Accept setup.py and setup.cfg files in compile (#2634)

## Summary

This costs us ~nothing now that we support using PEP 517 hooks for
`pyproject.toml`.

## Test Plan

`cargo test`

README.md

@@ -94,9 +94,10 @@ uv pip install "flask[dotenv]"      # Install Flask with "dotenv" extra.
 To generate a set of locked dependencies:
 
 ```shell
-uv pip compile pyproject.toml -o requirements.txt   # Read a pyproject.toml file.
-uv pip compile requirements.in -o requirements.txt  # Read a requirements.in file.
-echo flask | uv pip compile - -o requirements.txt  # Read from stdin.
+uv pip compile requirements.in -o requirements.txt    # Read a requirements.in file.
+uv pip compile pyproject.toml -o requirements.txt     # Read a pyproject.toml file.
+uv pip compile setup.py -o requirements.txt           # Read a setup.py file.
+echo flask | uv pip compile - -o requirements.txt     # Read from stdin.
 uv pip freeze | uv pip compile - -o requirements.txt  # Lock the current environment.
 ```
 

crates/uv-requirements/src/sources.rs

@@ -18,6 +18,10 @@ pub enum RequirementsSource {
     RequirementsTxt(PathBuf),
     /// Dependencies were provided via a `pyproject.toml` file (e.g., `pip-compile pyproject.toml`).
     PyprojectToml(PathBuf),
+    /// Dependencies were provided via a `setup.py` file (e.g., `pip-compile setup.py`).
+    SetupPy(PathBuf),
+    /// Dependencies were provided via a `setup.cfg` file (e.g., `pip-compile setup.cfg`).
+    SetupCfg(PathBuf),
 }
 
 impl RequirementsSource {
@@ -26,6 +30,10 @@ impl RequirementsSource {
     pub fn from_requirements_file(path: PathBuf) -> Self {
         if path.ends_with("pyproject.toml") {
             Self::PyprojectToml(path)
+        } else if path.ends_with("setup.py") {
+            Self::SetupPy(path)
+        } else if path.ends_with("setup.cfg") {
+            Self::SetupCfg(path)
         } else {
             Self::RequirementsTxt(path)
         }
@@ -74,16 +82,27 @@ impl RequirementsSource {
 
         Self::Package(name)
     }
+
+    /// Returns `true` if the source allows extras to be specified.
+    pub fn allows_extras(&self) -> bool {
+        matches!(
+            self,
+            Self::PyprojectToml(_) | Self::SetupPy(_) | Self::SetupCfg(_)
+        )
+    }
 }
 
 impl std::fmt::Display for RequirementsSource {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            Self::Package(package) => write!(f, "{package}"),
             Self::Editable(path) => write!(f, "-e {path}"),
-            Self::RequirementsTxt(path) | Self::PyprojectToml(path) => {
+            Self::RequirementsTxt(path)
+            | Self::PyprojectToml(path)
+            | Self::SetupPy(path)
+            | Self::SetupCfg(path) => {
                 write!(f, "{}", path.simplified_display())
             }
-            Self::Package(package) => write!(f, "{package}"),
         }
     }
 }

crates/uv-requirements/src/specification.rs

@@ -177,6 +177,28 @@ impl RequirementsSpecification {
                     }
                 }
             }
+            RequirementsSource::SetupPy(path) | RequirementsSource::SetupCfg(path) => {
+                let path = fs_err::canonicalize(path)?;
+                let source_tree = path.parent().ok_or_else(|| {
+                    anyhow::anyhow!(
+                        "The file `{}` appears to be a `setup.py` or `setup.cfg` file, which must be in a directory",
+                        path.user_display()
+                    )
+                })?;
+                Self {
+                    project: None,
+                    requirements: vec![],
+                    constraints: vec![],
+                    overrides: vec![],
+                    editables: vec![],
+                    source_trees: vec![source_tree.to_path_buf()],
+                    extras: FxHashSet::default(),
+                    index_url: None,
+                    extra_index_urls: vec![],
+                    no_index: false,
+                    find_links: vec![],
+                }
+            }
         })
     }
 

crates/uv/src/commands/pip_compile.rs

@@ -80,14 +80,11 @@ pub(crate) async fn pip_compile(
 ) -> Result<ExitStatus> {
     let start = std::time::Instant::now();
 
-    // If the user requests `extras` but does not provide a pyproject toml source
-    if !matches!(extras, ExtrasSpecification::None)
-        && !requirements
-            .iter()
-            .any(|source| matches!(source, RequirementsSource::PyprojectToml(_)))
-    {
+    // If the user requests `extras` but does not provide a valid source (e.g., a `pyproject.toml`),
+    // return an error.
+    if !extras.is_empty() && !requirements.iter().any(RequirementsSource::allows_extras) {
         return Err(anyhow!(
-            "Requesting extras requires a pyproject.toml input file."
+            "Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file."
         ));
     }
 

crates/uv/tests/pip_compile.rs

@@ -510,6 +510,108 @@ setup(
     Ok(())
 }
 
+/// Compile a `setup.cfg` file.
+#[test]
+fn compile_setup_cfg() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let setup_cfg = context.temp_dir.child("setup.cfg");
+    setup_cfg.write_str(
+        r#"[options]
+packages = find:
+install_requires=
+    anyio
+
+[options.extras_require]
+dev =
+    iniconfig; python_version >= "3.7"
+    mypy; python_version <= "3.8"
+"#,
+    )?;
+
+    let setup_py = context.temp_dir.child("setup.py");
+    setup_py.write_str(
+        r#"# setup.py
+from setuptools import setup
+
+
+setup(
+    name="dummypkg",
+    description="A dummy package",
+)
+"#,
+    )?;
+
+    uv_snapshot!(context.compile()
+            .arg("setup.cfg")
+            .arg("--extra")
+            .arg("dev"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z setup.cfg --extra dev
+    anyio==4.3.0
+    idna==3.6
+        # via anyio
+    iniconfig==2.0.0
+    sniffio==1.3.1
+        # via anyio
+
+    ----- stderr -----
+    Resolved 4 packages in [TIME]
+    "###
+    );
+
+    Ok(())
+}
+
+/// Compile a `setup.py` file.
+#[test]
+fn compile_setup_py() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let setup_py = context.temp_dir.child("setup.py");
+    setup_py.write_str(
+        r#"# setup.py
+from setuptools import setup
+
+
+setup(
+    name="dummypkg",
+    description="A dummy package",
+    install_requires=["anyio"],
+    extras_require={
+        "dev": ["iniconfig; python_version >= '3.7'", "mypy; python_version <= '3.8'"],
+    },
+)
+"#,
+    )?;
+
+    uv_snapshot!(context.compile()
+            .arg("setup.py")
+            .arg("--extra")
+            .arg("dev"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] --exclude-newer 2024-03-25T00:00:00Z setup.py --extra dev
+    anyio==4.3.0
+    idna==3.6
+        # via anyio
+    iniconfig==2.0.0
+    sniffio==1.3.1
+        # via anyio
+
+    ----- stderr -----
+    Resolved 4 packages in [TIME]
+    "###
+    );
+
+    Ok(())
+}
+
 /// Request multiple extras that do not exist as a dependency group in a `pyproject.toml` file.
 #[test]
 fn compile_pyproject_toml_extras_missing() -> Result<()> {
@@ -564,7 +666,7 @@ fn compile_requirements_file_extra() -> Result<()> {
     ----- stdout -----
 
     ----- stderr -----
-    error: Requesting extras requires a pyproject.toml input file.
+    error: Requesting extras requires a `pyproject.toml`, `setup.cfg`, or `setup.py` file.
     "###
     );