Add Rust based LSP

Signed-off-by: Micha Reiser <micha@reiser.io>

crates/ruff_cli/Cargo.toml

@@ -19,6 +19,7 @@ ruff_linter = { path = "../ruff_linter", features = ["clap"] }
 ruff_cache = { path = "../ruff_cache" }
 ruff_diagnostics = { path = "../ruff_diagnostics" }
 ruff_formatter = { path = "../ruff_formatter" }
+ruff_lsp = { path = "../ruff_lsp" }
 ruff_notebook = { path = "../ruff_notebook" }
 ruff_macros = { path = "../ruff_macros" }
 ruff_python_ast = { path = "../ruff_python_ast" }
@@ -59,6 +60,8 @@ similar = { workspace = true }
 strum = { workspace = true, features = [] }
 thiserror = { workspace = true }
 tracing = { workspace = true, features = ["log"] }
+tracing-subscriber = { version="0.3.17",features = ["registry"] }
+tracing-tree = "0.2.4"
 walkdir = { version = "2.3.2" }
 wild = { version = "2" }
 

crates/ruff_cli/src/args.rs

@@ -51,7 +51,9 @@ pub enum Command {
         format: HelpFormat,
     },
     /// List or describe the available configuration options.
-    Config { option: Option<String> },
+    Config {
+        option: Option<String>,
+    },
     /// List all supported upstream linters.
     Linter {
         /// Output format
@@ -63,11 +65,15 @@ pub enum Command {
     Clean,
     /// Generate shell completion.
     #[clap(alias = "--generate-shell-completion", hide = true)]
-    GenerateShellCompletion { shell: clap_complete_command::Shell },
+    GenerateShellCompletion {
+        shell: clap_complete_command::Shell,
+    },
     /// Run the Ruff formatter on the given files or directories.
     #[doc(hidden)]
     #[clap(hide = true)]
     Format(FormatCommand),
+
+    Lsp(LspCommand),
 }
 
 // The `Parser` derive is for ruff_dev, for ruff_cli `Args` would be sufficient
@@ -397,6 +403,32 @@ pub struct FormatCommand {
     no_preview: bool,
 }
 
+#[derive(Clone, Debug, clap::Parser)]
+#[allow(clippy::struct_excessive_bools)]
+pub struct LspCommand {
+    /// Path to the `pyproject.toml` or `ruff.toml` file to use for configuration.
+    #[arg(long, conflicts_with = "isolated")]
+    pub config: Option<PathBuf>,
+    /// Ignore all configuration files.
+    #[arg(long, conflicts_with = "config", help_heading = "Miscellaneous")]
+    pub isolated: bool,
+    /// Respect file exclusions via `.gitignore` and other standard ignore files.
+    #[arg(
+        long,
+        overrides_with("no_respect_gitignore"),
+        help_heading = "File selection"
+    )]
+    respect_gitignore: bool,
+    #[clap(long, overrides_with("respect_gitignore"), hide = true)]
+    no_respect_gitignore: bool,
+
+    /// Enable preview mode; checks will include unstable rules and fixes.
+    #[arg(long, overrides_with("no_preview"), hide = true)]
+    preview: bool,
+    #[clap(long, overrides_with("preview"), hide = true)]
+    no_preview: bool,
+}
+
 #[derive(Debug, Clone, Copy, clap::ValueEnum)]
 pub enum HelpFormat {
     Text,
@@ -565,7 +597,6 @@ pub struct CheckArguments {
 
 /// CLI settings that are distinct from configuration (commands, lists of files,
 /// etc.).
-#[allow(clippy::struct_excessive_bools)]
 pub struct FormatArguments {
     pub check: bool,
     pub config: Option<PathBuf>,
@@ -574,6 +605,11 @@ pub struct FormatArguments {
     pub stdin_filename: Option<PathBuf>,
 }
 
+pub struct LspArguments {
+    pub config: Option<PathBuf>,
+    pub isolated: bool,
+}
+
 /// CLI settings that function as configuration overrides.
 #[derive(Clone, Default)]
 #[allow(clippy::struct_excessive_bools)]

crates/ruff_cli/src/commands/lsp.rs

@@ -0,0 +1,51 @@
+use std::fmt::{Display, Formatter};
+use std::io;
+use std::num::NonZeroU16;
+use std::path::{Path, PathBuf};
+use std::time::Instant;
+
+use anyhow::Result;
+use colored::Colorize;
+use rayon::iter::Either::{Left, Right};
+use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use thiserror::Error;
+use tracing::metadata::Level;
+use tracing::{debug, warn};
+use tracing_subscriber::filter::LevelFilter;
+use tracing_subscriber::layer::SubscriberExt;
+use tracing_subscriber::util::SubscriberInitExt;
+use tracing_subscriber::{Layer, Registry};
+use tracing_tree::time::Uptime;
+
+use ruff::fs;
+use ruff::logging::LogLevel;
+use ruff::settings::types::PreviewMode;
+use ruff::warn_user_once;
+use ruff_formatter::LineWidth;
+use ruff_python_ast::{PySourceType, SourceType};
+use ruff_python_formatter::{format_module, FormatModuleError, PyFormatOptions};
+use ruff_source_file::{find_newline, LineEnding};
+use ruff_workspace::resolver::python_files_in_path;
+
+use crate::args::{FormatArguments, LspArguments, LspCommand, Overrides};
+use crate::resolve::resolve;
+use crate::ExitStatus;
+
+/// Format a set of files, and return the exit status.
+pub(crate) fn lsp(arguments: LspCommand, log_level: LogLevel) -> Result<ExitStatus> {
+    let subscriber = Registry::default().with(
+        tracing_tree::HierarchicalLayer::default()
+            .with_indent_lines(true)
+            .with_indent_amount(2)
+            .with_bracketed_fields(true)
+            .with_targets(true)
+            .with_writer(|| Box::new(std::io::stderr()))
+            .with_timer(Uptime::default())
+            .with_filter(LevelFilter::from(Some(Level::DEBUG))),
+    );
+    tracing::subscriber::with_default(subscriber, || {
+        ruff_lsp::stdio();
+    });
+
+    Ok(ExitStatus::Success)
+}

crates/ruff_cli/src/commands/mod.rs

@@ -6,6 +6,7 @@ pub(crate) mod config;
 pub(crate) mod format;
 pub(crate) mod format_stdin;
 pub(crate) mod linter;
+pub(crate) mod lsp;
 pub(crate) mod rule;
 pub(crate) mod show_files;
 pub(crate) mod show_settings;

crates/ruff_cli/src/lib.rs

@@ -16,6 +16,7 @@ use ruff_linter::{fs, warn_user, warn_user_once};
 use ruff_workspace::Settings;
 
 use crate::args::{Args, CheckCommand, Command, FormatCommand};
+use crate::commands::lsp::lsp;
 use crate::printer::{Flags as PrinterFlags, Printer};
 
 pub mod args;
@@ -162,6 +163,7 @@ pub fn run(
         }
         Command::Check(args) => check(args, log_level),
         Command::Format(args) => format(args, log_level),
+        Command::Lsp(args) => lsp(args, log_level),
     }
 }
 

crates/ruff_lsp/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "ruff_lsp"
+version = "0.0.0"
+publish = false
+authors = { workspace = true }
+edition = { workspace = true }
+rust-version = { workspace = true }
+homepage = { workspace = true }
+documentation = { workspace = true }
+repository = { workspace = true }
+license = { workspace = true }
+
+[dependencies]
+ruff_linter = { path = "../ruff_linter" }
+ruff_cache = { path = "../ruff_cache" }
+ruff_diagnostics = { path = "../ruff_diagnostics" }
+ruff_formatter = { path = "../ruff_formatter" }
+ruff_notebook = { path = "../ruff_notebook" }
+ruff_macros = { path = "../ruff_macros" }
+ruff_python_ast = { path = "../ruff_python_ast" }
+ruff_python_formatter = { path = "../ruff_python_formatter" }
+ruff_source_file = { path = "../ruff_source_file" }
+ruff_python_trivia = { path = "../ruff_python_trivia" }
+ruff_workspace = { path = "../ruff_workspace" }
+ruff_text_size = { path = "../ruff_text_size" }
+
+tower-lsp = "0.20.0"
+tracing = {workspace = true}
+tokio = { version = "1.31.0", features = ["io-std", "rt", "rt-multi-thread"] }
+
+[dev-dependencies]
+
+

crates/ruff_lsp/src/lib.rs

@@ -0,0 +1,77 @@
+use ruff::RUFF_PKG_VERSION;
+use std::future::Future;
+use std::pin::Pin;
+use tower_lsp::jsonrpc::Result as LspResult;
+use tower_lsp::lsp_types::{
+    DidChangeTextDocumentParams, DidCloseTextDocumentParams, DidOpenTextDocumentParams,
+    DocumentFormattingParams, InitializeParams, InitializeResult, InitializedParams, MessageType,
+    PositionEncodingKind, ServerCapabilities, ServerInfo, TextDocumentSyncCapability,
+    TextDocumentSyncKind, TextEdit,
+};
+use tower_lsp::{Client, LanguageServer, LspService};
+
+/// Creates a LSP server that reads from stdin and writes the output to stdout.
+pub fn stdio() {
+    let mut rt = tokio::runtime::Runtime::new().unwrap();
+    rt.block_on(async {
+        let stdin = tokio::io::stdin();
+        let stdout = tokio::io::stdout();
+
+        let (service, socket) = LspService::new(|client| Server { client });
+        tower_lsp::Server::new(stdin, stdout, socket)
+            .serve(service)
+            .await;
+    });
+}
+
+struct Server {
+    client: Client,
+}
+
+#[tower_lsp::async_trait]
+impl LanguageServer for Server {
+    #[tracing::instrument(level="debug", skip_all, err, fields(client=?params.client_info))]
+    async fn initialize(&self, params: InitializeParams) -> LspResult<InitializeResult> {
+        let init = InitializeResult {
+            capabilities: ServerCapabilities {
+                // TODO
+                position_encoding: None,
+                text_document_sync: Some(TextDocumentSyncCapability::Kind(
+                    TextDocumentSyncKind::INCREMENTAL,
+                )),
+                ..Default::default()
+            },
+            server_info: Some(ServerInfo {
+                name: String::from(env!("CARGO_PKG_NAME")),
+                version: Some(RUFF_PKG_VERSION.to_string()),
+            }),
+        };
+
+        Ok(init)
+    }
+
+    #[tracing::instrument(skip_all)]
+    async fn initialized(&self, params: InitializedParams) {}
+
+    #[tracing::instrument(skip_all, fields(file=%params.text_document.uri))]
+    async fn did_open(&self, params: DidOpenTextDocumentParams) {}
+
+    #[tracing::instrument(skip_all, fields(file=%params.text_document.uri))]
+    async fn did_change(&self, params: DidChangeTextDocumentParams) {}
+
+    #[tracing::instrument(skip_all, fields(file=%params.text_document.uri))]
+    async fn did_close(&self, params: DidCloseTextDocumentParams) {}
+
+    #[tracing::instrument(skip_all, fields(file=%params.text_document.uri))]
+    async fn formatting(
+        &self,
+        params: DocumentFormattingParams,
+    ) -> LspResult<Option<Vec<TextEdit>>> {
+        Ok(Some(vec![]))
+    }
+
+    #[tracing::instrument(skip_all, err)]
+    async fn shutdown(&self) -> LspResult<()> {
+        Ok(())
+    }
+}

editors/vscode/.eslintrc.js

@@ -0,0 +1,30 @@
+module.exports = {
+  env: {
+    es2021: true,
+    node: true,
+  },
+  extends: ["eslint:recommended", "plugin:@typescript-eslint/recommended"],
+  overrides: [
+    {
+      env: {
+        node: true,
+      },
+      files: [".eslintrc.{js,cjs}"],
+      parserOptions: {
+        sourceType: "script",
+      },
+    },
+  ],
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    ecmaVersion: "latest",
+    sourceType: "module",
+  },
+  plugins: ["@typescript-eslint"],
+  rules: {
+    "@typescript-eslint/no-unused-vars": [
+      "error",
+      { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+    ],
+  },
+};

editors/vscode/.gitignore

@@ -0,0 +1,2 @@
+out
+node_modules

editors/vscode/.vscodeignore

@@ -0,0 +1,8 @@
+**
+!icon.png
+!LICENSE
+!out/main.js
+!package.json
+!server/ruff
+!server/ruff.exe
+!README.md