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
280                .selections
281                .newest_display(&editor.display_snapshot(cx))
282                .head();
283            let pixel_position = editor.pixel_position_of_newest_cursor.unwrap();
284            let line_height = editor
285                .style()
286                .unwrap()
287                .text
288                .line_height_in_pixels(window.rem_size());
289            let snapshot = editor.snapshot(window, cx);
290            let details = editor.text_layout_details(window);
291
292            let y = pixel_position.y
293                + f32::from(line_height)
294                    * Pixels::from(display_point.row().as_f64() - newest_point.row().as_f64());
295            let x = pixel_position.x + snapshot.x_for_display_point(display_point, &details)
296                - snapshot.x_for_display_point(newest_point, &details);
297            Point::new(x, y)
298        })
299    }
300
301    // Returns anchors for the current buffer using `«` and `»`
302    pub fn text_anchor_range(&mut self, marked_text: &str) -> Range<language::Anchor> {
303        let ranges = self.ranges(marked_text);
304        let snapshot = self.buffer_snapshot();
305        snapshot.anchor_before(ranges[0].start)..snapshot.anchor_after(ranges[0].end)
306    }
307
308    pub fn set_head_text(&mut self, diff_base: &str) {
309        self.cx.run_until_parked();
310        let fs =
311            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
312        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
313        fs.set_head_for_repo(
314            &Self::root_path().join(".git"),
315            &[(path.as_unix_str(), diff_base.to_string())],
316            "deadbeef",
317        );
318        self.cx.run_until_parked();
319    }
320
321    pub fn clear_index_text(&mut self) {
322        self.cx.run_until_parked();
323        let fs =
324            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
325        fs.set_index_for_repo(&Self::root_path().join(".git"), &[]);
326        self.cx.run_until_parked();
327    }
328
329    pub fn set_index_text(&mut self, diff_base: &str) {
330        self.cx.run_until_parked();
331        let fs =
332            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
333        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
334        fs.set_index_for_repo(
335            &Self::root_path().join(".git"),
336            &[(path.as_unix_str(), diff_base.to_string())],
337        );
338        self.cx.run_until_parked();
339    }
340
341    #[track_caller]
342    pub fn assert_index_text(&mut self, expected: Option<&str>) {
343        let fs =
344            self.update_editor(|editor, _, cx| editor.project().unwrap().read(cx).fs().as_fake());
345        let path = self.update_buffer(|buffer, _| buffer.file().unwrap().path().clone());
346        let mut found = None;
347        fs.with_git_state(&Self::root_path().join(".git"), false, |git_state| {
348            found = git_state.index_contents.get(&path.into()).cloned();
349        })
350        .unwrap();
351        assert_eq!(expected, found.as_deref());
352    }
353
354    /// Change the editor's text and selections using a string containing
355    /// embedded range markers that represent the ranges and directions of
356    /// each selection.
357    ///
358    /// Returns a context handle so that assertion failures can print what
359    /// editor state was needed to cause the failure.
360    ///
361    /// See the `util::test::marked_text_ranges` function for more information.
362    #[track_caller]
363    pub fn set_state(&mut self, marked_text: &str) -> ContextHandle {
364        let state_context = self.add_assertion_context(format!(
365            "Initial Editor State: \"{}\"",
366            marked_text.escape_debug()
367        ));
368        let (unmarked_text, selection_ranges) = marked_text_ranges(marked_text, true);
369        self.editor.update_in(&mut self.cx, |editor, window, cx| {
370            editor.set_text(unmarked_text, window, cx);
371            editor.change_selections(Default::default(), window, cx, |s| {
372                s.select_ranges(selection_ranges)
373            })
374        });
375        state_context
376    }
377
378    /// Only change the editor's selections
379    #[track_caller]
380    pub fn set_selections_state(&mut self, marked_text: &str) -> ContextHandle {
381        let state_context = self.add_assertion_context(format!(
382            "Initial Editor State: \"{}\"",
383            marked_text.escape_debug()
384        ));
385        let (unmarked_text, selection_ranges) = marked_text_ranges(marked_text, true);
386        self.editor.update_in(&mut self.cx, |editor, window, cx| {
387            assert_eq!(editor.text(cx), unmarked_text);
388            editor.change_selections(Default::default(), window, cx, |s| {
389                s.select_ranges(selection_ranges)
390            })
391        });
392        state_context
393    }
394
395    /// Assert about the text of the editor, the selections, and the expanded
396    /// diff hunks.
397    ///
398    /// Diff hunks are indicated by lines starting with `+` and `-`.
399    #[track_caller]
400    pub fn assert_state_with_diff(&mut self, expected_diff_text: String) {
401        assert_state_with_diff(&self.editor, &mut self.cx, &expected_diff_text);
402    }
403
404    #[track_caller]
405    pub fn assert_excerpts_with_selections(&mut self, marked_text: &str) {
406        let actual_text = self.to_format_multibuffer_as_marked_text();
407        let fmt_additional_notes = || {
408            struct Format<'a, T: std::fmt::Display>(&'a str, &'a T);
409
410            impl<T: std::fmt::Display> std::fmt::Display for Format<'_, T> {
411                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
412                    write!(
413                        f,
414                        "\n\n----- EXPECTED: -----\n\n{}\n\n----- ACTUAL: -----\n\n{}\n\n",
415                        self.0, self.1
416                    )
417                }
418            }
419
420            Format(marked_text, &actual_text)
421        };
422
423        let expected_excerpts = marked_text
424            .strip_prefix("[EXCERPT]\n")
425            .unwrap()
426            .split("[EXCERPT]\n")
427            .collect::<Vec<_>>();
428
429        let (multibuffer_snapshot, selections, excerpts) = self.update_editor(|editor, _, cx| {
430            let multibuffer_snapshot = editor.buffer.read(cx).snapshot(cx);
431
432            let selections = editor.selections.disjoint_anchors_arc();
433            let excerpts = multibuffer_snapshot
434                .excerpts()
435                .map(|(e_id, snapshot, range)| (e_id, snapshot.clone(), range))
436                .collect::<Vec<_>>();
437
438            (multibuffer_snapshot, selections, excerpts)
439        });
440
441        assert!(
442            excerpts.len() == expected_excerpts.len(),
443            "should have {} excerpts, got {}{}",
444            expected_excerpts.len(),
445            excerpts.len(),
446            fmt_additional_notes(),
447        );
448
449        for (ix, (excerpt_id, snapshot, range)) in excerpts.into_iter().enumerate() {
450            let is_folded = self
451                .update_editor(|editor, _, cx| editor.is_buffer_folded(snapshot.remote_id(), cx));
452            let (expected_text, expected_selections) =
453                marked_text_ranges(expected_excerpts[ix], true);
454            if expected_text == "[FOLDED]\n" {
455                assert!(is_folded, "excerpt {} should be folded", ix);
456                let is_selected = selections.iter().any(|s| s.head().excerpt_id == excerpt_id);
457                if !expected_selections.is_empty() {
458                    assert!(
459                        is_selected,
460                        "excerpt {ix} should contain selections. got {:?}{}",
461                        self.editor_state(),
462                        fmt_additional_notes(),
463                    );
464                } else {
465                    assert!(
466                        !is_selected,
467                        "excerpt {ix} should not contain selections, got: {selections:?}{}",
468                        fmt_additional_notes(),
469                    );
470                }
471                continue;
472            }
473            assert!(
474                !is_folded,
475                "excerpt {} should not be folded{}",
476                ix,
477                fmt_additional_notes()
478            );
479            assert_eq!(
480                multibuffer_snapshot
481                    .text_for_range(Anchor::range_in_buffer(
482                        excerpt_id,
483                        snapshot.remote_id(),
484                        range.context.clone()
485                    ))
486                    .collect::<String>(),
487                expected_text,
488                "{}",
489                fmt_additional_notes(),
490            );
491
492            let selections = selections
493                .iter()
494                .filter(|s| s.head().excerpt_id == excerpt_id)
495                .map(|s| {
496                    let head = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
497                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
498                    let tail = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
499                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
500                    tail..head
501                })
502                .collect::<Vec<_>>();
503            // todo: selections that cross excerpt boundaries..
504            assert_eq!(
505                selections,
506                expected_selections,
507                "excerpt {} has incorrect selections{}",
508                ix,
509                fmt_additional_notes()
510            );
511        }
512    }
513
514    fn to_format_multibuffer_as_marked_text(&mut self) -> FormatMultiBufferAsMarkedText {
515        let (multibuffer_snapshot, selections, excerpts) = self.update_editor(|editor, _, cx| {
516            let multibuffer_snapshot = editor.buffer.read(cx).snapshot(cx);
517
518            let selections = editor.selections.disjoint_anchors_arc().to_vec();
519            let excerpts = multibuffer_snapshot
520                .excerpts()
521                .map(|(e_id, snapshot, range)| {
522                    let is_folded = editor.is_buffer_folded(snapshot.remote_id(), cx);
523                    (e_id, snapshot.clone(), range, is_folded)
524                })
525                .collect::<Vec<_>>();
526
527            (multibuffer_snapshot, selections, excerpts)
528        });
529
530        FormatMultiBufferAsMarkedText {
531            multibuffer_snapshot,
532            selections,
533            excerpts,
534        }
535    }
536
537    /// Make an assertion about the editor's text and the ranges and directions
538    /// of its selections using a string containing embedded range markers.
539    ///
540    /// See the `util::test::marked_text_ranges` function for more information.
541    #[track_caller]
542    pub fn assert_editor_state(&mut self, marked_text: &str) {
543        let (expected_text, expected_selections) = marked_text_ranges(marked_text, true);
544        pretty_assertions::assert_eq!(self.buffer_text(), expected_text, "unexpected buffer text");
545        self.assert_selections(expected_selections, marked_text.to_string())
546    }
547
548    /// Make an assertion about the editor's text and the ranges and directions
549    /// of its selections using a string containing embedded range markers.
550    ///
551    /// See the `util::test::marked_text_ranges` function for more information.
552    #[track_caller]
553    pub fn assert_display_state(&mut self, marked_text: &str) {
554        let (expected_text, expected_selections) = marked_text_ranges(marked_text, true);
555        pretty_assertions::assert_eq!(self.display_text(), expected_text, "unexpected buffer text");
556        self.assert_selections(expected_selections, marked_text.to_string())
557    }
558
559    pub fn editor_state(&mut self) -> String {
560        generate_marked_text(self.buffer_text().as_str(), &self.editor_selections(), true)
561    }
562
563    #[track_caller]
564    pub fn assert_editor_background_highlights<Tag: 'static>(&mut self, marked_text: &str) {
565        let expected_ranges = self.ranges(marked_text);
566        let actual_ranges: Vec<Range<usize>> = self.update_editor(|editor, window, cx| {
567            let snapshot = editor.snapshot(window, cx);
568            editor
569                .background_highlights
570                .get(&HighlightKey::Type(TypeId::of::<Tag>()))
571                .map(|h| h.1.clone())
572                .unwrap_or_default()
573                .iter()
574                .map(|range| range.to_offset(&snapshot.buffer_snapshot()))
575                .collect()
576        });
577        assert_set_eq!(actual_ranges, expected_ranges);
578    }
579
580    #[track_caller]
581    pub fn assert_editor_text_highlights<Tag: ?Sized + 'static>(&mut self, marked_text: &str) {
582        let expected_ranges = self.ranges(marked_text);
583        let snapshot = self.update_editor(|editor, window, cx| editor.snapshot(window, cx));
584        let actual_ranges: Vec<Range<usize>> = snapshot
585            .text_highlight_ranges::<Tag>()
586            .map(|ranges| ranges.as_ref().clone().1)
587            .unwrap_or_default()
588            .into_iter()
589            .map(|range| range.to_offset(&snapshot.buffer_snapshot()))
590            .collect();
591        assert_set_eq!(actual_ranges, expected_ranges);
592    }
593
594    #[track_caller]
595    pub fn assert_editor_selections(&mut self, expected_selections: Vec<Range<usize>>) {
596        let expected_marked_text =
597            generate_marked_text(&self.buffer_text(), &expected_selections, true)
598                .replace(" \n", "\n");
599
600        self.assert_selections(expected_selections, expected_marked_text)
601    }
602
603    #[track_caller]
604    fn editor_selections(&mut self) -> Vec<Range<usize>> {
605        self.editor
606            .update(&mut self.cx, |editor, cx| {
607                editor.selections.all::<usize>(&editor.display_snapshot(cx))
608            })
609            .into_iter()
610            .map(|s| {
611                if s.reversed {
612                    s.end..s.start
613                } else {
614                    s.start..s.end
615                }
616            })
617            .collect::<Vec<_>>()
618    }
619
620    #[track_caller]
621    fn assert_selections(
622        &mut self,
623        expected_selections: Vec<Range<usize>>,
624        expected_marked_text: String,
625    ) {
626        let actual_selections = self.editor_selections();
627        let actual_marked_text =
628            generate_marked_text(&self.buffer_text(), &actual_selections, true)
629                .replace(" \n", "\n");
630        if expected_selections != actual_selections {
631            pretty_assertions::assert_eq!(
632                actual_marked_text,
633                expected_marked_text,
634                "{}Editor has unexpected selections",
635                self.assertion_context(),
636            );
637        }
638    }
639}
640
641struct FormatMultiBufferAsMarkedText {
642    multibuffer_snapshot: MultiBufferSnapshot,
643    selections: Vec<Selection<Anchor>>,
644    excerpts: Vec<(ExcerptId, BufferSnapshot, ExcerptRange<text::Anchor>, bool)>,
645}
646
647impl std::fmt::Display for FormatMultiBufferAsMarkedText {
648    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
649        let Self {
650            multibuffer_snapshot,
651            selections,
652            excerpts,
653        } = self;
654
655        for (excerpt_id, snapshot, range, is_folded) in excerpts.into_iter() {
656            write!(f, "[EXCERPT]\n")?;
657            if *is_folded {
658                write!(f, "[FOLDED]\n")?;
659            }
660
661            let mut text = multibuffer_snapshot
662                .text_for_range(Anchor::range_in_buffer(
663                    *excerpt_id,
664                    snapshot.remote_id(),
665                    range.context.clone(),
666                ))
667                .collect::<String>();
668
669            let selections = selections
670                .iter()
671                .filter(|&s| s.head().excerpt_id == *excerpt_id)
672                .map(|s| {
673                    let head = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
674                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
675                    let tail = text::ToOffset::to_offset(&s.head().text_anchor, &snapshot)
676                        - text::ToOffset::to_offset(&range.context.start, &snapshot);
677                    tail..head
678                })
679                .rev()
680                .collect::<Vec<_>>();
681
682            for selection in selections {
683                if selection.is_empty() {
684                    text.insert(selection.start, 'ˇ');
685                    continue;
686                }
687                text.insert(selection.end, '»');
688                text.insert(selection.start, '«');
689            }
690
691            write!(f, "{text}")?;
692        }
693
694        Ok(())
695    }
696}
697
698#[track_caller]
699pub fn assert_state_with_diff(
700    editor: &Entity<Editor>,
701    cx: &mut VisualTestContext,
702    expected_diff_text: &str,
703) {
704    let (snapshot, selections) = editor.update_in(cx, |editor, window, cx| {
705        let snapshot = editor.snapshot(window, cx);
706        (
707            snapshot.buffer_snapshot().clone(),
708            editor
709                .selections
710                .ranges::<usize>(&snapshot.display_snapshot),
711        )
712    });
713
714    let actual_marked_text = generate_marked_text(&snapshot.text(), &selections, true);
715
716    // Read the actual diff.
717    let line_infos = snapshot.row_infos(MultiBufferRow(0)).collect::<Vec<_>>();
718    let has_diff = line_infos.iter().any(|info| info.diff_status.is_some());
719    let actual_diff = actual_marked_text
720        .split('\n')
721        .zip(line_infos)
722        .map(|(line, info)| {
723            let mut marker = match info.diff_status.map(|status| status.kind) {
724                Some(DiffHunkStatusKind::Added) => "+ ",
725                Some(DiffHunkStatusKind::Deleted) => "- ",
726                Some(DiffHunkStatusKind::Modified) => unreachable!(),
727                None => {
728                    if has_diff {
729                        "  "
730                    } else {
731                        ""
732                    }
733                }
734            };
735            if line.is_empty() {
736                marker = marker.trim();
737            }
738            format!("{marker}{line}")
739        })
740        .collect::<Vec<_>>()
741        .join("\n");
742
743    pretty_assertions::assert_eq!(actual_diff, expected_diff_text, "unexpected diff state");
744}
745
746impl Deref for EditorTestContext {
747    type Target = gpui::VisualTestContext;
748
749    fn deref(&self) -> &Self::Target {
750        &self.cx
751    }
752}
753
754impl DerefMut for EditorTestContext {
755    fn deref_mut(&mut self) -> &mut Self::Target {
756        &mut self.cx
757    }
758}
759
760/// Tracks string context to be printed when assertions fail.
761/// Often this is done by storing a context string in the manager and returning the handle.
762#[derive(Clone)]
763pub struct AssertionContextManager {
764    id: Arc<AtomicUsize>,
765    contexts: Arc<RwLock<BTreeMap<usize, String>>>,
766}
767
768impl Default for AssertionContextManager {
769    fn default() -> Self {
770        Self::new()
771    }
772}
773
774impl AssertionContextManager {
775    pub fn new() -> Self {
776        Self {
777            id: Arc::new(AtomicUsize::new(0)),
778            contexts: Arc::new(RwLock::new(BTreeMap::new())),
779        }
780    }
781
782    pub fn add_context(&self, context: String) -> ContextHandle {
783        let id = self.id.fetch_add(1, Ordering::Relaxed);
784        let mut contexts = self.contexts.write();
785        contexts.insert(id, context);
786        ContextHandle {
787            id,
788            manager: self.clone(),
789        }
790    }
791
792    pub fn context(&self) -> String {
793        let contexts = self.contexts.read();
794        format!("\n{}\n", contexts.values().join("\n"))
795    }
796}
797
798/// Used to track the lifetime of a piece of context so that it can be provided when an assertion fails.
799/// For example, in the EditorTestContext, `set_state` returns a context handle so that if an assertion fails,
800/// the state that was set initially for the failure can be printed in the error message
801pub struct ContextHandle {
802    id: usize,
803    manager: AssertionContextManager,
804}
805
806impl Drop for ContextHandle {
807    fn drop(&mut self) {
808        let mut contexts = self.manager.contexts.write();
809        contexts.remove(&self.id);
810    }
811}