rust.rs

  1use anyhow::{anyhow, bail, Context, Result};
  2use async_compression::futures::bufread::GzipDecoder;
  3use async_trait::async_trait;
  4use futures::{io::BufReader, StreamExt};
  5use gpui::AsyncAppContext;
  6pub use language::*;
  7use lazy_static::lazy_static;
  8use lsp::LanguageServerBinary;
  9use project::project_settings::ProjectSettings;
 10use regex::Regex;
 11use settings::Settings;
 12use smol::fs::{self, File};
 13use std::{
 14    any::Any,
 15    borrow::Cow,
 16    env::consts,
 17    path::{Path, PathBuf},
 18    sync::Arc,
 19};
 20use task::{TaskTemplate, TaskTemplates, TaskVariables, VariableName};
 21use util::{
 22    fs::remove_matching,
 23    github::{latest_github_release, GitHubLspBinaryVersion},
 24    maybe, ResultExt,
 25};
 26
 27pub struct RustLspAdapter;
 28
 29impl RustLspAdapter {
 30    const SERVER_NAME: &'static str = "rust-analyzer";
 31}
 32
 33#[async_trait(?Send)]
 34impl LspAdapter for RustLspAdapter {
 35    fn name(&self) -> LanguageServerName {
 36        LanguageServerName(Self::SERVER_NAME.into())
 37    }
 38
 39    async fn check_if_user_installed(
 40        &self,
 41        _delegate: &dyn LspAdapterDelegate,
 42        cx: &AsyncAppContext,
 43    ) -> Option<LanguageServerBinary> {
 44        let binary = cx
 45            .update(|cx| {
 46                ProjectSettings::get_global(cx)
 47                    .lsp
 48                    .get(Self::SERVER_NAME)
 49                    .and_then(|s| s.binary.clone())
 50            })
 51            .ok()??;
 52
 53        let path = binary.path?;
 54        Some(LanguageServerBinary {
 55            path: path.into(),
 56            arguments: binary
 57                .arguments
 58                .unwrap_or_default()
 59                .iter()
 60                .map(|arg| arg.into())
 61                .collect(),
 62            env: None,
 63        })
 64    }
 65
 66    async fn fetch_latest_server_version(
 67        &self,
 68        delegate: &dyn LspAdapterDelegate,
 69    ) -> Result<Box<dyn 'static + Send + Any>> {
 70        let release = latest_github_release(
 71            "rust-lang/rust-analyzer",
 72            true,
 73            false,
 74            delegate.http_client(),
 75        )
 76        .await?;
 77        let os = match consts::OS {
 78            "macos" => "apple-darwin",
 79            "linux" => "unknown-linux-gnu",
 80            "windows" => "pc-windows-msvc",
 81            other => bail!("Running on unsupported os: {other}"),
 82        };
 83        let asset_name = format!("rust-analyzer-{}-{os}.gz", consts::ARCH);
 84        let asset = release
 85            .assets
 86            .iter()
 87            .find(|asset| asset.name == asset_name)
 88            .with_context(|| format!("no asset found matching `{asset_name:?}`"))?;
 89        Ok(Box::new(GitHubLspBinaryVersion {
 90            name: release.tag_name,
 91            url: asset.browser_download_url.clone(),
 92        }))
 93    }
 94
 95    async fn fetch_server_binary(
 96        &self,
 97        version: Box<dyn 'static + Send + Any>,
 98        container_dir: PathBuf,
 99        delegate: &dyn LspAdapterDelegate,
100    ) -> Result<LanguageServerBinary> {
101        let version = version.downcast::<GitHubLspBinaryVersion>().unwrap();
102        let destination_path = container_dir.join(format!("rust-analyzer-{}", version.name));
103
104        if fs::metadata(&destination_path).await.is_err() {
105            let mut response = delegate
106                .http_client()
107                .get(&version.url, Default::default(), true)
108                .await
109                .map_err(|err| anyhow!("error downloading release: {}", err))?;
110            let decompressed_bytes = GzipDecoder::new(BufReader::new(response.body_mut()));
111            let mut file = File::create(&destination_path).await?;
112            futures::io::copy(decompressed_bytes, &mut file).await?;
113            // todo("windows")
114            #[cfg(not(windows))]
115            {
116                fs::set_permissions(
117                    &destination_path,
118                    <fs::Permissions as fs::unix::PermissionsExt>::from_mode(0o755),
119                )
120                .await?;
121            }
122
123            remove_matching(&container_dir, |entry| entry != destination_path).await;
124        }
125
126        Ok(LanguageServerBinary {
127            path: destination_path,
128            env: None,
129            arguments: Default::default(),
130        })
131    }
132
133    async fn cached_server_binary(
134        &self,
135        container_dir: PathBuf,
136        _: &dyn LspAdapterDelegate,
137    ) -> Option<LanguageServerBinary> {
138        get_cached_server_binary(container_dir).await
139    }
140
141    async fn installation_test_binary(
142        &self,
143        container_dir: PathBuf,
144    ) -> Option<LanguageServerBinary> {
145        get_cached_server_binary(container_dir)
146            .await
147            .map(|mut binary| {
148                binary.arguments = vec!["--help".into()];
149                binary
150            })
151    }
152
153    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
154        vec!["rustc".into()]
155    }
156
157    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
158        Some("rust-analyzer/flycheck".into())
159    }
160
161    fn process_diagnostics(&self, params: &mut lsp::PublishDiagnosticsParams) {
162        lazy_static! {
163            static ref REGEX: Regex = Regex::new("(?m)`([^`]+)\n`$").unwrap();
164        }
165
166        for diagnostic in &mut params.diagnostics {
167            for message in diagnostic
168                .related_information
169                .iter_mut()
170                .flatten()
171                .map(|info| &mut info.message)
172                .chain([&mut diagnostic.message])
173            {
174                if let Cow::Owned(sanitized) = REGEX.replace_all(message, "`$1`") {
175                    *message = sanitized;
176                }
177            }
178        }
179    }
180
181    async fn label_for_completion(
182        &self,
183        completion: &lsp::CompletionItem,
184        language: &Arc<Language>,
185    ) -> Option<CodeLabel> {
186        match completion.kind {
187            Some(lsp::CompletionItemKind::FIELD) if completion.detail.is_some() => {
188                let detail = completion.detail.as_ref().unwrap();
189                let name = &completion.label;
190                let text = format!("{}: {}", name, detail);
191                let source = Rope::from(format!("struct S {{ {} }}", text).as_str());
192                let runs = language.highlight_text(&source, 11..11 + text.len());
193                return Some(CodeLabel {
194                    text,
195                    runs,
196                    filter_range: 0..name.len(),
197                });
198            }
199            Some(lsp::CompletionItemKind::CONSTANT | lsp::CompletionItemKind::VARIABLE)
200                if completion.detail.is_some()
201                    && completion.insert_text_format != Some(lsp::InsertTextFormat::SNIPPET) =>
202            {
203                let detail = completion.detail.as_ref().unwrap();
204                let name = &completion.label;
205                let text = format!("{}: {}", name, detail);
206                let source = Rope::from(format!("let {} = ();", text).as_str());
207                let runs = language.highlight_text(&source, 4..4 + text.len());
208                return Some(CodeLabel {
209                    text,
210                    runs,
211                    filter_range: 0..name.len(),
212                });
213            }
214            Some(lsp::CompletionItemKind::FUNCTION | lsp::CompletionItemKind::METHOD)
215                if completion.detail.is_some() =>
216            {
217                lazy_static! {
218                    static ref REGEX: Regex = Regex::new("\\(…?\\)").unwrap();
219                }
220                let detail = completion.detail.as_ref().unwrap();
221                const FUNCTION_PREFIXES: [&'static str; 2] = ["async fn", "fn"];
222                let prefix = FUNCTION_PREFIXES
223                    .iter()
224                    .find_map(|prefix| detail.strip_prefix(*prefix).map(|suffix| (prefix, suffix)));
225                // fn keyword should be followed by opening parenthesis.
226                if let Some((prefix, suffix)) = prefix {
227                    if suffix.starts_with('(') {
228                        let text = REGEX.replace(&completion.label, suffix).to_string();
229                        let source = Rope::from(format!("{prefix} {} {{}}", text).as_str());
230                        let run_start = prefix.len() + 1;
231                        let runs =
232                            language.highlight_text(&source, run_start..run_start + text.len());
233                        return Some(CodeLabel {
234                            filter_range: 0..completion.label.find('(').unwrap_or(text.len()),
235                            text,
236                            runs,
237                        });
238                    }
239                }
240            }
241            Some(kind) => {
242                let highlight_name = match kind {
243                    lsp::CompletionItemKind::STRUCT
244                    | lsp::CompletionItemKind::INTERFACE
245                    | lsp::CompletionItemKind::ENUM => Some("type"),
246                    lsp::CompletionItemKind::ENUM_MEMBER => Some("variant"),
247                    lsp::CompletionItemKind::KEYWORD => Some("keyword"),
248                    lsp::CompletionItemKind::VALUE | lsp::CompletionItemKind::CONSTANT => {
249                        Some("constant")
250                    }
251                    _ => None,
252                };
253                let highlight_id = language.grammar()?.highlight_id_for_name(highlight_name?)?;
254                let mut label = CodeLabel::plain(completion.label.clone(), None);
255                label.runs.push((
256                    0..label.text.rfind('(').unwrap_or(label.text.len()),
257                    highlight_id,
258                ));
259                return Some(label);
260            }
261            _ => {}
262        }
263        None
264    }
265
266    async fn label_for_symbol(
267        &self,
268        name: &str,
269        kind: lsp::SymbolKind,
270        language: &Arc<Language>,
271    ) -> Option<CodeLabel> {
272        let (text, filter_range, display_range) = match kind {
273            lsp::SymbolKind::METHOD | lsp::SymbolKind::FUNCTION => {
274                let text = format!("fn {} () {{}}", name);
275                let filter_range = 3..3 + name.len();
276                let display_range = 0..filter_range.end;
277                (text, filter_range, display_range)
278            }
279            lsp::SymbolKind::STRUCT => {
280                let text = format!("struct {} {{}}", name);
281                let filter_range = 7..7 + name.len();
282                let display_range = 0..filter_range.end;
283                (text, filter_range, display_range)
284            }
285            lsp::SymbolKind::ENUM => {
286                let text = format!("enum {} {{}}", name);
287                let filter_range = 5..5 + name.len();
288                let display_range = 0..filter_range.end;
289                (text, filter_range, display_range)
290            }
291            lsp::SymbolKind::INTERFACE => {
292                let text = format!("trait {} {{}}", name);
293                let filter_range = 6..6 + name.len();
294                let display_range = 0..filter_range.end;
295                (text, filter_range, display_range)
296            }
297            lsp::SymbolKind::CONSTANT => {
298                let text = format!("const {}: () = ();", name);
299                let filter_range = 6..6 + name.len();
300                let display_range = 0..filter_range.end;
301                (text, filter_range, display_range)
302            }
303            lsp::SymbolKind::MODULE => {
304                let text = format!("mod {} {{}}", name);
305                let filter_range = 4..4 + name.len();
306                let display_range = 0..filter_range.end;
307                (text, filter_range, display_range)
308            }
309            lsp::SymbolKind::TYPE_PARAMETER => {
310                let text = format!("type {} {{}}", name);
311                let filter_range = 5..5 + name.len();
312                let display_range = 0..filter_range.end;
313                (text, filter_range, display_range)
314            }
315            _ => return None,
316        };
317
318        Some(CodeLabel {
319            runs: language.highlight_text(&text.as_str().into(), display_range.clone()),
320            text: text[display_range].to_string(),
321            filter_range,
322        })
323    }
324}
325
326pub(crate) struct RustContextProvider;
327
328const RUST_PACKAGE_TASK_VARIABLE: VariableName =
329    VariableName::Custom(Cow::Borrowed("RUST_PACKAGE"));
330
331impl ContextProvider for RustContextProvider {
332    fn build_context(
333        &self,
334        location: Location,
335        cx: &mut gpui::AppContext,
336    ) -> Result<TaskVariables> {
337        let mut context = SymbolContextProvider.build_context(location.clone(), cx)?;
338
339        let local_abs_path = location
340            .buffer
341            .read(cx)
342            .file()
343            .and_then(|file| Some(file.as_local()?.abs_path(cx)));
344        if let Some(package_name) = local_abs_path
345            .as_deref()
346            .and_then(|local_abs_path| local_abs_path.parent())
347            .and_then(human_readable_package_name)
348        {
349            context.insert(RUST_PACKAGE_TASK_VARIABLE.clone(), package_name);
350        }
351
352        Ok(context)
353    }
354
355    fn associated_tasks(&self) -> Option<TaskTemplates> {
356        Some(TaskTemplates(vec![
357            TaskTemplate {
358                label: format!(
359                    "cargo check -p {}",
360                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
361                ),
362                command: "cargo".into(),
363                args: vec![
364                    "check".into(),
365                    "-p".into(),
366                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
367                ],
368                ..TaskTemplate::default()
369            },
370            TaskTemplate {
371                label: "cargo check --workspace --all-targets".into(),
372                command: "cargo".into(),
373                args: vec!["check".into(), "--workspace".into(), "--all-targets".into()],
374                ..TaskTemplate::default()
375            },
376            TaskTemplate {
377                label: format!(
378                    "cargo test -p {} {} -- --nocapture",
379                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
380                    VariableName::Symbol.template_value(),
381                ),
382                command: "cargo".into(),
383                args: vec![
384                    "test".into(),
385                    "-p".into(),
386                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
387                    VariableName::Symbol.template_value(),
388                    "--".into(),
389                    "--nocapture".into(),
390                ],
391                ..TaskTemplate::default()
392            },
393            TaskTemplate {
394                label: format!(
395                    "cargo test -p {}",
396                    RUST_PACKAGE_TASK_VARIABLE.template_value()
397                ),
398                command: "cargo".into(),
399                args: vec![
400                    "test".into(),
401                    "-p".into(),
402                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
403                ],
404                ..TaskTemplate::default()
405            },
406            TaskTemplate {
407                label: "cargo run".into(),
408                command: "cargo".into(),
409                args: vec!["run".into()],
410                ..TaskTemplate::default()
411            },
412            TaskTemplate {
413                label: "cargo clean".into(),
414                command: "cargo".into(),
415                args: vec!["clean".into()],
416                ..TaskTemplate::default()
417            },
418        ]))
419    }
420}
421
422fn human_readable_package_name(package_directory: &Path) -> Option<String> {
423    fn split_off_suffix(input: &str, suffix_start: char) -> &str {
424        match input.rsplit_once(suffix_start) {
425            Some((without_suffix, _)) => without_suffix,
426            None => input,
427        }
428    }
429
430    let pkgid = String::from_utf8(
431        std::process::Command::new("cargo")
432            .current_dir(package_directory)
433            .arg("pkgid")
434            .output()
435            .log_err()?
436            .stdout,
437    )
438    .ok()?;
439    // For providing local `cargo check -p $pkgid` task, we do not need most of the information we have returned.
440    // Output example in the root of Zed project:
441    // ```bash
442    // ❯ cargo pkgid zed
443    // path+file:///absolute/path/to/project/zed/crates/zed#0.131.0
444    // ```
445    // Extrarct the package name from the output according to the spec:
446    // https://doc.rust-lang.org/cargo/reference/pkgid-spec.html#specification-grammar
447    let mut package_name = pkgid.trim();
448    package_name = split_off_suffix(package_name, '#');
449    package_name = split_off_suffix(package_name, '?');
450    let (_, package_name) = package_name.rsplit_once('/')?;
451    Some(package_name.to_string())
452}
453
454async fn get_cached_server_binary(container_dir: PathBuf) -> Option<LanguageServerBinary> {
455    maybe!(async {
456        let mut last = None;
457        let mut entries = fs::read_dir(&container_dir).await?;
458        while let Some(entry) = entries.next().await {
459            last = Some(entry?.path());
460        }
461
462        anyhow::Ok(LanguageServerBinary {
463            path: last.ok_or_else(|| anyhow!("no cached binary"))?,
464            env: None,
465            arguments: Default::default(),
466        })
467    })
468    .await
469    .log_err()
470}
471
472#[cfg(test)]
473mod tests {
474    use std::num::NonZeroU32;
475
476    use super::*;
477    use crate::language;
478    use gpui::{BorrowAppContext, Context, Hsla, TestAppContext};
479    use language::language_settings::AllLanguageSettings;
480    use settings::SettingsStore;
481    use theme::SyntaxTheme;
482
483    #[gpui::test]
484    async fn test_process_rust_diagnostics() {
485        let mut params = lsp::PublishDiagnosticsParams {
486            uri: lsp::Url::from_file_path("/a").unwrap(),
487            version: None,
488            diagnostics: vec![
489                // no newlines
490                lsp::Diagnostic {
491                    message: "use of moved value `a`".to_string(),
492                    ..Default::default()
493                },
494                // newline at the end of a code span
495                lsp::Diagnostic {
496                    message: "consider importing this struct: `use b::c;\n`".to_string(),
497                    ..Default::default()
498                },
499                // code span starting right after a newline
500                lsp::Diagnostic {
501                    message: "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
502                        .to_string(),
503                    ..Default::default()
504                },
505            ],
506        };
507        RustLspAdapter.process_diagnostics(&mut params);
508
509        assert_eq!(params.diagnostics[0].message, "use of moved value `a`");
510
511        // remove trailing newline from code span
512        assert_eq!(
513            params.diagnostics[1].message,
514            "consider importing this struct: `use b::c;`"
515        );
516
517        // do not remove newline before the start of code span
518        assert_eq!(
519            params.diagnostics[2].message,
520            "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
521        );
522    }
523
524    #[gpui::test]
525    async fn test_rust_label_for_completion() {
526        let adapter = Arc::new(RustLspAdapter);
527        let language = language("rust", tree_sitter_rust::language());
528        let grammar = language.grammar().unwrap();
529        let theme = SyntaxTheme::new_test([
530            ("type", Hsla::default()),
531            ("keyword", Hsla::default()),
532            ("function", Hsla::default()),
533            ("property", Hsla::default()),
534        ]);
535
536        language.set_theme(&theme);
537
538        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
539        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
540        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
541        let highlight_field = grammar.highlight_id_for_name("property").unwrap();
542
543        assert_eq!(
544            adapter
545                .label_for_completion(
546                    &lsp::CompletionItem {
547                        kind: Some(lsp::CompletionItemKind::FUNCTION),
548                        label: "hello(…)".to_string(),
549                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
550                        ..Default::default()
551                    },
552                    &language
553                )
554                .await,
555            Some(CodeLabel {
556                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
557                filter_range: 0..5,
558                runs: vec![
559                    (0..5, highlight_function),
560                    (7..10, highlight_keyword),
561                    (11..17, highlight_type),
562                    (18..19, highlight_type),
563                    (25..28, highlight_type),
564                    (29..30, highlight_type),
565                ],
566            })
567        );
568        assert_eq!(
569            adapter
570                .label_for_completion(
571                    &lsp::CompletionItem {
572                        kind: Some(lsp::CompletionItemKind::FUNCTION),
573                        label: "hello(…)".to_string(),
574                        detail: Some("async fn(&mut Option<T>) -> Vec<T>".to_string()),
575                        ..Default::default()
576                    },
577                    &language
578                )
579                .await,
580            Some(CodeLabel {
581                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
582                filter_range: 0..5,
583                runs: vec![
584                    (0..5, highlight_function),
585                    (7..10, highlight_keyword),
586                    (11..17, highlight_type),
587                    (18..19, highlight_type),
588                    (25..28, highlight_type),
589                    (29..30, highlight_type),
590                ],
591            })
592        );
593        assert_eq!(
594            adapter
595                .label_for_completion(
596                    &lsp::CompletionItem {
597                        kind: Some(lsp::CompletionItemKind::FIELD),
598                        label: "len".to_string(),
599                        detail: Some("usize".to_string()),
600                        ..Default::default()
601                    },
602                    &language
603                )
604                .await,
605            Some(CodeLabel {
606                text: "len: usize".to_string(),
607                filter_range: 0..3,
608                runs: vec![(0..3, highlight_field), (5..10, highlight_type),],
609            })
610        );
611
612        assert_eq!(
613            adapter
614                .label_for_completion(
615                    &lsp::CompletionItem {
616                        kind: Some(lsp::CompletionItemKind::FUNCTION),
617                        label: "hello(…)".to_string(),
618                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
619                        ..Default::default()
620                    },
621                    &language
622                )
623                .await,
624            Some(CodeLabel {
625                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
626                filter_range: 0..5,
627                runs: vec![
628                    (0..5, highlight_function),
629                    (7..10, highlight_keyword),
630                    (11..17, highlight_type),
631                    (18..19, highlight_type),
632                    (25..28, highlight_type),
633                    (29..30, highlight_type),
634                ],
635            })
636        );
637    }
638
639    #[gpui::test]
640    async fn test_rust_label_for_symbol() {
641        let adapter = Arc::new(RustLspAdapter);
642        let language = language("rust", tree_sitter_rust::language());
643        let grammar = language.grammar().unwrap();
644        let theme = SyntaxTheme::new_test([
645            ("type", Hsla::default()),
646            ("keyword", Hsla::default()),
647            ("function", Hsla::default()),
648            ("property", Hsla::default()),
649        ]);
650
651        language.set_theme(&theme);
652
653        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
654        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
655        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
656
657        assert_eq!(
658            adapter
659                .label_for_symbol("hello", lsp::SymbolKind::FUNCTION, &language)
660                .await,
661            Some(CodeLabel {
662                text: "fn hello".to_string(),
663                filter_range: 3..8,
664                runs: vec![(0..2, highlight_keyword), (3..8, highlight_function)],
665            })
666        );
667
668        assert_eq!(
669            adapter
670                .label_for_symbol("World", lsp::SymbolKind::TYPE_PARAMETER, &language)
671                .await,
672            Some(CodeLabel {
673                text: "type World".to_string(),
674                filter_range: 5..10,
675                runs: vec![(0..4, highlight_keyword), (5..10, highlight_type)],
676            })
677        );
678    }
679
680    #[gpui::test]
681    async fn test_rust_autoindent(cx: &mut TestAppContext) {
682        // cx.executor().set_block_on_ticks(usize::MAX..=usize::MAX);
683        cx.update(|cx| {
684            let test_settings = SettingsStore::test(cx);
685            cx.set_global(test_settings);
686            language::init(cx);
687            cx.update_global::<SettingsStore, _>(|store, cx| {
688                store.update_user_settings::<AllLanguageSettings>(cx, |s| {
689                    s.defaults.tab_size = NonZeroU32::new(2);
690                });
691            });
692        });
693
694        let language = crate::language("rust", tree_sitter_rust::language());
695
696        cx.new_model(|cx| {
697            let mut buffer = Buffer::local("", cx).with_language(language, cx);
698
699            // indent between braces
700            buffer.set_text("fn a() {}", cx);
701            let ix = buffer.len() - 1;
702            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
703            assert_eq!(buffer.text(), "fn a() {\n  \n}");
704
705            // indent between braces, even after empty lines
706            buffer.set_text("fn a() {\n\n\n}", cx);
707            let ix = buffer.len() - 2;
708            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
709            assert_eq!(buffer.text(), "fn a() {\n\n\n  \n}");
710
711            // indent a line that continues a field expression
712            buffer.set_text("fn a() {\n  \n}", cx);
713            let ix = buffer.len() - 2;
714            buffer.edit([(ix..ix, "b\n.c")], Some(AutoindentMode::EachLine), cx);
715            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n}");
716
717            // indent further lines that continue the field expression, even after empty lines
718            let ix = buffer.len() - 2;
719            buffer.edit([(ix..ix, "\n\n.d")], Some(AutoindentMode::EachLine), cx);
720            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n    \n    .d\n}");
721
722            // dedent the line after the field expression
723            let ix = buffer.len() - 2;
724            buffer.edit([(ix..ix, ";\ne")], Some(AutoindentMode::EachLine), cx);
725            assert_eq!(
726                buffer.text(),
727                "fn a() {\n  b\n    .c\n    \n    .d;\n  e\n}"
728            );
729
730            // indent inside a struct within a call
731            buffer.set_text("const a: B = c(D {});", cx);
732            let ix = buffer.len() - 3;
733            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
734            assert_eq!(buffer.text(), "const a: B = c(D {\n  \n});");
735
736            // indent further inside a nested call
737            let ix = buffer.len() - 4;
738            buffer.edit([(ix..ix, "e: f(\n\n)")], Some(AutoindentMode::EachLine), cx);
739            assert_eq!(buffer.text(), "const a: B = c(D {\n  e: f(\n    \n  )\n});");
740
741            // keep that indent after an empty line
742            let ix = buffer.len() - 8;
743            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
744            assert_eq!(
745                buffer.text(),
746                "const a: B = c(D {\n  e: f(\n    \n    \n  )\n});"
747            );
748
749            buffer
750        });
751    }
752}