diff options
Diffstat (limited to 'src/tools/rust-analyzer/lib/lsp-server/examples')
3 files changed, 388 insertions, 132 deletions
diff --git a/src/tools/rust-analyzer/lib/lsp-server/examples/goto_def.rs b/src/tools/rust-analyzer/lib/lsp-server/examples/goto_def.rs deleted file mode 100644 index 6b3acda7bcd..00000000000 --- a/src/tools/rust-analyzer/lib/lsp-server/examples/goto_def.rs +++ /dev/null @@ -1,132 +0,0 @@ -//! A minimal example LSP server that can only respond to the `gotoDefinition` request. To use -//! this example, execute it and then send an `initialize` request. -//! -//! ```no_run -//! Content-Length: 85 -//! -//! {"jsonrpc": "2.0", "method": "initialize", "id": 1, "params": {"capabilities": {}}} -//! ``` -//! -//! This will respond with a server response. Then send it a `initialized` notification which will -//! have no response. -//! -//! ```no_run -//! Content-Length: 59 -//! -//! {"jsonrpc": "2.0", "method": "initialized", "params": {}} -//! ``` -//! -//! Once these two are sent, then we enter the main loop of the server. The only request this -//! example can handle is `gotoDefinition`: -//! -//! ```no_run -//! Content-Length: 159 -//! -//! {"jsonrpc": "2.0", "method": "textDocument/definition", "id": 2, "params": {"textDocument": {"uri": "file://temp"}, "position": {"line": 1, "character": 1}}} -//! ``` -//! -//! To finish up without errors, send a shutdown request: -//! -//! ```no_run -//! Content-Length: 67 -//! -//! {"jsonrpc": "2.0", "method": "shutdown", "id": 3, "params": null} -//! ``` -//! -//! The server will exit the main loop and finally we send a `shutdown` notification to stop -//! the server. -//! -//! ``` -//! Content-Length: 54 -//! -//! {"jsonrpc": "2.0", "method": "exit", "params": null} -//! ``` - -#![allow(clippy::print_stderr)] - -use std::error::Error; - -use lsp_types::OneOf; -use lsp_types::{ - GotoDefinitionResponse, InitializeParams, ServerCapabilities, request::GotoDefinition, -}; - -use lsp_server::{Connection, ExtractError, Message, Request, RequestId, Response}; - -fn main() -> Result<(), Box<dyn Error + Sync + Send>> { - // Note that we must have our logging only write out to stderr. - eprintln!("starting generic LSP server"); - - // Create the transport. Includes the stdio (stdin and stdout) versions but this could - // also be implemented to use sockets or HTTP. - let (connection, io_threads) = Connection::stdio(); - - // Run the server and wait for the two threads to end (typically by trigger LSP Exit event). - let server_capabilities = serde_json::to_value(&ServerCapabilities { - definition_provider: Some(OneOf::Left(true)), - ..Default::default() - }) - .unwrap(); - let initialization_params = match connection.initialize(server_capabilities) { - Ok(it) => it, - Err(e) => { - if e.channel_is_disconnected() { - io_threads.join()?; - } - return Err(e.into()); - } - }; - main_loop(connection, initialization_params)?; - io_threads.join()?; - - // Shut down gracefully. - eprintln!("shutting down server"); - Ok(()) -} - -fn main_loop( - connection: Connection, - params: serde_json::Value, -) -> Result<(), Box<dyn Error + Sync + Send>> { - let _params: InitializeParams = serde_json::from_value(params).unwrap(); - eprintln!("starting example main loop"); - for msg in &connection.receiver { - eprintln!("got msg: {msg:?}"); - match msg { - Message::Request(req) => { - if connection.handle_shutdown(&req)? { - return Ok(()); - } - eprintln!("got request: {req:?}"); - match cast::<GotoDefinition>(req) { - Ok((id, params)) => { - eprintln!("got gotoDefinition request #{id}: {params:?}"); - let result = Some(GotoDefinitionResponse::Array(Vec::new())); - let result = serde_json::to_value(&result).unwrap(); - let resp = Response { id, result: Some(result), error: None }; - connection.sender.send(Message::Response(resp))?; - continue; - } - Err(err @ ExtractError::JsonError { .. }) => panic!("{err:?}"), - Err(ExtractError::MethodMismatch(req)) => req, - }; - // ... - } - Message::Response(resp) => { - eprintln!("got response: {resp:?}"); - } - Message::Notification(not) => { - eprintln!("got notification: {not:?}"); - } - } - } - Ok(()) -} - -fn cast<R>(req: Request) -> Result<(RequestId, R::Params), ExtractError<Request>> -where - R: lsp_types::request::Request, - R::Params: serde::de::DeserializeOwned, -{ - req.extract(R::METHOD) -} diff --git a/src/tools/rust-analyzer/lib/lsp-server/examples/manual_test.sh b/src/tools/rust-analyzer/lib/lsp-server/examples/manual_test.sh new file mode 100755 index 00000000000..d028ac43301 --- /dev/null +++ b/src/tools/rust-analyzer/lib/lsp-server/examples/manual_test.sh @@ -0,0 +1,53 @@ +#!/usr/bin/env bash +# Simple nine-packet LSP test for examples/minimal_lsp.rs +# Usage (two tabs): +# +# mkfifo /tmp/lsp_pipe # one-time setup +# # tab 1 – run the server +# cat /tmp/lsp_pipe | cargo run --example minimal_lsp +# +# # tab 2 – fire the packets (this script) +# bash examples/manual_test.sh # blocks until server exits +# +# If you don’t use a second tab, run the script in the background: +# +# bash examples/manual_test.sh & # writer in background +# cat /tmp/lsp_pipe | cargo run --example minimal_lsp +# +# The script opens /tmp/lsp_pipe for writing (exec 3>) and sends each JSON +# packet with a correct Content-Length header. +# +# One-liner alternative (single terminal, no FIFO): +# +# cargo run --example minimal_lsp <<'EOF' +# … nine packets … +# EOF +# +# Both approaches feed identical bytes to minimal_lsp via stdin. + +set -eu +PIPE=${1:-/tmp/lsp_pipe} + +mkfifo -m 600 "$PIPE" 2>/dev/null || true # create once, ignore if exists + +# open write end so the fifo stays open +exec 3> "$PIPE" + +send() { + local body=$1 + local len=$(printf '%s' "$body" | wc -c) + printf 'Content-Length: %d\r\n\r\n%s' "$len" "$body" >&3 +} + +send '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{}}}' +send '{"jsonrpc":"2.0","method":"initialized","params":{}}' +send '{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///tmp/foo.rs","languageId":"rust","version":1,"text":"fn main( ){println!(\"hi\") }"}}}' +send '{"jsonrpc":"2.0","id":2,"method":"textDocument/completion","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}}' +send '{"jsonrpc":"2.0","id":3,"method":"textDocument/hover","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}}' +send '{"jsonrpc":"2.0","id":4,"method":"textDocument/definition","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}}' +send '{"jsonrpc":"2.0","id":5,"method":"textDocument/formatting","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"options":{"tabSize":4,"insertSpaces":true}}}' +send '{"jsonrpc":"2.0","id":6,"method":"shutdown","params":null}' +send '{"jsonrpc":"2.0","method":"exit","params":null}' + +exec 3>&- +echo "Packets sent – watch the other terminal for responses." diff --git a/src/tools/rust-analyzer/lib/lsp-server/examples/minimal_lsp.rs b/src/tools/rust-analyzer/lib/lsp-server/examples/minimal_lsp.rs new file mode 100644 index 00000000000..5eef999e062 --- /dev/null +++ b/src/tools/rust-analyzer/lib/lsp-server/examples/minimal_lsp.rs @@ -0,0 +1,335 @@ +//! Minimal Language‑Server‑Protocol example: **`minimal_lsp.rs`** +//! ============================================================= +//! +//! | ↔ / ← | LSP method | What the implementation does | +//! |-------|------------|------------------------------| +//! | ↔ | `initialize` / `initialized` | capability handshake | +//! | ← | `textDocument/publishDiagnostics` | pushes a dummy info diagnostic whenever the buffer changes | +//! | ← | `textDocument/definition` | echoes an empty location array so the jump works | +//! | ← | `textDocument/completion` | offers one hard‑coded item `HelloFromLSP` | +//! | ← | `textDocument/hover` | shows *Hello from minimal_lsp* markdown | +//! | ← | `textDocument/formatting` | pipes the doc through **rustfmt** and returns a full‑file edit | +//! +//! ### Quick start +//! ```bash +//! cd rust-analyzer/lib/lsp-server +//! cargo run --example minimal_lsp +//! ``` +//! +//! ### Minimal manual session (all nine packets) +//! ```no_run +//! # 1. initialize - server replies with capabilities +//! Content-Length: 85 + +//! {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{}}} +//! +//! # 2. initialized - no response expected +//! Content-Length: 59 + +//! {"jsonrpc":"2.0","method":"initialized","params":{}} +//! +//! # 3. didOpen - provide initial buffer text +//! Content-Length: 173 + +//! {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///tmp/foo.rs","languageId":"rust","version":1,"text":"fn main( ){println!(\"hi\") }"}}} +//! +//! # 4. completion - expect HelloFromLSP +//! Content-Length: 139 + +//! {"jsonrpc":"2.0","id":2,"method":"textDocument/completion","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}} +//! +//! # 5. hover - expect markdown greeting +//! Content-Length: 135 + +//! {"jsonrpc":"2.0","id":3,"method":"textDocument/hover","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}} +//! +//! # 6. goto-definition - dummy empty array +//! Content-Length: 139 + +//! {"jsonrpc":"2.0","id":4,"method":"textDocument/definition","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"position":{"line":0,"character":0}}} +//! +//! # 7. formatting - rustfmt full document +//! Content-Length: 157 + +//! {"jsonrpc":"2.0","id":5,"method":"textDocument/formatting","params":{"textDocument":{"uri":"file:///tmp/foo.rs"},"options":{"tabSize":4,"insertSpaces":true}}} +//! +//! # 8. shutdown request - server acks and prepares to exit +//! Content-Length: 67 + +//! {"jsonrpc":"2.0","id":6,"method":"shutdown","params":null} +//! +//! # 9. exit notification - terminates the server +//! Content-Length: 54 + +//! {"jsonrpc":"2.0","method":"exit","params":null} +//! ``` +//! + +use std::{error::Error, io::Write}; + +use rustc_hash::FxHashMap; // fast hash map +use std::process::Stdio; +use toolchain::command; // clippy-approved wrapper + +#[allow(clippy::print_stderr, clippy::disallowed_types, clippy::disallowed_methods)] +use anyhow::{Context, Result, anyhow, bail}; +use lsp_server::{Connection, Message, Request as ServerRequest, RequestId, Response}; +use lsp_types::notification::Notification as _; // for METHOD consts +use lsp_types::request::Request as _; +use lsp_types::{ + CompletionItem, + CompletionItemKind, + // capability helpers + CompletionOptions, + CompletionResponse, + Diagnostic, + DiagnosticSeverity, + DidChangeTextDocumentParams, + DidOpenTextDocumentParams, + DocumentFormattingParams, + Hover, + HoverContents, + HoverProviderCapability, + // core + InitializeParams, + MarkedString, + OneOf, + Position, + PublishDiagnosticsParams, + Range, + ServerCapabilities, + TextDocumentSyncCapability, + TextDocumentSyncKind, + TextEdit, + Url, + // notifications + notification::{DidChangeTextDocument, DidOpenTextDocument, PublishDiagnostics}, + // requests + request::{Completion, Formatting, GotoDefinition, HoverRequest}, +}; // for METHOD consts + +// ===================================================================== +// main +// ===================================================================== + +#[allow(clippy::print_stderr)] +fn main() -> std::result::Result<(), Box<dyn Error + Sync + Send>> { + log::error!("starting minimal_lsp"); + + // transport + let (connection, io_thread) = Connection::stdio(); + + // advertised capabilities + let caps = ServerCapabilities { + text_document_sync: Some(TextDocumentSyncCapability::Kind(TextDocumentSyncKind::FULL)), + completion_provider: Some(CompletionOptions::default()), + definition_provider: Some(OneOf::Left(true)), + hover_provider: Some(HoverProviderCapability::Simple(true)), + document_formatting_provider: Some(OneOf::Left(true)), + ..Default::default() + }; + let init_value = serde_json::json!({ + "capabilities": caps, + "offsetEncoding": ["utf-8"], + }); + + let init_params = connection.initialize(init_value)?; + main_loop(connection, init_params)?; + io_thread.join()?; + log::error!("shutting down server"); + Ok(()) +} + +// ===================================================================== +// event loop +// ===================================================================== + +fn main_loop( + connection: Connection, + params: serde_json::Value, +) -> std::result::Result<(), Box<dyn Error + Sync + Send>> { + let _init: InitializeParams = serde_json::from_value(params)?; + let mut docs: FxHashMap<Url, String> = FxHashMap::default(); + + for msg in &connection.receiver { + match msg { + Message::Request(req) => { + if connection.handle_shutdown(&req)? { + break; + } + if let Err(err) = handle_request(&connection, &req, &mut docs) { + log::error!("[lsp] request {} failed: {err}", &req.method); + } + } + Message::Notification(note) => { + if let Err(err) = handle_notification(&connection, ¬e, &mut docs) { + log::error!("[lsp] notification {} failed: {err}", note.method); + } + } + Message::Response(resp) => log::error!("[lsp] response: {resp:?}"), + } + } + Ok(()) +} + +// ===================================================================== +// notifications +// ===================================================================== + +fn handle_notification( + conn: &Connection, + note: &lsp_server::Notification, + docs: &mut FxHashMap<Url, String>, +) -> Result<()> { + match note.method.as_str() { + DidOpenTextDocument::METHOD => { + let p: DidOpenTextDocumentParams = serde_json::from_value(note.params.clone())?; + let uri = p.text_document.uri; + docs.insert(uri.clone(), p.text_document.text); + publish_dummy_diag(conn, &uri)?; + } + DidChangeTextDocument::METHOD => { + let p: DidChangeTextDocumentParams = serde_json::from_value(note.params.clone())?; + if let Some(change) = p.content_changes.into_iter().next() { + let uri = p.text_document.uri; + docs.insert(uri.clone(), change.text); + publish_dummy_diag(conn, &uri)?; + } + } + _ => {} + } + Ok(()) +} + +// ===================================================================== +// requests +// ===================================================================== + +fn handle_request( + conn: &Connection, + req: &ServerRequest, + docs: &mut FxHashMap<Url, String>, +) -> Result<()> { + match req.method.as_str() { + GotoDefinition::METHOD => { + send_ok(conn, req.id.clone(), &lsp_types::GotoDefinitionResponse::Array(Vec::new()))?; + } + Completion::METHOD => { + let item = CompletionItem { + label: "HelloFromLSP".into(), + kind: Some(CompletionItemKind::FUNCTION), + detail: Some("dummy completion".into()), + ..Default::default() + }; + send_ok(conn, req.id.clone(), &CompletionResponse::Array(vec![item]))?; + } + HoverRequest::METHOD => { + let hover = Hover { + contents: HoverContents::Scalar(MarkedString::String( + "Hello from *minimal_lsp*".into(), + )), + range: None, + }; + send_ok(conn, req.id.clone(), &hover)?; + } + Formatting::METHOD => { + let p: DocumentFormattingParams = serde_json::from_value(req.params.clone())?; + let uri = p.text_document.uri; + let text = docs + .get(&uri) + .ok_or_else(|| anyhow!("document not in cache – did you send DidOpen?"))?; + let formatted = run_rustfmt(text)?; + let edit = TextEdit { range: full_range(text), new_text: formatted }; + send_ok(conn, req.id.clone(), &vec![edit])?; + } + _ => send_err( + conn, + req.id.clone(), + lsp_server::ErrorCode::MethodNotFound, + "unhandled method", + )?, + } + Ok(()) +} + +// ===================================================================== +// diagnostics +// ===================================================================== +fn publish_dummy_diag(conn: &Connection, uri: &Url) -> Result<()> { + let diag = Diagnostic { + range: Range::new(Position::new(0, 0), Position::new(0, 1)), + severity: Some(DiagnosticSeverity::INFORMATION), + code: None, + code_description: None, + source: Some("minimal_lsp".into()), + message: "dummy diagnostic".into(), + related_information: None, + tags: None, + data: None, + }; + let params = + PublishDiagnosticsParams { uri: uri.clone(), diagnostics: vec![diag], version: None }; + conn.sender.send(Message::Notification(lsp_server::Notification::new( + PublishDiagnostics::METHOD.to_owned(), + params, + )))?; + Ok(()) +} + +// ===================================================================== +// helpers +// ===================================================================== + +fn run_rustfmt(input: &str) -> Result<String> { + let cwd = std::env::current_dir().expect("can't determine CWD"); + let mut child = command("rustfmt", &cwd, &FxHashMap::default()) + .arg("--emit") + .arg("stdout") + .stdin(Stdio::piped()) + .stdout(Stdio::piped()) + .stderr(Stdio::piped()) + .spawn() + .context("failed to spawn rustfmt – is it installed?")?; + + let Some(stdin) = child.stdin.as_mut() else { + bail!("stdin unavailable"); + }; + stdin.write_all(input.as_bytes())?; + let output = child.wait_with_output()?; + if !output.status.success() { + let stderr = String::from_utf8_lossy(&output.stderr); + bail!("rustfmt failed: {stderr}"); + } + Ok(String::from_utf8(output.stdout)?) +} + +fn full_range(text: &str) -> Range { + let last_line_idx = text.lines().count().saturating_sub(1) as u32; + let last_col = text.lines().last().map_or(0, |l| l.chars().count()) as u32; + Range::new(Position::new(0, 0), Position::new(last_line_idx, last_col)) +} + +fn send_ok<T: serde::Serialize>(conn: &Connection, id: RequestId, result: &T) -> Result<()> { + let resp = Response { id, result: Some(serde_json::to_value(result)?), error: None }; + conn.sender.send(Message::Response(resp))?; + Ok(()) +} + +fn send_err( + conn: &Connection, + id: RequestId, + code: lsp_server::ErrorCode, + msg: &str, +) -> Result<()> { + let resp = Response { + id, + result: None, + error: Some(lsp_server::ResponseError { + code: code as i32, + message: msg.into(), + data: None, + }), + }; + conn.sender.send(Message::Response(resp))?; + Ok(()) +} |