language.rs

   1//! The `language` crate provides a large chunk of Zed's language-related
   2//! features (the other big contributors being project and lsp crates that revolve around LSP features).
   3//! Namely, this crate:
   4//! - Provides [`Language`], [`Grammar`] and [`LanguageRegistry`] types that
   5//!   use Tree-sitter to provide syntax highlighting to the editor; note though that `language` doesn't perform the highlighting by itself. It only maps ranges in a buffer to colors. Treesitter is also used for buffer outlines (lists of symbols in a buffer)
   6//! - Exposes [`LanguageConfig`] that describes how constructs (like brackets or line comments) should be handled by the editor for a source file of a particular language.
   7//!
   8//! Notably we do *not* assign a single language to a single file; in real world a single file can consist of multiple programming languages - HTML is a good example of that - and `language` crate tends to reflect that status quo in its API.
   9mod buffer;
  10mod diagnostic_set;
  11mod highlight_map;
  12mod language_registry;
  13pub mod language_settings;
  14mod outline;
  15pub mod proto;
  16mod syntax_map;
  17mod task_context;
  18mod toolchain;
  19
  20#[cfg(test)]
  21pub mod buffer_tests;
  22pub mod markdown;
  23
  24pub use crate::language_settings::InlineCompletionPreviewMode;
  25use crate::language_settings::SoftWrap;
  26use anyhow::{anyhow, Context as _, Result};
  27use async_trait::async_trait;
  28use collections::{HashMap, HashSet};
  29use fs::Fs;
  30use futures::Future;
  31use gpui::{App, AsyncApp, Entity, SharedString, Task};
  32pub use highlight_map::HighlightMap;
  33use http_client::HttpClient;
  34pub use language_registry::{LanguageName, LoadedLanguage};
  35use lsp::{CodeActionKind, InitializeParams, LanguageServerBinary, LanguageServerBinaryOptions};
  36use parking_lot::Mutex;
  37use regex::Regex;
  38use schemars::{
  39    gen::SchemaGenerator,
  40    schema::{InstanceType, Schema, SchemaObject},
  41    JsonSchema,
  42};
  43use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
  44use serde_json::Value;
  45use settings::WorktreeId;
  46use smol::future::FutureExt as _;
  47use std::num::NonZeroU32;
  48use std::{
  49    any::Any,
  50    ffi::OsStr,
  51    fmt::Debug,
  52    hash::Hash,
  53    mem,
  54    ops::{DerefMut, Range},
  55    path::{Path, PathBuf},
  56    pin::Pin,
  57    str,
  58    sync::{
  59        atomic::{AtomicU64, AtomicUsize, Ordering::SeqCst},
  60        Arc, LazyLock,
  61    },
  62};
  63use syntax_map::{QueryCursorHandle, SyntaxSnapshot};
  64use task::RunnableTag;
  65pub use task_context::{ContextProvider, RunnableRange};
  66use theme::SyntaxTheme;
  67pub use toolchain::{LanguageToolchainStore, Toolchain, ToolchainList, ToolchainLister};
  68use tree_sitter::{self, wasmtime, Query, QueryCursor, WasmStore};
  69use util::serde::default_true;
  70
  71pub use buffer::Operation;
  72pub use buffer::*;
  73pub use diagnostic_set::{DiagnosticEntry, DiagnosticGroup};
  74pub use language_registry::{
  75    AvailableLanguage, LanguageNotFound, LanguageQueries, LanguageRegistry,
  76    LanguageServerBinaryStatus, QUERY_FILENAME_PREFIXES,
  77};
  78pub use lsp::{LanguageServerId, LanguageServerName};
  79pub use outline::*;
  80pub use syntax_map::{OwnedSyntaxLayer, SyntaxLayer, ToTreeSitterPoint, TreeSitterOptions};
  81pub use text::{AnchorRangeExt, LineEnding};
  82pub use tree_sitter::{Node, Parser, Tree, TreeCursor};
  83
  84/// Initializes the `language` crate.
  85///
  86/// This should be called before making use of items from the create.
  87pub fn init(cx: &mut App) {
  88    language_settings::init(cx);
  89}
  90
  91static QUERY_CURSORS: Mutex<Vec<QueryCursor>> = Mutex::new(vec![]);
  92static PARSERS: Mutex<Vec<Parser>> = Mutex::new(vec![]);
  93
  94pub fn with_parser<F, R>(func: F) -> R
  95where
  96    F: FnOnce(&mut Parser) -> R,
  97{
  98    let mut parser = PARSERS.lock().pop().unwrap_or_else(|| {
  99        let mut parser = Parser::new();
 100        parser
 101            .set_wasm_store(WasmStore::new(&WASM_ENGINE).unwrap())
 102            .unwrap();
 103        parser
 104    });
 105    parser.set_included_ranges(&[]).unwrap();
 106    let result = func(&mut parser);
 107    PARSERS.lock().push(parser);
 108    result
 109}
 110
 111pub fn with_query_cursor<F, R>(func: F) -> R
 112where
 113    F: FnOnce(&mut QueryCursor) -> R,
 114{
 115    let mut cursor = QueryCursorHandle::new();
 116    func(cursor.deref_mut())
 117}
 118
 119static NEXT_LANGUAGE_ID: LazyLock<AtomicUsize> = LazyLock::new(Default::default);
 120static NEXT_GRAMMAR_ID: LazyLock<AtomicUsize> = LazyLock::new(Default::default);
 121static WASM_ENGINE: LazyLock<wasmtime::Engine> = LazyLock::new(|| {
 122    wasmtime::Engine::new(&wasmtime::Config::new()).expect("Failed to create Wasmtime engine")
 123});
 124
 125/// A shared grammar for plain text, exposed for reuse by downstream crates.
 126pub static PLAIN_TEXT: LazyLock<Arc<Language>> = LazyLock::new(|| {
 127    Arc::new(Language::new(
 128        LanguageConfig {
 129            name: "Plain Text".into(),
 130            soft_wrap: Some(SoftWrap::EditorWidth),
 131            matcher: LanguageMatcher {
 132                path_suffixes: vec!["txt".to_owned()],
 133                first_line_pattern: None,
 134            },
 135            ..Default::default()
 136        },
 137        None,
 138    ))
 139});
 140
 141/// Types that represent a position in a buffer, and can be converted into
 142/// an LSP position, to send to a language server.
 143pub trait ToLspPosition {
 144    /// Converts the value into an LSP position.
 145    fn to_lsp_position(self) -> lsp::Position;
 146}
 147
 148#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 149pub struct Location {
 150    pub buffer: Entity<Buffer>,
 151    pub range: Range<Anchor>,
 152}
 153
 154/// Represents a Language Server, with certain cached sync properties.
 155/// Uses [`LspAdapter`] under the hood, but calls all 'static' methods
 156/// once at startup, and caches the results.
 157pub struct CachedLspAdapter {
 158    pub name: LanguageServerName,
 159    pub disk_based_diagnostic_sources: Vec<String>,
 160    pub disk_based_diagnostics_progress_token: Option<String>,
 161    language_ids: HashMap<String, String>,
 162    pub adapter: Arc<dyn LspAdapter>,
 163    pub reinstall_attempt_count: AtomicU64,
 164    cached_binary: futures::lock::Mutex<Option<LanguageServerBinary>>,
 165}
 166
 167impl Debug for CachedLspAdapter {
 168    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 169        f.debug_struct("CachedLspAdapter")
 170            .field("name", &self.name)
 171            .field(
 172                "disk_based_diagnostic_sources",
 173                &self.disk_based_diagnostic_sources,
 174            )
 175            .field(
 176                "disk_based_diagnostics_progress_token",
 177                &self.disk_based_diagnostics_progress_token,
 178            )
 179            .field("language_ids", &self.language_ids)
 180            .field("reinstall_attempt_count", &self.reinstall_attempt_count)
 181            .finish_non_exhaustive()
 182    }
 183}
 184
 185impl CachedLspAdapter {
 186    pub fn new(adapter: Arc<dyn LspAdapter>) -> Arc<Self> {
 187        let name = adapter.name();
 188        let disk_based_diagnostic_sources = adapter.disk_based_diagnostic_sources();
 189        let disk_based_diagnostics_progress_token = adapter.disk_based_diagnostics_progress_token();
 190        let language_ids = adapter.language_ids();
 191
 192        Arc::new(CachedLspAdapter {
 193            name,
 194            disk_based_diagnostic_sources,
 195            disk_based_diagnostics_progress_token,
 196            language_ids,
 197            adapter,
 198            cached_binary: Default::default(),
 199            reinstall_attempt_count: AtomicU64::new(0),
 200        })
 201    }
 202
 203    pub fn name(&self) -> LanguageServerName {
 204        self.adapter.name().clone()
 205    }
 206
 207    pub async fn get_language_server_command(
 208        self: Arc<Self>,
 209        delegate: Arc<dyn LspAdapterDelegate>,
 210        toolchains: Arc<dyn LanguageToolchainStore>,
 211        binary_options: LanguageServerBinaryOptions,
 212        cx: &mut AsyncApp,
 213    ) -> Result<LanguageServerBinary> {
 214        let cached_binary = self.cached_binary.lock().await;
 215        self.adapter
 216            .clone()
 217            .get_language_server_command(delegate, toolchains, binary_options, cached_binary, cx)
 218            .await
 219    }
 220
 221    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 222        self.adapter.code_action_kinds()
 223    }
 224
 225    pub fn process_diagnostics(&self, params: &mut lsp::PublishDiagnosticsParams) {
 226        self.adapter.process_diagnostics(params)
 227    }
 228
 229    pub async fn process_completions(&self, completion_items: &mut [lsp::CompletionItem]) {
 230        self.adapter.process_completions(completion_items).await
 231    }
 232
 233    pub async fn labels_for_completions(
 234        &self,
 235        completion_items: &[lsp::CompletionItem],
 236        language: &Arc<Language>,
 237    ) -> Result<Vec<Option<CodeLabel>>> {
 238        self.adapter
 239            .clone()
 240            .labels_for_completions(completion_items, language)
 241            .await
 242    }
 243
 244    pub async fn labels_for_symbols(
 245        &self,
 246        symbols: &[(String, lsp::SymbolKind)],
 247        language: &Arc<Language>,
 248    ) -> Result<Vec<Option<CodeLabel>>> {
 249        self.adapter
 250            .clone()
 251            .labels_for_symbols(symbols, language)
 252            .await
 253    }
 254
 255    pub fn language_id(&self, language_name: &LanguageName) -> String {
 256        self.language_ids
 257            .get(language_name.as_ref())
 258            .cloned()
 259            .unwrap_or_else(|| language_name.lsp_id())
 260    }
 261}
 262
 263/// [`LspAdapterDelegate`] allows [`LspAdapter]` implementations to interface with the application
 264// e.g. to display a notification or fetch data from the web.
 265#[async_trait]
 266pub trait LspAdapterDelegate: Send + Sync {
 267    fn show_notification(&self, message: &str, cx: &mut App);
 268    fn http_client(&self) -> Arc<dyn HttpClient>;
 269    fn worktree_id(&self) -> WorktreeId;
 270    fn worktree_root_path(&self) -> &Path;
 271    fn update_status(&self, language: LanguageServerName, status: LanguageServerBinaryStatus);
 272    async fn language_server_download_dir(&self, name: &LanguageServerName) -> Option<Arc<Path>>;
 273
 274    async fn npm_package_installed_version(
 275        &self,
 276        package_name: &str,
 277    ) -> Result<Option<(PathBuf, String)>>;
 278    async fn which(&self, command: &OsStr) -> Option<PathBuf>;
 279    async fn shell_env(&self) -> HashMap<String, String>;
 280    async fn read_text_file(&self, path: PathBuf) -> Result<String>;
 281    async fn try_exec(&self, binary: LanguageServerBinary) -> Result<()>;
 282}
 283
 284#[async_trait(?Send)]
 285pub trait LspAdapter: 'static + Send + Sync {
 286    fn name(&self) -> LanguageServerName;
 287
 288    fn get_language_server_command<'a>(
 289        self: Arc<Self>,
 290        delegate: Arc<dyn LspAdapterDelegate>,
 291        toolchains: Arc<dyn LanguageToolchainStore>,
 292        binary_options: LanguageServerBinaryOptions,
 293        mut cached_binary: futures::lock::MutexGuard<'a, Option<LanguageServerBinary>>,
 294        cx: &'a mut AsyncApp,
 295    ) -> Pin<Box<dyn 'a + Future<Output = Result<LanguageServerBinary>>>> {
 296        async move {
 297            // First we check whether the adapter can give us a user-installed binary.
 298            // If so, we do *not* want to cache that, because each worktree might give us a different
 299            // binary:
 300            //
 301            //      worktree 1: user-installed at `.bin/gopls`
 302            //      worktree 2: user-installed at `~/bin/gopls`
 303            //      worktree 3: no gopls found in PATH -> fallback to Zed installation
 304            //
 305            // We only want to cache when we fall back to the global one,
 306            // because we don't want to download and overwrite our global one
 307            // for each worktree we might have open.
 308            if binary_options.allow_path_lookup {
 309                if let Some(binary) = self.check_if_user_installed(delegate.as_ref(), toolchains, cx).await {
 310                    log::info!(
 311                        "found user-installed language server for {}. path: {:?}, arguments: {:?}",
 312                        self.name().0,
 313                        binary.path,
 314                        binary.arguments
 315                    );
 316                    return Ok(binary);
 317                }
 318            }
 319
 320            if !binary_options.allow_binary_download {
 321                return Err(anyhow!("downloading language servers disabled"));
 322            }
 323
 324            if let Some(cached_binary) = cached_binary.as_ref() {
 325                return Ok(cached_binary.clone());
 326            }
 327
 328            let Some(container_dir) = delegate.language_server_download_dir(&self.name()).await else {
 329                anyhow::bail!("no language server download dir defined")
 330            };
 331
 332            let mut binary = try_fetch_server_binary(self.as_ref(), &delegate, container_dir.to_path_buf(), cx).await;
 333
 334            if let Err(error) = binary.as_ref() {
 335                if let Some(prev_downloaded_binary) = self
 336                    .cached_server_binary(container_dir.to_path_buf(), delegate.as_ref())
 337                    .await
 338                {
 339                    log::info!(
 340                        "failed to fetch newest version of language server {:?}. error: {:?}, falling back to using {:?}",
 341                        self.name(),
 342                        error,
 343                        prev_downloaded_binary.path
 344                    );
 345                    binary = Ok(prev_downloaded_binary);
 346                } else {
 347                    delegate.update_status(
 348                        self.name(),
 349                        LanguageServerBinaryStatus::Failed {
 350                            error: format!("{error:?}"),
 351                        },
 352                    );
 353                }
 354            }
 355
 356            if let Ok(binary) = &binary {
 357                *cached_binary = Some(binary.clone());
 358            }
 359
 360            binary
 361        }
 362        .boxed_local()
 363    }
 364
 365    async fn check_if_user_installed(
 366        &self,
 367        _: &dyn LspAdapterDelegate,
 368        _: Arc<dyn LanguageToolchainStore>,
 369        _: &AsyncApp,
 370    ) -> Option<LanguageServerBinary> {
 371        None
 372    }
 373
 374    async fn fetch_latest_server_version(
 375        &self,
 376        delegate: &dyn LspAdapterDelegate,
 377    ) -> Result<Box<dyn 'static + Send + Any>>;
 378
 379    fn will_fetch_server(
 380        &self,
 381        _: &Arc<dyn LspAdapterDelegate>,
 382        _: &mut AsyncApp,
 383    ) -> Option<Task<Result<()>>> {
 384        None
 385    }
 386
 387    async fn check_if_version_installed(
 388        &self,
 389        _version: &(dyn 'static + Send + Any),
 390        _container_dir: &PathBuf,
 391        _delegate: &dyn LspAdapterDelegate,
 392    ) -> Option<LanguageServerBinary> {
 393        None
 394    }
 395
 396    async fn fetch_server_binary(
 397        &self,
 398        latest_version: Box<dyn 'static + Send + Any>,
 399        container_dir: PathBuf,
 400        delegate: &dyn LspAdapterDelegate,
 401    ) -> Result<LanguageServerBinary>;
 402
 403    async fn cached_server_binary(
 404        &self,
 405        container_dir: PathBuf,
 406        delegate: &dyn LspAdapterDelegate,
 407    ) -> Option<LanguageServerBinary>;
 408
 409    fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
 410
 411    /// Post-processes completions provided by the language server.
 412    async fn process_completions(&self, _: &mut [lsp::CompletionItem]) {}
 413
 414    async fn labels_for_completions(
 415        self: Arc<Self>,
 416        completions: &[lsp::CompletionItem],
 417        language: &Arc<Language>,
 418    ) -> Result<Vec<Option<CodeLabel>>> {
 419        let mut labels = Vec::new();
 420        for (ix, completion) in completions.iter().enumerate() {
 421            let label = self.label_for_completion(completion, language).await;
 422            if let Some(label) = label {
 423                labels.resize(ix + 1, None);
 424                *labels.last_mut().unwrap() = Some(label);
 425            }
 426        }
 427        Ok(labels)
 428    }
 429
 430    async fn label_for_completion(
 431        &self,
 432        _: &lsp::CompletionItem,
 433        _: &Arc<Language>,
 434    ) -> Option<CodeLabel> {
 435        None
 436    }
 437
 438    async fn labels_for_symbols(
 439        self: Arc<Self>,
 440        symbols: &[(String, lsp::SymbolKind)],
 441        language: &Arc<Language>,
 442    ) -> Result<Vec<Option<CodeLabel>>> {
 443        let mut labels = Vec::new();
 444        for (ix, (name, kind)) in symbols.iter().enumerate() {
 445            let label = self.label_for_symbol(name, *kind, language).await;
 446            if let Some(label) = label {
 447                labels.resize(ix + 1, None);
 448                *labels.last_mut().unwrap() = Some(label);
 449            }
 450        }
 451        Ok(labels)
 452    }
 453
 454    async fn label_for_symbol(
 455        &self,
 456        _: &str,
 457        _: lsp::SymbolKind,
 458        _: &Arc<Language>,
 459    ) -> Option<CodeLabel> {
 460        None
 461    }
 462
 463    /// Returns initialization options that are going to be sent to a LSP server as a part of [`lsp::InitializeParams`]
 464    async fn initialization_options(
 465        self: Arc<Self>,
 466        _: &dyn Fs,
 467        _: &Arc<dyn LspAdapterDelegate>,
 468    ) -> Result<Option<Value>> {
 469        Ok(None)
 470    }
 471
 472    async fn workspace_configuration(
 473        self: Arc<Self>,
 474        _: &dyn Fs,
 475        _: &Arc<dyn LspAdapterDelegate>,
 476        _: Arc<dyn LanguageToolchainStore>,
 477        _cx: &mut AsyncApp,
 478    ) -> Result<Value> {
 479        Ok(serde_json::json!({}))
 480    }
 481
 482    /// Returns a list of code actions supported by a given LspAdapter
 483    fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 484        Some(vec![
 485            CodeActionKind::EMPTY,
 486            CodeActionKind::QUICKFIX,
 487            CodeActionKind::REFACTOR,
 488            CodeActionKind::REFACTOR_EXTRACT,
 489            CodeActionKind::SOURCE,
 490        ])
 491    }
 492
 493    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
 494        Default::default()
 495    }
 496
 497    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
 498        None
 499    }
 500
 501    fn language_ids(&self) -> HashMap<String, String> {
 502        Default::default()
 503    }
 504
 505    /// Support custom initialize params.
 506    fn prepare_initialize_params(&self, original: InitializeParams) -> Result<InitializeParams> {
 507        Ok(original)
 508    }
 509}
 510
 511async fn try_fetch_server_binary<L: LspAdapter + 'static + Send + Sync + ?Sized>(
 512    adapter: &L,
 513    delegate: &Arc<dyn LspAdapterDelegate>,
 514    container_dir: PathBuf,
 515    cx: &mut AsyncApp,
 516) -> Result<LanguageServerBinary> {
 517    if let Some(task) = adapter.will_fetch_server(delegate, cx) {
 518        task.await?;
 519    }
 520
 521    let name = adapter.name();
 522    log::info!("fetching latest version of language server {:?}", name.0);
 523    delegate.update_status(name.clone(), LanguageServerBinaryStatus::CheckingForUpdate);
 524
 525    let latest_version = adapter
 526        .fetch_latest_server_version(delegate.as_ref())
 527        .await?;
 528
 529    if let Some(binary) = adapter
 530        .check_if_version_installed(latest_version.as_ref(), &container_dir, delegate.as_ref())
 531        .await
 532    {
 533        log::info!("language server {:?} is already installed", name.0);
 534        delegate.update_status(name.clone(), LanguageServerBinaryStatus::None);
 535        Ok(binary)
 536    } else {
 537        log::info!("downloading language server {:?}", name.0);
 538        delegate.update_status(adapter.name(), LanguageServerBinaryStatus::Downloading);
 539        let binary = adapter
 540            .fetch_server_binary(latest_version, container_dir, delegate.as_ref())
 541            .await;
 542
 543        delegate.update_status(name.clone(), LanguageServerBinaryStatus::None);
 544        binary
 545    }
 546}
 547
 548#[derive(Clone, Debug, Default, PartialEq, Eq)]
 549pub struct CodeLabel {
 550    /// The text to display.
 551    pub text: String,
 552    /// Syntax highlighting runs.
 553    pub runs: Vec<(Range<usize>, HighlightId)>,
 554    /// The portion of the text that should be used in fuzzy filtering.
 555    pub filter_range: Range<usize>,
 556}
 557
 558#[derive(Clone, Deserialize, JsonSchema)]
 559pub struct LanguageConfig {
 560    /// Human-readable name of the language.
 561    pub name: LanguageName,
 562    /// The name of this language for a Markdown code fence block
 563    pub code_fence_block_name: Option<Arc<str>>,
 564    // The name of the grammar in a WASM bundle (experimental).
 565    pub grammar: Option<Arc<str>>,
 566    /// The criteria for matching this language to a given file.
 567    #[serde(flatten)]
 568    pub matcher: LanguageMatcher,
 569    /// List of bracket types in a language.
 570    #[serde(default)]
 571    #[schemars(schema_with = "bracket_pair_config_json_schema")]
 572    pub brackets: BracketPairConfig,
 573    /// If set to true, auto indentation uses last non empty line to determine
 574    /// the indentation level for a new line.
 575    #[serde(default = "auto_indent_using_last_non_empty_line_default")]
 576    pub auto_indent_using_last_non_empty_line: bool,
 577    // Whether indentation of pasted content should be adjusted based on the context.
 578    #[serde(default)]
 579    pub auto_indent_on_paste: Option<bool>,
 580    /// A regex that is used to determine whether the indentation level should be
 581    /// increased in the following line.
 582    #[serde(default, deserialize_with = "deserialize_regex")]
 583    #[schemars(schema_with = "regex_json_schema")]
 584    pub increase_indent_pattern: Option<Regex>,
 585    /// A regex that is used to determine whether the indentation level should be
 586    /// decreased in the following line.
 587    #[serde(default, deserialize_with = "deserialize_regex")]
 588    #[schemars(schema_with = "regex_json_schema")]
 589    pub decrease_indent_pattern: Option<Regex>,
 590    /// A list of characters that trigger the automatic insertion of a closing
 591    /// bracket when they immediately precede the point where an opening
 592    /// bracket is inserted.
 593    #[serde(default)]
 594    pub autoclose_before: String,
 595    /// A placeholder used internally by Semantic Index.
 596    #[serde(default)]
 597    pub collapsed_placeholder: String,
 598    /// A line comment string that is inserted in e.g. `toggle comments` action.
 599    /// A language can have multiple flavours of line comments. All of the provided line comments are
 600    /// used for comment continuations on the next line, but only the first one is used for Editor::ToggleComments.
 601    #[serde(default)]
 602    pub line_comments: Vec<Arc<str>>,
 603    /// Starting and closing characters of a block comment.
 604    #[serde(default)]
 605    pub block_comment: Option<(Arc<str>, Arc<str>)>,
 606    /// A list of language servers that are allowed to run on subranges of a given language.
 607    #[serde(default)]
 608    pub scope_opt_in_language_servers: Vec<LanguageServerName>,
 609    #[serde(default)]
 610    pub overrides: HashMap<String, LanguageConfigOverride>,
 611    /// A list of characters that Zed should treat as word characters for the
 612    /// purpose of features that operate on word boundaries, like 'move to next word end'
 613    /// or a whole-word search in buffer search.
 614    #[serde(default)]
 615    pub word_characters: HashSet<char>,
 616    /// Whether to indent lines using tab characters, as opposed to multiple
 617    /// spaces.
 618    #[serde(default)]
 619    pub hard_tabs: Option<bool>,
 620    /// How many columns a tab should occupy.
 621    #[serde(default)]
 622    pub tab_size: Option<NonZeroU32>,
 623    /// How to soft-wrap long lines of text.
 624    #[serde(default)]
 625    pub soft_wrap: Option<SoftWrap>,
 626    /// The name of a Prettier parser that will be used for this language when no file path is available.
 627    /// If there's a parser name in the language settings, that will be used instead.
 628    #[serde(default)]
 629    pub prettier_parser_name: Option<String>,
 630    /// If true, this language is only for syntax highlighting via an injection into other
 631    /// languages, but should not appear to the user as a distinct language.
 632    #[serde(default)]
 633    pub hidden: bool,
 634}
 635
 636#[derive(Clone, Debug, Serialize, Deserialize, Default, JsonSchema)]
 637pub struct LanguageMatcher {
 638    /// Given a list of `LanguageConfig`'s, the language of a file can be determined based on the path extension matching any of the `path_suffixes`.
 639    #[serde(default)]
 640    pub path_suffixes: Vec<String>,
 641    /// A regex pattern that determines whether the language should be assigned to a file or not.
 642    #[serde(
 643        default,
 644        serialize_with = "serialize_regex",
 645        deserialize_with = "deserialize_regex"
 646    )]
 647    #[schemars(schema_with = "regex_json_schema")]
 648    pub first_line_pattern: Option<Regex>,
 649}
 650
 651/// Represents a language for the given range. Some languages (e.g. HTML)
 652/// interleave several languages together, thus a single buffer might actually contain
 653/// several nested scopes.
 654#[derive(Clone, Debug)]
 655pub struct LanguageScope {
 656    language: Arc<Language>,
 657    override_id: Option<u32>,
 658}
 659
 660#[derive(Clone, Deserialize, Default, Debug, JsonSchema)]
 661pub struct LanguageConfigOverride {
 662    #[serde(default)]
 663    pub line_comments: Override<Vec<Arc<str>>>,
 664    #[serde(default)]
 665    pub block_comment: Override<(Arc<str>, Arc<str>)>,
 666    #[serde(skip)]
 667    pub disabled_bracket_ixs: Vec<u16>,
 668    #[serde(default)]
 669    pub word_characters: Override<HashSet<char>>,
 670    #[serde(default)]
 671    pub opt_into_language_servers: Vec<LanguageServerName>,
 672}
 673
 674#[derive(Clone, Deserialize, Debug, Serialize, JsonSchema)]
 675#[serde(untagged)]
 676pub enum Override<T> {
 677    Remove { remove: bool },
 678    Set(T),
 679}
 680
 681impl<T> Default for Override<T> {
 682    fn default() -> Self {
 683        Override::Remove { remove: false }
 684    }
 685}
 686
 687impl<T> Override<T> {
 688    fn as_option<'a>(this: Option<&'a Self>, original: Option<&'a T>) -> Option<&'a T> {
 689        match this {
 690            Some(Self::Set(value)) => Some(value),
 691            Some(Self::Remove { remove: true }) => None,
 692            Some(Self::Remove { remove: false }) | None => original,
 693        }
 694    }
 695}
 696
 697impl Default for LanguageConfig {
 698    fn default() -> Self {
 699        Self {
 700            name: LanguageName::new(""),
 701            code_fence_block_name: None,
 702            grammar: None,
 703            matcher: LanguageMatcher::default(),
 704            brackets: Default::default(),
 705            auto_indent_using_last_non_empty_line: auto_indent_using_last_non_empty_line_default(),
 706            auto_indent_on_paste: None,
 707            increase_indent_pattern: Default::default(),
 708            decrease_indent_pattern: Default::default(),
 709            autoclose_before: Default::default(),
 710            line_comments: Default::default(),
 711            block_comment: Default::default(),
 712            scope_opt_in_language_servers: Default::default(),
 713            overrides: Default::default(),
 714            word_characters: Default::default(),
 715            collapsed_placeholder: Default::default(),
 716            hard_tabs: None,
 717            tab_size: None,
 718            soft_wrap: None,
 719            prettier_parser_name: None,
 720            hidden: false,
 721        }
 722    }
 723}
 724
 725fn auto_indent_using_last_non_empty_line_default() -> bool {
 726    true
 727}
 728
 729fn deserialize_regex<'de, D: Deserializer<'de>>(d: D) -> Result<Option<Regex>, D::Error> {
 730    let source = Option::<String>::deserialize(d)?;
 731    if let Some(source) = source {
 732        Ok(Some(regex::Regex::new(&source).map_err(de::Error::custom)?))
 733    } else {
 734        Ok(None)
 735    }
 736}
 737
 738fn regex_json_schema(_: &mut SchemaGenerator) -> Schema {
 739    Schema::Object(SchemaObject {
 740        instance_type: Some(InstanceType::String.into()),
 741        ..Default::default()
 742    })
 743}
 744
 745fn serialize_regex<S>(regex: &Option<Regex>, serializer: S) -> Result<S::Ok, S::Error>
 746where
 747    S: Serializer,
 748{
 749    match regex {
 750        Some(regex) => serializer.serialize_str(regex.as_str()),
 751        None => serializer.serialize_none(),
 752    }
 753}
 754
 755#[doc(hidden)]
 756#[cfg(any(test, feature = "test-support"))]
 757pub struct FakeLspAdapter {
 758    pub name: &'static str,
 759    pub initialization_options: Option<Value>,
 760    pub prettier_plugins: Vec<&'static str>,
 761    pub disk_based_diagnostics_progress_token: Option<String>,
 762    pub disk_based_diagnostics_sources: Vec<String>,
 763    pub language_server_binary: LanguageServerBinary,
 764
 765    pub capabilities: lsp::ServerCapabilities,
 766    pub initializer: Option<Box<dyn 'static + Send + Sync + Fn(&mut lsp::FakeLanguageServer)>>,
 767    pub label_for_completion: Option<
 768        Box<
 769            dyn 'static
 770                + Send
 771                + Sync
 772                + Fn(&lsp::CompletionItem, &Arc<Language>) -> Option<CodeLabel>,
 773        >,
 774    >,
 775}
 776
 777/// Configuration of handling bracket pairs for a given language.
 778///
 779/// This struct includes settings for defining which pairs of characters are considered brackets and
 780/// also specifies any language-specific scopes where these pairs should be ignored for bracket matching purposes.
 781#[derive(Clone, Debug, Default, JsonSchema)]
 782pub struct BracketPairConfig {
 783    /// A list of character pairs that should be treated as brackets in the context of a given language.
 784    pub pairs: Vec<BracketPair>,
 785    /// A list of tree-sitter scopes for which a given bracket should not be active.
 786    /// N-th entry in `[Self::disabled_scopes_by_bracket_ix]` contains a list of disabled scopes for an n-th entry in `[Self::pairs]`
 787    #[serde(skip)]
 788    pub disabled_scopes_by_bracket_ix: Vec<Vec<String>>,
 789}
 790
 791fn bracket_pair_config_json_schema(gen: &mut SchemaGenerator) -> Schema {
 792    Option::<Vec<BracketPairContent>>::json_schema(gen)
 793}
 794
 795#[derive(Deserialize, JsonSchema)]
 796pub struct BracketPairContent {
 797    #[serde(flatten)]
 798    pub bracket_pair: BracketPair,
 799    #[serde(default)]
 800    pub not_in: Vec<String>,
 801}
 802
 803impl<'de> Deserialize<'de> for BracketPairConfig {
 804    fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
 805    where
 806        D: Deserializer<'de>,
 807    {
 808        let result = Vec::<BracketPairContent>::deserialize(deserializer)?;
 809        let mut brackets = Vec::with_capacity(result.len());
 810        let mut disabled_scopes_by_bracket_ix = Vec::with_capacity(result.len());
 811        for entry in result {
 812            brackets.push(entry.bracket_pair);
 813            disabled_scopes_by_bracket_ix.push(entry.not_in);
 814        }
 815
 816        Ok(BracketPairConfig {
 817            pairs: brackets,
 818            disabled_scopes_by_bracket_ix,
 819        })
 820    }
 821}
 822
 823/// Describes a single bracket pair and how an editor should react to e.g. inserting
 824/// an opening bracket or to a newline character insertion in between `start` and `end` characters.
 825#[derive(Clone, Debug, Default, Deserialize, PartialEq, JsonSchema)]
 826pub struct BracketPair {
 827    /// Starting substring for a bracket.
 828    pub start: String,
 829    /// Ending substring for a bracket.
 830    pub end: String,
 831    /// True if `end` should be automatically inserted right after `start` characters.
 832    pub close: bool,
 833    /// True if selected text should be surrounded by `start` and `end` characters.
 834    #[serde(default = "default_true")]
 835    pub surround: bool,
 836    /// True if an extra newline should be inserted while the cursor is in the middle
 837    /// of that bracket pair.
 838    pub newline: bool,
 839}
 840
 841#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
 842pub(crate) struct LanguageId(usize);
 843
 844impl LanguageId {
 845    pub(crate) fn new() -> Self {
 846        Self(NEXT_LANGUAGE_ID.fetch_add(1, SeqCst))
 847    }
 848}
 849
 850pub struct Language {
 851    pub(crate) id: LanguageId,
 852    pub(crate) config: LanguageConfig,
 853    pub(crate) grammar: Option<Arc<Grammar>>,
 854    pub(crate) context_provider: Option<Arc<dyn ContextProvider>>,
 855    pub(crate) toolchain: Option<Arc<dyn ToolchainLister>>,
 856}
 857
 858#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
 859pub struct GrammarId(pub usize);
 860
 861impl GrammarId {
 862    pub(crate) fn new() -> Self {
 863        Self(NEXT_GRAMMAR_ID.fetch_add(1, SeqCst))
 864    }
 865}
 866
 867pub struct Grammar {
 868    id: GrammarId,
 869    pub ts_language: tree_sitter::Language,
 870    pub(crate) error_query: Query,
 871    pub(crate) highlights_query: Option<Query>,
 872    pub(crate) brackets_config: Option<BracketConfig>,
 873    pub(crate) redactions_config: Option<RedactionConfig>,
 874    pub(crate) runnable_config: Option<RunnableConfig>,
 875    pub(crate) indents_config: Option<IndentConfig>,
 876    pub outline_config: Option<OutlineConfig>,
 877    pub text_object_config: Option<TextObjectConfig>,
 878    pub embedding_config: Option<EmbeddingConfig>,
 879    pub(crate) injection_config: Option<InjectionConfig>,
 880    pub(crate) override_config: Option<OverrideConfig>,
 881    pub(crate) highlight_map: Mutex<HighlightMap>,
 882}
 883
 884struct IndentConfig {
 885    query: Query,
 886    indent_capture_ix: u32,
 887    start_capture_ix: Option<u32>,
 888    end_capture_ix: Option<u32>,
 889    outdent_capture_ix: Option<u32>,
 890}
 891
 892pub struct OutlineConfig {
 893    pub query: Query,
 894    pub item_capture_ix: u32,
 895    pub name_capture_ix: u32,
 896    pub context_capture_ix: Option<u32>,
 897    pub extra_context_capture_ix: Option<u32>,
 898    pub open_capture_ix: Option<u32>,
 899    pub close_capture_ix: Option<u32>,
 900    pub annotation_capture_ix: Option<u32>,
 901}
 902
 903#[derive(Debug, Clone, Copy, PartialEq)]
 904pub enum TextObject {
 905    InsideFunction,
 906    AroundFunction,
 907    InsideClass,
 908    AroundClass,
 909    InsideComment,
 910    AroundComment,
 911}
 912
 913impl TextObject {
 914    pub fn from_capture_name(name: &str) -> Option<TextObject> {
 915        match name {
 916            "function.inside" => Some(TextObject::InsideFunction),
 917            "function.around" => Some(TextObject::AroundFunction),
 918            "class.inside" => Some(TextObject::InsideClass),
 919            "class.around" => Some(TextObject::AroundClass),
 920            "comment.inside" => Some(TextObject::InsideComment),
 921            "comment.around" => Some(TextObject::AroundComment),
 922            _ => None,
 923        }
 924    }
 925
 926    pub fn around(&self) -> Option<Self> {
 927        match self {
 928            TextObject::InsideFunction => Some(TextObject::AroundFunction),
 929            TextObject::InsideClass => Some(TextObject::AroundClass),
 930            TextObject::InsideComment => Some(TextObject::AroundComment),
 931            _ => None,
 932        }
 933    }
 934}
 935
 936pub struct TextObjectConfig {
 937    pub query: Query,
 938    pub text_objects_by_capture_ix: Vec<(u32, TextObject)>,
 939}
 940
 941#[derive(Debug)]
 942pub struct EmbeddingConfig {
 943    pub query: Query,
 944    pub item_capture_ix: u32,
 945    pub name_capture_ix: Option<u32>,
 946    pub context_capture_ix: Option<u32>,
 947    pub collapse_capture_ix: Option<u32>,
 948    pub keep_capture_ix: Option<u32>,
 949}
 950
 951struct InjectionConfig {
 952    query: Query,
 953    content_capture_ix: u32,
 954    language_capture_ix: Option<u32>,
 955    patterns: Vec<InjectionPatternConfig>,
 956}
 957
 958struct RedactionConfig {
 959    pub query: Query,
 960    pub redaction_capture_ix: u32,
 961}
 962
 963#[derive(Clone, Debug, PartialEq)]
 964enum RunnableCapture {
 965    Named(SharedString),
 966    Run,
 967}
 968
 969struct RunnableConfig {
 970    pub query: Query,
 971    /// A mapping from capture indice to capture kind
 972    pub extra_captures: Vec<RunnableCapture>,
 973}
 974
 975struct OverrideConfig {
 976    query: Query,
 977    values: HashMap<u32, OverrideEntry>,
 978}
 979
 980#[derive(Debug)]
 981struct OverrideEntry {
 982    name: String,
 983    range_is_inclusive: bool,
 984    value: LanguageConfigOverride,
 985}
 986
 987#[derive(Default, Clone)]
 988struct InjectionPatternConfig {
 989    language: Option<Box<str>>,
 990    combined: bool,
 991}
 992
 993struct BracketConfig {
 994    query: Query,
 995    open_capture_ix: u32,
 996    close_capture_ix: u32,
 997}
 998
 999impl Language {
1000    pub fn new(config: LanguageConfig, ts_language: Option<tree_sitter::Language>) -> Self {
1001        Self::new_with_id(LanguageId::new(), config, ts_language)
1002    }
1003
1004    fn new_with_id(
1005        id: LanguageId,
1006        config: LanguageConfig,
1007        ts_language: Option<tree_sitter::Language>,
1008    ) -> Self {
1009        Self {
1010            id,
1011            config,
1012            grammar: ts_language.map(|ts_language| {
1013                Arc::new(Grammar {
1014                    id: GrammarId::new(),
1015                    highlights_query: None,
1016                    brackets_config: None,
1017                    outline_config: None,
1018                    text_object_config: None,
1019                    embedding_config: None,
1020                    indents_config: None,
1021                    injection_config: None,
1022                    override_config: None,
1023                    redactions_config: None,
1024                    runnable_config: None,
1025                    error_query: Query::new(&ts_language, "(ERROR) @error").unwrap(),
1026                    ts_language,
1027                    highlight_map: Default::default(),
1028                })
1029            }),
1030            context_provider: None,
1031            toolchain: None,
1032        }
1033    }
1034
1035    pub fn with_context_provider(mut self, provider: Option<Arc<dyn ContextProvider>>) -> Self {
1036        self.context_provider = provider;
1037        self
1038    }
1039
1040    pub fn with_toolchain_lister(mut self, provider: Option<Arc<dyn ToolchainLister>>) -> Self {
1041        self.toolchain = provider;
1042        self
1043    }
1044
1045    pub fn with_queries(mut self, queries: LanguageQueries) -> Result<Self> {
1046        if let Some(query) = queries.highlights {
1047            self = self
1048                .with_highlights_query(query.as_ref())
1049                .context("Error loading highlights query")?;
1050        }
1051        if let Some(query) = queries.brackets {
1052            self = self
1053                .with_brackets_query(query.as_ref())
1054                .context("Error loading brackets query")?;
1055        }
1056        if let Some(query) = queries.indents {
1057            self = self
1058                .with_indents_query(query.as_ref())
1059                .context("Error loading indents query")?;
1060        }
1061        if let Some(query) = queries.outline {
1062            self = self
1063                .with_outline_query(query.as_ref())
1064                .context("Error loading outline query")?;
1065        }
1066        if let Some(query) = queries.embedding {
1067            self = self
1068                .with_embedding_query(query.as_ref())
1069                .context("Error loading embedding query")?;
1070        }
1071        if let Some(query) = queries.injections {
1072            self = self
1073                .with_injection_query(query.as_ref())
1074                .context("Error loading injection query")?;
1075        }
1076        if let Some(query) = queries.overrides {
1077            self = self
1078                .with_override_query(query.as_ref())
1079                .context("Error loading override query")?;
1080        }
1081        if let Some(query) = queries.redactions {
1082            self = self
1083                .with_redaction_query(query.as_ref())
1084                .context("Error loading redaction query")?;
1085        }
1086        if let Some(query) = queries.runnables {
1087            self = self
1088                .with_runnable_query(query.as_ref())
1089                .context("Error loading runnables query")?;
1090        }
1091        if let Some(query) = queries.text_objects {
1092            self = self
1093                .with_text_object_query(query.as_ref())
1094                .context("Error loading textobject query")?;
1095        }
1096        Ok(self)
1097    }
1098
1099    pub fn with_highlights_query(mut self, source: &str) -> Result<Self> {
1100        let grammar = self
1101            .grammar_mut()
1102            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1103        grammar.highlights_query = Some(Query::new(&grammar.ts_language, source)?);
1104        Ok(self)
1105    }
1106
1107    pub fn with_runnable_query(mut self, source: &str) -> Result<Self> {
1108        let grammar = self
1109            .grammar_mut()
1110            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1111
1112        let query = Query::new(&grammar.ts_language, source)?;
1113        let mut extra_captures = Vec::with_capacity(query.capture_names().len());
1114
1115        for name in query.capture_names().iter() {
1116            let kind = if *name == "run" {
1117                RunnableCapture::Run
1118            } else {
1119                RunnableCapture::Named(name.to_string().into())
1120            };
1121            extra_captures.push(kind);
1122        }
1123
1124        grammar.runnable_config = Some(RunnableConfig {
1125            extra_captures,
1126            query,
1127        });
1128
1129        Ok(self)
1130    }
1131
1132    pub fn with_outline_query(mut self, source: &str) -> Result<Self> {
1133        let grammar = self
1134            .grammar_mut()
1135            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1136        let query = Query::new(&grammar.ts_language, source)?;
1137        let mut item_capture_ix = None;
1138        let mut name_capture_ix = None;
1139        let mut context_capture_ix = None;
1140        let mut extra_context_capture_ix = None;
1141        let mut open_capture_ix = None;
1142        let mut close_capture_ix = None;
1143        let mut annotation_capture_ix = None;
1144        get_capture_indices(
1145            &query,
1146            &mut [
1147                ("item", &mut item_capture_ix),
1148                ("name", &mut name_capture_ix),
1149                ("context", &mut context_capture_ix),
1150                ("context.extra", &mut extra_context_capture_ix),
1151                ("open", &mut open_capture_ix),
1152                ("close", &mut close_capture_ix),
1153                ("annotation", &mut annotation_capture_ix),
1154            ],
1155        );
1156        if let Some((item_capture_ix, name_capture_ix)) = item_capture_ix.zip(name_capture_ix) {
1157            grammar.outline_config = Some(OutlineConfig {
1158                query,
1159                item_capture_ix,
1160                name_capture_ix,
1161                context_capture_ix,
1162                extra_context_capture_ix,
1163                open_capture_ix,
1164                close_capture_ix,
1165                annotation_capture_ix,
1166            });
1167        }
1168        Ok(self)
1169    }
1170
1171    pub fn with_text_object_query(mut self, source: &str) -> Result<Self> {
1172        let grammar = self
1173            .grammar_mut()
1174            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1175        let query = Query::new(&grammar.ts_language, source)?;
1176
1177        let mut text_objects_by_capture_ix = Vec::new();
1178        for (ix, name) in query.capture_names().iter().enumerate() {
1179            if let Some(text_object) = TextObject::from_capture_name(name) {
1180                text_objects_by_capture_ix.push((ix as u32, text_object));
1181            }
1182        }
1183
1184        grammar.text_object_config = Some(TextObjectConfig {
1185            query,
1186            text_objects_by_capture_ix,
1187        });
1188        Ok(self)
1189    }
1190
1191    pub fn with_embedding_query(mut self, source: &str) -> Result<Self> {
1192        let grammar = self
1193            .grammar_mut()
1194            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1195        let query = Query::new(&grammar.ts_language, source)?;
1196        let mut item_capture_ix = None;
1197        let mut name_capture_ix = None;
1198        let mut context_capture_ix = None;
1199        let mut collapse_capture_ix = None;
1200        let mut keep_capture_ix = None;
1201        get_capture_indices(
1202            &query,
1203            &mut [
1204                ("item", &mut item_capture_ix),
1205                ("name", &mut name_capture_ix),
1206                ("context", &mut context_capture_ix),
1207                ("keep", &mut keep_capture_ix),
1208                ("collapse", &mut collapse_capture_ix),
1209            ],
1210        );
1211        if let Some(item_capture_ix) = item_capture_ix {
1212            grammar.embedding_config = Some(EmbeddingConfig {
1213                query,
1214                item_capture_ix,
1215                name_capture_ix,
1216                context_capture_ix,
1217                collapse_capture_ix,
1218                keep_capture_ix,
1219            });
1220        }
1221        Ok(self)
1222    }
1223
1224    pub fn with_brackets_query(mut self, source: &str) -> Result<Self> {
1225        let grammar = self
1226            .grammar_mut()
1227            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1228        let query = Query::new(&grammar.ts_language, source)?;
1229        let mut open_capture_ix = None;
1230        let mut close_capture_ix = None;
1231        get_capture_indices(
1232            &query,
1233            &mut [
1234                ("open", &mut open_capture_ix),
1235                ("close", &mut close_capture_ix),
1236            ],
1237        );
1238        if let Some((open_capture_ix, close_capture_ix)) = open_capture_ix.zip(close_capture_ix) {
1239            grammar.brackets_config = Some(BracketConfig {
1240                query,
1241                open_capture_ix,
1242                close_capture_ix,
1243            });
1244        }
1245        Ok(self)
1246    }
1247
1248    pub fn with_indents_query(mut self, source: &str) -> Result<Self> {
1249        let grammar = self
1250            .grammar_mut()
1251            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1252        let query = Query::new(&grammar.ts_language, source)?;
1253        let mut indent_capture_ix = None;
1254        let mut start_capture_ix = None;
1255        let mut end_capture_ix = None;
1256        let mut outdent_capture_ix = None;
1257        get_capture_indices(
1258            &query,
1259            &mut [
1260                ("indent", &mut indent_capture_ix),
1261                ("start", &mut start_capture_ix),
1262                ("end", &mut end_capture_ix),
1263                ("outdent", &mut outdent_capture_ix),
1264            ],
1265        );
1266        if let Some(indent_capture_ix) = indent_capture_ix {
1267            grammar.indents_config = Some(IndentConfig {
1268                query,
1269                indent_capture_ix,
1270                start_capture_ix,
1271                end_capture_ix,
1272                outdent_capture_ix,
1273            });
1274        }
1275        Ok(self)
1276    }
1277
1278    pub fn with_injection_query(mut self, source: &str) -> Result<Self> {
1279        let grammar = self
1280            .grammar_mut()
1281            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1282        let query = Query::new(&grammar.ts_language, source)?;
1283        let mut language_capture_ix = None;
1284        let mut injection_language_capture_ix = None;
1285        let mut content_capture_ix = None;
1286        let mut injection_content_capture_ix = None;
1287        get_capture_indices(
1288            &query,
1289            &mut [
1290                ("language", &mut language_capture_ix),
1291                ("injection.language", &mut injection_language_capture_ix),
1292                ("content", &mut content_capture_ix),
1293                ("injection.content", &mut injection_content_capture_ix),
1294            ],
1295        );
1296        language_capture_ix = match (language_capture_ix, injection_language_capture_ix) {
1297            (None, Some(ix)) => Some(ix),
1298            (Some(_), Some(_)) => {
1299                return Err(anyhow!(
1300                    "both language and injection.language captures are present"
1301                ));
1302            }
1303            _ => language_capture_ix,
1304        };
1305        content_capture_ix = match (content_capture_ix, injection_content_capture_ix) {
1306            (None, Some(ix)) => Some(ix),
1307            (Some(_), Some(_)) => {
1308                return Err(anyhow!(
1309                    "both content and injection.content captures are present"
1310                ));
1311            }
1312            _ => content_capture_ix,
1313        };
1314        let patterns = (0..query.pattern_count())
1315            .map(|ix| {
1316                let mut config = InjectionPatternConfig::default();
1317                for setting in query.property_settings(ix) {
1318                    match setting.key.as_ref() {
1319                        "language" | "injection.language" => {
1320                            config.language.clone_from(&setting.value);
1321                        }
1322                        "combined" | "injection.combined" => {
1323                            config.combined = true;
1324                        }
1325                        _ => {}
1326                    }
1327                }
1328                config
1329            })
1330            .collect();
1331        if let Some(content_capture_ix) = content_capture_ix {
1332            grammar.injection_config = Some(InjectionConfig {
1333                query,
1334                language_capture_ix,
1335                content_capture_ix,
1336                patterns,
1337            });
1338        }
1339        Ok(self)
1340    }
1341
1342    pub fn with_override_query(mut self, source: &str) -> anyhow::Result<Self> {
1343        let query = {
1344            let grammar = self
1345                .grammar
1346                .as_ref()
1347                .ok_or_else(|| anyhow!("no grammar for language"))?;
1348            Query::new(&grammar.ts_language, source)?
1349        };
1350
1351        let mut override_configs_by_id = HashMap::default();
1352        for (ix, mut name) in query.capture_names().iter().copied().enumerate() {
1353            let mut range_is_inclusive = false;
1354            if name.starts_with('_') {
1355                continue;
1356            }
1357            if let Some(prefix) = name.strip_suffix(".inclusive") {
1358                name = prefix;
1359                range_is_inclusive = true;
1360            }
1361
1362            let value = self.config.overrides.get(name).cloned().unwrap_or_default();
1363            for server_name in &value.opt_into_language_servers {
1364                if !self
1365                    .config
1366                    .scope_opt_in_language_servers
1367                    .contains(server_name)
1368                {
1369                    util::debug_panic!("Server {server_name:?} has been opted-in by scope {name:?} but has not been marked as an opt-in server");
1370                }
1371            }
1372
1373            override_configs_by_id.insert(
1374                ix as u32,
1375                OverrideEntry {
1376                    name: name.to_string(),
1377                    range_is_inclusive,
1378                    value,
1379                },
1380            );
1381        }
1382
1383        let referenced_override_names = self.config.overrides.keys().chain(
1384            self.config
1385                .brackets
1386                .disabled_scopes_by_bracket_ix
1387                .iter()
1388                .flatten(),
1389        );
1390
1391        for referenced_name in referenced_override_names {
1392            if !override_configs_by_id
1393                .values()
1394                .any(|entry| entry.name == *referenced_name)
1395            {
1396                Err(anyhow!(
1397                    "language {:?} has overrides in config not in query: {referenced_name:?}",
1398                    self.config.name
1399                ))?;
1400            }
1401        }
1402
1403        for entry in override_configs_by_id.values_mut() {
1404            entry.value.disabled_bracket_ixs = self
1405                .config
1406                .brackets
1407                .disabled_scopes_by_bracket_ix
1408                .iter()
1409                .enumerate()
1410                .filter_map(|(ix, disabled_scope_names)| {
1411                    if disabled_scope_names.contains(&entry.name) {
1412                        Some(ix as u16)
1413                    } else {
1414                        None
1415                    }
1416                })
1417                .collect();
1418        }
1419
1420        self.config.brackets.disabled_scopes_by_bracket_ix.clear();
1421
1422        let grammar = self
1423            .grammar_mut()
1424            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1425        grammar.override_config = Some(OverrideConfig {
1426            query,
1427            values: override_configs_by_id,
1428        });
1429        Ok(self)
1430    }
1431
1432    pub fn with_redaction_query(mut self, source: &str) -> anyhow::Result<Self> {
1433        let grammar = self
1434            .grammar_mut()
1435            .ok_or_else(|| anyhow!("cannot mutate grammar"))?;
1436
1437        let query = Query::new(&grammar.ts_language, source)?;
1438        let mut redaction_capture_ix = None;
1439        get_capture_indices(&query, &mut [("redact", &mut redaction_capture_ix)]);
1440
1441        if let Some(redaction_capture_ix) = redaction_capture_ix {
1442            grammar.redactions_config = Some(RedactionConfig {
1443                query,
1444                redaction_capture_ix,
1445            });
1446        }
1447
1448        Ok(self)
1449    }
1450
1451    fn grammar_mut(&mut self) -> Option<&mut Grammar> {
1452        Arc::get_mut(self.grammar.as_mut()?)
1453    }
1454
1455    pub fn name(&self) -> LanguageName {
1456        self.config.name.clone()
1457    }
1458
1459    pub fn code_fence_block_name(&self) -> Arc<str> {
1460        self.config
1461            .code_fence_block_name
1462            .clone()
1463            .unwrap_or_else(|| self.config.name.as_ref().to_lowercase().into())
1464    }
1465
1466    pub fn context_provider(&self) -> Option<Arc<dyn ContextProvider>> {
1467        self.context_provider.clone()
1468    }
1469
1470    pub fn toolchain_lister(&self) -> Option<Arc<dyn ToolchainLister>> {
1471        self.toolchain.clone()
1472    }
1473
1474    pub fn highlight_text<'a>(
1475        self: &'a Arc<Self>,
1476        text: &'a Rope,
1477        range: Range<usize>,
1478    ) -> Vec<(Range<usize>, HighlightId)> {
1479        let mut result = Vec::new();
1480        if let Some(grammar) = &self.grammar {
1481            let tree = grammar.parse_text(text, None);
1482            let captures =
1483                SyntaxSnapshot::single_tree_captures(range.clone(), text, &tree, self, |grammar| {
1484                    grammar.highlights_query.as_ref()
1485                });
1486            let highlight_maps = vec![grammar.highlight_map()];
1487            let mut offset = 0;
1488            for chunk in
1489                BufferChunks::new(text, range, Some((captures, highlight_maps)), false, None)
1490            {
1491                let end_offset = offset + chunk.text.len();
1492                if let Some(highlight_id) = chunk.syntax_highlight_id {
1493                    if !highlight_id.is_default() {
1494                        result.push((offset..end_offset, highlight_id));
1495                    }
1496                }
1497                offset = end_offset;
1498            }
1499        }
1500        result
1501    }
1502
1503    pub fn path_suffixes(&self) -> &[String] {
1504        &self.config.matcher.path_suffixes
1505    }
1506
1507    pub fn should_autoclose_before(&self, c: char) -> bool {
1508        c.is_whitespace() || self.config.autoclose_before.contains(c)
1509    }
1510
1511    pub fn set_theme(&self, theme: &SyntaxTheme) {
1512        if let Some(grammar) = self.grammar.as_ref() {
1513            if let Some(highlights_query) = &grammar.highlights_query {
1514                *grammar.highlight_map.lock() =
1515                    HighlightMap::new(highlights_query.capture_names(), theme);
1516            }
1517        }
1518    }
1519
1520    pub fn grammar(&self) -> Option<&Arc<Grammar>> {
1521        self.grammar.as_ref()
1522    }
1523
1524    pub fn default_scope(self: &Arc<Self>) -> LanguageScope {
1525        LanguageScope {
1526            language: self.clone(),
1527            override_id: None,
1528        }
1529    }
1530
1531    pub fn lsp_id(&self) -> String {
1532        self.config.name.lsp_id()
1533    }
1534
1535    pub fn prettier_parser_name(&self) -> Option<&str> {
1536        self.config.prettier_parser_name.as_deref()
1537    }
1538
1539    pub fn config(&self) -> &LanguageConfig {
1540        &self.config
1541    }
1542}
1543
1544impl LanguageScope {
1545    pub fn path_suffixes(&self) -> &[String] {
1546        &self.language.path_suffixes()
1547    }
1548
1549    pub fn language_name(&self) -> LanguageName {
1550        self.language.config.name.clone()
1551    }
1552
1553    pub fn collapsed_placeholder(&self) -> &str {
1554        self.language.config.collapsed_placeholder.as_ref()
1555    }
1556
1557    /// Returns line prefix that is inserted in e.g. line continuations or
1558    /// in `toggle comments` action.
1559    pub fn line_comment_prefixes(&self) -> &[Arc<str>] {
1560        Override::as_option(
1561            self.config_override().map(|o| &o.line_comments),
1562            Some(&self.language.config.line_comments),
1563        )
1564        .map_or([].as_slice(), |e| e.as_slice())
1565    }
1566
1567    pub fn block_comment_delimiters(&self) -> Option<(&Arc<str>, &Arc<str>)> {
1568        Override::as_option(
1569            self.config_override().map(|o| &o.block_comment),
1570            self.language.config.block_comment.as_ref(),
1571        )
1572        .map(|e| (&e.0, &e.1))
1573    }
1574
1575    /// Returns a list of language-specific word characters.
1576    ///
1577    /// By default, Zed treats alphanumeric characters (and '_') as word characters for
1578    /// the purpose of actions like 'move to next word end` or whole-word search.
1579    /// It additionally accounts for language's additional word characters.
1580    pub fn word_characters(&self) -> Option<&HashSet<char>> {
1581        Override::as_option(
1582            self.config_override().map(|o| &o.word_characters),
1583            Some(&self.language.config.word_characters),
1584        )
1585    }
1586
1587    /// Returns a list of bracket pairs for a given language with an additional
1588    /// piece of information about whether the particular bracket pair is currently active for a given language.
1589    pub fn brackets(&self) -> impl Iterator<Item = (&BracketPair, bool)> {
1590        let mut disabled_ids = self
1591            .config_override()
1592            .map_or(&[] as _, |o| o.disabled_bracket_ixs.as_slice());
1593        self.language
1594            .config
1595            .brackets
1596            .pairs
1597            .iter()
1598            .enumerate()
1599            .map(move |(ix, bracket)| {
1600                let mut is_enabled = true;
1601                if let Some(next_disabled_ix) = disabled_ids.first() {
1602                    if ix == *next_disabled_ix as usize {
1603                        disabled_ids = &disabled_ids[1..];
1604                        is_enabled = false;
1605                    }
1606                }
1607                (bracket, is_enabled)
1608            })
1609    }
1610
1611    pub fn should_autoclose_before(&self, c: char) -> bool {
1612        c.is_whitespace() || self.language.config.autoclose_before.contains(c)
1613    }
1614
1615    pub fn language_allowed(&self, name: &LanguageServerName) -> bool {
1616        let config = &self.language.config;
1617        let opt_in_servers = &config.scope_opt_in_language_servers;
1618        if opt_in_servers.iter().any(|o| *o == *name) {
1619            if let Some(over) = self.config_override() {
1620                over.opt_into_language_servers.iter().any(|o| *o == *name)
1621            } else {
1622                false
1623            }
1624        } else {
1625            true
1626        }
1627    }
1628
1629    pub fn override_name(&self) -> Option<&str> {
1630        let id = self.override_id?;
1631        let grammar = self.language.grammar.as_ref()?;
1632        let override_config = grammar.override_config.as_ref()?;
1633        override_config.values.get(&id).map(|e| e.name.as_str())
1634    }
1635
1636    fn config_override(&self) -> Option<&LanguageConfigOverride> {
1637        let id = self.override_id?;
1638        let grammar = self.language.grammar.as_ref()?;
1639        let override_config = grammar.override_config.as_ref()?;
1640        override_config.values.get(&id).map(|e| &e.value)
1641    }
1642}
1643
1644impl Hash for Language {
1645    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
1646        self.id.hash(state)
1647    }
1648}
1649
1650impl PartialEq for Language {
1651    fn eq(&self, other: &Self) -> bool {
1652        self.id.eq(&other.id)
1653    }
1654}
1655
1656impl Eq for Language {}
1657
1658impl Debug for Language {
1659    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1660        f.debug_struct("Language")
1661            .field("name", &self.config.name)
1662            .finish()
1663    }
1664}
1665
1666impl Grammar {
1667    pub fn id(&self) -> GrammarId {
1668        self.id
1669    }
1670
1671    fn parse_text(&self, text: &Rope, old_tree: Option<Tree>) -> Tree {
1672        with_parser(|parser| {
1673            parser
1674                .set_language(&self.ts_language)
1675                .expect("incompatible grammar");
1676            let mut chunks = text.chunks_in_range(0..text.len());
1677            parser
1678                .parse_with(
1679                    &mut move |offset, _| {
1680                        chunks.seek(offset);
1681                        chunks.next().unwrap_or("").as_bytes()
1682                    },
1683                    old_tree.as_ref(),
1684                )
1685                .unwrap()
1686        })
1687    }
1688
1689    pub fn highlight_map(&self) -> HighlightMap {
1690        self.highlight_map.lock().clone()
1691    }
1692
1693    pub fn highlight_id_for_name(&self, name: &str) -> Option<HighlightId> {
1694        let capture_id = self
1695            .highlights_query
1696            .as_ref()?
1697            .capture_index_for_name(name)?;
1698        Some(self.highlight_map.lock().get(capture_id))
1699    }
1700}
1701
1702impl CodeLabel {
1703    pub fn fallback_for_completion(
1704        item: &lsp::CompletionItem,
1705        language: Option<&Language>,
1706    ) -> Self {
1707        let highlight_id = item.kind.and_then(|kind| {
1708            let grammar = language?.grammar()?;
1709            use lsp::CompletionItemKind as Kind;
1710            match kind {
1711                Kind::CLASS => grammar.highlight_id_for_name("type"),
1712                Kind::CONSTANT => grammar.highlight_id_for_name("constant"),
1713                Kind::CONSTRUCTOR => grammar.highlight_id_for_name("constructor"),
1714                Kind::ENUM => grammar
1715                    .highlight_id_for_name("enum")
1716                    .or_else(|| grammar.highlight_id_for_name("type")),
1717                Kind::FIELD => grammar.highlight_id_for_name("property"),
1718                Kind::FUNCTION => grammar.highlight_id_for_name("function"),
1719                Kind::INTERFACE => grammar.highlight_id_for_name("type"),
1720                Kind::METHOD => grammar
1721                    .highlight_id_for_name("function.method")
1722                    .or_else(|| grammar.highlight_id_for_name("function")),
1723                Kind::OPERATOR => grammar.highlight_id_for_name("operator"),
1724                Kind::PROPERTY => grammar.highlight_id_for_name("property"),
1725                Kind::STRUCT => grammar.highlight_id_for_name("type"),
1726                Kind::VARIABLE => grammar.highlight_id_for_name("variable"),
1727                Kind::KEYWORD => grammar.highlight_id_for_name("keyword"),
1728                _ => None,
1729            }
1730        });
1731
1732        let label = &item.label;
1733        let label_length = label.len();
1734        let runs = highlight_id
1735            .map(|highlight_id| vec![(0..label_length, highlight_id)])
1736            .unwrap_or_default();
1737        let text = if let Some(detail) = &item.detail {
1738            format!("{label} {detail}")
1739        } else if let Some(description) = item
1740            .label_details
1741            .as_ref()
1742            .and_then(|label_details| label_details.description.as_ref())
1743        {
1744            format!("{label} {description}")
1745        } else {
1746            label.clone()
1747        };
1748        Self {
1749            text,
1750            runs,
1751            filter_range: 0..label_length,
1752        }
1753    }
1754
1755    pub fn plain(text: String, filter_text: Option<&str>) -> Self {
1756        let mut result = Self {
1757            runs: Vec::new(),
1758            filter_range: 0..text.len(),
1759            text,
1760        };
1761        if let Some(filter_text) = filter_text {
1762            if let Some(ix) = result.text.find(filter_text) {
1763                result.filter_range = ix..ix + filter_text.len();
1764            }
1765        }
1766        result
1767    }
1768
1769    pub fn push_str(&mut self, text: &str, highlight: Option<HighlightId>) {
1770        let start_ix = self.text.len();
1771        self.text.push_str(text);
1772        let end_ix = self.text.len();
1773        if let Some(highlight) = highlight {
1774            self.runs.push((start_ix..end_ix, highlight));
1775        }
1776    }
1777
1778    pub fn text(&self) -> &str {
1779        self.text.as_str()
1780    }
1781
1782    pub fn filter_text(&self) -> &str {
1783        &self.text[self.filter_range.clone()]
1784    }
1785}
1786
1787impl From<String> for CodeLabel {
1788    fn from(value: String) -> Self {
1789        Self::plain(value, None)
1790    }
1791}
1792
1793impl From<&str> for CodeLabel {
1794    fn from(value: &str) -> Self {
1795        Self::plain(value.to_string(), None)
1796    }
1797}
1798
1799impl Ord for LanguageMatcher {
1800    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
1801        self.path_suffixes.cmp(&other.path_suffixes).then_with(|| {
1802            self.first_line_pattern
1803                .as_ref()
1804                .map(Regex::as_str)
1805                .cmp(&other.first_line_pattern.as_ref().map(Regex::as_str))
1806        })
1807    }
1808}
1809
1810impl PartialOrd for LanguageMatcher {
1811    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
1812        Some(self.cmp(other))
1813    }
1814}
1815
1816impl Eq for LanguageMatcher {}
1817
1818impl PartialEq for LanguageMatcher {
1819    fn eq(&self, other: &Self) -> bool {
1820        self.path_suffixes == other.path_suffixes
1821            && self.first_line_pattern.as_ref().map(Regex::as_str)
1822                == other.first_line_pattern.as_ref().map(Regex::as_str)
1823    }
1824}
1825
1826#[cfg(any(test, feature = "test-support"))]
1827impl Default for FakeLspAdapter {
1828    fn default() -> Self {
1829        Self {
1830            name: "the-fake-language-server",
1831            capabilities: lsp::LanguageServer::full_capabilities(),
1832            initializer: None,
1833            disk_based_diagnostics_progress_token: None,
1834            initialization_options: None,
1835            disk_based_diagnostics_sources: Vec::new(),
1836            prettier_plugins: Vec::new(),
1837            language_server_binary: LanguageServerBinary {
1838                path: "/the/fake/lsp/path".into(),
1839                arguments: vec![],
1840                env: Default::default(),
1841            },
1842            label_for_completion: None,
1843        }
1844    }
1845}
1846
1847#[cfg(any(test, feature = "test-support"))]
1848#[async_trait(?Send)]
1849impl LspAdapter for FakeLspAdapter {
1850    fn name(&self) -> LanguageServerName {
1851        LanguageServerName(self.name.into())
1852    }
1853
1854    async fn check_if_user_installed(
1855        &self,
1856        _: &dyn LspAdapterDelegate,
1857        _: Arc<dyn LanguageToolchainStore>,
1858        _: &AsyncApp,
1859    ) -> Option<LanguageServerBinary> {
1860        Some(self.language_server_binary.clone())
1861    }
1862
1863    fn get_language_server_command<'a>(
1864        self: Arc<Self>,
1865        _: Arc<dyn LspAdapterDelegate>,
1866        _: Arc<dyn LanguageToolchainStore>,
1867        _: LanguageServerBinaryOptions,
1868        _: futures::lock::MutexGuard<'a, Option<LanguageServerBinary>>,
1869        _: &'a mut AsyncApp,
1870    ) -> Pin<Box<dyn 'a + Future<Output = Result<LanguageServerBinary>>>> {
1871        async move { Ok(self.language_server_binary.clone()) }.boxed_local()
1872    }
1873
1874    async fn fetch_latest_server_version(
1875        &self,
1876        _: &dyn LspAdapterDelegate,
1877    ) -> Result<Box<dyn 'static + Send + Any>> {
1878        unreachable!();
1879    }
1880
1881    async fn fetch_server_binary(
1882        &self,
1883        _: Box<dyn 'static + Send + Any>,
1884        _: PathBuf,
1885        _: &dyn LspAdapterDelegate,
1886    ) -> Result<LanguageServerBinary> {
1887        unreachable!();
1888    }
1889
1890    async fn cached_server_binary(
1891        &self,
1892        _: PathBuf,
1893        _: &dyn LspAdapterDelegate,
1894    ) -> Option<LanguageServerBinary> {
1895        unreachable!();
1896    }
1897
1898    fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
1899
1900    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
1901        self.disk_based_diagnostics_sources.clone()
1902    }
1903
1904    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
1905        self.disk_based_diagnostics_progress_token.clone()
1906    }
1907
1908    async fn initialization_options(
1909        self: Arc<Self>,
1910        _: &dyn Fs,
1911        _: &Arc<dyn LspAdapterDelegate>,
1912    ) -> Result<Option<Value>> {
1913        Ok(self.initialization_options.clone())
1914    }
1915
1916    async fn label_for_completion(
1917        &self,
1918        item: &lsp::CompletionItem,
1919        language: &Arc<Language>,
1920    ) -> Option<CodeLabel> {
1921        let label_for_completion = self.label_for_completion.as_ref()?;
1922        label_for_completion(item, language)
1923    }
1924}
1925
1926fn get_capture_indices(query: &Query, captures: &mut [(&str, &mut Option<u32>)]) {
1927    for (ix, name) in query.capture_names().iter().enumerate() {
1928        for (capture_name, index) in captures.iter_mut() {
1929            if capture_name == name {
1930                **index = Some(ix as u32);
1931                break;
1932            }
1933        }
1934    }
1935}
1936
1937pub fn point_to_lsp(point: PointUtf16) -> lsp::Position {
1938    lsp::Position::new(point.row, point.column)
1939}
1940
1941pub fn point_from_lsp(point: lsp::Position) -> Unclipped<PointUtf16> {
1942    Unclipped(PointUtf16::new(point.line, point.character))
1943}
1944
1945pub fn range_to_lsp(range: Range<PointUtf16>) -> Result<lsp::Range> {
1946    if range.start > range.end {
1947        Err(anyhow!(
1948            "Inverted range provided to an LSP request: {:?}-{:?}",
1949            range.start,
1950            range.end
1951        ))
1952    } else {
1953        Ok(lsp::Range {
1954            start: point_to_lsp(range.start),
1955            end: point_to_lsp(range.end),
1956        })
1957    }
1958}
1959
1960pub fn range_from_lsp(range: lsp::Range) -> Range<Unclipped<PointUtf16>> {
1961    let mut start = point_from_lsp(range.start);
1962    let mut end = point_from_lsp(range.end);
1963    if start > end {
1964        log::warn!("range_from_lsp called with inverted range {start:?}-{end:?}");
1965        mem::swap(&mut start, &mut end);
1966    }
1967    start..end
1968}
1969
1970#[cfg(test)]
1971mod tests {
1972    use super::*;
1973    use gpui::TestAppContext;
1974
1975    #[gpui::test(iterations = 10)]
1976    async fn test_language_loading(cx: &mut TestAppContext) {
1977        let languages = LanguageRegistry::test(cx.executor());
1978        let languages = Arc::new(languages);
1979        languages.register_native_grammars([
1980            ("json", tree_sitter_json::LANGUAGE),
1981            ("rust", tree_sitter_rust::LANGUAGE),
1982        ]);
1983        languages.register_test_language(LanguageConfig {
1984            name: "JSON".into(),
1985            grammar: Some("json".into()),
1986            matcher: LanguageMatcher {
1987                path_suffixes: vec!["json".into()],
1988                ..Default::default()
1989            },
1990            ..Default::default()
1991        });
1992        languages.register_test_language(LanguageConfig {
1993            name: "Rust".into(),
1994            grammar: Some("rust".into()),
1995            matcher: LanguageMatcher {
1996                path_suffixes: vec!["rs".into()],
1997                ..Default::default()
1998            },
1999            ..Default::default()
2000        });
2001        assert_eq!(
2002            languages.language_names(),
2003            &[
2004                "JSON".to_string(),
2005                "Plain Text".to_string(),
2006                "Rust".to_string(),
2007            ]
2008        );
2009
2010        let rust1 = languages.language_for_name("Rust");
2011        let rust2 = languages.language_for_name("Rust");
2012
2013        // Ensure language is still listed even if it's being loaded.
2014        assert_eq!(
2015            languages.language_names(),
2016            &[
2017                "JSON".to_string(),
2018                "Plain Text".to_string(),
2019                "Rust".to_string(),
2020            ]
2021        );
2022
2023        let (rust1, rust2) = futures::join!(rust1, rust2);
2024        assert!(Arc::ptr_eq(&rust1.unwrap(), &rust2.unwrap()));
2025
2026        // Ensure language is still listed even after loading it.
2027        assert_eq!(
2028            languages.language_names(),
2029            &[
2030                "JSON".to_string(),
2031                "Plain Text".to_string(),
2032                "Rust".to_string(),
2033            ]
2034        );
2035
2036        // Loading an unknown language returns an error.
2037        assert!(languages.language_for_name("Unknown").await.is_err());
2038    }
2039}