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        _: Option<&Path>,
335        location: &Location,
336        cx: &mut gpui::AppContext,
337    ) -> Result<TaskVariables> {
338        let local_abs_path = location
339            .buffer
340            .read(cx)
341            .file()
342            .and_then(|file| Some(file.as_local()?.abs_path(cx)));
343        Ok(
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                TaskVariables::from_iter(Some((RUST_PACKAGE_TASK_VARIABLE.clone(), package_name)))
350            } else {
351                TaskVariables::default()
352            },
353        )
354    }
355
356    fn associated_tasks(&self) -> Option<TaskTemplates> {
357        Some(TaskTemplates(vec![
358            TaskTemplate {
359                label: format!(
360                    "cargo check -p {}",
361                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
362                ),
363                command: "cargo".into(),
364                args: vec![
365                    "check".into(),
366                    "-p".into(),
367                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
368                ],
369                ..TaskTemplate::default()
370            },
371            TaskTemplate {
372                label: "cargo check --workspace --all-targets".into(),
373                command: "cargo".into(),
374                args: vec!["check".into(), "--workspace".into(), "--all-targets".into()],
375                ..TaskTemplate::default()
376            },
377            TaskTemplate {
378                label: format!(
379                    "cargo test -p {} {} -- --nocapture",
380                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
381                    VariableName::Symbol.template_value(),
382                ),
383                command: "cargo".into(),
384                args: vec![
385                    "test".into(),
386                    "-p".into(),
387                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
388                    VariableName::Symbol.template_value(),
389                    "--".into(),
390                    "--nocapture".into(),
391                ],
392                ..TaskTemplate::default()
393            },
394            TaskTemplate {
395                label: format!(
396                    "cargo test -p {}",
397                    RUST_PACKAGE_TASK_VARIABLE.template_value()
398                ),
399                command: "cargo".into(),
400                args: vec![
401                    "test".into(),
402                    "-p".into(),
403                    RUST_PACKAGE_TASK_VARIABLE.template_value(),
404                ],
405                ..TaskTemplate::default()
406            },
407            TaskTemplate {
408                label: "cargo run".into(),
409                command: "cargo".into(),
410                args: vec!["run".into()],
411                ..TaskTemplate::default()
412            },
413            TaskTemplate {
414                label: "cargo clean".into(),
415                command: "cargo".into(),
416                args: vec!["clean".into()],
417                ..TaskTemplate::default()
418            },
419        ]))
420    }
421}
422
423fn human_readable_package_name(package_directory: &Path) -> Option<String> {
424    fn split_off_suffix(input: &str, suffix_start: char) -> &str {
425        match input.rsplit_once(suffix_start) {
426            Some((without_suffix, _)) => without_suffix,
427            None => input,
428        }
429    }
430
431    let pkgid = String::from_utf8(
432        std::process::Command::new("cargo")
433            .current_dir(package_directory)
434            .arg("pkgid")
435            .output()
436            .log_err()?
437            .stdout,
438    )
439    .ok()?;
440    // For providing local `cargo check -p $pkgid` task, we do not need most of the information we have returned.
441    // Output example in the root of Zed project:
442    // ```bash
443    // ❯ cargo pkgid zed
444    // path+file:///absolute/path/to/project/zed/crates/zed#0.131.0
445    // ```
446    // Extrarct the package name from the output according to the spec:
447    // https://doc.rust-lang.org/cargo/reference/pkgid-spec.html#specification-grammar
448    let mut package_name = pkgid.trim();
449    package_name = split_off_suffix(package_name, '#');
450    package_name = split_off_suffix(package_name, '?');
451    let (_, package_name) = package_name.rsplit_once('/')?;
452    Some(package_name.to_string())
453}
454
455async fn get_cached_server_binary(container_dir: PathBuf) -> Option<LanguageServerBinary> {
456    maybe!(async {
457        let mut last = None;
458        let mut entries = fs::read_dir(&container_dir).await?;
459        while let Some(entry) = entries.next().await {
460            last = Some(entry?.path());
461        }
462
463        anyhow::Ok(LanguageServerBinary {
464            path: last.ok_or_else(|| anyhow!("no cached binary"))?,
465            env: None,
466            arguments: Default::default(),
467        })
468    })
469    .await
470    .log_err()
471}
472
473#[cfg(test)]
474mod tests {
475    use std::num::NonZeroU32;
476
477    use super::*;
478    use crate::language;
479    use gpui::{BorrowAppContext, Context, Hsla, TestAppContext};
480    use language::language_settings::AllLanguageSettings;
481    use settings::SettingsStore;
482    use theme::SyntaxTheme;
483
484    #[gpui::test]
485    async fn test_process_rust_diagnostics() {
486        let mut params = lsp::PublishDiagnosticsParams {
487            uri: lsp::Url::from_file_path("/a").unwrap(),
488            version: None,
489            diagnostics: vec![
490                // no newlines
491                lsp::Diagnostic {
492                    message: "use of moved value `a`".to_string(),
493                    ..Default::default()
494                },
495                // newline at the end of a code span
496                lsp::Diagnostic {
497                    message: "consider importing this struct: `use b::c;\n`".to_string(),
498                    ..Default::default()
499                },
500                // code span starting right after a newline
501                lsp::Diagnostic {
502                    message: "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
503                        .to_string(),
504                    ..Default::default()
505                },
506            ],
507        };
508        RustLspAdapter.process_diagnostics(&mut params);
509
510        assert_eq!(params.diagnostics[0].message, "use of moved value `a`");
511
512        // remove trailing newline from code span
513        assert_eq!(
514            params.diagnostics[1].message,
515            "consider importing this struct: `use b::c;`"
516        );
517
518        // do not remove newline before the start of code span
519        assert_eq!(
520            params.diagnostics[2].message,
521            "cannot borrow `self.d` as mutable\n`self` is a `&` reference"
522        );
523    }
524
525    #[gpui::test]
526    async fn test_rust_label_for_completion() {
527        let adapter = Arc::new(RustLspAdapter);
528        let language = language("rust", tree_sitter_rust::language());
529        let grammar = language.grammar().unwrap();
530        let theme = SyntaxTheme::new_test([
531            ("type", Hsla::default()),
532            ("keyword", Hsla::default()),
533            ("function", Hsla::default()),
534            ("property", Hsla::default()),
535        ]);
536
537        language.set_theme(&theme);
538
539        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
540        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
541        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
542        let highlight_field = grammar.highlight_id_for_name("property").unwrap();
543
544        assert_eq!(
545            adapter
546                .label_for_completion(
547                    &lsp::CompletionItem {
548                        kind: Some(lsp::CompletionItemKind::FUNCTION),
549                        label: "hello(…)".to_string(),
550                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
551                        ..Default::default()
552                    },
553                    &language
554                )
555                .await,
556            Some(CodeLabel {
557                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
558                filter_range: 0..5,
559                runs: vec![
560                    (0..5, highlight_function),
561                    (7..10, highlight_keyword),
562                    (11..17, highlight_type),
563                    (18..19, highlight_type),
564                    (25..28, highlight_type),
565                    (29..30, highlight_type),
566                ],
567            })
568        );
569        assert_eq!(
570            adapter
571                .label_for_completion(
572                    &lsp::CompletionItem {
573                        kind: Some(lsp::CompletionItemKind::FUNCTION),
574                        label: "hello(…)".to_string(),
575                        detail: Some("async fn(&mut Option<T>) -> Vec<T>".to_string()),
576                        ..Default::default()
577                    },
578                    &language
579                )
580                .await,
581            Some(CodeLabel {
582                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
583                filter_range: 0..5,
584                runs: vec![
585                    (0..5, highlight_function),
586                    (7..10, highlight_keyword),
587                    (11..17, highlight_type),
588                    (18..19, highlight_type),
589                    (25..28, highlight_type),
590                    (29..30, highlight_type),
591                ],
592            })
593        );
594        assert_eq!(
595            adapter
596                .label_for_completion(
597                    &lsp::CompletionItem {
598                        kind: Some(lsp::CompletionItemKind::FIELD),
599                        label: "len".to_string(),
600                        detail: Some("usize".to_string()),
601                        ..Default::default()
602                    },
603                    &language
604                )
605                .await,
606            Some(CodeLabel {
607                text: "len: usize".to_string(),
608                filter_range: 0..3,
609                runs: vec![(0..3, highlight_field), (5..10, highlight_type),],
610            })
611        );
612
613        assert_eq!(
614            adapter
615                .label_for_completion(
616                    &lsp::CompletionItem {
617                        kind: Some(lsp::CompletionItemKind::FUNCTION),
618                        label: "hello(…)".to_string(),
619                        detail: Some("fn(&mut Option<T>) -> Vec<T>".to_string()),
620                        ..Default::default()
621                    },
622                    &language
623                )
624                .await,
625            Some(CodeLabel {
626                text: "hello(&mut Option<T>) -> Vec<T>".to_string(),
627                filter_range: 0..5,
628                runs: vec![
629                    (0..5, highlight_function),
630                    (7..10, highlight_keyword),
631                    (11..17, highlight_type),
632                    (18..19, highlight_type),
633                    (25..28, highlight_type),
634                    (29..30, highlight_type),
635                ],
636            })
637        );
638    }
639
640    #[gpui::test]
641    async fn test_rust_label_for_symbol() {
642        let adapter = Arc::new(RustLspAdapter);
643        let language = language("rust", tree_sitter_rust::language());
644        let grammar = language.grammar().unwrap();
645        let theme = SyntaxTheme::new_test([
646            ("type", Hsla::default()),
647            ("keyword", Hsla::default()),
648            ("function", Hsla::default()),
649            ("property", Hsla::default()),
650        ]);
651
652        language.set_theme(&theme);
653
654        let highlight_function = grammar.highlight_id_for_name("function").unwrap();
655        let highlight_type = grammar.highlight_id_for_name("type").unwrap();
656        let highlight_keyword = grammar.highlight_id_for_name("keyword").unwrap();
657
658        assert_eq!(
659            adapter
660                .label_for_symbol("hello", lsp::SymbolKind::FUNCTION, &language)
661                .await,
662            Some(CodeLabel {
663                text: "fn hello".to_string(),
664                filter_range: 3..8,
665                runs: vec![(0..2, highlight_keyword), (3..8, highlight_function)],
666            })
667        );
668
669        assert_eq!(
670            adapter
671                .label_for_symbol("World", lsp::SymbolKind::TYPE_PARAMETER, &language)
672                .await,
673            Some(CodeLabel {
674                text: "type World".to_string(),
675                filter_range: 5..10,
676                runs: vec![(0..4, highlight_keyword), (5..10, highlight_type)],
677            })
678        );
679    }
680
681    #[gpui::test]
682    async fn test_rust_autoindent(cx: &mut TestAppContext) {
683        // cx.executor().set_block_on_ticks(usize::MAX..=usize::MAX);
684        cx.update(|cx| {
685            let test_settings = SettingsStore::test(cx);
686            cx.set_global(test_settings);
687            language::init(cx);
688            cx.update_global::<SettingsStore, _>(|store, cx| {
689                store.update_user_settings::<AllLanguageSettings>(cx, |s| {
690                    s.defaults.tab_size = NonZeroU32::new(2);
691                });
692            });
693        });
694
695        let language = crate::language("rust", tree_sitter_rust::language());
696
697        cx.new_model(|cx| {
698            let mut buffer = Buffer::local("", cx).with_language(language, cx);
699
700            // indent between braces
701            buffer.set_text("fn a() {}", cx);
702            let ix = buffer.len() - 1;
703            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
704            assert_eq!(buffer.text(), "fn a() {\n  \n}");
705
706            // indent between braces, even after empty lines
707            buffer.set_text("fn a() {\n\n\n}", cx);
708            let ix = buffer.len() - 2;
709            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
710            assert_eq!(buffer.text(), "fn a() {\n\n\n  \n}");
711
712            // indent a line that continues a field expression
713            buffer.set_text("fn a() {\n  \n}", cx);
714            let ix = buffer.len() - 2;
715            buffer.edit([(ix..ix, "b\n.c")], Some(AutoindentMode::EachLine), cx);
716            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n}");
717
718            // indent further lines that continue the field expression, even after empty lines
719            let ix = buffer.len() - 2;
720            buffer.edit([(ix..ix, "\n\n.d")], Some(AutoindentMode::EachLine), cx);
721            assert_eq!(buffer.text(), "fn a() {\n  b\n    .c\n    \n    .d\n}");
722
723            // dedent the line after the field expression
724            let ix = buffer.len() - 2;
725            buffer.edit([(ix..ix, ";\ne")], Some(AutoindentMode::EachLine), cx);
726            assert_eq!(
727                buffer.text(),
728                "fn a() {\n  b\n    .c\n    \n    .d;\n  e\n}"
729            );
730
731            // indent inside a struct within a call
732            buffer.set_text("const a: B = c(D {});", cx);
733            let ix = buffer.len() - 3;
734            buffer.edit([(ix..ix, "\n\n")], Some(AutoindentMode::EachLine), cx);
735            assert_eq!(buffer.text(), "const a: B = c(D {\n  \n});");
736
737            // indent further inside a nested call
738            let ix = buffer.len() - 4;
739            buffer.edit([(ix..ix, "e: f(\n\n)")], Some(AutoindentMode::EachLine), cx);
740            assert_eq!(buffer.text(), "const a: B = c(D {\n  e: f(\n    \n  )\n});");
741
742            // keep that indent after an empty line
743            let ix = buffer.len() - 8;
744            buffer.edit([(ix..ix, "\n")], Some(AutoindentMode::EachLine), cx);
745            assert_eq!(
746                buffer.text(),
747                "const a: B = c(D {\n  e: f(\n    \n    \n  )\n});"
748            );
749
750            buffer
751        });
752    }
753}