Add support for unnamed local directory requirements (#2571)

## Summary

For example: `cargo run pip install .`

The strategy taken here is to attempt to extract the package name from
the distribution without executing the PEP 517 build steps. We could
choose to do that in the future if this proves lacking, but it adds
complexity.

Part of: https://github.com/astral-sh/uv/issues/313.

Cargo.lock

@@ -4355,6 +4355,7 @@ dependencies = [
  "chrono",
  "clap",
  "clap_complete_command",
+ "configparser",
  "console",
  "ctrlc",
  "distribution-filename",
@@ -4370,6 +4371,7 @@ dependencies = [
  "itertools 0.12.1",
  "miette 6.0.1",
  "mimalloc",
+ "once_cell",
  "owo-colors 4.0.0",
  "pep508_rs",
  "platform-tags",

crates/pypi-types/src/metadata.rs

@@ -210,6 +210,30 @@ impl Metadata23 {
     }
 }
 
+/// Python Package Metadata 1.0 and later as specified in
+/// <https://peps.python.org/pep-0241/>.
+///
+/// This is a subset of the full metadata specification, and only includes the
+/// fields that have been consistent across all versions of the specification.
+#[derive(Serialize, Deserialize, Debug, Clone, Eq, PartialEq)]
+#[serde(rename_all = "kebab-case")]
+pub struct Metadata10 {
+    pub name: PackageName,
+}
+
+impl Metadata10 {
+    /// Parse the [`Metadata10`] from a `PKG-INFO` file, as included in a source distribution.
+    pub fn parse_pkg_info(content: &[u8]) -> Result<Self, Error> {
+        let headers = Headers::parse(content)?;
+        let name = PackageName::new(
+            headers
+                .get_first_value("Name")
+                .ok_or(Error::FieldNotFound("Name"))?,
+        )?;
+        Ok(Self { name })
+    }
+}
+
 /// Parse a `Metadata-Version` field into a (major, minor) tuple.
 fn parse_version(metadata_version: &str) -> Result<(u8, u8), Error> {
     let (major, minor) = metadata_version

crates/uv/Cargo.toml

@@ -14,6 +14,7 @@ default-run = "uv"
 workspace = true
 
 [dependencies]
+distribution-filename = { workspace = true }
 distribution-types = { workspace = true }
 install-wheel-rs = { workspace = true, features = ["clap"], default-features = false }
 pep508_rs = { workspace = true }
@@ -40,6 +41,7 @@ base64 = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true, features = ["derive", "string"] }
 clap_complete_command = { workspace = true }
+configparser = { workspace = true }
 console = { workspace = true }
 ctrlc = { workspace = true }
 flate2 = { workspace = true, default-features = false }
@@ -48,8 +50,10 @@ indexmap = { workspace = true }
 indicatif = { workspace = true }
 itertools = { workspace = true }
 miette = { workspace = true, features = ["fancy"] }
+once_cell = { workspace = true }
 owo-colors = { workspace = true }
 pyproject-toml = { workspace = true }
+regex = { workspace = true }
 rustc-hash = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
@@ -64,7 +68,6 @@ tracing-subscriber = { workspace = true, features = ["json"] }
 tracing-tree = { workspace = true }
 unicode-width = { workspace = true }
 url = { workspace = true }
-distribution-filename = { version = "0.0.1", path = "../distribution-filename" }
 
 [target.'cfg(target_os = "windows")'.dependencies]
 mimalloc = { version = "0.1.39" }

crates/uv/src/requirements.rs

@@ -4,14 +4,21 @@ use std::path::{Path, PathBuf};
 use std::str::FromStr;
 
 use anyhow::{Context, Result};
+use configparser::ini::Ini;
 use console::Term;
 use distribution_filename::{SourceDistFilename, WheelFilename};
 use indexmap::IndexMap;
+use once_cell::sync::Lazy;
+use regex::Regex;
 use rustc_hash::FxHashSet;
-use tracing::{instrument, Level};
+use serde::Deserialize;
+use tracing::{debug, instrument, Level};
 
 use distribution_types::{FlatIndexLocation, IndexUrl, RemoteSource};
-use pep508_rs::{Requirement, RequirementsTxtRequirement, UnnamedRequirement, VersionOrUrl};
+use pep508_rs::{
+    Requirement, RequirementsTxtRequirement, Scheme, UnnamedRequirement, VersionOrUrl,
+};
+use pypi_types::Metadata10;
 use requirements_txt::{EditableRequirement, FindLink, RequirementsTxt};
 use uv_client::Connectivity;
 use uv_fs::Simplified;
@@ -576,8 +583,160 @@ impl NamedRequirements {
             });
         }
 
+        // Otherwise, download and/or extract the source archive.
+        if Scheme::parse(requirement.url.scheme()) == Some(Scheme::File) {
+            let path = requirement.url.to_file_path().map_err(|()| {
+                anyhow::anyhow!("Unable to convert file URL to path: {requirement}")
+            })?;
+
+            if !path.exists() {
+                return Err(anyhow::anyhow!(
+                    "Unnamed requirement at {path} not found",
+                    path = path.simplified_display()
+                ));
+            }
+
+            // Attempt to read a `PKG-INFO` from the directory.
+            if let Some(metadata) = fs_err::read(path.join("PKG-INFO"))
+                .ok()
+                .and_then(|contents| Metadata10::parse_pkg_info(&contents).ok())
+            {
+                debug!(
+                    "Found PKG-INFO metadata for {path} ({name})",
+                    path = path.display(),
+                    name = metadata.name
+                );
+                return Ok(Requirement {
+                    name: metadata.name,
+                    extras: requirement.extras,
+                    version_or_url: Some(VersionOrUrl::Url(requirement.url)),
+                    marker: requirement.marker,
+                });
+            }
+
+            // Attempt to read a `pyproject.toml` file.
+            if let Some(pyproject) = fs_err::read_to_string(path.join("pyproject.toml"))
+                .ok()
+                .and_then(|contents| toml::from_str::<PyProjectToml>(&contents).ok())
+            {
+                // Read PEP 621 metadata from the `pyproject.toml`.
+                if let Some(project) = pyproject.project {
+                    debug!(
+                        "Found PEP 621 metadata for {path} in `pyproject.toml` ({name})",
+                        path = path.display(),
+                        name = project.name
+                    );
+                    return Ok(Requirement {
+                        name: project.name,
+                        extras: requirement.extras,
+                        version_or_url: Some(VersionOrUrl::Url(requirement.url)),
+                        marker: requirement.marker,
+                    });
+                }
+
+                // Read Poetry-specific metadata from the `pyproject.toml`.
+                if let Some(tool) = pyproject.tool {
+                    if let Some(poetry) = tool.poetry {
+                        if let Some(name) = poetry.name {
+                            debug!(
+                                "Found Poetry metadata for {path} in `pyproject.toml` ({name})",
+                                path = path.display(),
+                                name = name
+                            );
+                            return Ok(Requirement {
+                                name,
+                                extras: requirement.extras,
+                                version_or_url: Some(VersionOrUrl::Url(requirement.url)),
+                                marker: requirement.marker,
+                            });
+                        }
+                    }
+                }
+            }
+
+            // Attempt to read a `setup.cfg` from the directory.
+            if let Some(setup_cfg) = fs_err::read_to_string(path.join("setup.cfg"))
+                .ok()
+                .and_then(|contents| {
+                    let mut ini = Ini::new_cs();
+                    ini.set_multiline(true);
+                    ini.read(contents).ok()
+                })
+            {
+                if let Some(section) = setup_cfg.get("metadata") {
+                    if let Some(Some(name)) = section.get("name") {
+                        if let Ok(name) = PackageName::from_str(name) {
+                            debug!(
+                                "Found setuptools metadata for {path} in `setup.cfg` ({name})",
+                                path = path.display(),
+                                name = name
+                            );
+                            return Ok(Requirement {
+                                name,
+                                extras: requirement.extras,
+                                version_or_url: Some(VersionOrUrl::Url(requirement.url)),
+                                marker: requirement.marker,
+                            });
+                        }
+                    }
+                }
+            }
+
+            // Attempt to read a `setup.py` from the directory.
+            if let Ok(setup_py) = fs_err::read_to_string(path.join("setup.py")) {
+                static SETUP_PY_NAME: Lazy<Regex> =
+                    Lazy::new(|| Regex::new(r#"name\s*[=:]\s*['"](?P<name>[^'"]+)['"]"#).unwrap());
+
+                if let Some(name) = SETUP_PY_NAME
+                    .captures(&setup_py)
+                    .and_then(|captures| captures.name("name"))
+                    .map(|name| name.as_str())
+                {
+                    if let Ok(name) = PackageName::from_str(name) {
+                        debug!(
+                            "Found setuptools metadata for {path} in `setup.py` ({name})",
+                            path = path.display(),
+                            name = name
+                        );
+                        return Ok(Requirement {
+                            name,
+                            extras: requirement.extras,
+                            version_or_url: Some(VersionOrUrl::Url(requirement.url)),
+                            marker: requirement.marker,
+                        });
+                    }
+                }
+            }
+        }
+
         Err(anyhow::anyhow!(
             "Unable to infer package name for the unnamed requirement: {requirement}"
         ))
     }
 }
+
+/// A pyproject.toml as specified in PEP 517.
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "kebab-case")]
+struct PyProjectToml {
+    project: Option<Project>,
+    tool: Option<Tool>,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "kebab-case")]
+struct Project {
+    name: PackageName,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "kebab-case")]
+struct Tool {
+    poetry: Option<ToolPoetry>,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "kebab-case")]
+struct ToolPoetry {
+    name: Option<PackageName>,
+}

crates/uv/tests/pip_compile.rs

@@ -5746,3 +5746,72 @@ fn preserve_hashes_newer_version() -> Result<()> {
 
     Ok(())
 }
+
+/// Detect the package name from metadata sources from local directories.
+#[test]
+fn detect_package_name() -> Result<()> {
+    let context = TestContext::new("3.12");
+    let requirements_in = context.temp_dir.child("requirements.in");
+    requirements_in.write_str(indoc! {r"
+        ../../scripts/editable-installs/poetry_editable
+        ../../scripts/editable-installs/black_editable
+        ../../scripts/editable-installs/setup_py_editable
+        ../../scripts/editable-installs/setup_cfg_editable
+        "
+    })?;
+
+    let filter_path = regex::escape(&requirements_in.user_display().to_string());
+    let filters: Vec<_> = [(filter_path.as_str(), "requirements.in")]
+        .into_iter()
+        .chain(INSTA_FILTERS.to_vec())
+        .collect();
+
+    uv_snapshot!(filters, context.compile()
+        .arg(requirements_in.path())
+        .current_dir(current_dir()?), @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 2023-11-18T12:00:00Z requirements.in
+    anyio==4.0.0
+        # via
+        #   httpx
+        #   poetry-editable
+    black @ ../../scripts/editable-installs/black_editable
+    certifi==2023.11.17
+        # via
+        #   httpcore
+        #   httpx
+        #   requests
+    charset-normalizer==3.3.2
+        # via requests
+    h11==0.14.0
+        # via httpcore
+    httpcore==1.0.2
+        # via httpx
+    httpx==0.25.1
+        # via setup-py-editable
+    idna==3.4
+        # via
+        #   anyio
+        #   httpx
+        #   requests
+    poetry-editable @ ../../scripts/editable-installs/poetry_editable
+    requests==2.31.0
+        # via setup-cfg-editable
+    setup-cfg-editable @ ../../scripts/editable-installs/setup_cfg_editable
+    setup-py-editable @ ../../scripts/editable-installs/setup_py_editable
+    sniffio==1.3.0
+        # via
+        #   anyio
+        #   httpx
+    urllib3==2.1.0
+        # via requests
+
+    ----- stderr -----
+    Resolved 14 packages in [TIME]
+    "###);
+
+    Ok(())
+}

scripts/editable-installs/setup_cfg_editable/.gitignore

@@ -0,0 +1,2 @@
+# Artifacts from the build process.
+*.egg-info/

scripts/editable-installs/setup_cfg_editable/setup.cfg

@@ -0,0 +1,3 @@
+[metadata]
+name = setup-cfg-editable
+version = 0.0.1

scripts/editable-installs/setup_cfg_editable/setup.py

@@ -0,0 +1,8 @@
+from setuptools import setup
+
+setup(
+    install_requires=[
+        "requests",
+        'importlib-metadata; python_version<"3.10"',
+    ],
+)

scripts/editable-installs/setup_py_editable/.gitignore

@@ -0,0 +1,2 @@
+# Artifacts from the build process.
+*.egg-info/

scripts/editable-installs/setup_py_editable/setup.py

@@ -0,0 +1,9 @@
+from setuptools import setup
+
+setup(
+    name="setup-py-editable",
+    version="0.0.1",
+    install_requires=[
+        "httpx",
+    ],
+)