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::{any::Any, borrow::Cow, env::consts, path::PathBuf, sync::Arc};
 14use task::{
 15    static_source::{Definition, TaskDefinitions},
 16    TaskVariables, VariableName,
 17};
 18use util::{
 19    fs::remove_matching,
 20    github::{latest_github_release, GitHubLspBinaryVersion},
 21    maybe, ResultExt,
 22};
 23
 24pub struct RustLspAdapter;
 25
 26impl RustLspAdapter {
 27    const SERVER_NAME: &'static str = "rust-analyzer";
 28}
 29
 30#[async_trait(?Send)]
 31impl LspAdapter for RustLspAdapter {
 32    fn name(&self) -> LanguageServerName {
 33        LanguageServerName(Self::SERVER_NAME.into())
 34    }
 35
 36    async fn check_if_user_installed(
 37        &self,
 38        _delegate: &dyn LspAdapterDelegate,
 39        cx: &AsyncAppContext,
 40    ) -> Option<LanguageServerBinary> {
 41        let binary = cx
 42            .update(|cx| {
 43                ProjectSettings::get_global(cx)
 44                    .lsp
 45                    .get(Self::SERVER_NAME)
 46                    .and_then(|s| s.binary.clone())
 47            })
 48            .ok()??;
 49
 50        let path = binary.path?;
 51        Some(LanguageServerBinary {
 52            path: path.into(),
 53            arguments: binary
 54                .arguments
 55                .unwrap_or_default()
 56                .iter()
 57                .map(|arg| arg.into())
 58                .collect(),
 59            env: None,
 60        })
 61    }
 62
 63    async fn fetch_latest_server_version(
 64        &self,
 65        delegate: &dyn LspAdapterDelegate,
 66    ) -> Result<Box<dyn 'static + Send + Any>> {
 67        let release = latest_github_release(
 68            "rust-lang/rust-analyzer",
 69            true,
 70            false,
 71            delegate.http_client(),
 72        )
 73        .await?;
 74        let os = match consts::OS {
 75            "macos" => "apple-darwin",
 76            "linux" => "unknown-linux-gnu",
 77            "windows" => "pc-windows-msvc",
 78            other => bail!("Running on unsupported os: {other}"),
 79        };
 80        let asset_name = format!("rust-analyzer-{}-{os}.gz", consts::ARCH);
 81        let asset = release
 82            .assets
 83            .iter()
 84            .find(|asset| asset.name == asset_name)
 85            .with_context(|| format!("no asset found matching `{asset_name:?}`"))?;
 86        Ok(Box::new(GitHubLspBinaryVersion {
 87            name: release.tag_name,
 88            url: asset.browser_download_url.clone(),
 89        }))
 90    }
 91
 92    async fn fetch_server_binary(
 93        &self,
 94        version: Box<dyn 'static + Send + Any>,
 95        container_dir: PathBuf,
 96        delegate: &dyn LspAdapterDelegate,
 97    ) -> Result<LanguageServerBinary> {
 98        let version = version.downcast::<GitHubLspBinaryVersion>().unwrap();
 99        let destination_path = container_dir.join(format!("rust-analyzer-{}", version.name));
100
101        if fs::metadata(&destination_path).await.is_err() {
102            let mut response = delegate
103                .http_client()
104                .get(&version.url, Default::default(), true)
105                .await
106                .map_err(|err| anyhow!("error downloading release: {}", err))?;
107            let decompressed_bytes = GzipDecoder::new(BufReader::new(response.body_mut()));
108            let mut file = File::create(&destination_path).await?;
109            futures::io::copy(decompressed_bytes, &mut file).await?;
110            // todo("windows")
111            #[cfg(not(windows))]
112            {
113                fs::set_permissions(
114                    &destination_path,
115                    <fs::Permissions as fs::unix::PermissionsExt>::from_mode(0o755),
116                )
117                .await?;
118            }
119
120            remove_matching(&container_dir, |entry| entry != destination_path).await;
121        }
122
123        Ok(LanguageServerBinary {
124            path: destination_path,
125            env: None,
126            arguments: Default::default(),
127        })
128    }
129
130    async fn cached_server_binary(
131        &self,
132        container_dir: PathBuf,
133        _: &dyn LspAdapterDelegate,
134    ) -> Option<LanguageServerBinary> {
135        get_cached_server_binary(container_dir).await
136    }
137
138    async fn installation_test_binary(
139        &self,
140        container_dir: PathBuf,
141    ) -> Option<LanguageServerBinary> {
142        get_cached_server_binary(container_dir)
143            .await
144            .map(|mut binary| {
145                binary.arguments = vec!["--help".into()];
146                binary
147            })
148    }
149
150    fn disk_based_diagnostic_sources(&self) -> Vec<String> {
151        vec!["rustc".into()]
152    }
153
154    fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
155        Some("rust-analyzer/flycheck".into())
156    }
157
158    fn process_diagnostics(&self, params: &mut lsp::PublishDiagnosticsParams) {
159        lazy_static! {
160            static ref REGEX: Regex = Regex::new("(?m)`([^`]+)\n`$").unwrap();
161        }
162
163        for diagnostic in &mut params.diagnostics {
164            for message in diagnostic
165                .related_information
166                .iter_mut()
167                .flatten()
168                .map(|info| &mut info.message)
169                .chain([&mut diagnostic.message])
170            {
171                if let Cow::Owned(sanitized) = REGEX.replace_all(message, "`$1`") {
172                    *message = sanitized;
173                }
174            }
175        }
176    }
177
178    async fn label_for_completion(
179        &self,
180        completion: &lsp::CompletionItem,
181        language: &Arc<Language>,
182    ) -> Option<CodeLabel> {
183        match completion.kind {
184            Some(lsp::CompletionItemKind::FIELD) if completion.detail.is_some() => {
185                let detail = completion.detail.as_ref().unwrap();
186                let name = &completion.label;
187                let text = format!("{}: {}", name, detail);
188                let source = Rope::from(format!("struct S {{ {} }}", text).as_str());
189                let runs = language.highlight_text(&source, 11..11 + text.len());
190                return Some(CodeLabel {
191                    text,
192                    runs,
193                    filter_range: 0..name.len(),
194                });
195            }
196            Some(lsp::CompletionItemKind::CONSTANT | lsp::CompletionItemKind::VARIABLE)
197                if completion.detail.is_some()
198                    && completion.insert_text_format != Some(lsp::InsertTextFormat::SNIPPET) =>
199            {
200                let detail = completion.detail.as_ref().unwrap();
201                let name = &completion.label;
202                let text = format!("{}: {}", name, detail);
203                let source = Rope::from(format!("let {} = ();", text).as_str());
204                let runs = language.highlight_text(&source, 4..4 + text.len());
205                return Some(CodeLabel {
206                    text,
207                    runs,
208                    filter_range: 0..name.len(),
209                });
210            }
211            Some(lsp::CompletionItemKind::FUNCTION | lsp::CompletionItemKind::METHOD)
212                if completion.detail.is_some() =>
213            {
214                lazy_static! {
215                    static ref REGEX: Regex = Regex::new("\\(…?\\)").unwrap();
216                }
217                let detail = completion.detail.as_ref().unwrap();
218                const FUNCTION_PREFIXES: [&'static str; 2] = ["async fn", "fn"];
219                let prefix = FUNCTION_PREFIXES
220                    .iter()
221                    .find_map(|prefix| detail.strip_prefix(*prefix).map(|suffix| (prefix, suffix)));
222                // fn keyword should be followed by opening parenthesis.
223                if let Some((prefix, suffix)) = prefix {
224                    if suffix.starts_with('(') {
225                        let text = REGEX.replace(&completion.label, suffix).to_string();
226                        let source = Rope::from(format!("{prefix} {} {{}}", text).as_str());
227                        let run_start = prefix.len() + 1;
228                        let runs =
229                            language.highlight_text(&source, run_start..run_start + text.len());
230                        return Some(CodeLabel {
231                            filter_range: 0..completion.label.find('(').unwrap_or(text.len()),
232                            text,
233                            runs,
234                        });
235                    }
236                }
237            }
238            Some(kind) => {
239                let highlight_name = match kind {
240                    lsp::CompletionItemKind::STRUCT
241                    | lsp::CompletionItemKind::INTERFACE
242                    | lsp::CompletionItemKind::ENUM => Some("type"),
243                    lsp::CompletionItemKind::ENUM_MEMBER => Some("variant"),
244                    lsp::CompletionItemKind::KEYWORD => Some("keyword"),
245                    lsp::CompletionItemKind::VALUE | lsp::CompletionItemKind::CONSTANT => {
246                        Some("constant")
247                    }
248                    _ => None,
249                };
250                let highlight_id = language.grammar()?.highlight_id_for_name(highlight_name?)?;
251                let mut label = CodeLabel::plain(completion.label.clone(), None);
252                label.runs.push((
253                    0..label.text.rfind('(').unwrap_or(label.text.len()),
254                    highlight_id,
255                ));
256                return Some(label);
257            }
258            _ => {}
259        }
260        None
261    }
262
263    async fn label_for_symbol(
264        &self,
265        name: &str,
266        kind: lsp::SymbolKind,
267        language: &Arc<Language>,
268    ) -> Option<CodeLabel> {
269        let (text, filter_range, display_range) = match kind {
270            lsp::SymbolKind::METHOD | lsp::SymbolKind::FUNCTION => {
271                let text = format!("fn {} () {{}}", name);
272                let filter_range = 3..3 + name.len();
273                let display_range = 0..filter_range.end;
274                (text, filter_range, display_range)
275            }
276            lsp::SymbolKind::STRUCT => {
277                let text = format!("struct {} {{}}", name);
278                let filter_range = 7..7 + name.len();
279                let display_range = 0..filter_range.end;
280                (text, filter_range, display_range)
281            }
282            lsp::SymbolKind::ENUM => {
283                let text = format!("enum {} {{}}", name);
284                let filter_range = 5..5 + name.len();
285                let display_range = 0..filter_range.end;
286                (text, filter_range, display_range)
287            }
288            lsp::SymbolKind::INTERFACE => {
289                let text = format!("trait {} {{}}", name);
290                let filter_range = 6..6 + name.len();
291                let display_range = 0..filter_range.end;
292                (text, filter_range, display_range)
293            }
294            lsp::SymbolKind::CONSTANT => {
295                let text = format!("const {}: () = ();", name);
296                let filter_range = 6..6 + name.len();
297                let display_range = 0..filter_range.end;
298                (text, filter_range, display_range)
299            }
300            lsp::SymbolKind::MODULE => {
301                let text = format!("mod {} {{}}", name);
302                let filter_range = 4..4 + name.len();
303                let display_range = 0..filter_range.end;
304                (text, filter_range, display_range)
305            }
306            lsp::SymbolKind::TYPE_PARAMETER => {
307                let text = format!("type {} {{}}", name);
308                let filter_range = 5..5 + name.len();
309                let display_range = 0..filter_range.end;
310                (text, filter_range, display_range)
311            }
312            _ => return None,
313        };
314
315        Some(CodeLabel {
316            runs: language.highlight_text(&text.as_str().into(), display_range.clone()),
317            text: text[display_range].to_string(),
318            filter_range,
319        })
320    }
321}
322
323pub(crate) struct RustContextProvider;
324
325const RUST_PACKAGE_TASK_VARIABLE: VariableName =
326    VariableName::Custom(Cow::Borrowed("RUST_PACKAGE"));
327
328impl ContextProvider for RustContextProvider {
329    fn build_context(
330        &self,
331        location: Location,
332        cx: &mut gpui::AppContext,
333    ) -> Result<TaskVariables> {
334        let mut context = SymbolContextProvider.build_context(location.clone(), cx)?;
335
336        if let Some(path) = location.buffer.read(cx).file().and_then(|file| {
337            let local_file = file.as_local()?.abs_path(cx);
338            local_file.parent().map(PathBuf::from)
339        }) {
340            let Some(pkgid) = std::process::Command::new("cargo")
341                .current_dir(path)
342                .arg("pkgid")
343                .output()
344                .log_err()
345            else {
346                return Ok(context);
347            };
348            let package_name = String::from_utf8(pkgid.stdout)
349                .map(|name| name.trim().to_owned())
350                .ok();
351
352            if let Some(package_name) = package_name {
353                context.insert(RUST_PACKAGE_TASK_VARIABLE.clone(), package_name);
354            }
355        }
356
357        Ok(context)
358    }
359
360    fn associated_tasks(&self) -> Option<TaskDefinitions> {
361        Some(TaskDefinitions(vec![
362            Definition {
363                label: "Rust: Test current crate".to_owned(),
364                command: "cargo".into(),
365                args: vec![
366                    "test".into(),
367                    "-p".into(),
368                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
369                ],
370                ..Definition::default()
371            },
372            Definition {
373                label: "Rust: Test current function".to_owned(),
374                command: "cargo".into(),
375                args: vec![
376                    "test".into(),
377                    "-p".into(),
378                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
379                    VariableName::Symbol.template_value(),
380                    "--".into(),
381                    "--nocapture".into(),
382                ],
383                ..Definition::default()
384            },
385            Definition {
386                label: "Rust: cargo run".into(),
387                command: "cargo".into(),
388                args: vec!["run".into()],
389                ..Definition::default()
390            },
391            Definition {
392                label: "Rust: cargo check current crate".into(),
393                command: "cargo".into(),
394                args: vec![
395                    "check".into(),
396                    "-p".into(),
397                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
398                ],
399                ..Definition::default()
400            },
401            Definition {
402                label: "Rust: cargo check workspace".into(),
403                command: "cargo".into(),
404                args: vec!["check".into(), "--workspace".into()],
405                ..Definition::default()
406            },
407        ]))
408    }
409}
410
411async fn get_cached_server_binary(container_dir: PathBuf) -> Option<LanguageServerBinary> {
412    maybe!(async {
413        let mut last = None;
414        let mut entries = fs::read_dir(&container_dir).await?;
415        while let Some(entry) = entries.next().await {
416            last = Some(entry?.path());
417        }
418
419        anyhow::Ok(LanguageServerBinary {
420            path: last.ok_or_else(|| anyhow!("no cached binary"))?,
421            env: None,
422            arguments: Default::default(),
423        })
424    })
425    .await
426    .log_err()
427}
428
429#[cfg(test)]
430mod tests {
431    use std::num::NonZeroU32;
432
433    use super::*;
434    use crate::language;
435    use gpui::{BorrowAppContext, Context, Hsla, TestAppContext};
436    use language::language_settings::AllLanguageSettings;
437    use settings::SettingsStore;
438    use text::BufferId;
439    use theme::SyntaxTheme;
440
441    #[gpui::test]
442    async fn test_process_rust_diagnostics() {
443        let mut params = lsp::PublishDiagnosticsParams {
444            uri: lsp::Url::from_file_path("/a").unwrap(),
445            version: None,
446            diagnostics: vec![
447                // no newlines
448                lsp::Diagnostic {
449                    message: "use of moved value `a`".to_string(),
450                    ..Default::default()
451                },
452                // newline at the end of a code span
453                lsp::Diagnostic {
454                    message: "consider importing this struct: `use b::c;\n`".to_string(),
455                    ..Default::default()
456                },
457                // code span starting right after a newline
458                lsp::Diagnostic {
459                    message: "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
460                        .to_string(),
461                    ..Default::default()
462                },
463            ],
464        };
465        RustLspAdapter.process_diagnostics(&mut params);
466
467        assert_eq!(params.diagnostics[0].message, "use of moved value `a`");
468
469        // remove trailing newline from code span
470        assert_eq!(
471            params.diagnostics[1].message,
472            "consider importing this struct: `use b::c;`"
473        );
474
475        // do not remove newline before the start of code span
476        assert_eq!(
477            params.diagnostics[2].message,
478            "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
479        );
480    }
481
482    #[gpui::test]
483    async fn test_rust_label_for_completion() {
484        let adapter = Arc::new(RustLspAdapter);
485        let language = language("rust", tree_sitter_rust::language());
486        let grammar = language.grammar().unwrap();
487        let theme = SyntaxTheme::new_test([
488            ("type", Hsla::default()),
489            ("keyword", Hsla::default()),
490            ("function", Hsla::default()),
491            ("property", Hsla::default()),
492        ]);
493
494        language.set_theme(&theme);
495
496        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
497        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
498        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
499        let highlight_field = grammar.highlight_id_for_name("property").unwrap();
500
501        assert_eq!(
502            adapter
503                .label_for_completion(
504                    &lsp::CompletionItem {
505                        kind: Some(lsp::CompletionItemKind::FUNCTION),
506                        label: "hello(…)".to_string(),
507                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
508                        ..Default::default()
509                    },
510                    &language
511                )
512                .await,
513            Some(CodeLabel {
514                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
515                filter_range: 0..5,
516                runs: vec![
517                    (0..5, highlight_function),
518                    (7..10, highlight_keyword),
519                    (11..17, highlight_type),
520                    (18..19, highlight_type),
521                    (25..28, highlight_type),
522                    (29..30, highlight_type),
523                ],
524            })
525        );
526        assert_eq!(
527            adapter
528                .label_for_completion(
529                    &lsp::CompletionItem {
530                        kind: Some(lsp::CompletionItemKind::FUNCTION),
531                        label: "hello(…)".to_string(),
532                        detail: Some("async fn(&mut Option<T>) -> Vec<T>".to_string()),
533                        ..Default::default()
534                    },
535                    &language
536                )
537                .await,
538            Some(CodeLabel {
539                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
540                filter_range: 0..5,
541                runs: vec![
542                    (0..5, highlight_function),
543                    (7..10, highlight_keyword),
544                    (11..17, highlight_type),
545                    (18..19, highlight_type),
546                    (25..28, highlight_type),
547                    (29..30, highlight_type),
548                ],
549            })
550        );
551        assert_eq!(
552            adapter
553                .label_for_completion(
554                    &lsp::CompletionItem {
555                        kind: Some(lsp::CompletionItemKind::FIELD),
556                        label: "len".to_string(),
557                        detail: Some("usize".to_string()),
558                        ..Default::default()
559                    },
560                    &language
561                )
562                .await,
563            Some(CodeLabel {
564                text: "len: usize".to_string(),
565                filter_range: 0..3,
566                runs: vec![(0..3, highlight_field), (5..10, highlight_type),],
567            })
568        );
569
570        assert_eq!(
571            adapter
572                .label_for_completion(
573                    &lsp::CompletionItem {
574                        kind: Some(lsp::CompletionItemKind::FUNCTION),
575                        label: "hello(…)".to_string(),
576                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
577                        ..Default::default()
578                    },
579                    &language
580                )
581                .await,
582            Some(CodeLabel {
583                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
584                filter_range: 0..5,
585                runs: vec![
586                    (0..5, highlight_function),
587                    (7..10, highlight_keyword),
588                    (11..17, highlight_type),
589                    (18..19, highlight_type),
590                    (25..28, highlight_type),
591                    (29..30, highlight_type),
592                ],
593            })
594        );
595    }
596
597    #[gpui::test]
598    async fn test_rust_label_for_symbol() {
599        let adapter = Arc::new(RustLspAdapter);
600        let language = language("rust", tree_sitter_rust::language());
601        let grammar = language.grammar().unwrap();
602        let theme = SyntaxTheme::new_test([
603            ("type", Hsla::default()),
604            ("keyword", Hsla::default()),
605            ("function", Hsla::default()),
606            ("property", Hsla::default()),
607        ]);
608
609        language.set_theme(&theme);
610
611        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
612        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
613        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
614
615        assert_eq!(
616            adapter
617                .label_for_symbol("hello", lsp::SymbolKind::FUNCTION, &language)
618                .await,
619            Some(CodeLabel {
620                text: "fn hello".to_string(),
621                filter_range: 3..8,
622                runs: vec![(0..2, highlight_keyword), (3..8, highlight_function)],
623            })
624        );
625
626        assert_eq!(
627            adapter
628                .label_for_symbol("World", lsp::SymbolKind::TYPE_PARAMETER, &language)
629                .await,
630            Some(CodeLabel {
631                text: "type World".to_string(),
632                filter_range: 5..10,
633                runs: vec![(0..4, highlight_keyword), (5..10, highlight_type)],
634            })
635        );
636    }
637
638    #[gpui::test]
639    async fn test_rust_autoindent(cx: &mut TestAppContext) {
640        // cx.executor().set_block_on_ticks(usize::MAX..=usize::MAX);
641        cx.update(|cx| {
642            let test_settings = SettingsStore::test(cx);
643            cx.set_global(test_settings);
644            language::init(cx);
645            cx.update_global::<SettingsStore, _>(|store, cx| {
646                store.update_user_settings::<AllLanguageSettings>(cx, |s| {
647                    s.defaults.tab_size = NonZeroU32::new(2);
648                });
649            });
650        });
651
652        let language = crate::language("rust", tree_sitter_rust::language());
653
654        cx.new_model(|cx| {
655            let mut buffer = Buffer::new(0, BufferId::new(cx.entity_id().as_u64()).unwrap(), "")
656                .with_language(language, cx);
657
658            // indent between braces
659            buffer.set_text("fn a() {}", cx);
660            let ix = buffer.len() - 1;
661            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
662            assert_eq!(buffer.text(), "fn a() {\n  \n}");
663
664            // indent between braces, even after empty lines
665            buffer.set_text("fn a() {\n\n\n}", cx);
666            let ix = buffer.len() - 2;
667            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
668            assert_eq!(buffer.text(), "fn a() {\n\n\n  \n}");
669
670            // indent a line that continues a field expression
671            buffer.set_text("fn a() {\n  \n}", cx);
672            let ix = buffer.len() - 2;
673            buffer.edit([(ix..ix, "b\n.c")], Some(AutoindentMode::EachLine), cx);
674            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n}");
675
676            // indent further lines that continue the field expression, even after empty lines
677            let ix = buffer.len() - 2;
678            buffer.edit([(ix..ix, "\n\n.d")], Some(AutoindentMode::EachLine), cx);
679            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n    \n    .d\n}");
680
681            // dedent the line after the field expression
682            let ix = buffer.len() - 2;
683            buffer.edit([(ix..ix, ";\ne")], Some(AutoindentMode::EachLine), cx);
684            assert_eq!(
685                buffer.text(),
686                "fn a() {\n  b\n    .c\n    \n    .d;\n  e\n}"
687            );
688
689            // indent inside a struct within a call
690            buffer.set_text("const a: B = c(D {});", cx);
691            let ix = buffer.len() - 3;
692            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
693            assert_eq!(buffer.text(), "const a: B = c(D {\n  \n});");
694
695            // indent further inside a nested call
696            let ix = buffer.len() - 4;
697            buffer.edit([(ix..ix, "e: f(\n\n)")], Some(AutoindentMode::EachLine), cx);
698            assert_eq!(buffer.text(), "const a: B = c(D {\n  e: f(\n    \n  )\n});");
699
700            // keep that indent after an empty line
701            let ix = buffer.len() - 8;
702            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
703            assert_eq!(
704                buffer.text(),
705                "const a: B = c(D {\n  e: f(\n    \n    \n  )\n});"
706            );
707
708            buffer
709        });
710    }
711}