editor_test_context.rs

  1use crate::{
  2    AnchorRangeExt, DisplayPoint, Editor, ExcerptId, MultiBuffer, MultiBufferSnapshot, RowExt,
  3    display_map::{HighlightKey, ToDisplayPoint},
  4};
  5use buffer_diff::DiffHunkStatusKind;
  6use collections::BTreeMap;
  7use futures::Future;
  8
  9use gpui::{
 10    AnyWindowHandle, App, Context, Entity, Focusable as _, Keystroke, Pixels, Point,
 11    VisualTestContext, Window, WindowHandle, prelude::*,
 12};
 13use itertools::Itertools;
 14use language::{Buffer, BufferSnapshot, LanguageRegistry};
 15use multi_buffer::{Anchor, ExcerptRange, MultiBufferRow};
 16use parking_lot::RwLock;
 17use project::{FakeFs, Project};
 18use std::{
 19    any::TypeId,
 20    ops::{Deref, DerefMut, Range},
 21    path::Path,
 22    sync::{
 23        Arc,
 24        atomic::{AtomicUsize, Ordering},
 25    },
 26};
 27use text::Selection;
 28use util::{
 29    assert_set_eq,
 30    test::{generate_marked_text, marked_text_ranges},
 31};
 32
 33use super::{build_editor, build_editor_with_project};
 34
 35pub struct EditorTestContext {
 36    pub cx: gpui::VisualTestContext,
 37    pub window: AnyWindowHandle,
 38    pub editor: Entity<Editor>,
 39    pub assertion_cx: AssertionContextManager,
 40}
 41
 42impl EditorTestContext {
 43    pub async fn new(cx: &mut gpui::TestAppContext) -> EditorTestContext {
 44        let fs = FakeFs::new(cx.executor());
 45        let root = Self::root_path();
 46        fs.insert_tree(
 47            root,
 48            serde_json::json!({
 49                ".git": {},
 50                "file": "",
 51            }),
 52        )
 53        .await;
 54        let project = Project::test(fs.clone(), [root], cx).await;
 55        let buffer = project
 56            .update(cx, |project, cx| {
 57                project.open_local_buffer(root.join("file"), cx)
 58            })
 59            .await
 60            .unwrap();
 61
 62        let language = project
 63            .read_with(cx, |project, cx| {
 64                project.languages().language_for_name("Plain Text")
 65            })
 66            .await
 67            .unwrap();
 68        buffer.update(cx, |buffer, cx| {
 69            buffer.set_language(Some(language), cx);
 70        });
 71
 72        let editor = cx.add_window(|window, cx| {
 73            let editor = build_editor_with_project(
 74                project,
 75                MultiBuffer::build_from_buffer(buffer, cx),
 76                window,
 77                cx,
 78            );
 79
 80            window.focus(&editor.focus_handle(cx));
 81            editor
 82        });
 83        let editor_view = editor.root(cx).unwrap();
 84
 85        cx.run_until_parked();
 86        Self {
 87            cx: VisualTestContext::from_window(*editor.deref(), cx),
 88            window: editor.into(),
 89            editor: editor_view,
 90            assertion_cx: AssertionContextManager::new(),
 91        }
 92    }
 93
 94    #[cfg(target_os = "windows")]
 95    fn root_path() -> &'static Path {
 96        Path::new("C:\\root")
 97    }
 98
 99    #[cfg(not(target_os = "windows"))]
100    fn root_path() -> &'static Path {
101        Path::new("/root")
102    }
103
104    pub async fn for_editor_in(editor: Entity<Editor>, cx: &mut gpui::VisualTestContext) -> Self {
105        cx.focus(&editor);
106        Self {
107            window: cx.windows()[0],
108            cx: cx.clone(),
109            editor,
110            assertion_cx: AssertionContextManager::new(),
111        }
112    }
113
114    pub async fn for_editor(editor: WindowHandle<Editor>, cx: &mut gpui::TestAppContext) -> Self {
115        let editor_view = editor.root(cx).unwrap();
116        Self {
117            cx: VisualTestContext::from_window(*editor.deref(), cx),
118            window: editor.into(),
119            editor: editor_view,
120            assertion_cx: AssertionContextManager::new(),
121        }
122    }
123
124    #[track_caller]
125    pub fn new_multibuffer<const COUNT: usize>(
126        cx: &mut gpui::TestAppContext,
127        excerpts: [&str; COUNT],
128    ) -> EditorTestContext {
129        let mut multibuffer = MultiBuffer::new(language::Capability::ReadWrite);
130        let buffer = cx.new(|cx| {
131            for excerpt in excerpts.into_iter() {
132                let (text, ranges) = marked_text_ranges(excerpt, false);
133                let buffer = cx.new(|cx| Buffer::local(text, cx));
134                multibuffer.push_excerpts(buffer, ranges.into_iter().map(ExcerptRange::new), cx);
135            }
136            multibuffer
137        });
138
139        let editor = cx.add_window(|window, cx| {
140            let editor = build_editor(buffer, window, cx);
141            window.focus(&editor.focus_handle(cx));
142
143            editor
144        });
145
146        let editor_view = editor.root(cx).unwrap();
147        Self {
148            cx: VisualTestContext::from_window(*editor.deref(), cx),
149            window: editor.into(),
150            editor: editor_view,
151            assertion_cx: AssertionContextManager::new(),
152        }
153    }
154
155    pub fn condition(
156        &self,
157        predicate: impl FnMut(&Editor, &App) -> bool,
158    ) -> impl Future<Output = ()> {
159        self.editor
160            .condition::<crate::EditorEvent>(&self.cx, predicate)
161    }
162
163    #[track_caller]
164    pub fn editor<F, T>(&mut self, read: F) -> T
165    where
166        F: FnOnce(&Editor, &Window, &mut Context<Editor>) -> T,
167    {
168        self.editor
169            .update_in(&mut self.cx, |this, window, cx| read(this, window, cx))
170    }
171
172    #[track_caller]
173    pub fn update_editor<F, T>(&mut self, update: F) -> T
174    where
175        F: FnOnce(&mut Editor, &mut Window, &mut Context<Editor>) -> T,
176    {
177        self.editor.update_in(&mut self.cx, update)
178    }
179
180    pub fn multibuffer<F, T>(&mut self, read: F) -> T
181    where
182        F: FnOnce(&MultiBuffer, &App) -> T,
183    {
184        self.editor(|editor, _, cx| read(editor.buffer().read(cx), cx))
185    }
186
187    pub fn update_multibuffer<F, T>(&mut self, update: F) -> T
188    where
189        F: FnOnce(&mut MultiBuffer, &mut Context<MultiBuffer>) -> T,
190    {
191        self.update_editor(|editor, _, cx| editor.buffer().update(cx, update))
192    }
193
194    pub fn buffer_text(&mut self) -> String {
195        self.multibuffer(|buffer, cx| buffer.snapshot(cx).text())
196    }
197
198    pub fn display_text(&mut self) -> String {
199        self.update_editor(|editor, _, cx| editor.display_text(cx))
200    }
201
202    pub fn buffer<F, T>(&mut self, read: F) -> T
203    where
204        F: FnOnce(&Buffer, &App) -> T,
205    {
206        self.multibuffer(|multibuffer, cx| {
207            let buffer = multibuffer.as_singleton().unwrap().read(cx);
208            read(buffer, cx)
209        })
210    }
211
212    pub fn language_registry(&mut self) -> Arc<LanguageRegistry> {
213        self.editor(|editor, _, cx| {
214            editor
215                .project
216                .as_ref()
217                .unwrap()
218                .read(cx)
219                .languages()
220                .clone()
221        })
222    }
223
224    pub fn update_buffer<F, T>(&mut self, update: F) -> T
225    where
226        F: FnOnce(&mut Buffer, &mut Context<Buffer>) -> T,
227    {
228        self.update_multibuffer(|multibuffer, cx| {
229            let buffer = multibuffer.as_singleton().unwrap();
230            buffer.update(cx, update)
231        })
232    }
233
234    pub fn buffer_snapshot(&mut self) -> BufferSnapshot {
235        self.buffer(|buffer, _| buffer.snapshot())
236    }
237
238    pub fn add_assertion_context(&self, context: String) -> ContextHandle {
239        self.assertion_cx.add_context(context)
240    }
241
242    pub fn assertion_context(&self) -> String {
243        self.assertion_cx.context()
244    }
245
246    // unlike cx.simulate_keystrokes(), this does not run_until_parked
247    // so you can use it to test detailed timing
248    pub fn simulate_keystroke(&mut self, keystroke_text: &str) {
249        let keystroke = Keystroke::parse(keystroke_text).unwrap();
250        self.cx.dispatch_keystroke(self.window, keystroke);
251    }
252
253    pub fn run_until_parked(&mut self) {
254        self.cx.background_executor.run_until_parked();
255    }
256
257    #[track_caller]
258    pub fn ranges(&mut self, marked_text: &str) -> Vec<Range<usize>> {
259        let (unmarked_text, ranges) = marked_text_ranges(marked_text, false);
260        assert_eq!(self.buffer_text(), unmarked_text);
261        ranges
262    }
263
264    pub fn display_point(&mut self, marked_text: &str) -> DisplayPoint {
265        let ranges = self.ranges(marked_text);
266        let snapshot = self.editor.update_in(&mut self.cx, |editor, window, cx| {
267            editor.snapshot(window, cx)
268        });
269        ranges[0].start.to_display_point(&snapshot)
270    }
271
272    pub fn pixel_position(&mut self, marked_text: &str) -> Point<Pixels> {
273        let display_point = self.display_point(marked_text);
274        self.pixel_position_for(display_point)
275    }
276
277    pub fn pixel_position_for(&mut self, display_point: DisplayPoint) -> Point<Pixels> {
278        self.update_editor(|editor, window, cx| {
279            let newest_point = editor.selections.newest_display(cx).head();
280            let pixel_position = editor.pixel_position_of_newest_cursor.unwrap();
281            let line_height = editor
282                .style()
283                .unwrap()
284                .text
285                .line_height_in_pixels(window.rem_size());
286            let snapshot = editor.snapshot(window, cx);
287            let details = editor.text_layout_details(window);
288
289            let y = pixel_position.y
290                + f32::from(line_height)
291                    * Pixels::from(display_point.row().as_f64() - newest_point.row().as_f64());
292            let x = pixel_position.x + snapshot.x_for_display_point(display_point, &details)
293                - snapshot.x_for_display_point(newest_point, &details);
294            Point::new(x, y)
295        })
296    }
297
298    // Returns anchors for the current buffer using `«` and `»`
299    pub fn text_anchor_range(&mut self, marked_text: &str) -> Range<language::Anchor> {
300        let ranges = self.ranges(marked_text);
301        let snapshot = self.buffer_snapshot();
302        snapshot.anchor_before(ranges[0].start)..snapshot.anchor_after(ranges[0].end)
303    }
304
305    pub fn set_head_text(&mut self, diff_base: &str) {
306        self.cx.run_until_parked();
307        let fs =
308            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
309        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
310        fs.set_head_for_repo(
311            &Self::root_path().join(".git"),
312            &[(path.as_unix_str(), diff_base.to_string())],
313            "deadbeef",
314        );
315        self.cx.run_until_parked();
316    }
317
318    pub fn clear_index_text(&mut self) {
319        self.cx.run_until_parked();
320        let fs =
321            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
322        fs.set_index_for_repo(&Self::root_path().join(".git"), &[]);
323        self.cx.run_until_parked();
324    }
325
326    pub fn set_index_text(&mut self, diff_base: &str) {
327        self.cx.run_until_parked();
328        let fs =
329            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
330        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
331        fs.set_index_for_repo(
332            &Self::root_path().join(".git"),
333            &[(path.as_unix_str(), diff_base.to_string())],
334        );
335        self.cx.run_until_parked();
336    }
337
338    #[track_caller]
339    pub fn assert_index_text(&mut self, expected: Option<&str>) {
340        let fs =
341            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
342        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
343        let mut found = None;
344        fs.with_git_state(&Self::root_path().join(".git"), false, |git_state| {
345            found = git_state.index_contents.get(&path.into()).cloned();
346        })
347        .unwrap();
348        assert_eq!(expected, found.as_deref());
349    }
350
351    /// Change the editor's text and selections using a string containing
352    /// embedded range markers that represent the ranges and directions of
353    /// each selection.
354    ///
355    /// Returns a context handle so that assertion failures can print what
356    /// editor state was needed to cause the failure.
357    ///
358    /// See the `util::test::marked_text_ranges` function for more information.
359    #[track_caller]
360    pub fn set_state(&mut self, marked_text: &str) -> ContextHandle {
361        let state_context = self.add_assertion_context(format!(
362            "Initial Editor State: \"{}\"",
363            marked_text.escape_debug()
364        ));
365        let (unmarked_text, selection_ranges) = marked_text_ranges(marked_text, true);
366        self.editor.update_in(&mut self.cx, |editor, window, cx| {
367            editor.set_text(unmarked_text, window, cx);
368            editor.change_selections(Default::default(), window, cx, |s| {
369                s.select_ranges(selection_ranges)
370            })
371        });
372        state_context
373    }
374
375    /// Only change the editor's selections
376    #[track_caller]
377    pub fn set_selections_state(&mut self, marked_text: &str) -> ContextHandle {
378        let state_context = self.add_assertion_context(format!(
379            "Initial Editor State: \"{}\"",
380            marked_text.escape_debug()
381        ));
382        let (unmarked_text, selection_ranges) = marked_text_ranges(marked_text, true);
383        self.editor.update_in(&mut self.cx, |editor, window, cx| {
384            assert_eq!(editor.text(cx), unmarked_text);
385            editor.change_selections(Default::default(), window, cx, |s| {
386                s.select_ranges(selection_ranges)
387            })
388        });
389        state_context
390    }
391
392    /// Assert about the text of the editor, the selections, and the expanded
393    /// diff hunks.
394    ///
395    /// Diff hunks are indicated by lines starting with `+` and `-`.
396    #[track_caller]
397    pub fn assert_state_with_diff(&mut self, expected_diff_text: String) {
398        assert_state_with_diff(&self.editor, &mut self.cx, &expected_diff_text);
399    }
400
401    #[track_caller]
402    pub fn assert_excerpts_with_selections(&mut self, marked_text: &str) {
403        let actual_text = self.to_format_multibuffer_as_marked_text();
404        let fmt_additional_notes = || {
405            struct Format<'a, T: std::fmt::Display>(&'a str, &'a T);
406
407            impl<T: std::fmt::Display> std::fmt::Display for Format<'_, T> {
408                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
409                    write!(
410                        f,
411                        "\n\n----- EXPECTED: -----\n\n{}\n\n----- ACTUAL: -----\n\n{}\n\n",
412                        self.0, self.1
413                    )
414                }
415            }
416
417            Format(marked_text, &actual_text)
418        };
419
420        let expected_excerpts = marked_text
421            .strip_prefix("[EXCERPT]\n")
422            .unwrap()
423            .split("[EXCERPT]\n")
424            .collect::<Vec<_>>();
425
426        let (multibuffer_snapshot, selections, excerpts) = self.update_editor(|editor, _, cx| {
427            let multibuffer_snapshot = editor.buffer.read(cx).snapshot(cx);
428
429            let selections = editor.selections.disjoint_anchors_arc();
430            let excerpts = multibuffer_snapshot
431                .excerpts()
432                .map(|(e_id, snapshot, range)| (e_id, snapshot.clone(), range))
433                .collect::<Vec<_>>();
434
435            (multibuffer_snapshot, selections, excerpts)
436        });
437
438        assert!(
439            excerpts.len() == expected_excerpts.len(),
440            "should have {} excerpts, got {}{}",
441            expected_excerpts.len(),
442            excerpts.len(),
443            fmt_additional_notes(),
444        );
445
446        for (ix, (excerpt_id, snapshot, range)) in excerpts.into_iter().enumerate() {
447            let is_folded = self
448                .update_editor(|editor, _, cx| editor.is_buffer_folded(snapshot.remote_id(), cx));
449            let (expected_text, expected_selections) =
450                marked_text_ranges(expected_excerpts[ix], true);
451            if expected_text == "[FOLDED]\n" {
452                assert!(is_folded, "excerpt {} should be folded", ix);
453                let is_selected = selections.iter().any(|s| s.head().excerpt_id == excerpt_id);
454                if !expected_selections.is_empty() {
455                    assert!(
456                        is_selected,
457                        "excerpt {ix} should contain selections. got {:?}{}",
458                        self.editor_state(),
459                        fmt_additional_notes(),
460                    );
461                } else {
462                    assert!(
463                        !is_selected,
464                        "excerpt {ix} should not contain selections, got: {selections:?}{}",
465                        fmt_additional_notes(),
466                    );
467                }
468                continue;
469            }
470            assert!(
471                !is_folded,
472                "excerpt {} should not be folded{}",
473                ix,
474                fmt_additional_notes()
475            );
476            assert_eq!(
477                multibuffer_snapshot
478                    .text_for_range(Anchor::range_in_buffer(
479                        excerpt_id,
480                        snapshot.remote_id(),
481                        range.context.clone()
482                    ))
483                    .collect::<String>(),
484                expected_text,
485                "{}",
486                fmt_additional_notes(),
487            );
488
489            let selections = selections
490                .iter()
491                .filter(|s| s.head().excerpt_id == excerpt_id)
492                .map(|s| {
493                    let head = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
494                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
495                    let tail = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
496                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
497                    tail..head
498                })
499                .collect::<Vec<_>>();
500            // todo: selections that cross excerpt boundaries..
501            assert_eq!(
502                selections,
503                expected_selections,
504                "excerpt {} has incorrect selections{}",
505                ix,
506                fmt_additional_notes()
507            );
508        }
509    }
510
511    fn to_format_multibuffer_as_marked_text(&mut self) -> FormatMultiBufferAsMarkedText {
512        let (multibuffer_snapshot, selections, excerpts) = self.update_editor(|editor, _, cx| {
513            let multibuffer_snapshot = editor.buffer.read(cx).snapshot(cx);
514
515            let selections = editor.selections.disjoint_anchors_arc().to_vec();
516            let excerpts = multibuffer_snapshot
517                .excerpts()
518                .map(|(e_id, snapshot, range)| {
519                    let is_folded = editor.is_buffer_folded(snapshot.remote_id(), cx);
520                    (e_id, snapshot.clone(), range, is_folded)
521                })
522                .collect::<Vec<_>>();
523
524            (multibuffer_snapshot, selections, excerpts)
525        });
526
527        FormatMultiBufferAsMarkedText {
528            multibuffer_snapshot,
529            selections,
530            excerpts,
531        }
532    }
533
534    /// Make an assertion about the editor's text and the ranges and directions
535    /// of its selections using a string containing embedded range markers.
536    ///
537    /// See the `util::test::marked_text_ranges` function for more information.
538    #[track_caller]
539    pub fn assert_editor_state(&mut self, marked_text: &str) {
540        let (expected_text, expected_selections) = marked_text_ranges(marked_text, true);
541        pretty_assertions::assert_eq!(self.buffer_text(), expected_text, "unexpected buffer text");
542        self.assert_selections(expected_selections, marked_text.to_string())
543    }
544
545    /// Make an assertion about the editor's text and the ranges and directions
546    /// of its selections using a string containing embedded range markers.
547    ///
548    /// See the `util::test::marked_text_ranges` function for more information.
549    #[track_caller]
550    pub fn assert_display_state(&mut self, marked_text: &str) {
551        let (expected_text, expected_selections) = marked_text_ranges(marked_text, true);
552        pretty_assertions::assert_eq!(self.display_text(), expected_text, "unexpected buffer text");
553        self.assert_selections(expected_selections, marked_text.to_string())
554    }
555
556    pub fn editor_state(&mut self) -> String {
557        generate_marked_text(self.buffer_text().as_str(), &self.editor_selections(), true)
558    }
559
560    #[track_caller]
561    pub fn assert_editor_background_highlights<Tag: 'static>(&mut self, marked_text: &str) {
562        let expected_ranges = self.ranges(marked_text);
563        let actual_ranges: Vec<Range<usize>> = self.update_editor(|editor, window, cx| {
564            let snapshot = editor.snapshot(window, cx);
565            editor
566                .background_highlights
567                .get(&HighlightKey::Type(TypeId::of::<Tag>()))
568                .map(|h| h.1.clone())
569                .unwrap_or_default()
570                .iter()
571                .map(|range| range.to_offset(&snapshot.buffer_snapshot()))
572                .collect()
573        });
574        assert_set_eq!(actual_ranges, expected_ranges);
575    }
576
577    #[track_caller]
578    pub fn assert_editor_text_highlights<Tag: ?Sized + 'static>(&mut self, marked_text: &str) {
579        let expected_ranges = self.ranges(marked_text);
580        let snapshot = self.update_editor(|editor, window, cx| editor.snapshot(window, cx));
581        let actual_ranges: Vec<Range<usize>> = snapshot
582            .text_highlight_ranges::<Tag>()
583            .map(|ranges| ranges.as_ref().clone().1)
584            .unwrap_or_default()
585            .into_iter()
586            .map(|range| range.to_offset(&snapshot.buffer_snapshot()))
587            .collect();
588        assert_set_eq!(actual_ranges, expected_ranges);
589    }
590
591    #[track_caller]
592    pub fn assert_editor_selections(&mut self, expected_selections: Vec<Range<usize>>) {
593        let expected_marked_text =
594            generate_marked_text(&self.buffer_text(), &expected_selections, true)
595                .replace(" \n", "\n");
596
597        self.assert_selections(expected_selections, expected_marked_text)
598    }
599
600    #[track_caller]
601    fn editor_selections(&mut self) -> Vec<Range<usize>> {
602        self.editor
603            .update(&mut self.cx, |editor, cx| {
604                editor.selections.all::<usize>(cx)
605            })
606            .into_iter()
607            .map(|s| {
608                if s.reversed {
609                    s.end..s.start
610                } else {
611                    s.start..s.end
612                }
613            })
614            .collect::<Vec<_>>()
615    }
616
617    #[track_caller]
618    fn assert_selections(
619        &mut self,
620        expected_selections: Vec<Range<usize>>,
621        expected_marked_text: String,
622    ) {
623        let actual_selections = self.editor_selections();
624        let actual_marked_text =
625            generate_marked_text(&self.buffer_text(), &actual_selections, true)
626                .replace(" \n", "\n");
627        if expected_selections != actual_selections {
628            pretty_assertions::assert_eq!(
629                actual_marked_text,
630                expected_marked_text,
631                "{}Editor has unexpected selections",
632                self.assertion_context(),
633            );
634        }
635    }
636}
637
638struct FormatMultiBufferAsMarkedText {
639    multibuffer_snapshot: MultiBufferSnapshot,
640    selections: Vec<Selection<Anchor>>,
641    excerpts: Vec<(ExcerptId, BufferSnapshot, ExcerptRange<text::Anchor>, bool)>,
642}
643
644impl std::fmt::Display for FormatMultiBufferAsMarkedText {
645    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
646        let Self {
647            multibuffer_snapshot,
648            selections,
649            excerpts,
650        } = self;
651
652        for (excerpt_id, snapshot, range, is_folded) in excerpts.into_iter() {
653            write!(f, "[EXCERPT]\n")?;
654            if *is_folded {
655                write!(f, "[FOLDED]\n")?;
656            }
657
658            let mut text = multibuffer_snapshot
659                .text_for_range(Anchor::range_in_buffer(
660                    *excerpt_id,
661                    snapshot.remote_id(),
662                    range.context.clone(),
663                ))
664                .collect::<String>();
665
666            let selections = selections
667                .iter()
668                .filter(|&s| s.head().excerpt_id == *excerpt_id)
669                .map(|s| {
670                    let head = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
671                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
672                    let tail = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
673                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
674                    tail..head
675                })
676                .rev()
677                .collect::<Vec<_>>();
678
679            for selection in selections {
680                if selection.is_empty() {
681                    text.insert(selection.start, 'ˇ');
682                    continue;
683                }
684                text.insert(selection.end, '»');
685                text.insert(selection.start, '«');
686            }
687
688            write!(f, "{text}")?;
689        }
690
691        Ok(())
692    }
693}
694
695#[track_caller]
696pub fn assert_state_with_diff(
697    editor: &Entity<Editor>,
698    cx: &mut VisualTestContext,
699    expected_diff_text: &str,
700) {
701    let (snapshot, selections) = editor.update_in(cx, |editor, window, cx| {
702        (
703            editor.snapshot(window, cx).buffer_snapshot().clone(),
704            editor.selections.ranges::<usize>(cx),
705        )
706    });
707
708    let actual_marked_text = generate_marked_text(&snapshot.text(), &selections, true);
709
710    // Read the actual diff.
711    let line_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
712    let has_diff = line_infos.iter().any(|info| info.diff_status.is_some());
713    let actual_diff = actual_marked_text
714        .split('\n')
715        .zip(line_infos)
716        .map(|(line, info)| {
717            let mut marker = match info.diff_status.map(|status| status.kind) {
718                Some(DiffHunkStatusKind::Added) => "+ ",
719                Some(DiffHunkStatusKind::Deleted) => "- ",
720                Some(DiffHunkStatusKind::Modified) => unreachable!(),
721                None => {
722                    if has_diff {
723                        "  "
724                    } else {
725                        ""
726                    }
727                }
728            };
729            if line.is_empty() {
730                marker = marker.trim();
731            }
732            format!("{marker}{line}")
733        })
734        .collect::<Vec<_>>()
735        .join("\n");
736
737    pretty_assertions::assert_eq!(actual_diff, expected_diff_text, "unexpected diff state");
738}
739
740impl Deref for EditorTestContext {
741    type Target = gpui::VisualTestContext;
742
743    fn deref(&self) -> &Self::Target {
744        &self.cx
745    }
746}
747
748impl DerefMut for EditorTestContext {
749    fn deref_mut(&mut self) -> &mut Self::Target {
750        &mut self.cx
751    }
752}
753
754/// Tracks string context to be printed when assertions fail.
755/// Often this is done by storing a context string in the manager and returning the handle.
756#[derive(Clone)]
757pub struct AssertionContextManager {
758    id: Arc<AtomicUsize>,
759    contexts: Arc<RwLock<BTreeMap<usize, String>>>,
760}
761
762impl Default for AssertionContextManager {
763    fn default() -> Self {
764        Self::new()
765    }
766}
767
768impl AssertionContextManager {
769    pub fn new() -> Self {
770        Self {
771            id: Arc::new(AtomicUsize::new(0)),
772            contexts: Arc::new(RwLock::new(BTreeMap::new())),
773        }
774    }
775
776    pub fn add_context(&self, context: String) -> ContextHandle {
777        let id = self.id.fetch_add(1, Ordering::Relaxed);
778        let mut contexts = self.contexts.write();
779        contexts.insert(id, context);
780        ContextHandle {
781            id,
782            manager: self.clone(),
783        }
784    }
785
786    pub fn context(&self) -> String {
787        let contexts = self.contexts.read();
788        format!("\n{}\n", contexts.values().join("\n"))
789    }
790}
791
792/// Used to track the lifetime of a piece of context so that it can be provided when an assertion fails.
793/// For example, in the EditorTestContext, `set_state` returns a context handle so that if an assertion fails,
794/// the state that was set initially for the failure can be printed in the error message
795pub struct ContextHandle {
796    id: usize,
797    manager: AssertionContextManager,
798}
799
800impl Drop for ContextHandle {
801    fn drop(&mut self) {
802        let mut contexts = self.manager.contexts.write();
803        contexts.remove(&self.id);
804    }
805}