buffer.rs

  1use crate::*;
  2use clock::ReplicaId;
  3use rand::prelude::*;
  4use std::{
  5    cell::RefCell,
  6    cmp::Ordering,
  7    env,
  8    iter::Iterator,
  9    mem,
 10    rc::Rc,
 11    time::{Duration, Instant},
 12};
 13
 14#[test]
 15fn test_edit() {
 16    let mut buffer = TextBuffer::new(0, 0, History::new("abc".into()));
 17    assert_eq!(buffer.text(), "abc");
 18    buffer.edit(vec![3..3], "def");
 19    assert_eq!(buffer.text(), "abcdef");
 20    buffer.edit(vec![0..0], "ghi");
 21    assert_eq!(buffer.text(), "ghiabcdef");
 22    buffer.edit(vec![5..5], "jkl");
 23    assert_eq!(buffer.text(), "ghiabjklcdef");
 24    buffer.edit(vec![6..7], "");
 25    assert_eq!(buffer.text(), "ghiabjlcdef");
 26    buffer.edit(vec![4..9], "mno");
 27    assert_eq!(buffer.text(), "ghiamnoef");
 28}
 29
 30#[gpui::test]
 31fn test_edit_events(cx: &mut gpui::MutableAppContext) {
 32    let mut now = Instant::now();
 33    let buffer_1_events = Rc::new(RefCell::new(Vec::new()));
 34    let buffer_2_events = Rc::new(RefCell::new(Vec::new()));
 35
 36    let buffer1 = cx.add_model(|cx| Buffer::new(0, "abcdef", cx));
 37    let buffer2 = cx.add_model(|cx| Buffer::new(1, "abcdef", cx));
 38    let buffer_ops = buffer1.update(cx, |buffer, cx| {
 39        let buffer_1_events = buffer_1_events.clone();
 40        cx.subscribe(&buffer1, move |_, _, event, _| {
 41            buffer_1_events.borrow_mut().push(event.clone())
 42        })
 43        .detach();
 44        let buffer_2_events = buffer_2_events.clone();
 45        cx.subscribe(&buffer2, move |_, _, event, _| {
 46            buffer_2_events.borrow_mut().push(event.clone())
 47        })
 48        .detach();
 49
 50        // An edit emits an edited event, followed by a dirtied event,
 51        // since the buffer was previously in a clean state.
 52        buffer.edit(Some(2..4), "XYZ", cx);
 53
 54        // An empty transaction does not emit any events.
 55        buffer.start_transaction(None).unwrap();
 56        buffer.end_transaction(None, cx).unwrap();
 57
 58        // A transaction containing two edits emits one edited event.
 59        now += Duration::from_secs(1);
 60        buffer.start_transaction_at(None, now).unwrap();
 61        buffer.edit(Some(5..5), "u", cx);
 62        buffer.edit(Some(6..6), "w", cx);
 63        buffer.end_transaction_at(None, now, cx).unwrap();
 64
 65        // Undoing a transaction emits one edited event.
 66        buffer.undo(cx);
 67
 68        buffer.operations.clone()
 69    });
 70
 71    // Incorporating a set of remote ops emits a single edited event,
 72    // followed by a dirtied event.
 73    buffer2.update(cx, |buffer, cx| {
 74        buffer.apply_ops(buffer_ops, cx).unwrap();
 75    });
 76
 77    let buffer_1_events = buffer_1_events.borrow();
 78    assert_eq!(
 79        *buffer_1_events,
 80        vec![Event::Edited, Event::Dirtied, Event::Edited, Event::Edited]
 81    );
 82
 83    let buffer_2_events = buffer_2_events.borrow();
 84    assert_eq!(*buffer_2_events, vec![Event::Edited, Event::Dirtied]);
 85}
 86
 87#[gpui::test(iterations = 100)]
 88fn test_random_edits(mut rng: StdRng) {
 89    let operations = env::var("OPERATIONS")
 90        .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
 91        .unwrap_or(10);
 92
 93    let reference_string_len = rng.gen_range(0..3);
 94    let mut reference_string = RandomCharIter::new(&mut rng)
 95        .take(reference_string_len)
 96        .collect::<String>();
 97    let mut buffer = TextBuffer::new(0, 0, History::new(reference_string.clone().into()));
 98    buffer.history.group_interval = Duration::from_millis(rng.gen_range(0..=200));
 99    let mut buffer_versions = Vec::new();
100    log::info!(
101        "buffer text {:?}, version: {:?}",
102        buffer.text(),
103        buffer.version()
104    );
105
106    for _i in 0..operations {
107        let (old_ranges, new_text) = buffer.randomly_mutate(&mut rng);
108        for old_range in old_ranges.iter().rev() {
109            reference_string.replace_range(old_range.clone(), &new_text);
110        }
111        assert_eq!(buffer.text(), reference_string);
112        log::info!(
113            "buffer text {:?}, version: {:?}",
114            buffer.text(),
115            buffer.version()
116        );
117
118        if rng.gen_bool(0.25) {
119            buffer.randomly_undo_redo(&mut rng);
120            reference_string = buffer.text();
121            log::info!(
122                "buffer text {:?}, version: {:?}",
123                buffer.text(),
124                buffer.version()
125            );
126        }
127
128        let range = buffer.random_byte_range(0, &mut rng);
129        assert_eq!(
130            buffer.text_summary_for_range(range.clone()),
131            TextSummary::from(&reference_string[range])
132        );
133
134        if rng.gen_bool(0.3) {
135            buffer_versions.push(buffer.clone());
136        }
137    }
138
139    for mut old_buffer in buffer_versions {
140        let edits = buffer
141            .edits_since(old_buffer.version.clone())
142            .collect::<Vec<_>>();
143
144        log::info!(
145            "mutating old buffer version {:?}, text: {:?}, edits since: {:?}",
146            old_buffer.version(),
147            old_buffer.text(),
148            edits,
149        );
150
151        let mut delta = 0_isize;
152        for edit in edits {
153            let old_start = (edit.old_bytes.start as isize + delta) as usize;
154            let new_text: String = buffer.text_for_range(edit.new_bytes.clone()).collect();
155            old_buffer.edit(Some(old_start..old_start + edit.deleted_bytes()), new_text);
156            delta += edit.delta();
157        }
158        assert_eq!(old_buffer.text(), buffer.text());
159    }
160}
161
162#[test]
163fn test_line_len() {
164    let mut buffer = TextBuffer::new(0, 0, History::new("".into()));
165    buffer.edit(vec![0..0], "abcd\nefg\nhij");
166    buffer.edit(vec![12..12], "kl\nmno");
167    buffer.edit(vec![18..18], "\npqrs\n");
168    buffer.edit(vec![18..21], "\nPQ");
169
170    assert_eq!(buffer.line_len(0), 4);
171    assert_eq!(buffer.line_len(1), 3);
172    assert_eq!(buffer.line_len(2), 5);
173    assert_eq!(buffer.line_len(3), 3);
174    assert_eq!(buffer.line_len(4), 4);
175    assert_eq!(buffer.line_len(5), 0);
176}
177
178#[test]
179fn test_text_summary_for_range() {
180    let buffer = TextBuffer::new(0, 0, History::new("ab\nefg\nhklm\nnopqrs\ntuvwxyz".into()));
181    assert_eq!(
182        buffer.text_summary_for_range(1..3),
183        TextSummary {
184            bytes: 2,
185            lines: Point::new(1, 0),
186            first_line_chars: 1,
187            last_line_chars: 0,
188            longest_row: 0,
189            longest_row_chars: 1,
190        }
191    );
192    assert_eq!(
193        buffer.text_summary_for_range(1..12),
194        TextSummary {
195            bytes: 11,
196            lines: Point::new(3, 0),
197            first_line_chars: 1,
198            last_line_chars: 0,
199            longest_row: 2,
200            longest_row_chars: 4,
201        }
202    );
203    assert_eq!(
204        buffer.text_summary_for_range(0..20),
205        TextSummary {
206            bytes: 20,
207            lines: Point::new(4, 1),
208            first_line_chars: 2,
209            last_line_chars: 1,
210            longest_row: 3,
211            longest_row_chars: 6,
212        }
213    );
214    assert_eq!(
215        buffer.text_summary_for_range(0..22),
216        TextSummary {
217            bytes: 22,
218            lines: Point::new(4, 3),
219            first_line_chars: 2,
220            last_line_chars: 3,
221            longest_row: 3,
222            longest_row_chars: 6,
223        }
224    );
225    assert_eq!(
226        buffer.text_summary_for_range(7..22),
227        TextSummary {
228            bytes: 15,
229            lines: Point::new(2, 3),
230            first_line_chars: 4,
231            last_line_chars: 3,
232            longest_row: 1,
233            longest_row_chars: 6,
234        }
235    );
236}
237
238#[test]
239fn test_chars_at() {
240    let mut buffer = TextBuffer::new(0, 0, History::new("".into()));
241    buffer.edit(vec![0..0], "abcd\nefgh\nij");
242    buffer.edit(vec![12..12], "kl\nmno");
243    buffer.edit(vec![18..18], "\npqrs");
244    buffer.edit(vec![18..21], "\nPQ");
245
246    let chars = buffer.chars_at(Point::new(0, 0));
247    assert_eq!(chars.collect::<String>(), "abcd\nefgh\nijkl\nmno\nPQrs");
248
249    let chars = buffer.chars_at(Point::new(1, 0));
250    assert_eq!(chars.collect::<String>(), "efgh\nijkl\nmno\nPQrs");
251
252    let chars = buffer.chars_at(Point::new(2, 0));
253    assert_eq!(chars.collect::<String>(), "ijkl\nmno\nPQrs");
254
255    let chars = buffer.chars_at(Point::new(3, 0));
256    assert_eq!(chars.collect::<String>(), "mno\nPQrs");
257
258    let chars = buffer.chars_at(Point::new(4, 0));
259    assert_eq!(chars.collect::<String>(), "PQrs");
260
261    // Regression test:
262    let mut buffer = TextBuffer::new(0, 0, History::new("".into()));
263    buffer.edit(vec![0..0], "[workspace]\nmembers = [\n    \"xray_core\",\n    \"xray_server\",\n    \"xray_cli\",\n    \"xray_wasm\",\n]\n");
264    buffer.edit(vec![60..60], "\n");
265
266    let chars = buffer.chars_at(Point::new(6, 0));
267    assert_eq!(chars.collect::<String>(), "    \"xray_wasm\",\n]\n");
268}
269
270#[test]
271fn test_anchors() {
272    let mut buffer = TextBuffer::new(0, 0, History::new("".into()));
273    buffer.edit(vec![0..0], "abc");
274    let left_anchor = buffer.anchor_before(2);
275    let right_anchor = buffer.anchor_after(2);
276
277    buffer.edit(vec![1..1], "def\n");
278    assert_eq!(buffer.text(), "adef\nbc");
279    assert_eq!(left_anchor.to_offset(&buffer), 6);
280    assert_eq!(right_anchor.to_offset(&buffer), 6);
281    assert_eq!(left_anchor.to_point(&buffer), Point { row: 1, column: 1 });
282    assert_eq!(right_anchor.to_point(&buffer), Point { row: 1, column: 1 });
283
284    buffer.edit(vec![2..3], "");
285    assert_eq!(buffer.text(), "adf\nbc");
286    assert_eq!(left_anchor.to_offset(&buffer), 5);
287    assert_eq!(right_anchor.to_offset(&buffer), 5);
288    assert_eq!(left_anchor.to_point(&buffer), Point { row: 1, column: 1 });
289    assert_eq!(right_anchor.to_point(&buffer), Point { row: 1, column: 1 });
290
291    buffer.edit(vec![5..5], "ghi\n");
292    assert_eq!(buffer.text(), "adf\nbghi\nc");
293    assert_eq!(left_anchor.to_offset(&buffer), 5);
294    assert_eq!(right_anchor.to_offset(&buffer), 9);
295    assert_eq!(left_anchor.to_point(&buffer), Point { row: 1, column: 1 });
296    assert_eq!(right_anchor.to_point(&buffer), Point { row: 2, column: 0 });
297
298    buffer.edit(vec![7..9], "");
299    assert_eq!(buffer.text(), "adf\nbghc");
300    assert_eq!(left_anchor.to_offset(&buffer), 5);
301    assert_eq!(right_anchor.to_offset(&buffer), 7);
302    assert_eq!(left_anchor.to_point(&buffer), Point { row: 1, column: 1 },);
303    assert_eq!(right_anchor.to_point(&buffer), Point { row: 1, column: 3 });
304
305    // Ensure anchoring to a point is equivalent to anchoring to an offset.
306    assert_eq!(
307        buffer.anchor_before(Point { row: 0, column: 0 }),
308        buffer.anchor_before(0)
309    );
310    assert_eq!(
311        buffer.anchor_before(Point { row: 0, column: 1 }),
312        buffer.anchor_before(1)
313    );
314    assert_eq!(
315        buffer.anchor_before(Point { row: 0, column: 2 }),
316        buffer.anchor_before(2)
317    );
318    assert_eq!(
319        buffer.anchor_before(Point { row: 0, column: 3 }),
320        buffer.anchor_before(3)
321    );
322    assert_eq!(
323        buffer.anchor_before(Point { row: 1, column: 0 }),
324        buffer.anchor_before(4)
325    );
326    assert_eq!(
327        buffer.anchor_before(Point { row: 1, column: 1 }),
328        buffer.anchor_before(5)
329    );
330    assert_eq!(
331        buffer.anchor_before(Point { row: 1, column: 2 }),
332        buffer.anchor_before(6)
333    );
334    assert_eq!(
335        buffer.anchor_before(Point { row: 1, column: 3 }),
336        buffer.anchor_before(7)
337    );
338    assert_eq!(
339        buffer.anchor_before(Point { row: 1, column: 4 }),
340        buffer.anchor_before(8)
341    );
342
343    // Comparison between anchors.
344    let anchor_at_offset_0 = buffer.anchor_before(0);
345    let anchor_at_offset_1 = buffer.anchor_before(1);
346    let anchor_at_offset_2 = buffer.anchor_before(2);
347
348    assert_eq!(
349        anchor_at_offset_0
350            .cmp(&anchor_at_offset_0, &buffer)
351            .unwrap(),
352        Ordering::Equal
353    );
354    assert_eq!(
355        anchor_at_offset_1
356            .cmp(&anchor_at_offset_1, &buffer)
357            .unwrap(),
358        Ordering::Equal
359    );
360    assert_eq!(
361        anchor_at_offset_2
362            .cmp(&anchor_at_offset_2, &buffer)
363            .unwrap(),
364        Ordering::Equal
365    );
366
367    assert_eq!(
368        anchor_at_offset_0
369            .cmp(&anchor_at_offset_1, &buffer)
370            .unwrap(),
371        Ordering::Less
372    );
373    assert_eq!(
374        anchor_at_offset_1
375            .cmp(&anchor_at_offset_2, &buffer)
376            .unwrap(),
377        Ordering::Less
378    );
379    assert_eq!(
380        anchor_at_offset_0
381            .cmp(&anchor_at_offset_2, &buffer)
382            .unwrap(),
383        Ordering::Less
384    );
385
386    assert_eq!(
387        anchor_at_offset_1
388            .cmp(&anchor_at_offset_0, &buffer)
389            .unwrap(),
390        Ordering::Greater
391    );
392    assert_eq!(
393        anchor_at_offset_2
394            .cmp(&anchor_at_offset_1, &buffer)
395            .unwrap(),
396        Ordering::Greater
397    );
398    assert_eq!(
399        anchor_at_offset_2
400            .cmp(&anchor_at_offset_0, &buffer)
401            .unwrap(),
402        Ordering::Greater
403    );
404}
405
406#[test]
407fn test_anchors_at_start_and_end() {
408    let mut buffer = TextBuffer::new(0, 0, History::new("".into()));
409    let before_start_anchor = buffer.anchor_before(0);
410    let after_end_anchor = buffer.anchor_after(0);
411
412    buffer.edit(vec![0..0], "abc");
413    assert_eq!(buffer.text(), "abc");
414    assert_eq!(before_start_anchor.to_offset(&buffer), 0);
415    assert_eq!(after_end_anchor.to_offset(&buffer), 3);
416
417    let after_start_anchor = buffer.anchor_after(0);
418    let before_end_anchor = buffer.anchor_before(3);
419
420    buffer.edit(vec![3..3], "def");
421    buffer.edit(vec![0..0], "ghi");
422    assert_eq!(buffer.text(), "ghiabcdef");
423    assert_eq!(before_start_anchor.to_offset(&buffer), 0);
424    assert_eq!(after_start_anchor.to_offset(&buffer), 3);
425    assert_eq!(before_end_anchor.to_offset(&buffer), 6);
426    assert_eq!(after_end_anchor.to_offset(&buffer), 9);
427}
428
429#[gpui::test]
430async fn test_apply_diff(mut cx: gpui::TestAppContext) {
431    let text = "a\nbb\nccc\ndddd\neeeee\nffffff\n";
432    let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
433
434    let text = "a\nccc\ndddd\nffffff\n";
435    let diff = buffer.read_with(&cx, |b, cx| b.diff(text.into(), cx)).await;
436    buffer.update(&mut cx, |b, cx| b.apply_diff(diff, cx));
437    cx.read(|cx| assert_eq!(buffer.read(cx).text(), text));
438
439    let text = "a\n1\n\nccc\ndd2dd\nffffff\n";
440    let diff = buffer.read_with(&cx, |b, cx| b.diff(text.into(), cx)).await;
441    buffer.update(&mut cx, |b, cx| b.apply_diff(diff, cx));
442    cx.read(|cx| assert_eq!(buffer.read(cx).text(), text));
443}
444
445#[test]
446fn test_undo_redo() {
447    let mut buffer = TextBuffer::new(0, 0, History::new("1234".into()));
448    // Set group interval to zero so as to not group edits in the undo stack.
449    buffer.history.group_interval = Duration::from_secs(0);
450
451    buffer.edit(vec![1..1], "abx");
452    buffer.edit(vec![3..4], "yzef");
453    buffer.edit(vec![3..5], "cd");
454    assert_eq!(buffer.text(), "1abcdef234");
455
456    let transactions = buffer.history.undo_stack.clone();
457    assert_eq!(transactions.len(), 3);
458
459    buffer.undo_or_redo(transactions[0].clone()).unwrap();
460    assert_eq!(buffer.text(), "1cdef234");
461    buffer.undo_or_redo(transactions[0].clone()).unwrap();
462    assert_eq!(buffer.text(), "1abcdef234");
463
464    buffer.undo_or_redo(transactions[1].clone()).unwrap();
465    assert_eq!(buffer.text(), "1abcdx234");
466    buffer.undo_or_redo(transactions[2].clone()).unwrap();
467    assert_eq!(buffer.text(), "1abx234");
468    buffer.undo_or_redo(transactions[1].clone()).unwrap();
469    assert_eq!(buffer.text(), "1abyzef234");
470    buffer.undo_or_redo(transactions[2].clone()).unwrap();
471    assert_eq!(buffer.text(), "1abcdef234");
472
473    buffer.undo_or_redo(transactions[2].clone()).unwrap();
474    assert_eq!(buffer.text(), "1abyzef234");
475    buffer.undo_or_redo(transactions[0].clone()).unwrap();
476    assert_eq!(buffer.text(), "1yzef234");
477    buffer.undo_or_redo(transactions[1].clone()).unwrap();
478    assert_eq!(buffer.text(), "1234");
479}
480
481#[test]
482fn test_history() {
483    let mut now = Instant::now();
484    let mut buffer = TextBuffer::new(0, 0, History::new("123456".into()));
485
486    let set_id = if let Operation::UpdateSelections { set_id, .. } =
487        buffer.add_selection_set(buffer.selections_from_ranges(vec![4..4]).unwrap())
488    {
489        set_id
490    } else {
491        unreachable!()
492    };
493    buffer.start_transaction_at(Some(set_id), now).unwrap();
494    buffer.edit(vec![2..4], "cd");
495    buffer.end_transaction_at(Some(set_id), now).unwrap();
496    assert_eq!(buffer.text(), "12cd56");
497    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![4..4]);
498
499    buffer.start_transaction_at(Some(set_id), now).unwrap();
500    buffer
501        .update_selection_set(set_id, buffer.selections_from_ranges(vec![1..3]).unwrap())
502        .unwrap();
503    buffer.edit(vec![4..5], "e");
504    buffer.end_transaction_at(Some(set_id), now).unwrap();
505    assert_eq!(buffer.text(), "12cde6");
506    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![1..3]);
507
508    now += buffer.history.group_interval + Duration::from_millis(1);
509    buffer.start_transaction_at(Some(set_id), now).unwrap();
510    buffer
511        .update_selection_set(set_id, buffer.selections_from_ranges(vec![2..2]).unwrap())
512        .unwrap();
513    buffer.edit(vec![0..1], "a");
514    buffer.edit(vec![1..1], "b");
515    buffer.end_transaction_at(Some(set_id), now).unwrap();
516    assert_eq!(buffer.text(), "ab2cde6");
517    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![3..3]);
518
519    // Last transaction happened past the group interval, undo it on its
520    // own.
521    buffer.undo();
522    assert_eq!(buffer.text(), "12cde6");
523    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![1..3]);
524
525    // First two transactions happened within the group interval, undo them
526    // together.
527    buffer.undo();
528    assert_eq!(buffer.text(), "123456");
529    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![4..4]);
530
531    // Redo the first two transactions together.
532    buffer.redo();
533    assert_eq!(buffer.text(), "12cde6");
534    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![1..3]);
535
536    // Redo the last transaction on its own.
537    buffer.redo();
538    assert_eq!(buffer.text(), "ab2cde6");
539    assert_eq!(buffer.selection_ranges(set_id).unwrap(), vec![3..3]);
540
541    buffer.start_transaction_at(None, now).unwrap();
542    assert!(buffer.end_transaction_at(None, now).is_none());
543    buffer.undo();
544    assert_eq!(buffer.text(), "12cde6");
545}
546
547#[test]
548fn test_concurrent_edits() {
549    let text = "abcdef";
550
551    let mut buffer1 = TextBuffer::new(1, 0, History::new(text.into()));
552    let mut buffer2 = TextBuffer::new(2, 0, History::new(text.into()));
553    let mut buffer3 = TextBuffer::new(3, 0, History::new(text.into()));
554
555    let buf1_op = buffer1.edit(vec![1..2], "12");
556    assert_eq!(buffer1.text(), "a12cdef");
557    let buf2_op = buffer2.edit(vec![3..4], "34");
558    assert_eq!(buffer2.text(), "abc34ef");
559    let buf3_op = buffer3.edit(vec![5..6], "56");
560    assert_eq!(buffer3.text(), "abcde56");
561
562    buffer1.apply_op(Operation::Edit(buf2_op.clone())).unwrap();
563    buffer1.apply_op(Operation::Edit(buf3_op.clone())).unwrap();
564    buffer2.apply_op(Operation::Edit(buf1_op.clone())).unwrap();
565    buffer2.apply_op(Operation::Edit(buf3_op.clone())).unwrap();
566    buffer3.apply_op(Operation::Edit(buf1_op.clone())).unwrap();
567    buffer3.apply_op(Operation::Edit(buf2_op.clone())).unwrap();
568
569    assert_eq!(buffer1.text(), "a12c34e56");
570    assert_eq!(buffer2.text(), "a12c34e56");
571    assert_eq!(buffer3.text(), "a12c34e56");
572}
573
574// #[gpui::test(iterations = 100)]
575// fn test_random_concurrent_edits(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
576//     let peers = env::var("PEERS")
577//         .map(|i| i.parse().expect("invalid `PEERS` variable"))
578//         .unwrap_or(5);
579//     let operations = env::var("OPERATIONS")
580//         .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
581//         .unwrap_or(10);
582
583//     let base_text_len = rng.gen_range(0..10);
584//     let base_text = RandomCharIter::new(&mut rng)
585//         .take(base_text_len)
586//         .collect::<String>();
587//     let mut replica_ids = Vec::new();
588//     let mut buffers = Vec::new();
589//     let mut network = Network::new(rng.clone());
590
591//     for i in 0..peers {
592//         let buffer = cx.add_model(|cx| {
593//             let mut buf = Buffer::new(i as ReplicaId, base_text.as_str(), cx);
594//             buf.history.group_interval = Duration::from_millis(rng.gen_range(0..=200));
595//             buf
596//         });
597//         buffers.push(buffer);
598//         replica_ids.push(i as u16);
599//         network.add_peer(i as u16);
600//     }
601
602//     log::info!("initial text: {:?}", base_text);
603
604//     let mut mutation_count = operations;
605//     loop {
606//         let replica_index = rng.gen_range(0..peers);
607//         let replica_id = replica_ids[replica_index];
608//         buffers[replica_index].update(cx, |buffer, cx| match rng.gen_range(0..=100) {
609//             0..=50 if mutation_count != 0 => {
610//                 buffer.randomly_mutate(&mut rng, cx);
611//                 network.broadcast(buffer.replica_id, mem::take(&mut buffer.operations));
612//                 log::info!("buffer {} text: {:?}", buffer.replica_id, buffer.text());
613//                 mutation_count -= 1;
614//             }
615//             51..=70 if mutation_count != 0 => {
616//                 buffer.randomly_undo_redo(&mut rng, cx);
617//                 network.broadcast(buffer.replica_id, mem::take(&mut buffer.operations));
618//                 mutation_count -= 1;
619//             }
620//             71..=100 if network.has_unreceived(replica_id) => {
621//                 let ops = network.receive(replica_id);
622//                 if !ops.is_empty() {
623//                     log::info!(
624//                         "peer {} applying {} ops from the network.",
625//                         replica_id,
626//                         ops.len()
627//                     );
628//                     buffer.apply_ops(ops, cx).unwrap();
629//                 }
630//             }
631//             _ => {}
632//         });
633
634//         if mutation_count == 0 && network.is_idle() {
635//             break;
636//         }
637//     }
638
639//     let first_buffer = buffers[0].read(cx);
640//     for buffer in &buffers[1..] {
641//         let buffer = buffer.read(cx);
642//         assert_eq!(
643//             buffer.text(),
644//             first_buffer.text(),
645//             "Replica {} text != Replica 0 text",
646//             buffer.replica_id
647//         );
648//         assert_eq!(
649//             buffer.selection_sets().collect::<HashMap<_, _>>(),
650//             first_buffer.selection_sets().collect::<HashMap<_, _>>()
651//         );
652//         assert_eq!(
653//             buffer.all_selection_ranges().collect::<HashMap<_, _>>(),
654//             first_buffer
655//                 .all_selection_ranges()
656//                 .collect::<HashMap<_, _>>()
657//         );
658//     }
659// }
660
661#[derive(Clone)]
662struct Envelope<T: Clone> {
663    message: T,
664    sender: ReplicaId,
665}
666
667struct Network<T: Clone, R: rand::Rng> {
668    inboxes: std::collections::BTreeMap<ReplicaId, Vec<Envelope<T>>>,
669    all_messages: Vec<T>,
670    rng: R,
671}
672
673impl<T: Clone, R: rand::Rng> Network<T, R> {
674    fn new(rng: R) -> Self {
675        Network {
676            inboxes: Default::default(),
677            all_messages: Vec::new(),
678            rng,
679        }
680    }
681
682    fn add_peer(&mut self, id: ReplicaId) {
683        self.inboxes.insert(id, Vec::new());
684    }
685
686    fn is_idle(&self) -> bool {
687        self.inboxes.values().all(|i| i.is_empty())
688    }
689
690    fn broadcast(&mut self, sender: ReplicaId, messages: Vec<T>) {
691        for (replica, inbox) in self.inboxes.iter_mut() {
692            if *replica != sender {
693                for message in &messages {
694                    let min_index = inbox
695                        .iter()
696                        .enumerate()
697                        .rev()
698                        .find_map(|(index, envelope)| {
699                            if sender == envelope.sender {
700                                Some(index + 1)
701                            } else {
702                                None
703                            }
704                        })
705                        .unwrap_or(0);
706
707                    // Insert one or more duplicates of this message *after* the previous
708                    // message delivered by this replica.
709                    for _ in 0..self.rng.gen_range(1..4) {
710                        let insertion_index = self.rng.gen_range(min_index..inbox.len() + 1);
711                        inbox.insert(
712                            insertion_index,
713                            Envelope {
714                                message: message.clone(),
715                                sender,
716                            },
717                        );
718                    }
719                }
720            }
721        }
722        self.all_messages.extend(messages);
723    }
724
725    fn has_unreceived(&self, receiver: ReplicaId) -> bool {
726        !self.inboxes[&receiver].is_empty()
727    }
728
729    fn receive(&mut self, receiver: ReplicaId) -> Vec<T> {
730        let inbox = self.inboxes.get_mut(&receiver).unwrap();
731        let count = self.rng.gen_range(0..inbox.len() + 1);
732        inbox
733            .drain(0..count)
734            .map(|envelope| envelope.message)
735            .collect()
736    }
737}