Report project name instead of root when using pyproject.toml files (#295)

Part of https://github.com/astral-sh/puffin/issues/214

Adds a `project: Option<PackageName>` to the `Manifest`, `Resolver`, and
`RequirementsSpecification`.
To populate an optional `name` for `PubGubPackage::Root`.

I'll work on removing the version number next.

Should we consider using the parent directory name when a
`pyproject.toml` file is not present?

crates/puffin-cli/src/commands/pip_compile.rs

@@ -44,6 +44,7 @@ pub(crate) async fn pip_compile(
 
     // Read all requirements from the provided sources.
     let RequirementsSpecification {
+        project,
         requirements,
         constraints,
         extras: used_extras,
@@ -84,6 +85,7 @@ pub(crate) async fn pip_compile(
         preferences,
         resolution_mode,
         prerelease_mode,
+        project,
     );
 
     // Detect the current Python interpreter.

crates/puffin-cli/src/commands/pip_sync.rs

@@ -33,6 +33,7 @@ pub(crate) async fn pip_sync(
 ) -> Result<ExitStatus> {
     // Read all requirements from the provided sources.
     let RequirementsSpecification {
+        project: _,
         requirements,
         constraints: _,
         extras: _,

crates/puffin-cli/src/commands/pip_uninstall.rs

@@ -22,6 +22,7 @@ pub(crate) async fn pip_uninstall(
 
     // Read all requirements from the provided sources.
     let RequirementsSpecification {
+        project: _,
         requirements,
         constraints: _,
         extras: _,

crates/puffin-cli/src/requirements.rs

@@ -8,7 +8,7 @@ use anyhow::{Context, Result};
 use fs_err as fs;
 
 use pep508_rs::Requirement;
-use puffin_normalize::ExtraName;
+use puffin_normalize::{ExtraName, PackageName};
 use puffin_package::requirements_txt::RequirementsTxt;
 
 #[derive(Debug)]
@@ -58,6 +58,8 @@ impl ExtrasSpecification<'_> {
 
 #[derive(Debug, Default)]
 pub(crate) struct RequirementsSpecification {
+    /// The name of the project specifying requirements.
+    pub(crate) project: Option<PackageName>,
     /// The requirements for the project.
     pub(crate) requirements: Vec<Requirement>,
     /// The constraints for the project.
@@ -77,6 +79,7 @@ impl RequirementsSpecification {
                 let requirement = Requirement::from_str(name)
                     .with_context(|| format!("Failed to parse `{name}`"))?;
                 Self {
+                    project: None,
                     requirements: vec![requirement],
                     constraints: vec![],
                     extras: HashSet::new(),
@@ -85,6 +88,7 @@ impl RequirementsSpecification {
             RequirementsSource::RequirementsTxt(path) => {
                 let requirements_txt = RequirementsTxt::parse(path, std::env::current_dir()?)?;
                 Self {
+                    project: None,
                     requirements: requirements_txt
                         .requirements
                         .into_iter()
@@ -100,6 +104,7 @@ impl RequirementsSpecification {
                     .with_context(|| format!("Failed to read `{}`", path.display()))?;
                 let mut used_extras = HashSet::new();
                 let mut requirements = Vec::new();
+                let mut project_name = None;
                 if let Some(project) = pyproject_toml.project {
                     requirements.extend(project.dependencies.unwrap_or_default());
                     // Include any optional dependencies specified in `extras`
@@ -114,9 +119,12 @@ impl RequirementsSpecification {
                             }
                         }
                     }
+                    // Parse the project name
+                    project_name = Some(PackageName::new(project.name));
                 }
 
                 Self {
+                    project: project_name,
                     requirements,
                     constraints: vec![],
                     extras: used_extras,
@@ -141,6 +149,11 @@ impl RequirementsSpecification {
             spec.requirements.extend(source.requirements);
             spec.constraints.extend(source.constraints);
             spec.extras.extend(source.extras);
+
+            // Use the first project name discovered
+            if spec.project.is_none() {
+                spec.project = source.project;
+            }
         }
 
         // Read all constraints, treating both requirements _and_ constraints as constraints.

crates/puffin-cli/tests/pip_compile.rs

@@ -1047,3 +1047,51 @@ optional-dependencies.bar = [
 
     Ok(())
 }
+
+/// Compile requirements that cannot be solved due to conflict in a `pyproject.toml` fil;e.
+#[test]
+fn compile_unsolvable_requirements() -> Result<()> {
+    let temp_dir = assert_fs::TempDir::new()?;
+    let cache_dir = assert_fs::TempDir::new()?;
+    let venv = temp_dir.child(".venv");
+
+    Command::new(get_cargo_bin(BIN_NAME))
+        .arg("venv")
+        .arg(venv.as_os_str())
+        .arg("--cache-dir")
+        .arg(cache_dir.path())
+        .current_dir(&temp_dir)
+        .assert()
+        .success();
+    venv.assert(predicates::path::is_dir());
+
+    let pyproject_toml = temp_dir.child("pyproject.toml");
+    pyproject_toml.touch()?;
+    pyproject_toml.write_str(
+        r#"[build-system]
+requires = ["setuptools", "wheel"]
+
+[project]
+name = "my-project"
+dependencies = ["django==5.0b1", "django==5.0a1"]
+"#,
+    )?;
+
+    insta::with_settings!({
+        filters => vec![
+            (r"\d(ms|s)", "[TIME]"),
+            (r"#    .* pip-compile", "#    [BIN_PATH] pip-compile"),
+            (r"--cache-dir .*", "--cache-dir [CACHE_DIR]"),
+        ]
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+            .arg("pip-compile")
+            .arg("pyproject.toml")
+            .arg("--cache-dir")
+            .arg(cache_dir.path())
+            .env("VIRTUAL_ENV", venv.as_os_str())
+            .current_dir(&temp_dir));
+    });
+
+    Ok(())
+}

crates/puffin-cli/tests/snapshots/pip_compile__compile_unsolvable_requirements.snap

@@ -0,0 +1,20 @@
+---
+source: crates/puffin-cli/tests/pip_compile.rs
+info:
+  program: puffin
+  args:
+    - pip-compile
+    - pyproject.toml
+    - "--cache-dir"
+    - /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmpfuaPhl
+  env:
+    VIRTUAL_ENV: /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmpLxUB5I/.venv
+---
+success: false
+exit_code: 1
+----- stdout -----
+
+----- stderr -----
+  × No solution found when resolving dependencies:
+  ╰─▶ my-project 0a0.dev0 depends on django ∅
+