| 1 | //! LSP integration: post-edit diagnostics injection (#136). |
| 2 | //! |
| 3 | //! After the agent performs a successful file edit (`edit_file`, |
| 4 | //! `apply_patch`, or `write_file`) the engine asks the [`LspManager`] for |
| 5 | //! diagnostics on that file. The manager spawns the appropriate LSP server |
| 6 | //! lazily on first use, sends `didOpen`/`didChange`, waits up to a bounded |
| 7 | //! timeout for `publishDiagnostics`, normalizes the result, and returns it |
| 8 | //! to the engine. |
| 9 | //! |
| 10 | //! Failure modes are non-blocking by design: a missing LSP binary, a |
| 11 | //! crashed server, or a timeout all degrade to "no diagnostics this turn" |
| 12 | //! rather than stalling the agent. We log a one-time warning per language |
| 13 | //! when the binary is missing. |
| 14 | //! |
| 15 | //! # Wiring |
| 16 | //! |
| 17 | //! ```text |
| 18 | //! Engine ── after successful edit ──▶ LspManager.diagnostics_for(path, seq) |
| 19 | //! │ |
| 20 | //! ▼ |
| 21 | //! per-language LspClient |
| 22 | //! │ |
| 23 | //! ▼ |
| 24 | //! LspTransport (stdio) |
| 25 | //! ``` |
| 26 | //! |
| 27 | //! # Configuration |
| 28 | //! |
| 29 | //! The `[lsp]` table in `~/.deepseek/config.toml` controls behavior: |
| 30 | //! `enabled`, `poll_after_edit_ms`, `max_diagnostics_per_file`, |
| 31 | //! `include_warnings`, and an optional `servers` override. See |
| 32 | //! [`LspConfig`] for defaults and `config.example.toml` for documentation. |
| 33 | |
| 34 | use std::collections::{HashMap, HashSet}; |
| 35 | use std::path::{Path, PathBuf}; |
| 36 | use std::sync::Arc; |
| 37 | use std::time::Duration; |
| 38 | |
| 39 | use serde::Deserialize; |
| 40 | use tokio::sync::Mutex as AsyncMutex; |
| 41 | use tokio::time::timeout; |
| 42 | |
| 43 | pub mod client; |
| 44 | pub mod diagnostics; |
| 45 | pub mod registry; |
| 46 | |
| 47 | pub use client::{LspTransport, StdioLspTransport}; |
| 48 | pub use diagnostics::{Diagnostic, DiagnosticBlock, Severity, render_blocks}; |
| 49 | pub use registry::Language; |
| 50 | |
| 51 | /// `[lsp]` config schema. Mirrors the TOML keys documented in |
| 52 | /// `config.example.toml`. Unknown keys are ignored. |
| 53 | #[derive(Debug, Clone, Deserialize, PartialEq, Eq)] |
| 54 | #[serde(default)] |
| 55 | pub struct LspConfig { |
| 56 | /// Master switch. When `false`, the manager skips every operation and |
| 57 | /// returns an empty diagnostics list. |
| 58 | pub enabled: bool, |
| 59 | /// Maximum time in milliseconds to wait for the LSP server to publish |
| 60 | /// diagnostics after a `didOpen`/`didChange`. Default 5000 ms. |
| 61 | pub poll_after_edit_ms: u64, |
| 62 | /// Maximum diagnostics to keep per file. Excess items are dropped after |
| 63 | /// sorting by severity. Default 20. |
| 64 | pub max_diagnostics_per_file: usize, |
| 65 | /// When `true`, warnings (severity 2) are kept in the output. When |
| 66 | /// `false` (default), only errors (severity 1) are surfaced. |
| 67 | pub include_warnings: bool, |
| 68 | /// Optional override for the `Language -> (cmd, args)` table. Keys use |
| 69 | /// [`Language::as_key`] (e.g. `"rust"`). |
| 70 | pub servers: HashMap<String, Vec<String>>, |
| 71 | } |
| 72 | |
| 73 | impl Default for LspConfig { |
| 74 | fn default() -> Self { |
| 75 | Self { |
| 76 | enabled: true, |
| 77 | poll_after_edit_ms: 5_000, |
| 78 | max_diagnostics_per_file: 20, |
| 79 | include_warnings: false, |
| 80 | servers: HashMap::new(), |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | impl LspConfig { |
| 86 | /// Resolve `(command, args)` for `lang`. User-supplied overrides take |
| 87 | /// precedence over the built-in registry. |
| 88 | fn resolve_command(&self, lang: Language) -> Option<(String, Vec<String>)> { |
| 89 | if let Some(parts) = self.servers.get(lang.as_key()) |
| 90 | && let Some((first, rest)) = parts.split_first() |
| 91 | { |
| 92 | return Some((first.clone(), rest.to_vec())); |
| 93 | } |
| 94 | let (cmd, args) = registry::server_for(lang)?; |
| 95 | Some(( |
| 96 | cmd.to_string(), |
| 97 | args.iter().map(|a| (*a).to_string()).collect(), |
| 98 | )) |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | /// The LspManager holds a lazily populated map of `Language -> Transport`. |
| 103 | /// One transport is reused across files of the same language for the |
| 104 | /// session's lifetime. |
| 105 | pub struct LspManager { |
| 106 | config: LspConfig, |
| 107 | workspace: PathBuf, |
| 108 | /// Per-language transports. Wrapped in `Arc` so we can release the outer |
| 109 | /// lock before driving I/O on a single transport. |
| 110 | transports: AsyncMutex<HashMap<Language, Arc<dyn LspTransport>>>, |
| 111 | /// Per-language "we already warned the user that the binary is missing" |
| 112 | /// guard so we do not spam the audit log on every edit. |
| 113 | missing_warned: AsyncMutex<HashSet<Language>>, |
| 114 | /// Test seam: when set, `diagnostics_for` uses these instead of spawning |
| 115 | /// real LSP processes. Keyed by language. |
| 116 | test_transports: AsyncMutex<HashMap<Language, Arc<dyn LspTransport>>>, |
| 117 | } |
| 118 | |
| 119 | impl LspManager { |
| 120 | /// Build a new manager. Does not spawn any LSP servers — that is lazy. |
| 121 | #[must_use] |
| 122 | pub fn new(config: LspConfig, workspace: PathBuf) -> Self { |
| 123 | Self { |
| 124 | config, |
| 125 | workspace, |
| 126 | transports: AsyncMutex::new(HashMap::new()), |
| 127 | missing_warned: AsyncMutex::new(HashSet::new()), |
| 128 | test_transports: AsyncMutex::new(HashMap::new()), |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | /// Read-only access to the resolved config. Used by the engine to skip |
| 133 | /// the post-edit hook entirely when `enabled = false`. |
| 134 | #[must_use] |
| 135 | pub fn config(&self) -> &LspConfig { |
| 136 | &self.config |
| 137 | } |
| 138 | |
| 139 | /// Inject a fake transport for a language. Used by tests so we never |
| 140 | /// fork a real LSP server in CI. |
| 141 | #[cfg(test)] |
| 142 | pub async fn install_test_transport(&self, lang: Language, transport: Arc<dyn LspTransport>) { |
| 143 | self.test_transports.lock().await.insert(lang, transport); |
| 144 | } |
| 145 | |
| 146 | /// Poll the LSP server for diagnostics on `file`. Returns the rendered |
| 147 | /// [`DiagnosticBlock`] (already truncated to the configured per-file |
| 148 | /// max) or `None` when the manager is disabled / has no server / the |
| 149 | /// poll times out. |
| 150 | /// |
| 151 | /// The `_edit_seq` argument is currently a no-op; it exists in the |
| 152 | /// signature so the engine can correlate diagnostics back to a specific |
| 153 | /// edit when we add request batching in v0.7.x. |
| 154 | pub async fn diagnostics_for(&self, file: &Path, _edit_seq: u64) -> Option<DiagnosticBlock> { |
| 155 | if !self.config.enabled { |
| 156 | return None; |
| 157 | } |
| 158 | let lang = registry::detect_language(file); |
| 159 | if lang == Language::Other { |
| 160 | return None; |
| 161 | } |
| 162 | |
| 163 | let text = match tokio::fs::read_to_string(file).await { |
| 164 | Ok(text) => text, |
| 165 | Err(err) => { |
| 166 | tracing::debug!(?err, file = %file.display(), "lsp: read file failed"); |
| 167 | return None; |
| 168 | } |
| 169 | }; |
| 170 | |
| 171 | let transport = match self.transport_for(lang).await { |
| 172 | Some(t) => t, |
| 173 | None => return None, |
| 174 | }; |
| 175 | |
| 176 | let wait = Duration::from_millis(self.config.poll_after_edit_ms); |
| 177 | let inner_wait = wait; |
| 178 | let raw = match timeout(wait, transport.diagnostics_for(file, &text, inner_wait)).await { |
| 179 | Ok(Ok(items)) => items, |
| 180 | Ok(Err(err)) => { |
| 181 | tracing::debug!(?err, file = %file.display(), "lsp: diagnostics call failed"); |
| 182 | return None; |
| 183 | } |
| 184 | Err(_) => { |
| 185 | tracing::debug!(file = %file.display(), "lsp: diagnostics timed out"); |
| 186 | return None; |
| 187 | } |
| 188 | }; |
| 189 | |
| 190 | // Filter, sort, and truncate. |
| 191 | let include_warnings = self.config.include_warnings; |
| 192 | let mut items: Vec<Diagnostic> = raw |
| 193 | .into_iter() |
| 194 | .filter(|d| match d.severity { |
| 195 | Severity::Error => true, |
| 196 | Severity::Warning => include_warnings, |
| 197 | _ => false, |
| 198 | }) |
| 199 | .collect(); |
| 200 | items.sort_by_key(|d| match d.severity { |
| 201 | Severity::Error => 0u8, |
| 202 | Severity::Warning => 1u8, |
| 203 | Severity::Information => 2u8, |
| 204 | Severity::Hint => 3u8, |
| 205 | }); |
| 206 | let mut block = DiagnosticBlock { |
| 207 | file: relative_to_workspace(&self.workspace, file), |
| 208 | items, |
| 209 | }; |
| 210 | block.truncate(self.config.max_diagnostics_per_file); |
| 211 | if block.items.is_empty() { |
| 212 | None |
| 213 | } else { |
| 214 | Some(block) |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | /// Resolve (and lazily spawn) the transport for `lang`. Tests can |
| 219 | /// short-circuit this via `install_test_transport` (cfg-test only). |
| 220 | async fn transport_for(&self, lang: Language) -> Option<Arc<dyn LspTransport>> { |
| 221 | if let Some(t) = self.test_transports.lock().await.get(&lang) { |
| 222 | return Some(t.clone()); |
| 223 | } |
| 224 | |
| 225 | if let Some(t) = self.transports.lock().await.get(&lang) { |
| 226 | return Some(t.clone()); |
| 227 | } |
| 228 | |
| 229 | let (cmd, args) = self.config.resolve_command(lang)?; |
| 230 | match StdioLspTransport::spawn(&cmd, &args, lang, self.workspace.clone()).await { |
| 231 | Ok(transport) => { |
| 232 | let arc: Arc<dyn LspTransport> = Arc::new(transport); |
| 233 | self.transports.lock().await.insert(lang, arc.clone()); |
| 234 | Some(arc) |
| 235 | } |
| 236 | Err(err) => { |
| 237 | self.warn_missing_once(lang, &cmd, &err).await; |
| 238 | None |
| 239 | } |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | async fn warn_missing_once(&self, lang: Language, cmd: &str, err: &anyhow::Error) { |
| 244 | let mut warned = self.missing_warned.lock().await; |
| 245 | if warned.insert(lang) { |
| 246 | tracing::warn!( |
| 247 | language = %lang.as_key(), |
| 248 | command = %cmd, |
| 249 | error = %err, |
| 250 | "lsp: server unavailable; diagnostics disabled for this language" |
| 251 | ); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | /// Best-effort shutdown of every spawned transport. Called when the |
| 256 | /// session ends. |
| 257 | #[allow(dead_code)] |
| 258 | pub async fn shutdown_all(&self) { |
| 259 | let transports: Vec<Arc<dyn LspTransport>> = |
| 260 | self.transports.lock().await.values().cloned().collect(); |
| 261 | for transport in transports { |
| 262 | transport.shutdown().await; |
| 263 | } |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | /// Render `path` relative to the workspace when possible. Falls back to |
| 268 | /// `path.file_name()` (per the issue's hard rule about not using |
| 269 | /// `display().to_string()` on the bare path) when relativization fails. |
| 270 | fn relative_to_workspace(workspace: &Path, path: &Path) -> PathBuf { |
| 271 | if let Ok(rel) = path.strip_prefix(workspace) { |
| 272 | return rel.to_path_buf(); |
| 273 | } |
| 274 | PathBuf::from( |
| 275 | path.file_name() |
| 276 | .map(|n| n.to_string_lossy().into_owned()) |
| 277 | .unwrap_or_else(|| String::from("unknown")), |
| 278 | ) |
| 279 | } |
| 280 | |
| 281 | /// Used for tests / no-op runs. Builds an empty manager that always returns |
| 282 | /// `None`. Needed because the engine constructs an `LspManager` even when |
| 283 | /// the user has disabled LSP, so the field is always present. |
| 284 | impl LspManager { |
| 285 | #[must_use] |
| 286 | pub fn disabled() -> Self { |
| 287 | Self::new( |
| 288 | LspConfig { |
| 289 | enabled: false, |
| 290 | ..LspConfig::default() |
| 291 | }, |
| 292 | PathBuf::new(), |
| 293 | ) |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | #[cfg(test)] |
| 298 | pub(crate) mod tests { |
| 299 | use super::*; |
| 300 | use async_trait::async_trait; |
| 301 | use std::sync::atomic::{AtomicUsize, Ordering}; |
| 302 | |
| 303 | /// Fake transport: returns a fixed list of diagnostics. Used by |
| 304 | /// integration tests so we never spawn a real LSP server in CI. |
| 305 | pub(crate) struct FakeTransport { |
| 306 | items: Vec<Diagnostic>, |
| 307 | calls: AtomicUsize, |
| 308 | } |
| 309 | |
| 310 | impl FakeTransport { |
| 311 | pub(crate) fn new(items: Vec<Diagnostic>) -> Self { |
| 312 | Self { |
| 313 | items, |
| 314 | calls: AtomicUsize::new(0), |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | pub(crate) fn call_count(&self) -> usize { |
| 319 | self.calls.load(Ordering::Relaxed) |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | #[async_trait] |
| 324 | impl LspTransport for FakeTransport { |
| 325 | async fn diagnostics_for( |
| 326 | &self, |
| 327 | _path: &Path, |
| 328 | _text: &str, |
| 329 | _wait: Duration, |
| 330 | ) -> anyhow::Result<Vec<Diagnostic>> { |
| 331 | self.calls.fetch_add(1, Ordering::Relaxed); |
| 332 | Ok(self.items.clone()) |
| 333 | } |
| 334 | |
| 335 | async fn shutdown(&self) {} |
| 336 | } |
| 337 | |
| 338 | #[tokio::test] |
| 339 | async fn returns_none_when_disabled() { |
| 340 | let mgr = LspManager::new( |
| 341 | LspConfig { |
| 342 | enabled: false, |
| 343 | ..LspConfig::default() |
| 344 | }, |
| 345 | PathBuf::from("/tmp"), |
| 346 | ); |
| 347 | let dir = tempfile::tempdir().unwrap(); |
| 348 | let path = dir.path().join("foo.rs"); |
| 349 | tokio::fs::write(&path, b"fn main() {}").await.unwrap(); |
| 350 | assert!(mgr.diagnostics_for(&path, 1).await.is_none()); |
| 351 | } |
| 352 | |
| 353 | #[tokio::test] |
| 354 | async fn returns_none_for_unknown_language() { |
| 355 | let dir = tempfile::tempdir().unwrap(); |
| 356 | let mgr = LspManager::new(LspConfig::default(), dir.path().to_path_buf()); |
| 357 | let path = dir.path().join("notes.txt"); |
| 358 | tokio::fs::write(&path, b"hi").await.unwrap(); |
| 359 | assert!(mgr.diagnostics_for(&path, 1).await.is_none()); |
| 360 | } |
| 361 | |
| 362 | #[tokio::test] |
| 363 | async fn forwards_errors_through_fake_transport() { |
| 364 | let dir = tempfile::tempdir().unwrap(); |
| 365 | let mgr = LspManager::new(LspConfig::default(), dir.path().to_path_buf()); |
| 366 | let path = dir.path().join("foo.rs"); |
| 367 | tokio::fs::write(&path, b"let x: i32 = \"oops\";") |
| 368 | .await |
| 369 | .unwrap(); |
| 370 | |
| 371 | let fake = Arc::new(FakeTransport::new(vec![Diagnostic { |
| 372 | line: 1, |
| 373 | column: 14, |
| 374 | severity: Severity::Error, |
| 375 | message: "expected i32, found &str".to_string(), |
| 376 | }])); |
| 377 | mgr.install_test_transport(Language::Rust, fake.clone()) |
| 378 | .await; |
| 379 | |
| 380 | let block = mgr.diagnostics_for(&path, 1).await.expect("has block"); |
| 381 | let rendered = block.render(); |
| 382 | assert!(rendered.contains("ERROR [1:14] expected i32, found &str")); |
| 383 | assert!(rendered.contains("foo.rs")); |
| 384 | assert_eq!(fake.call_count(), 1); |
| 385 | } |
| 386 | |
| 387 | #[tokio::test] |
| 388 | async fn drops_warnings_by_default() { |
| 389 | let dir = tempfile::tempdir().unwrap(); |
| 390 | let mgr = LspManager::new(LspConfig::default(), dir.path().to_path_buf()); |
| 391 | let path = dir.path().join("foo.rs"); |
| 392 | tokio::fs::write(&path, b"fn main() {}").await.unwrap(); |
| 393 | |
| 394 | let fake = Arc::new(FakeTransport::new(vec![ |
| 395 | Diagnostic { |
| 396 | line: 1, |
| 397 | column: 1, |
| 398 | severity: Severity::Warning, |
| 399 | message: "unused import".to_string(), |
| 400 | }, |
| 401 | Diagnostic { |
| 402 | line: 2, |
| 403 | column: 1, |
| 404 | severity: Severity::Error, |
| 405 | message: "type error".to_string(), |
| 406 | }, |
| 407 | ])); |
| 408 | mgr.install_test_transport(Language::Rust, fake).await; |
| 409 | |
| 410 | let block = mgr.diagnostics_for(&path, 1).await.expect("has block"); |
| 411 | assert_eq!(block.items.len(), 1); |
| 412 | assert_eq!(block.items[0].severity, Severity::Error); |
| 413 | } |
| 414 | |
| 415 | #[tokio::test] |
| 416 | async fn keeps_warnings_when_opted_in() { |
| 417 | let dir = tempfile::tempdir().unwrap(); |
| 418 | let mgr = LspManager::new( |
| 419 | LspConfig { |
| 420 | include_warnings: true, |
| 421 | ..LspConfig::default() |
| 422 | }, |
| 423 | dir.path().to_path_buf(), |
| 424 | ); |
| 425 | let path = dir.path().join("foo.rs"); |
| 426 | tokio::fs::write(&path, b"fn main() {}").await.unwrap(); |
| 427 | |
| 428 | let fake = Arc::new(FakeTransport::new(vec![ |
| 429 | Diagnostic { |
| 430 | line: 1, |
| 431 | column: 1, |
| 432 | severity: Severity::Warning, |
| 433 | message: "unused".to_string(), |
| 434 | }, |
| 435 | Diagnostic { |
| 436 | line: 2, |
| 437 | column: 1, |
| 438 | severity: Severity::Error, |
| 439 | message: "broken".to_string(), |
| 440 | }, |
| 441 | ])); |
| 442 | mgr.install_test_transport(Language::Rust, fake).await; |
| 443 | |
| 444 | let block = mgr.diagnostics_for(&path, 1).await.expect("has block"); |
| 445 | assert_eq!(block.items.len(), 2); |
| 446 | // Errors come first after sorting. |
| 447 | assert_eq!(block.items[0].severity, Severity::Error); |
| 448 | assert_eq!(block.items[1].severity, Severity::Warning); |
| 449 | } |
| 450 | |
| 451 | #[tokio::test] |
| 452 | async fn truncates_to_max_per_file() { |
| 453 | let dir = tempfile::tempdir().unwrap(); |
| 454 | let mgr = LspManager::new( |
| 455 | LspConfig { |
| 456 | max_diagnostics_per_file: 3, |
| 457 | ..LspConfig::default() |
| 458 | }, |
| 459 | dir.path().to_path_buf(), |
| 460 | ); |
| 461 | let path = dir.path().join("foo.rs"); |
| 462 | tokio::fs::write(&path, b"fn main() {}").await.unwrap(); |
| 463 | |
| 464 | let fake = Arc::new(FakeTransport::new( |
| 465 | (0..10) |
| 466 | .map(|i| Diagnostic { |
| 467 | line: i + 1, |
| 468 | column: 1, |
| 469 | severity: Severity::Error, |
| 470 | message: format!("err {i}"), |
| 471 | }) |
| 472 | .collect(), |
| 473 | )); |
| 474 | mgr.install_test_transport(Language::Rust, fake).await; |
| 475 | |
| 476 | let block = mgr.diagnostics_for(&path, 1).await.expect("has block"); |
| 477 | assert_eq!(block.items.len(), 3); |
| 478 | } |
| 479 | |
| 480 | #[tokio::test] |
| 481 | async fn render_blocks_concatenates() { |
| 482 | let blocks = vec![ |
| 483 | DiagnosticBlock { |
| 484 | file: PathBuf::from("a.rs"), |
| 485 | items: vec![Diagnostic { |
| 486 | line: 1, |
| 487 | column: 1, |
| 488 | severity: Severity::Error, |
| 489 | message: "err in a".to_string(), |
| 490 | }], |
| 491 | }, |
| 492 | DiagnosticBlock { |
| 493 | file: PathBuf::from("b.rs"), |
| 494 | items: vec![Diagnostic { |
| 495 | line: 2, |
| 496 | column: 2, |
| 497 | severity: Severity::Error, |
| 498 | message: "err in b".to_string(), |
| 499 | }], |
| 500 | }, |
| 501 | ]; |
| 502 | let rendered = render_blocks(&blocks); |
| 503 | assert!(rendered.contains("file=\"a.rs\"")); |
| 504 | assert!(rendered.contains("file=\"b.rs\"")); |
| 505 | } |
| 506 | |
| 507 | #[test] |
| 508 | fn relative_path_falls_back_to_filename_when_outside_workspace() { |
| 509 | let workspace = PathBuf::from("/foo/bar"); |
| 510 | let path = PathBuf::from("/baz/qux.rs"); |
| 511 | assert_eq!( |
| 512 | relative_to_workspace(&workspace, &path), |
| 513 | PathBuf::from("qux.rs") |
| 514 | ); |
| 515 | } |
| 516 | |
| 517 | #[test] |
| 518 | fn config_resolve_uses_overrides() { |
| 519 | let mut cfg = LspConfig::default(); |
| 520 | cfg.servers.insert( |
| 521 | "rust".to_string(), |
| 522 | vec!["custom-rls".to_string(), "--lsp".to_string()], |
| 523 | ); |
| 524 | let (cmd, args) = cfg.resolve_command(Language::Rust).unwrap(); |
| 525 | assert_eq!(cmd, "custom-rls"); |
| 526 | assert_eq!(args, vec!["--lsp".to_string()]); |
| 527 | } |
| 528 | |
| 529 | #[test] |
| 530 | fn config_resolve_falls_back_to_registry() { |
| 531 | let cfg = LspConfig::default(); |
| 532 | let (cmd, _) = cfg.resolve_command(Language::Rust).unwrap(); |
| 533 | assert_eq!(cmd, "rust-analyzer"); |
| 534 | } |
| 535 | } |
| 536 |