }
     }
 
@@ -250,6 +253,9 @@ 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

@@ -849,8 +849,8 @@ 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 {