Flatten `red_knot_project` import paths (#15616)

crates/red_knot/src/main.rs

@@ -6,11 +6,10 @@ use clap::Parser;
 use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
 use python_version::PythonVersion;
-use red_knot_project::db::ProjectDatabase;
+use red_knot_project::metadata::options::{EnvironmentOptions, Options};
-use red_knot_project::project::options::{EnvironmentOptions, Options};
-use red_knot_project::project::ProjectMetadata;
 use red_knot_project::watch;
 use red_knot_project::watch::ProjectWatcher;
+use red_knot_project::{ProjectDatabase, ProjectMetadata};
 use red_knot_python_semantic::SitePackages;
 use red_knot_server::run_server;
 use ruff_db::diagnostic::Diagnostic;

crates/red_knot/tests/file_watching.rs

@@ -4,11 +4,10 @@ use std::io::Write;
 use std::time::{Duration, Instant};
 
 use anyhow::{anyhow, Context};
-use red_knot_project::db::{Db, ProjectDatabase};
+use red_knot_project::metadata::options::{EnvironmentOptions, Options};
-use red_knot_project::project::options::{EnvironmentOptions, Options};
+use red_knot_project::metadata::pyproject::{PyProject, Tool};
-use red_knot_project::project::pyproject::{PyProject, Tool};
-use red_knot_project::project::ProjectMetadata;
 use red_knot_project::watch::{directory_watcher, ChangeEvent, ProjectWatcher};
+use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
 use red_knot_python_semantic::{
     resolve_module, ModuleName, PythonPlatform, PythonVersion, SitePackages,
 };

crates/red_knot_project/src/combine.rs

@@ -148,7 +148,7 @@ impl_noop_combine!(String);
 
 #[cfg(test)]
 mod tests {
-    use crate::project::combine::Combine;
+    use crate::combine::Combine;
     use std::collections::HashMap;
 
     #[test]

crates/red_knot_project/src/db.rs

@@ -1,8 +1,8 @@
 use std::panic::RefUnwindSafe;
 use std::sync::Arc;
 
-use crate::project::{check_file, Project, ProjectMetadata};
 use crate::DEFAULT_LINT_REGISTRY;
+use crate::{check_file, Project, ProjectMetadata};
 use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
 use red_knot_python_semantic::{Db as SemanticDb, Program};
 use ruff_db::diagnostic::Diagnostic;
@@ -179,8 +179,8 @@ pub(crate) mod tests {
     use ruff_db::{Db as SourceDb, Upcast};
 
     use crate::db::Db;
-    use crate::project::{Project, ProjectMetadata};
     use crate::DEFAULT_LINT_REGISTRY;
+    use crate::{Project, ProjectMetadata};
 
     #[salsa::db]
     #[derive(Clone)]

crates/red_knot_project/src/db/changes.rs

@@ -1,7 +1,7 @@
 use crate::db::{Db, ProjectDatabase};
-use crate::project::options::Options;
+use crate::metadata::options::Options;
-use crate::project::{Project, ProjectMetadata};
 use crate::watch::{ChangeEvent, CreatedKind, DeletedKind};
+use crate::{Project, ProjectMetadata};
 
 use red_knot_python_semantic::Program;
 use ruff_db::files::{system_path_to_file, File, Files};

crates/red_knot_project/src/files.rs

@@ -8,7 +8,7 @@ use salsa::Setter;
 use ruff_db::files::File;
 
 use crate::db::Db;
-use crate::project::Project;
+use crate::Project;
 
 /// Cheap cloneable hash set of files.
 type FileSet = Arc<FxHashSet<File>>;
@@ -234,8 +234,8 @@ mod tests {
 
     use crate::db::tests::TestDb;
     use crate::db::Db;
-    use crate::project::files::Index;
+    use crate::files::Index;
-    use crate::project::ProjectMetadata;
+    use crate::ProjectMetadata;
     use ruff_db::files::system_path_to_file;
     use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
     use ruff_python_ast::name::Name;

crates/red_knot_project/src/lib.rs

@@ -1,8 +1,31 @@
+#![allow(clippy::ref_option)]
+
 use red_knot_python_semantic::lint::{LintRegistry, LintRegistryBuilder};
 use red_knot_python_semantic::register_lints;
+use red_knot_python_semantic::types::check_types;
+use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity};
+use ruff_db::files::{system_path_to_file, File};
+use ruff_db::parsed::parsed_module;
+use ruff_db::source::{source_text, SourceTextError};
+use ruff_db::system::walk_directory::WalkState;
+use ruff_db::system::{FileType, SystemPath};
+use ruff_python_ast::PySourceType;
+use ruff_text_size::TextRange;
+use rustc_hash::{FxBuildHasher, FxHashSet};
+use salsa::Durability;
+use salsa::Setter;
+use std::borrow::Cow;
+use std::sync::Arc;
 
-pub mod db;
+pub use db::{Db, ProjectDatabase};
-pub mod project;
+use files::{Index, Indexed, IndexedFiles};
+pub use metadata::{ProjectDiscoveryError, ProjectMetadata};
+
+pub mod combine;
+
+mod db;
+mod files;
+pub mod metadata;
 pub mod watch;
 
 pub static DEFAULT_LINT_REGISTRY: std::sync::LazyLock<LintRegistry> =
@@ -13,3 +36,435 @@ pub fn default_lints_registry() -> LintRegistry {
     register_lints(&mut builder);
     builder.build()
 }
+
+/// The project as a Salsa ingredient.
+///
+/// ## How is a project different from a program?
+/// There are two (related) motivations:
+///
+/// 1. Program is defined in `ruff_db` and it can't reference the settings types for the linter and formatter
+///    without introducing a cyclic dependency. The project is defined in a higher level crate
+///    where it can reference these setting types.
+/// 2. Running `ruff check` with different target versions results in different programs (settings) but
+///    it remains the same project. That's why program is a narrowed view of the project only
+///    holding on to the most fundamental settings required for checking.
+#[salsa::input]
+pub struct Project {
+    /// The files that are open in the project.
+    ///
+    /// Setting the open files to a non-`None` value changes `check` to only check the
+    /// open files rather than all files in the project.
+    #[return_ref]
+    #[default]
+    open_fileset: Option<Arc<FxHashSet<File>>>,
+
+    /// The first-party files of this project.
+    #[default]
+    #[return_ref]
+    file_set: IndexedFiles,
+
+    /// The metadata describing the project, including the unresolved options.
+    #[return_ref]
+    pub metadata: ProjectMetadata,
+}
+
+impl Project {
+    pub fn from_metadata(db: &dyn Db, metadata: ProjectMetadata) -> Self {
+        Project::builder(metadata)
+            .durability(Durability::MEDIUM)
+            .open_fileset_durability(Durability::LOW)
+            .file_set_durability(Durability::LOW)
+            .new(db)
+    }
+
+    pub fn root(self, db: &dyn Db) -> &SystemPath {
+        self.metadata(db).root()
+    }
+
+    pub fn name(self, db: &dyn Db) -> &str {
+        self.metadata(db).name()
+    }
+
+    pub fn reload(self, db: &mut dyn Db, metadata: ProjectMetadata) {
+        tracing::debug!("Reloading project");
+        assert_eq!(self.root(db), metadata.root());
+
+        if &metadata != self.metadata(db) {
+            self.set_metadata(db).to(metadata);
+        }
+
+        self.reload_files(db);
+    }
+
+    /// Checks all open files in the project and its dependencies.
+    pub fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn Diagnostic>> {
+        let project_span = tracing::debug_span!("Project::check");
+        let _span = project_span.enter();
+
+        tracing::debug!("Checking project '{name}'", name = self.name(db));
+        let result = Arc::new(std::sync::Mutex::new(Vec::new()));
+        let inner_result = Arc::clone(&result);
+
+        let db = db.clone();
+        let project_span = project_span.clone();
+
+        rayon::scope(move |scope| {
+            let files = ProjectFiles::new(&db, self);
+            for file in &files {
+                let result = inner_result.clone();
+                let db = db.clone();
+                let project_span = project_span.clone();
+
+                scope.spawn(move |_| {
+                    let check_file_span = tracing::debug_span!(parent: &project_span, "check_file", file=%file.path(&db));
+                    let _entered = check_file_span.entered();
+
+                    let file_diagnostics = check_file(&db, file);
+                    result.lock().unwrap().extend(file_diagnostics);
+                });
+            }
+        });
+
+        Arc::into_inner(result).unwrap().into_inner().unwrap()
+    }
+
+    /// Opens a file in the project.
+    ///
+    /// This changes the behavior of `check` to only check the open files rather than all files in the project.
+    pub fn open_file(self, db: &mut dyn Db, file: File) {
+        tracing::debug!("Opening file `{}`", file.path(db));
+
+        let mut open_files = self.take_open_files(db);
+        open_files.insert(file);
+        self.set_open_files(db, open_files);
+    }
+
+    /// Closes a file in the project.
+    pub fn close_file(self, db: &mut dyn Db, file: File) -> bool {
+        tracing::debug!("Closing file `{}`", file.path(db));
+
+        let mut open_files = self.take_open_files(db);
+        let removed = open_files.remove(&file);
+
+        if removed {
+            self.set_open_files(db, open_files);
+        }
+
+        removed
+    }
+
+    /// Returns the open files in the project or `None` if the entire project should be checked.
+    pub fn open_files(self, db: &dyn Db) -> Option<&FxHashSet<File>> {
+        self.open_fileset(db).as_deref()
+    }
+
+    /// Sets the open files in the project.
+    ///
+    /// This changes the behavior of `check` to only check the open files rather than all files in the project.
+    #[tracing::instrument(level = "debug", skip(self, db))]
+    pub fn set_open_files(self, db: &mut dyn Db, open_files: FxHashSet<File>) {
+        tracing::debug!("Set open project files (count: {})", open_files.len());
+
+        self.set_open_fileset(db).to(Some(Arc::new(open_files)));
+    }
+
+    /// This takes the open files from the project and returns them.
+    ///
+    /// This changes the behavior of `check` to check all files in the project instead of just the open files.
+    fn take_open_files(self, db: &mut dyn Db) -> FxHashSet<File> {
+        tracing::debug!("Take open project files");
+
+        // Salsa will cancel any pending queries and remove its own reference to `open_files`
+        // so that the reference counter to `open_files` now drops to 1.
+        let open_files = self.set_open_fileset(db).to(None);
+
+        if let Some(open_files) = open_files {
+            Arc::try_unwrap(open_files).unwrap()
+        } else {
+            FxHashSet::default()
+        }
+    }
+
+    /// Returns `true` if the file is open in the project.
+    ///
+    /// A file is considered open when:
+    /// * explicitly set as an open file using [`open_file`](Self::open_file)
+    /// * It has a [`SystemPath`] and belongs to a package's `src` files
+    /// * It has a [`SystemVirtualPath`](ruff_db::system::SystemVirtualPath)
+    pub fn is_file_open(self, db: &dyn Db, file: File) -> bool {
+        if let Some(open_files) = self.open_files(db) {
+            open_files.contains(&file)
+        } else if file.path(db).is_system_path() {
+            self.contains_file(db, file)
+        } else {
+            file.path(db).is_system_virtual_path()
+        }
+    }
+
+    /// Returns `true` if `file` is a first-party file part of this package.
+    pub fn contains_file(self, db: &dyn Db, file: File) -> bool {
+        self.files(db).contains(&file)
+    }
+
+    #[tracing::instrument(level = "debug", skip(db))]
+    pub fn remove_file(self, db: &mut dyn Db, file: File) {
+        tracing::debug!(
+            "Removing file `{}` from project `{}`",
+            file.path(db),
+            self.name(db)
+        );
+
+        let Some(mut index) = IndexedFiles::indexed_mut(db, self) else {
+            return;
+        };
+
+        index.remove(file);
+    }
+
+    pub fn add_file(self, db: &mut dyn Db, file: File) {
+        tracing::debug!(
+            "Adding file `{}` to project `{}`",
+            file.path(db),
+            self.name(db)
+        );
+
+        let Some(mut index) = IndexedFiles::indexed_mut(db, self) else {
+            return;
+        };
+
+        index.insert(file);
+    }
+
+    /// Returns the files belonging to this project.
+    pub fn files(self, db: &dyn Db) -> Indexed<'_> {
+        let files = self.file_set(db);
+
+        let indexed = match files.get() {
+            Index::Lazy(vacant) => {
+                let _entered =
+                    tracing::debug_span!("Project::index_files", package = %self.name(db))
+                        .entered();
+
+                let files = discover_project_files(db, self);
+                tracing::info!("Found {} files in project `{}`", files.len(), self.name(db));
+                vacant.set(files)
+            }
+            Index::Indexed(indexed) => indexed,
+        };
+
+        indexed
+    }
+
+    pub fn reload_files(self, db: &mut dyn Db) {
+        tracing::debug!("Reloading files for project `{}`", self.name(db));
+
+        if !self.file_set(db).is_lazy() {
+            // Force a re-index of the files in the next revision.
+            self.set_file_set(db).to(IndexedFiles::lazy());
+        }
+    }
+}
+
+pub(crate) fn check_file(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
+    let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
+    // Abort checking if there are IO errors.
+    let source = source_text(db.upcast(), file);
+
+    if let Some(read_error) = source.read_error() {
+        diagnostics.push(Box::new(IOErrorDiagnostic {
+            file,
+            error: read_error.clone(),
+        }));
+        return diagnostics;
+    }
+
+    let parsed = parsed_module(db.upcast(), file);
+    diagnostics.extend(parsed.errors().iter().map(|error| {
+        let diagnostic: Box<dyn Diagnostic> = Box::new(ParseDiagnostic::new(file, error.clone()));
+        diagnostic
+    }));
+
+    diagnostics.extend(check_types(db.upcast(), file).iter().map(|diagnostic| {
+        let boxed: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+        boxed
+    }));
+
+    diagnostics.sort_unstable_by_key(|diagnostic| diagnostic.range().unwrap_or_default().start());
+
+    diagnostics
+}
+
+fn discover_project_files(db: &dyn Db, project: Project) -> FxHashSet<File> {
+    let paths = std::sync::Mutex::new(Vec::new());
+
+    db.system().walk_directory(project.root(db)).run(|| {
+        Box::new(|entry| {
+            match entry {
+                Ok(entry) => {
+                    // Skip over any non python files to avoid creating too many entries in `Files`.
+                    match entry.file_type() {
+                        FileType::File => {
+                            if entry
+                                .path()
+                                .extension()
+                                .and_then(PySourceType::try_from_extension)
+                                .is_some()
+                            {
+                                let mut paths = paths.lock().unwrap();
+                                paths.push(entry.into_path());
+                            }
+                        }
+                        FileType::Directory | FileType::Symlink => {}
+                    }
+                }
+                Err(error) => {
+                    // TODO Handle error
+                    tracing::error!("Failed to walk path: {error}");
+                }
+            }
+
+            WalkState::Continue
+        })
+    });
+
+    let paths = paths.into_inner().unwrap();
+    let mut files = FxHashSet::with_capacity_and_hasher(paths.len(), FxBuildHasher);
+
+    for path in paths {
+        // If this returns `None`, then the file was deleted between the `walk_directory` call and now.
+        // We can ignore this.
+        if let Ok(file) = system_path_to_file(db.upcast(), &path) {
+            files.insert(file);
+        }
+    }
+
+    files
+}
+
+#[derive(Debug)]
+enum ProjectFiles<'a> {
+    OpenFiles(&'a FxHashSet<File>),
+    Indexed(files::Indexed<'a>),
+}
+
+impl<'a> ProjectFiles<'a> {
+    fn new(db: &'a dyn Db, project: Project) -> Self {
+        if let Some(open_files) = project.open_files(db) {
+            ProjectFiles::OpenFiles(open_files)
+        } else {
+            ProjectFiles::Indexed(project.files(db))
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a ProjectFiles<'a> {
+    type Item = File;
+    type IntoIter = ProjectFilesIter<'a>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        match self {
+            ProjectFiles::OpenFiles(files) => ProjectFilesIter::OpenFiles(files.iter()),
+            ProjectFiles::Indexed(indexed) => ProjectFilesIter::Indexed {
+                files: indexed.into_iter(),
+            },
+        }
+    }
+}
+
+enum ProjectFilesIter<'db> {
+    OpenFiles(std::collections::hash_set::Iter<'db, File>),
+    Indexed { files: files::IndexedIter<'db> },
+}
+
+impl Iterator for ProjectFilesIter<'_> {
+    type Item = File;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self {
+            ProjectFilesIter::OpenFiles(files) => files.next().copied(),
+            ProjectFilesIter::Indexed { files } => files.next(),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct IOErrorDiagnostic {
+    file: File,
+    error: SourceTextError,
+}
+
+impl Diagnostic for IOErrorDiagnostic {
+    fn id(&self) -> DiagnosticId {
+        DiagnosticId::Io
+    }
+
+    fn message(&self) -> Cow<str> {
+        self.error.to_string().into()
+    }
+
+    fn file(&self) -> File {
+        self.file
+    }
+
+    fn range(&self) -> Option<TextRange> {
+        None
+    }
+
+    fn severity(&self) -> Severity {
+        Severity::Error
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::db::tests::TestDb;
+    use crate::{check_file, ProjectMetadata};
+    use red_knot_python_semantic::types::check_types;
+    use ruff_db::diagnostic::Diagnostic;
+    use ruff_db::files::system_path_to_file;
+    use ruff_db::source::source_text;
+    use ruff_db::system::{DbWithTestSystem, SystemPath, SystemPathBuf};
+    use ruff_db::testing::assert_function_query_was_not_run;
+    use ruff_python_ast::name::Name;
+
+    #[test]
+    fn check_file_skips_type_checking_when_file_cant_be_read() -> ruff_db::system::Result<()> {
+        let project = ProjectMetadata::new(Name::new_static("test"), SystemPathBuf::from("/"));
+        let mut db = TestDb::new(project);
+        let path = SystemPath::new("test.py");
+
+        db.write_file(path, "x = 10")?;
+        let file = system_path_to_file(&db, path).unwrap();
+
+        // Now the file gets deleted before we had a chance to read its source text.
+        db.memory_file_system().remove_file(path)?;
+        file.sync(&mut db);
+
+        assert_eq!(source_text(&db, file).as_str(), "");
+        assert_eq!(
+            check_file(&db, file)
+                .into_iter()
+                .map(|diagnostic| diagnostic.message().into_owned())
+                .collect::<Vec<_>>(),
+            vec!["Failed to read file: No such file or directory".to_string()]
+        );
+
+        let events = db.take_salsa_events();
+        assert_function_query_was_not_run(&db, check_types, file, &events);
+
+        // The user now creates a new file with an empty text. The source text
+        // content returned by `source_text` remains unchanged, but the diagnostics should get updated.
+        db.write_file(path, "").unwrap();
+
+        assert_eq!(source_text(&db, file).as_str(), "");
+        assert_eq!(
+            check_file(&db, file)
+                .into_iter()
+                .map(|diagnostic| diagnostic.message().into_owned())
+                .collect::<Vec<_>>(),
+            vec![] as Vec<String>
+        );
+
+        Ok(())
+    }
+}

crates/red_knot_project/src/metadata.rs

@@ -1,13 +1,15 @@
+use red_knot_python_semantic::ProgramSettings;
 use ruff_db::system::{System, SystemPath, SystemPathBuf};
 use ruff_python_ast::name::Name;
-
-use crate::project::combine::Combine;
-use crate::project::options::Options;
-use crate::project::pyproject::{Project, PyProject, PyProjectError};
-use red_knot_python_semantic::ProgramSettings;
 use thiserror::Error;
 
-use super::options::KnotTomlError;
+use crate::combine::Combine;
+use crate::metadata::pyproject::{Project, PyProject, PyProjectError};
+use options::KnotTomlError;
+use options::Options;
+
+pub mod options;
+pub mod pyproject;
 
 #[derive(Debug, PartialEq, Eq)]
 #[cfg_attr(test, derive(serde::Serialize))]
@@ -222,7 +224,7 @@ mod tests {
     use insta::assert_ron_snapshot;
     use ruff_db::system::{SystemPathBuf, TestSystem};
 
-    use crate::project::{ProjectDiscoveryError, ProjectMetadata};
+    use crate::{ProjectDiscoveryError, ProjectMetadata};
 
     #[test]
     fn project_without_pyproject() -> anyhow::Result<()> {

crates/red_knot_project/src/metadata/options.rs

@@ -16,12 +16,12 @@ pub struct Options {
 }
 
 impl Options {
-    pub(super) fn from_toml_str(content: &str) -> Result<Self, KnotTomlError> {
+    pub(crate) fn from_toml_str(content: &str) -> Result<Self, KnotTomlError> {
         let options = toml::from_str(content)?;
         Ok(options)
     }
 
-    pub(super) fn to_program_settings(
+    pub(crate) fn to_program_settings(
         &self,
         project_root: &SystemPath,
         system: &dyn System,

crates/red_knot_project/src/metadata/pyproject.rs

@@ -1,7 +1,61 @@
+use pep440_rs::{Version, VersionSpecifiers};
 use serde::{Deserialize, Deserializer, Serialize};
 use std::ops::Deref;
 use thiserror::Error;
 
+use crate::metadata::options::Options;
+
+/// A `pyproject.toml` as specified in PEP 517.
+#[derive(Deserialize, Serialize, Debug, Default, Clone)]
+#[serde(rename_all = "kebab-case")]
+pub struct PyProject {
+    /// PEP 621-compliant project metadata.
+    pub project: Option<Project>,
+    /// Tool-specific metadata.
+    pub tool: Option<Tool>,
+}
+
+impl PyProject {
+    pub(crate) fn knot(&self) -> Option<&Options> {
+        self.tool.as_ref().and_then(|tool| tool.knot.as_ref())
+    }
+}
+
+#[derive(Error, Debug)]
+pub enum PyProjectError {
+    #[error(transparent)]
+    TomlSyntax(#[from] toml::de::Error),
+}
+
+impl PyProject {
+    pub(crate) fn from_toml_str(content: &str) -> Result<Self, PyProjectError> {
+        toml::from_str(content).map_err(PyProjectError::TomlSyntax)
+    }
+}
+
+/// PEP 621 project metadata (`project`).
+///
+/// See <https://packaging.python.org/en/latest/specifications/pyproject-toml>.
+#[derive(Deserialize, Serialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "kebab-case")]
+pub struct Project {
+    /// The name of the project
+    ///
+    /// Note: Intentionally option to be more permissive during deserialization.
+    /// `PackageMetadata::from_pyproject` reports missing names.
+    pub name: Option<PackageName>,
+    /// The version of the project
+    pub version: Option<Version>,
+    /// The Python versions this project is compatible with.
+    pub requires_python: Option<VersionSpecifiers>,
+}
+
+#[derive(Deserialize, Serialize, Debug, Clone, PartialEq, Eq)]
+#[serde(rename_all = "kebab-case")]
+pub struct Tool {
+    pub knot: Option<Options>,
+}
+
 /// The normalized name of a package.
 ///
 /// Converts the name to lowercase and collapses runs of `-`, `_`, and `.` down to a single `-`.

crates/red_knot_project/src/project.rs

@@ -1,460 +0,0 @@
-#![allow(clippy::ref_option)]
-
-use crate::db::Db;
-use crate::db::ProjectDatabase;
-use crate::project::files::{Index, Indexed, IndexedFiles, IndexedIter};
-pub use metadata::{ProjectDiscoveryError, ProjectMetadata};
-
-use red_knot_python_semantic::types::check_types;
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity};
-use ruff_db::parsed::parsed_module;
-use ruff_db::source::{source_text, SourceTextError};
-use ruff_db::system::FileType;
-use ruff_db::{
-    files::{system_path_to_file, File},
-    system::{walk_directory::WalkState, SystemPath},
-};
-use ruff_python_ast::PySourceType;
-use ruff_text_size::TextRange;
-use rustc_hash::{FxBuildHasher, FxHashSet};
-use salsa::{Durability, Setter as _};
-use std::borrow::Cow;
-use std::sync::Arc;
-
-pub mod combine;
-mod files;
-mod metadata;
-pub mod options;
-pub mod pyproject;
-
-/// The project as a Salsa ingredient.
-///
-/// ## How is a project different from a program?
-/// There are two (related) motivations:
-///
-/// 1. Program is defined in `ruff_db` and it can't reference the settings types for the linter and formatter
-///    without introducing a cyclic dependency. The project is defined in a higher level crate
-///    where it can reference these setting types.
-/// 2. Running `ruff check` with different target versions results in different programs (settings) but
-///    it remains the same project. That's why program is a narrowed view of the project only
-///    holding on to the most fundamental settings required for checking.
-#[salsa::input]
-pub struct Project {
-    /// The files that are open in the project.
-    ///
-    /// Setting the open files to a non-`None` value changes `check` to only check the
-    /// open files rather than all files in the project.
-    #[return_ref]
-    #[default]
-    open_fileset: Option<Arc<FxHashSet<File>>>,
-
-    /// The first-party files of this project.
-    #[default]
-    #[return_ref]
-    file_set: IndexedFiles,
-
-    /// The metadata describing the project, including the unresolved options.
-    #[return_ref]
-    pub metadata: ProjectMetadata,
-}
-
-impl Project {
-    pub fn from_metadata(db: &dyn Db, metadata: ProjectMetadata) -> Self {
-        Project::builder(metadata)
-            .durability(Durability::MEDIUM)
-            .open_fileset_durability(Durability::LOW)
-            .file_set_durability(Durability::LOW)
-            .new(db)
-    }
-
-    pub fn root(self, db: &dyn Db) -> &SystemPath {
-        self.metadata(db).root()
-    }
-
-    pub fn name(self, db: &dyn Db) -> &str {
-        self.metadata(db).name()
-    }
-
-    pub fn reload(self, db: &mut dyn Db, metadata: ProjectMetadata) {
-        tracing::debug!("Reloading project");
-        assert_eq!(self.root(db), metadata.root());
-
-        if &metadata != self.metadata(db) {
-            self.set_metadata(db).to(metadata);
-        }
-
-        self.reload_files(db);
-    }
-
-    /// Checks all open files in the project and its dependencies.
-    pub fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn Diagnostic>> {
-        let project_span = tracing::debug_span!("Project::check");
-        let _span = project_span.enter();
-
-        tracing::debug!("Checking project '{name}'", name = self.name(db));
-        let result = Arc::new(std::sync::Mutex::new(Vec::new()));
-        let inner_result = Arc::clone(&result);
-
-        let db = db.clone();
-        let project_span = project_span.clone();
-
-        rayon::scope(move |scope| {
-            let files = ProjectFiles::new(&db, self);
-            for file in &files {
-                let result = inner_result.clone();
-                let db = db.clone();
-                let project_span = project_span.clone();
-
-                scope.spawn(move |_| {
-                    let check_file_span = tracing::debug_span!(parent: &project_span, "check_file", file=%file.path(&db));
-                    let _entered = check_file_span.entered();
-
-                    let file_diagnostics = check_file(&db, file);
-                    result.lock().unwrap().extend(file_diagnostics);
-                });
-            }
-        });
-
-        Arc::into_inner(result).unwrap().into_inner().unwrap()
-    }
-
-    /// Opens a file in the project.
-    ///
-    /// This changes the behavior of `check` to only check the open files rather than all files in the project.
-    pub fn open_file(self, db: &mut dyn Db, file: File) {
-        tracing::debug!("Opening file `{}`", file.path(db));
-
-        let mut open_files = self.take_open_files(db);
-        open_files.insert(file);
-        self.set_open_files(db, open_files);
-    }
-
-    /// Closes a file in the project.
-    pub fn close_file(self, db: &mut dyn Db, file: File) -> bool {
-        tracing::debug!("Closing file `{}`", file.path(db));
-
-        let mut open_files = self.take_open_files(db);
-        let removed = open_files.remove(&file);
-
-        if removed {
-            self.set_open_files(db, open_files);
-        }
-
-        removed
-    }
-
-    /// Returns the open files in the project or `None` if the entire project should be checked.
-    pub fn open_files(self, db: &dyn Db) -> Option<&FxHashSet<File>> {
-        self.open_fileset(db).as_deref()
-    }
-
-    /// Sets the open files in the project.
-    ///
-    /// This changes the behavior of `check` to only check the open files rather than all files in the project.
-    #[tracing::instrument(level = "debug", skip(self, db))]
-    pub fn set_open_files(self, db: &mut dyn Db, open_files: FxHashSet<File>) {
-        tracing::debug!("Set open project files (count: {})", open_files.len());
-
-        self.set_open_fileset(db).to(Some(Arc::new(open_files)));
-    }
-
-    /// This takes the open files from the project and returns them.
-    ///
-    /// This changes the behavior of `check` to check all files in the project instead of just the open files.
-    fn take_open_files(self, db: &mut dyn Db) -> FxHashSet<File> {
-        tracing::debug!("Take open project files");
-
-        // Salsa will cancel any pending queries and remove its own reference to `open_files`
-        // so that the reference counter to `open_files` now drops to 1.
-        let open_files = self.set_open_fileset(db).to(None);
-
-        if let Some(open_files) = open_files {
-            Arc::try_unwrap(open_files).unwrap()
-        } else {
-            FxHashSet::default()
-        }
-    }
-
-    /// Returns `true` if the file is open in the project.
-    ///
-    /// A file is considered open when:
-    /// * explicitly set as an open file using [`open_file`](Self::open_file)
-    /// * It has a [`SystemPath`] and belongs to a package's `src` files
-    /// * It has a [`SystemVirtualPath`](ruff_db::system::SystemVirtualPath)
-    pub fn is_file_open(self, db: &dyn Db, file: File) -> bool {
-        if let Some(open_files) = self.open_files(db) {
-            open_files.contains(&file)
-        } else if file.path(db).is_system_path() {
-            self.contains_file(db, file)
-        } else {
-            file.path(db).is_system_virtual_path()
-        }
-    }
-
-    /// Returns `true` if `file` is a first-party file part of this package.
-    pub fn contains_file(self, db: &dyn Db, file: File) -> bool {
-        self.files(db).contains(&file)
-    }
-
-    #[tracing::instrument(level = "debug", skip(db))]
-    pub fn remove_file(self, db: &mut dyn Db, file: File) {
-        tracing::debug!(
-            "Removing file `{}` from project `{}`",
-            file.path(db),
-            self.name(db)
-        );
-
-        let Some(mut index) = IndexedFiles::indexed_mut(db, self) else {
-            return;
-        };
-
-        index.remove(file);
-    }
-
-    pub fn add_file(self, db: &mut dyn Db, file: File) {
-        tracing::debug!(
-            "Adding file `{}` to project `{}`",
-            file.path(db),
-            self.name(db)
-        );
-
-        let Some(mut index) = IndexedFiles::indexed_mut(db, self) else {
-            return;
-        };
-
-        index.insert(file);
-    }
-
-    /// Returns the files belonging to this project.
-    pub fn files(self, db: &dyn Db) -> Indexed<'_> {
-        let files = self.file_set(db);
-
-        let indexed = match files.get() {
-            Index::Lazy(vacant) => {
-                let _entered =
-                    tracing::debug_span!("Project::index_files", package = %self.name(db))
-                        .entered();
-
-                let files = discover_project_files(db, self);
-                tracing::info!("Found {} files in project `{}`", files.len(), self.name(db));
-                vacant.set(files)
-            }
-            Index::Indexed(indexed) => indexed,
-        };
-
-        indexed
-    }
-
-    pub fn reload_files(self, db: &mut dyn Db) {
-        tracing::debug!("Reloading files for project `{}`", self.name(db));
-
-        if !self.file_set(db).is_lazy() {
-            // Force a re-index of the files in the next revision.
-            self.set_file_set(db).to(IndexedFiles::lazy());
-        }
-    }
-}
-
-pub(super) fn check_file(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
-    let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
-    // Abort checking if there are IO errors.
-    let source = source_text(db.upcast(), file);
-
-    if let Some(read_error) = source.read_error() {
-        diagnostics.push(Box::new(IOErrorDiagnostic {
-            file,
-            error: read_error.clone(),
-        }));
-        return diagnostics;
-    }
-
-    let parsed = parsed_module(db.upcast(), file);
-    diagnostics.extend(parsed.errors().iter().map(|error| {
-        let diagnostic: Box<dyn Diagnostic> = Box::new(ParseDiagnostic::new(file, error.clone()));
-        diagnostic
-    }));
-
-    diagnostics.extend(check_types(db.upcast(), file).iter().map(|diagnostic| {
-        let boxed: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
-        boxed
-    }));
-
-    diagnostics.sort_unstable_by_key(|diagnostic| diagnostic.range().unwrap_or_default().start());
-
-    diagnostics
-}
-
-fn discover_project_files(db: &dyn Db, project: Project) -> FxHashSet<File> {
-    let paths = std::sync::Mutex::new(Vec::new());
-
-    db.system().walk_directory(project.root(db)).run(|| {
-        Box::new(|entry| {
-            match entry {
-                Ok(entry) => {
-                    // Skip over any non python files to avoid creating too many entries in `Files`.
-                    match entry.file_type() {
-                        FileType::File => {
-                            if entry
-                                .path()
-                                .extension()
-                                .and_then(PySourceType::try_from_extension)
-                                .is_some()
-                            {
-                                let mut paths = paths.lock().unwrap();
-                                paths.push(entry.into_path());
-                            }
-                        }
-                        FileType::Directory | FileType::Symlink => {}
-                    }
-                }
-                Err(error) => {
-                    // TODO Handle error
-                    tracing::error!("Failed to walk path: {error}");
-                }
-            }
-
-            WalkState::Continue
-        })
-    });
-
-    let paths = paths.into_inner().unwrap();
-    let mut files = FxHashSet::with_capacity_and_hasher(paths.len(), FxBuildHasher);
-
-    for path in paths {
-        // If this returns `None`, then the file was deleted between the `walk_directory` call and now.
-        // We can ignore this.
-        if let Ok(file) = system_path_to_file(db.upcast(), &path) {
-            files.insert(file);
-        }
-    }
-
-    files
-}
-
-#[derive(Debug)]
-enum ProjectFiles<'a> {
-    OpenFiles(&'a FxHashSet<File>),
-    Indexed(Indexed<'a>),
-}
-
-impl<'a> ProjectFiles<'a> {
-    fn new(db: &'a dyn Db, project: Project) -> Self {
-        if let Some(open_files) = project.open_files(db) {
-            ProjectFiles::OpenFiles(open_files)
-        } else {
-            ProjectFiles::Indexed(project.files(db))
-        }
-    }
-}
-
-impl<'a> IntoIterator for &'a ProjectFiles<'a> {
-    type Item = File;
-    type IntoIter = ProjectFilesIter<'a>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        match self {
-            ProjectFiles::OpenFiles(files) => ProjectFilesIter::OpenFiles(files.iter()),
-            ProjectFiles::Indexed(indexed) => ProjectFilesIter::Indexed {
-                files: indexed.into_iter(),
-            },
-        }
-    }
-}
-
-enum ProjectFilesIter<'db> {
-    OpenFiles(std::collections::hash_set::Iter<'db, File>),
-    Indexed { files: IndexedIter<'db> },
-}
-
-impl Iterator for ProjectFilesIter<'_> {
-    type Item = File;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        match self {
-            ProjectFilesIter::OpenFiles(files) => files.next().copied(),
-            ProjectFilesIter::Indexed { files } => files.next(),
-        }
-    }
-}
-
-#[derive(Debug)]
-pub struct IOErrorDiagnostic {
-    file: File,
-    error: SourceTextError,
-}
-
-impl Diagnostic for IOErrorDiagnostic {
-    fn id(&self) -> DiagnosticId {
-        DiagnosticId::Io
-    }
-
-    fn message(&self) -> Cow<str> {
-        self.error.to_string().into()
-    }
-
-    fn file(&self) -> File {
-        self.file
-    }
-
-    fn range(&self) -> Option<TextRange> {
-        None
-    }
-
-    fn severity(&self) -> Severity {
-        Severity::Error
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::db::tests::TestDb;
-    use crate::project::{check_file, ProjectMetadata};
-    use red_knot_python_semantic::types::check_types;
-    use ruff_db::diagnostic::Diagnostic;
-    use ruff_db::files::system_path_to_file;
-    use ruff_db::source::source_text;
-    use ruff_db::system::{DbWithTestSystem, SystemPath, SystemPathBuf};
-    use ruff_db::testing::assert_function_query_was_not_run;
-    use ruff_python_ast::name::Name;
-
-    #[test]
-    fn check_file_skips_type_checking_when_file_cant_be_read() -> ruff_db::system::Result<()> {
-        let project = ProjectMetadata::new(Name::new_static("test"), SystemPathBuf::from("/"));
-        let mut db = TestDb::new(project);
-        let path = SystemPath::new("test.py");
-
-        db.write_file(path, "x = 10")?;
-        let file = system_path_to_file(&db, path).unwrap();
-
-        // Now the file gets deleted before we had a chance to read its source text.
-        db.memory_file_system().remove_file(path)?;
-        file.sync(&mut db);
-
-        assert_eq!(source_text(&db, file).as_str(), "");
-        assert_eq!(
-            check_file(&db, file)
-                .into_iter()
-                .map(|diagnostic| diagnostic.message().into_owned())
-                .collect::<Vec<_>>(),
-            vec!["Failed to read file: No such file or directory".to_string()]
-        );
-
-        let events = db.take_salsa_events();
-        assert_function_query_was_not_run(&db, check_types, file, &events);
-
-        // The user now creates a new file with an empty text. The source text
-        // content returned by `source_text` remains unchanged, but the diagnostics should get updated.
-        db.write_file(path, "").unwrap();
-
-        assert_eq!(source_text(&db, file).as_str(), "");
-        assert_eq!(
-            check_file(&db, file)
-                .into_iter()
-                .map(|diagnostic| diagnostic.message().into_owned())
-                .collect::<Vec<_>>(),
-            vec![] as Vec<String>
-        );
-
-        Ok(())
-    }
-}

crates/red_knot_project/src/project/pyproject.rs

@@ -1,59 +0,0 @@
-mod package_name;
-
-use pep440_rs::{Version, VersionSpecifiers};
-use serde::{Deserialize, Serialize};
-use thiserror::Error;
-
-use crate::project::options::Options;
-pub(crate) use package_name::PackageName;
-
-/// A `pyproject.toml` as specified in PEP 517.
-#[derive(Deserialize, Serialize, Debug, Default, Clone)]
-#[serde(rename_all = "kebab-case")]
-pub struct PyProject {
-    /// PEP 621-compliant project metadata.
-    pub project: Option<Project>,
-    /// Tool-specific metadata.
-    pub tool: Option<Tool>,
-}
-
-impl PyProject {
-    pub(crate) fn knot(&self) -> Option<&Options> {
-        self.tool.as_ref().and_then(|tool| tool.knot.as_ref())
-    }
-}
-
-#[derive(Error, Debug)]
-pub enum PyProjectError {
-    #[error(transparent)]
-    TomlSyntax(#[from] toml::de::Error),
-}
-
-impl PyProject {
-    pub(crate) fn from_toml_str(content: &str) -> Result<Self, PyProjectError> {
-        toml::from_str(content).map_err(PyProjectError::TomlSyntax)
-    }
-}
-
-/// PEP 621 project metadata (`project`).
-///
-/// See <https://packaging.python.org/en/latest/specifications/pyproject-toml>.
-#[derive(Deserialize, Serialize, Debug, Clone, PartialEq)]
-#[serde(rename_all = "kebab-case")]
-pub struct Project {
-    /// The name of the project
-    ///
-    /// Note: Intentionally option to be more permissive during deserialization.
-    /// `PackageMetadata::from_pyproject` reports missing names.
-    pub name: Option<PackageName>,
-    /// The version of the project
-    pub version: Option<Version>,
-    /// The Python versions this project is compatible with.
-    pub requires_python: Option<VersionSpecifiers>,
-}
-
-#[derive(Deserialize, Serialize, Debug, Clone, PartialEq, Eq)]
-#[serde(rename_all = "kebab-case")]
-pub struct Tool {
-    pub knot: Option<Options>,
-}

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__nested_projects_in_root_project.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: root
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__nested_projects_in_sub_project.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: sub_project
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__nested_projects_with_outer_knot_section.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: root
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__nested_projects_without_knot_sections.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: sub_project
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__project_with_knot_and_pyproject_toml.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: root
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__project_with_pyproject.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: project
 ---
 ProjectMetadata(

crates/red_knot_project/src/snapshots/red_knot_project__metadata__tests__project_without_pyproject.snap

@@ -1,5 +1,5 @@
 ---
-source: crates/red_knot_workspace/src/project/metadata.rs
+source: crates/red_knot_project/src/metadata.rs
 expression: project
 ---
 ProjectMetadata(

crates/red_knot_project/tests/check.rs

@@ -1,6 +1,5 @@
 use anyhow::{anyhow, Context};
-use red_knot_project::db::ProjectDatabase;
+use red_knot_project::{ProjectDatabase, ProjectMetadata};
-use red_knot_project::project::ProjectMetadata;
 use red_knot_python_semantic::{HasTy, SemanticModel};
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::parsed::parsed_module;

crates/red_knot_server/src/server/api/requests/diagnostic.rs

@@ -11,7 +11,7 @@ use crate::edit::ToRangeExt;
 use crate::server::api::traits::{BackgroundDocumentRequestHandler, RequestHandler};
 use crate::server::{client::Notifier, Result};
 use crate::session::DocumentSnapshot;
-use red_knot_project::db::{Db, ProjectDatabase};
+use red_knot_project::{Db, ProjectDatabase};
 use ruff_db::diagnostic::Severity;
 use ruff_db::source::{line_index, source_text};
 

crates/red_knot_server/src/server/api/traits.rs

@@ -5,7 +5,7 @@ use crate::session::{DocumentSnapshot, Session};
 
 use lsp_types::notification::Notification as LSPNotification;
 use lsp_types::request::Request;
-use red_knot_project::db::ProjectDatabase;
+use red_knot_project::ProjectDatabase;
 
 /// A supertrait for any server request handler.
 pub(super) trait RequestHandler {

crates/red_knot_server/src/session.rs

@@ -8,8 +8,7 @@ use std::sync::Arc;
 use anyhow::anyhow;
 use lsp_types::{ClientCapabilities, TextDocumentContentChangeEvent, Url};
 
-use red_knot_project::db::ProjectDatabase;
+use red_knot_project::{ProjectDatabase, ProjectMetadata};
-use red_knot_project::project::ProjectMetadata;
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::system::SystemPath;
 use ruff_db::Db;

crates/red_knot_wasm/src/lib.rs

@@ -3,9 +3,9 @@ use std::any::Any;
 use js_sys::Error;
 use wasm_bindgen::prelude::*;
 
-use red_knot_project::db::{Db, ProjectDatabase};
+use red_knot_project::metadata::options::{EnvironmentOptions, Options};
-use red_knot_project::project::options::{EnvironmentOptions, Options};
+use red_knot_project::ProjectMetadata;
-use red_knot_project::project::ProjectMetadata;
+use red_knot_project::{Db, ProjectDatabase};
 use ruff_db::diagnostic::Diagnostic;
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::system::walk_directory::WalkDirectoryBuilder;

crates/ruff_benchmark/benches/red_knot.rs

@@ -1,10 +1,9 @@
 #![allow(clippy::disallowed_names)]
 
 use rayon::ThreadPoolBuilder;
-use red_knot_project::db::{Db, ProjectDatabase};
+use red_knot_project::metadata::options::{EnvironmentOptions, Options};
-use red_knot_project::project::options::{EnvironmentOptions, Options};
-use red_knot_project::project::ProjectMetadata;
 use red_knot_project::watch::{ChangeEvent, ChangedKind};
+use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
 use red_knot_python_semantic::PythonVersion;
 use ruff_benchmark::criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 use ruff_benchmark::TestFile;

crates/ruff_macros/src/combine.rs

@@ -19,14 +19,14 @@ pub(crate) fn derive_impl(input: DeriveInput) -> syn::Result<proc_macro2::TokenS
                         .expect("Expected to handle named fields");
 
                     quote_spanned!(
-                        ident.span() => crate::project::combine::Combine::combine_with(&mut self.#ident, other.#ident)
+                        ident.span() => crate::combine::Combine::combine_with(&mut self.#ident, other.#ident)
                     )
                 })
                 .collect();
 
             Ok(quote! {
                 #[automatically_derived]
-                impl crate::project::combine::Combine for #ident {
+                impl crate::combine::Combine for #ident {
                     fn combine_with(&mut self, other: Self) {
                         #(
                             #output