1use crate::{
   2    ChunkRenderer, HighlightStyles,
   3    inlays::{Inlay, InlayContent},
   4};
   5use collections::BTreeSet;
   6use language::{Chunk, Edit, Point, TextSummary};
   7use multi_buffer::{MultiBufferRow, MultiBufferRows, MultiBufferSnapshot, RowInfo, ToOffset};
   8use project::InlayId;
   9use std::{
  10    cmp,
  11    ops::{Add, AddAssign, Range, Sub, SubAssign},
  12    sync::Arc,
  13};
  14use sum_tree::{Bias, Cursor, Dimensions, SumTree};
  15use text::{ChunkBitmaps, Patch};
  16use ui::{ActiveTheme, IntoElement as _, ParentElement as _, Styled as _, div};
  17
  18use super::{Highlights, custom_highlights::CustomHighlightsChunks, fold_map::ChunkRendererId};
  19
  20/// Decides where the [`Inlay`]s should be displayed.
  21///
  22/// See the [`display_map` module documentation](crate::display_map) for more information.
  23pub struct InlayMap {
  24    snapshot: InlaySnapshot,
  25    inlays: Vec<Inlay>,
  26}
  27
  28#[derive(Clone)]
  29pub struct InlaySnapshot {
  30    pub buffer: MultiBufferSnapshot,
  31    transforms: SumTree<Transform>,
  32    pub version: usize,
  33}
  34
  35#[derive(Clone, Debug)]
  36enum Transform {
  37    Isomorphic(TextSummary),
  38    Inlay(Inlay),
  39}
  40
  41impl sum_tree::Item for Transform {
  42    type Summary = TransformSummary;
  43
  44    fn summary(&self, _: ()) -> Self::Summary {
  45        match self {
  46            Transform::Isomorphic(summary) => TransformSummary {
  47                input: *summary,
  48                output: *summary,
  49            },
  50            Transform::Inlay(inlay) => TransformSummary {
  51                input: TextSummary::default(),
  52                output: inlay.text().summary(),
  53            },
  54        }
  55    }
  56}
  57
  58#[derive(Clone, Debug, Default)]
  59struct TransformSummary {
  60    input: TextSummary,
  61    output: TextSummary,
  62}
  63
  64impl sum_tree::ContextLessSummary for TransformSummary {
  65    fn zero() -> Self {
  66        Default::default()
  67    }
  68
  69    fn add_summary(&mut self, other: &Self) {
  70        self.input += &other.input;
  71        self.output += &other.output;
  72    }
  73}
  74
  75pub type InlayEdit = Edit<InlayOffset>;
  76
  77#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  78pub struct InlayOffset(pub usize);
  79
  80impl Add for InlayOffset {
  81    type Output = Self;
  82
  83    fn add(self, rhs: Self) -> Self::Output {
  84        Self(self.0 + rhs.0)
  85    }
  86}
  87
  88impl Sub for InlayOffset {
  89    type Output = Self;
  90
  91    fn sub(self, rhs: Self) -> Self::Output {
  92        Self(self.0 - rhs.0)
  93    }
  94}
  95
  96impl AddAssign for InlayOffset {
  97    fn add_assign(&mut self, rhs: Self) {
  98        self.0 += rhs.0;
  99    }
 100}
 101
 102impl SubAssign for InlayOffset {
 103    fn sub_assign(&mut self, rhs: Self) {
 104        self.0 -= rhs.0;
 105    }
 106}
 107
 108impl<'a> sum_tree::Dimension<'a, TransformSummary> for InlayOffset {
 109    fn zero(_cx: ()) -> Self {
 110        Default::default()
 111    }
 112
 113    fn add_summary(&mut self, summary: &'a TransformSummary, _: ()) {
 114        self.0 += &summary.output.len;
 115    }
 116}
 117
 118#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
 119pub struct InlayPoint(pub Point);
 120
 121impl Add for InlayPoint {
 122    type Output = Self;
 123
 124    fn add(self, rhs: Self) -> Self::Output {
 125        Self(self.0 + rhs.0)
 126    }
 127}
 128
 129impl Sub for InlayPoint {
 130    type Output = Self;
 131
 132    fn sub(self, rhs: Self) -> Self::Output {
 133        Self(self.0 - rhs.0)
 134    }
 135}
 136
 137impl<'a> sum_tree::Dimension<'a, TransformSummary> for InlayPoint {
 138    fn zero(_cx: ()) -> Self {
 139        Default::default()
 140    }
 141
 142    fn add_summary(&mut self, summary: &'a TransformSummary, _: ()) {
 143        self.0 += &summary.output.lines;
 144    }
 145}
 146
 147impl<'a> sum_tree::Dimension<'a, TransformSummary> for usize {
 148    fn zero(_cx: ()) -> Self {
 149        Default::default()
 150    }
 151
 152    fn add_summary(&mut self, summary: &'a TransformSummary, _: ()) {
 153        *self += &summary.input.len;
 154    }
 155}
 156
 157impl<'a> sum_tree::Dimension<'a, TransformSummary> for Point {
 158    fn zero(_cx: ()) -> Self {
 159        Default::default()
 160    }
 161
 162    fn add_summary(&mut self, summary: &'a TransformSummary, _: ()) {
 163        *self += &summary.input.lines;
 164    }
 165}
 166
 167#[derive(Clone)]
 168pub struct InlayBufferRows<'a> {
 169    transforms: Cursor<'a, 'static, Transform, Dimensions<InlayPoint, Point>>,
 170    buffer_rows: MultiBufferRows<'a>,
 171    inlay_row: u32,
 172    max_buffer_row: MultiBufferRow,
 173}
 174
 175pub struct InlayChunks<'a> {
 176    transforms: Cursor<'a, 'static, Transform, Dimensions<InlayOffset, usize>>,
 177    buffer_chunks: CustomHighlightsChunks<'a>,
 178    buffer_chunk: Option<Chunk<'a>>,
 179    inlay_chunks: Option<text::ChunkWithBitmaps<'a>>,
 180    /// text, char bitmap, tabs bitmap
 181    inlay_chunk: Option<ChunkBitmaps<'a>>,
 182    output_offset: InlayOffset,
 183    max_output_offset: InlayOffset,
 184    highlight_styles: HighlightStyles,
 185    highlights: Highlights<'a>,
 186    snapshot: &'a InlaySnapshot,
 187}
 188
 189#[derive(Clone)]
 190pub struct InlayChunk<'a> {
 191    pub chunk: Chunk<'a>,
 192    /// Whether the inlay should be customly rendered.
 193    pub renderer: Option<ChunkRenderer>,
 194}
 195
 196impl InlayChunks<'_> {
 197    pub fn seek(&mut self, new_range: Range<InlayOffset>) {
 198        self.transforms.seek(&new_range.start, Bias::Right);
 199
 200        let buffer_range = self.snapshot.to_buffer_offset(new_range.start)
 201            ..self.snapshot.to_buffer_offset(new_range.end);
 202        self.buffer_chunks.seek(buffer_range);
 203        self.inlay_chunks = None;
 204        self.buffer_chunk = None;
 205        self.output_offset = new_range.start;
 206        self.max_output_offset = new_range.end;
 207    }
 208
 209    pub fn offset(&self) -> InlayOffset {
 210        self.output_offset
 211    }
 212}
 213
 214impl<'a> Iterator for InlayChunks<'a> {
 215    type Item = InlayChunk<'a>;
 216
 217    fn next(&mut self) -> Option<Self::Item> {
 218        if self.output_offset == self.max_output_offset {
 219            return None;
 220        }
 221
 222        let chunk = match self.transforms.item()? {
 223            Transform::Isomorphic(_) => {
 224                let chunk = self
 225                    .buffer_chunk
 226                    .get_or_insert_with(|| self.buffer_chunks.next().unwrap());
 227                if chunk.text.is_empty() {
 228                    *chunk = self.buffer_chunks.next().unwrap();
 229                }
 230
 231                let desired_bytes = self.transforms.end().0.0 - self.output_offset.0;
 232
 233                // If we're already at the transform boundary, skip to the next transform
 234                if desired_bytes == 0 {
 235                    self.inlay_chunks = None;
 236                    self.transforms.next();
 237                    return self.next();
 238                }
 239
 240                // Determine split index handling edge cases
 241                let split_index = if desired_bytes >= chunk.text.len() {
 242                    chunk.text.len()
 243                } else if chunk.text.is_char_boundary(desired_bytes) {
 244                    desired_bytes
 245                } else {
 246                    find_next_utf8_boundary(chunk.text, desired_bytes)
 247                };
 248
 249                let (prefix, suffix) = chunk.text.split_at(split_index);
 250                self.output_offset.0 += prefix.len();
 251
 252                let mask = 1u128.unbounded_shl(split_index as u32).wrapping_sub(1);
 253                let chars = chunk.chars & mask;
 254                let tabs = chunk.tabs & mask;
 255
 256                chunk.chars = chunk.chars.unbounded_shr(split_index as u32);
 257                chunk.tabs = chunk.tabs.unbounded_shr(split_index as u32);
 258                chunk.text = suffix;
 259
 260                InlayChunk {
 261                    chunk: Chunk {
 262                        text: prefix,
 263                        chars,
 264                        tabs,
 265                        ..chunk.clone()
 266                    },
 267                    renderer: None,
 268                }
 269            }
 270            Transform::Inlay(inlay) => {
 271                let mut inlay_style_and_highlight = None;
 272                if let Some(inlay_highlights) = self.highlights.inlay_highlights {
 273                    for (_, inlay_id_to_data) in inlay_highlights.iter() {
 274                        let style_and_highlight = inlay_id_to_data.get(&inlay.id);
 275                        if style_and_highlight.is_some() {
 276                            inlay_style_and_highlight = style_and_highlight;
 277                            break;
 278                        }
 279                    }
 280                }
 281
 282                let mut renderer = None;
 283                let mut highlight_style = match inlay.id {
 284                    InlayId::EditPrediction(_) => self.highlight_styles.edit_prediction.map(|s| {
 285                        if inlay.text().chars().all(|c| c.is_whitespace()) {
 286                            s.whitespace
 287                        } else {
 288                            s.insertion
 289                        }
 290                    }),
 291                    InlayId::Hint(_) => self.highlight_styles.inlay_hint,
 292                    InlayId::DebuggerValue(_) => self.highlight_styles.inlay_hint,
 293                    InlayId::Color(_) => {
 294                        if let InlayContent::Color(color) = inlay.content {
 295                            renderer = Some(ChunkRenderer {
 296                                id: ChunkRendererId::Inlay(inlay.id),
 297                                render: Arc::new(move |cx| {
 298                                    div()
 299                                        .relative()
 300                                        .size_3p5()
 301                                        .child(
 302                                            div()
 303                                                .absolute()
 304                                                .right_1()
 305                                                .size_3()
 306                                                .border_1()
 307                                                .border_color(
 308                                                    if cx.theme().appearance().is_light() {
 309                                                        gpui::black().opacity(0.5)
 310                                                    } else {
 311                                                        gpui::white().opacity(0.5)
 312                                                    },
 313                                                )
 314                                                .bg(color),
 315                                        )
 316                                        .into_any_element()
 317                                }),
 318                                constrain_width: false,
 319                                measured_width: None,
 320                            });
 321                        }
 322                        self.highlight_styles.inlay_hint
 323                    }
 324                };
 325                let next_inlay_highlight_endpoint;
 326                let offset_in_inlay = self.output_offset - self.transforms.start().0;
 327                if let Some((style, highlight)) = inlay_style_and_highlight {
 328                    let range = &highlight.range;
 329                    if offset_in_inlay.0 < range.start {
 330                        next_inlay_highlight_endpoint = range.start - offset_in_inlay.0;
 331                    } else if offset_in_inlay.0 >= range.end {
 332                        next_inlay_highlight_endpoint = usize::MAX;
 333                    } else {
 334                        next_inlay_highlight_endpoint = range.end - offset_in_inlay.0;
 335                        highlight_style = highlight_style
 336                            .map(|highlight| highlight.highlight(*style))
 337                            .or_else(|| Some(*style));
 338                    }
 339                } else {
 340                    next_inlay_highlight_endpoint = usize::MAX;
 341                }
 342
 343                let inlay_chunks = self.inlay_chunks.get_or_insert_with(|| {
 344                    let start = offset_in_inlay;
 345                    let end = cmp::min(self.max_output_offset, self.transforms.end().0)
 346                        - self.transforms.start().0;
 347                    let chunks = inlay.text().chunks_in_range(start.0..end.0);
 348                    text::ChunkWithBitmaps(chunks)
 349                });
 350                let ChunkBitmaps {
 351                    text: inlay_chunk,
 352                    chars,
 353                    tabs,
 354                } = self
 355                    .inlay_chunk
 356                    .get_or_insert_with(|| inlay_chunks.next().unwrap());
 357
 358                // Determine split index handling edge cases
 359                let split_index = if next_inlay_highlight_endpoint >= inlay_chunk.len() {
 360                    inlay_chunk.len()
 361                } else if next_inlay_highlight_endpoint == 0 {
 362                    // Need to take at least one character to make progress
 363                    inlay_chunk
 364                        .chars()
 365                        .next()
 366                        .map(|c| c.len_utf8())
 367                        .unwrap_or(1)
 368                } else if inlay_chunk.is_char_boundary(next_inlay_highlight_endpoint) {
 369                    next_inlay_highlight_endpoint
 370                } else {
 371                    find_next_utf8_boundary(inlay_chunk, next_inlay_highlight_endpoint)
 372                };
 373
 374                let (chunk, remainder) = inlay_chunk.split_at(split_index);
 375                *inlay_chunk = remainder;
 376
 377                let mask = 1u128.unbounded_shl(split_index as u32).wrapping_sub(1);
 378                let new_chars = *chars & mask;
 379                let new_tabs = *tabs & mask;
 380
 381                *chars = chars.unbounded_shr(split_index as u32);
 382                *tabs = tabs.unbounded_shr(split_index as u32);
 383
 384                if inlay_chunk.is_empty() {
 385                    self.inlay_chunk = None;
 386                }
 387
 388                self.output_offset.0 += chunk.len();
 389
 390                InlayChunk {
 391                    chunk: Chunk {
 392                        text: chunk,
 393                        chars: new_chars,
 394                        tabs: new_tabs,
 395                        highlight_style,
 396                        is_inlay: true,
 397                        ..Chunk::default()
 398                    },
 399                    renderer,
 400                }
 401            }
 402        };
 403
 404        if self.output_offset >= self.transforms.end().0 {
 405            self.inlay_chunks = None;
 406            self.transforms.next();
 407        }
 408
 409        Some(chunk)
 410    }
 411}
 412
 413impl InlayBufferRows<'_> {
 414    pub fn seek(&mut self, row: u32) {
 415        let inlay_point = InlayPoint::new(row, 0);
 416        self.transforms.seek(&inlay_point, Bias::Left);
 417
 418        let mut buffer_point = self.transforms.start().1;
 419        let buffer_row = MultiBufferRow(if row == 0 {
 420            0
 421        } else {
 422            match self.transforms.item() {
 423                Some(Transform::Isomorphic(_)) => {
 424                    buffer_point += inlay_point.0 - self.transforms.start().0.0;
 425                    buffer_point.row
 426                }
 427                _ => cmp::min(buffer_point.row + 1, self.max_buffer_row.0),
 428            }
 429        });
 430        self.inlay_row = inlay_point.row();
 431        self.buffer_rows.seek(buffer_row);
 432    }
 433}
 434
 435impl Iterator for InlayBufferRows<'_> {
 436    type Item = RowInfo;
 437
 438    fn next(&mut self) -> Option<Self::Item> {
 439        let buffer_row = if self.inlay_row == 0 {
 440            self.buffer_rows.next().unwrap()
 441        } else {
 442            match self.transforms.item()? {
 443                Transform::Inlay(_) => Default::default(),
 444                Transform::Isomorphic(_) => self.buffer_rows.next().unwrap(),
 445            }
 446        };
 447
 448        self.inlay_row += 1;
 449        self.transforms
 450            .seek_forward(&InlayPoint::new(self.inlay_row, 0), Bias::Left);
 451
 452        Some(buffer_row)
 453    }
 454}
 455
 456impl InlayPoint {
 457    pub fn new(row: u32, column: u32) -> Self {
 458        Self(Point::new(row, column))
 459    }
 460
 461    pub fn row(self) -> u32 {
 462        self.0.row
 463    }
 464}
 465
 466impl InlayMap {
 467    pub fn new(buffer: MultiBufferSnapshot) -> (Self, InlaySnapshot) {
 468        let version = 0;
 469        let snapshot = InlaySnapshot {
 470            buffer: buffer.clone(),
 471            transforms: SumTree::from_iter(Some(Transform::Isomorphic(buffer.text_summary())), ()),
 472            version,
 473        };
 474
 475        (
 476            Self {
 477                snapshot: snapshot.clone(),
 478                inlays: Vec::new(),
 479            },
 480            snapshot,
 481        )
 482    }
 483
 484    pub fn sync(
 485        &mut self,
 486        buffer_snapshot: MultiBufferSnapshot,
 487        mut buffer_edits: Vec<text::Edit<usize>>,
 488    ) -> (InlaySnapshot, Vec<InlayEdit>) {
 489        let snapshot = &mut self.snapshot;
 490
 491        if buffer_edits.is_empty()
 492            && snapshot.buffer.trailing_excerpt_update_count()
 493                != buffer_snapshot.trailing_excerpt_update_count()
 494        {
 495            buffer_edits.push(Edit {
 496                old: snapshot.buffer.len()..snapshot.buffer.len(),
 497                new: buffer_snapshot.len()..buffer_snapshot.len(),
 498            });
 499        }
 500
 501        if buffer_edits.is_empty() {
 502            if snapshot.buffer.edit_count() != buffer_snapshot.edit_count()
 503                || snapshot.buffer.non_text_state_update_count()
 504                    != buffer_snapshot.non_text_state_update_count()
 505                || snapshot.buffer.trailing_excerpt_update_count()
 506                    != buffer_snapshot.trailing_excerpt_update_count()
 507            {
 508                snapshot.version += 1;
 509            }
 510
 511            snapshot.buffer = buffer_snapshot;
 512            (snapshot.clone(), Vec::new())
 513        } else {
 514            let mut inlay_edits = Patch::default();
 515            let mut new_transforms = SumTree::default();
 516            let mut cursor = snapshot
 517                .transforms
 518                .cursor::<Dimensions<usize, InlayOffset>>(());
 519            let mut buffer_edits_iter = buffer_edits.iter().peekable();
 520            while let Some(buffer_edit) = buffer_edits_iter.next() {
 521                new_transforms.append(cursor.slice(&buffer_edit.old.start, Bias::Left), ());
 522                if let Some(Transform::Isomorphic(transform)) = cursor.item()
 523                    && cursor.end().0 == buffer_edit.old.start
 524                {
 525                    push_isomorphic(&mut new_transforms, *transform);
 526                    cursor.next();
 527                }
 528
 529                // Remove all the inlays and transforms contained by the edit.
 530                let old_start =
 531                    cursor.start().1 + InlayOffset(buffer_edit.old.start - cursor.start().0);
 532                cursor.seek(&buffer_edit.old.end, Bias::Right);
 533                let old_end =
 534                    cursor.start().1 + InlayOffset(buffer_edit.old.end - cursor.start().0);
 535
 536                // Push the unchanged prefix.
 537                let prefix_start = new_transforms.summary().input.len;
 538                let prefix_end = buffer_edit.new.start;
 539                push_isomorphic(
 540                    &mut new_transforms,
 541                    buffer_snapshot.text_summary_for_range(prefix_start..prefix_end),
 542                );
 543                let new_start = InlayOffset(new_transforms.summary().output.len);
 544
 545                let start_ix = match self.inlays.binary_search_by(|probe| {
 546                    probe
 547                        .position
 548                        .to_offset(&buffer_snapshot)
 549                        .cmp(&buffer_edit.new.start)
 550                        .then(std::cmp::Ordering::Greater)
 551                }) {
 552                    Ok(ix) | Err(ix) => ix,
 553                };
 554
 555                for inlay in &self.inlays[start_ix..] {
 556                    if !inlay.position.is_valid(&buffer_snapshot) {
 557                        continue;
 558                    }
 559                    let buffer_offset = inlay.position.to_offset(&buffer_snapshot);
 560                    if buffer_offset > buffer_edit.new.end {
 561                        break;
 562                    }
 563
 564                    let prefix_start = new_transforms.summary().input.len;
 565                    let prefix_end = buffer_offset;
 566                    push_isomorphic(
 567                        &mut new_transforms,
 568                        buffer_snapshot.text_summary_for_range(prefix_start..prefix_end),
 569                    );
 570
 571                    new_transforms.push(Transform::Inlay(inlay.clone()), ());
 572                }
 573
 574                // Apply the rest of the edit.
 575                let transform_start = new_transforms.summary().input.len;
 576                push_isomorphic(
 577                    &mut new_transforms,
 578                    buffer_snapshot.text_summary_for_range(transform_start..buffer_edit.new.end),
 579                );
 580                let new_end = InlayOffset(new_transforms.summary().output.len);
 581                inlay_edits.push(Edit {
 582                    old: old_start..old_end,
 583                    new: new_start..new_end,
 584                });
 585
 586                // If the next edit doesn't intersect the current isomorphic transform, then
 587                // we can push its remainder.
 588                if buffer_edits_iter
 589                    .peek()
 590                    .is_none_or(|edit| edit.old.start >= cursor.end().0)
 591                {
 592                    let transform_start = new_transforms.summary().input.len;
 593                    let transform_end =
 594                        buffer_edit.new.end + (cursor.end().0 - buffer_edit.old.end);
 595                    push_isomorphic(
 596                        &mut new_transforms,
 597                        buffer_snapshot.text_summary_for_range(transform_start..transform_end),
 598                    );
 599                    cursor.next();
 600                }
 601            }
 602
 603            new_transforms.append(cursor.suffix(), ());
 604            if new_transforms.is_empty() {
 605                new_transforms.push(Transform::Isomorphic(Default::default()), ());
 606            }
 607
 608            drop(cursor);
 609            snapshot.transforms = new_transforms;
 610            snapshot.version += 1;
 611            snapshot.buffer = buffer_snapshot;
 612            snapshot.check_invariants();
 613
 614            (snapshot.clone(), inlay_edits.into_inner())
 615        }
 616    }
 617
 618    pub fn splice(
 619        &mut self,
 620        to_remove: &[InlayId],
 621        to_insert: Vec<Inlay>,
 622    ) -> (InlaySnapshot, Vec<InlayEdit>) {
 623        let snapshot = &mut self.snapshot;
 624        let mut edits = BTreeSet::new();
 625
 626        self.inlays.retain(|inlay| {
 627            let retain = !to_remove.contains(&inlay.id);
 628            if !retain {
 629                let offset = inlay.position.to_offset(&snapshot.buffer);
 630                edits.insert(offset);
 631            }
 632            retain
 633        });
 634
 635        for inlay_to_insert in to_insert {
 636            // Avoid inserting empty inlays.
 637            if inlay_to_insert.text().is_empty() {
 638                continue;
 639            }
 640
 641            let offset = inlay_to_insert.position.to_offset(&snapshot.buffer);
 642            match self.inlays.binary_search_by(|probe| {
 643                probe
 644                    .position
 645                    .cmp(&inlay_to_insert.position, &snapshot.buffer)
 646                    .then(std::cmp::Ordering::Less)
 647            }) {
 648                Ok(ix) | Err(ix) => {
 649                    self.inlays.insert(ix, inlay_to_insert);
 650                }
 651            }
 652
 653            edits.insert(offset);
 654        }
 655
 656        let buffer_edits = edits
 657            .into_iter()
 658            .map(|offset| Edit {
 659                old: offset..offset,
 660                new: offset..offset,
 661            })
 662            .collect();
 663        let buffer_snapshot = snapshot.buffer.clone();
 664        let (snapshot, edits) = self.sync(buffer_snapshot, buffer_edits);
 665        (snapshot, edits)
 666    }
 667
 668    pub fn current_inlays(&self) -> impl Iterator<Item = &Inlay> {
 669        self.inlays.iter()
 670    }
 671
 672    #[cfg(test)]
 673    pub(crate) fn randomly_mutate(
 674        &mut self,
 675        next_inlay_id: &mut usize,
 676        rng: &mut rand::rngs::StdRng,
 677    ) -> (InlaySnapshot, Vec<InlayEdit>) {
 678        use rand::prelude::*;
 679        use util::post_inc;
 680
 681        let mut to_remove = Vec::new();
 682        let mut to_insert = Vec::new();
 683        let snapshot = &mut self.snapshot;
 684        for i in 0..rng.random_range(1..=5) {
 685            if self.inlays.is_empty() || rng.random() {
 686                let position = snapshot.buffer.random_byte_range(0, rng).start;
 687                let bias = if rng.random() {
 688                    Bias::Left
 689                } else {
 690                    Bias::Right
 691                };
 692                let len = if rng.random_bool(0.01) {
 693                    0
 694                } else {
 695                    rng.random_range(1..=5)
 696                };
 697                let text = util::RandomCharIter::new(&mut *rng)
 698                    .filter(|ch| *ch != '\r')
 699                    .take(len)
 700                    .collect::<String>();
 701
 702                let next_inlay = if i % 2 == 0 {
 703                    Inlay::mock_hint(
 704                        post_inc(next_inlay_id),
 705                        snapshot.buffer.anchor_at(position, bias),
 706                        &text,
 707                    )
 708                } else {
 709                    Inlay::edit_prediction(
 710                        post_inc(next_inlay_id),
 711                        snapshot.buffer.anchor_at(position, bias),
 712                        &text,
 713                    )
 714                };
 715                let inlay_id = next_inlay.id;
 716                log::info!(
 717                    "creating inlay {inlay_id:?} at buffer offset {position} with bias {bias:?} and text {text:?}"
 718                );
 719                to_insert.push(next_inlay);
 720            } else {
 721                to_remove.push(
 722                    self.inlays
 723                        .iter()
 724                        .choose(rng)
 725                        .map(|inlay| inlay.id)
 726                        .unwrap(),
 727                );
 728            }
 729        }
 730        log::info!("removing inlays: {:?}", to_remove);
 731
 732        let (snapshot, edits) = self.splice(&to_remove, to_insert);
 733        (snapshot, edits)
 734    }
 735}
 736
 737impl InlaySnapshot {
 738    pub fn to_point(&self, offset: InlayOffset) -> InlayPoint {
 739        let (start, _, item) = self
 740            .transforms
 741            .find::<Dimensions<InlayOffset, InlayPoint, usize>, _>((), &offset, Bias::Right);
 742        let overshoot = offset.0 - start.0.0;
 743        match item {
 744            Some(Transform::Isomorphic(_)) => {
 745                let buffer_offset_start = start.2;
 746                let buffer_offset_end = buffer_offset_start + overshoot;
 747                let buffer_start = self.buffer.offset_to_point(buffer_offset_start);
 748                let buffer_end = self.buffer.offset_to_point(buffer_offset_end);
 749                InlayPoint(start.1.0 + (buffer_end - buffer_start))
 750            }
 751            Some(Transform::Inlay(inlay)) => {
 752                let overshoot = inlay.text().offset_to_point(overshoot);
 753                InlayPoint(start.1.0 + overshoot)
 754            }
 755            None => self.max_point(),
 756        }
 757    }
 758
 759    pub fn len(&self) -> InlayOffset {
 760        InlayOffset(self.transforms.summary().output.len)
 761    }
 762
 763    pub fn max_point(&self) -> InlayPoint {
 764        InlayPoint(self.transforms.summary().output.lines)
 765    }
 766
 767    pub fn to_offset(&self, point: InlayPoint) -> InlayOffset {
 768        let (start, _, item) = self
 769            .transforms
 770            .find::<Dimensions<InlayPoint, InlayOffset, Point>, _>((), &point, Bias::Right);
 771        let overshoot = point.0 - start.0.0;
 772        match item {
 773            Some(Transform::Isomorphic(_)) => {
 774                let buffer_point_start = start.2;
 775                let buffer_point_end = buffer_point_start + overshoot;
 776                let buffer_offset_start = self.buffer.point_to_offset(buffer_point_start);
 777                let buffer_offset_end = self.buffer.point_to_offset(buffer_point_end);
 778                InlayOffset(start.1.0 + (buffer_offset_end - buffer_offset_start))
 779            }
 780            Some(Transform::Inlay(inlay)) => {
 781                let overshoot = inlay.text().point_to_offset(overshoot);
 782                InlayOffset(start.1.0 + overshoot)
 783            }
 784            None => self.len(),
 785        }
 786    }
 787    pub fn to_buffer_point(&self, point: InlayPoint) -> Point {
 788        let (start, _, item) =
 789            self.transforms
 790                .find::<Dimensions<InlayPoint, Point>, _>((), &point, Bias::Right);
 791        match item {
 792            Some(Transform::Isomorphic(_)) => {
 793                let overshoot = point.0 - start.0.0;
 794                start.1 + overshoot
 795            }
 796            Some(Transform::Inlay(_)) => start.1,
 797            None => self.buffer.max_point(),
 798        }
 799    }
 800    pub fn to_buffer_offset(&self, offset: InlayOffset) -> usize {
 801        let (start, _, item) =
 802            self.transforms
 803                .find::<Dimensions<InlayOffset, usize>, _>((), &offset, Bias::Right);
 804        match item {
 805            Some(Transform::Isomorphic(_)) => {
 806                let overshoot = offset - start.0;
 807                start.1 + overshoot.0
 808            }
 809            Some(Transform::Inlay(_)) => start.1,
 810            None => self.buffer.len(),
 811        }
 812    }
 813
 814    pub fn to_inlay_offset(&self, offset: usize) -> InlayOffset {
 815        let mut cursor = self.transforms.cursor::<Dimensions<usize, InlayOffset>>(());
 816        cursor.seek(&offset, Bias::Left);
 817        loop {
 818            match cursor.item() {
 819                Some(Transform::Isomorphic(_)) => {
 820                    if offset == cursor.end().0 {
 821                        while let Some(Transform::Inlay(inlay)) = cursor.next_item() {
 822                            if inlay.position.bias() == Bias::Right {
 823                                break;
 824                            } else {
 825                                cursor.next();
 826                            }
 827                        }
 828                        return cursor.end().1;
 829                    } else {
 830                        let overshoot = offset - cursor.start().0;
 831                        return InlayOffset(cursor.start().1.0 + overshoot);
 832                    }
 833                }
 834                Some(Transform::Inlay(inlay)) => {
 835                    if inlay.position.bias() == Bias::Left {
 836                        cursor.next();
 837                    } else {
 838                        return cursor.start().1;
 839                    }
 840                }
 841                None => {
 842                    return self.len();
 843                }
 844            }
 845        }
 846    }
 847    pub fn to_inlay_point(&self, point: Point) -> InlayPoint {
 848        let mut cursor = self.transforms.cursor::<Dimensions<Point, InlayPoint>>(());
 849        cursor.seek(&point, Bias::Left);
 850        loop {
 851            match cursor.item() {
 852                Some(Transform::Isomorphic(_)) => {
 853                    if point == cursor.end().0 {
 854                        while let Some(Transform::Inlay(inlay)) = cursor.next_item() {
 855                            if inlay.position.bias() == Bias::Right {
 856                                break;
 857                            } else {
 858                                cursor.next();
 859                            }
 860                        }
 861                        return cursor.end().1;
 862                    } else {
 863                        let overshoot = point - cursor.start().0;
 864                        return InlayPoint(cursor.start().1.0 + overshoot);
 865                    }
 866                }
 867                Some(Transform::Inlay(inlay)) => {
 868                    if inlay.position.bias() == Bias::Left {
 869                        cursor.next();
 870                    } else {
 871                        return cursor.start().1;
 872                    }
 873                }
 874                None => {
 875                    return self.max_point();
 876                }
 877            }
 878        }
 879    }
 880
 881    pub fn clip_point(&self, mut point: InlayPoint, mut bias: Bias) -> InlayPoint {
 882        let mut cursor = self.transforms.cursor::<Dimensions<InlayPoint, Point>>(());
 883        cursor.seek(&point, Bias::Left);
 884        loop {
 885            match cursor.item() {
 886                Some(Transform::Isomorphic(transform)) => {
 887                    if cursor.start().0 == point {
 888                        if let Some(Transform::Inlay(inlay)) = cursor.prev_item() {
 889                            if inlay.position.bias() == Bias::Left {
 890                                return point;
 891                            } else if bias == Bias::Left {
 892                                cursor.prev();
 893                            } else if transform.first_line_chars == 0 {
 894                                point.0 += Point::new(1, 0);
 895                            } else {
 896                                point.0 += Point::new(0, 1);
 897                            }
 898                        } else {
 899                            return point;
 900                        }
 901                    } else if cursor.end().0 == point {
 902                        if let Some(Transform::Inlay(inlay)) = cursor.next_item() {
 903                            if inlay.position.bias() == Bias::Right {
 904                                return point;
 905                            } else if bias == Bias::Right {
 906                                cursor.next();
 907                            } else if point.0.column == 0 {
 908                                point.0.row -= 1;
 909                                point.0.column = self.line_len(point.0.row);
 910                            } else {
 911                                point.0.column -= 1;
 912                            }
 913                        } else {
 914                            return point;
 915                        }
 916                    } else {
 917                        let overshoot = point.0 - cursor.start().0.0;
 918                        let buffer_point = cursor.start().1 + overshoot;
 919                        let clipped_buffer_point = self.buffer.clip_point(buffer_point, bias);
 920                        let clipped_overshoot = clipped_buffer_point - cursor.start().1;
 921                        let clipped_point = InlayPoint(cursor.start().0.0 + clipped_overshoot);
 922                        if clipped_point == point {
 923                            return clipped_point;
 924                        } else {
 925                            point = clipped_point;
 926                        }
 927                    }
 928                }
 929                Some(Transform::Inlay(inlay)) => {
 930                    if point == cursor.start().0 && inlay.position.bias() == Bias::Right {
 931                        match cursor.prev_item() {
 932                            Some(Transform::Inlay(inlay)) => {
 933                                if inlay.position.bias() == Bias::Left {
 934                                    return point;
 935                                }
 936                            }
 937                            _ => return point,
 938                        }
 939                    } else if point == cursor.end().0 && inlay.position.bias() == Bias::Left {
 940                        match cursor.next_item() {
 941                            Some(Transform::Inlay(inlay)) => {
 942                                if inlay.position.bias() == Bias::Right {
 943                                    return point;
 944                                }
 945                            }
 946                            _ => return point,
 947                        }
 948                    }
 949
 950                    if bias == Bias::Left {
 951                        point = cursor.start().0;
 952                        cursor.prev();
 953                    } else {
 954                        cursor.next();
 955                        point = cursor.start().0;
 956                    }
 957                }
 958                None => {
 959                    bias = bias.invert();
 960                    if bias == Bias::Left {
 961                        point = cursor.start().0;
 962                        cursor.prev();
 963                    } else {
 964                        cursor.next();
 965                        point = cursor.start().0;
 966                    }
 967                }
 968            }
 969        }
 970    }
 971
 972    pub fn text_summary(&self) -> TextSummary {
 973        self.transforms.summary().output
 974    }
 975
 976    pub fn text_summary_for_range(&self, range: Range<InlayOffset>) -> TextSummary {
 977        let mut summary = TextSummary::default();
 978
 979        let mut cursor = self.transforms.cursor::<Dimensions<InlayOffset, usize>>(());
 980        cursor.seek(&range.start, Bias::Right);
 981
 982        let overshoot = range.start.0 - cursor.start().0.0;
 983        match cursor.item() {
 984            Some(Transform::Isomorphic(_)) => {
 985                let buffer_start = cursor.start().1;
 986                let suffix_start = buffer_start + overshoot;
 987                let suffix_end =
 988                    buffer_start + (cmp::min(cursor.end().0, range.end).0 - cursor.start().0.0);
 989                summary = self.buffer.text_summary_for_range(suffix_start..suffix_end);
 990                cursor.next();
 991            }
 992            Some(Transform::Inlay(inlay)) => {
 993                let suffix_start = overshoot;
 994                let suffix_end = cmp::min(cursor.end().0, range.end).0 - cursor.start().0.0;
 995                summary = inlay.text().cursor(suffix_start).summary(suffix_end);
 996                cursor.next();
 997            }
 998            None => {}
 999        }
1000
1001        if range.end > cursor.start().0 {
1002            summary += cursor
1003                .summary::<_, TransformSummary>(&range.end, Bias::Right)
1004                .output;
1005
1006            let overshoot = range.end.0 - cursor.start().0.0;
1007            match cursor.item() {
1008                Some(Transform::Isomorphic(_)) => {
1009                    let prefix_start = cursor.start().1;
1010                    let prefix_end = prefix_start + overshoot;
1011                    summary += self
1012                        .buffer
1013                        .text_summary_for_range::<TextSummary, _>(prefix_start..prefix_end);
1014                }
1015                Some(Transform::Inlay(inlay)) => {
1016                    let prefix_end = overshoot;
1017                    summary += inlay.text().cursor(0).summary::<TextSummary>(prefix_end);
1018                }
1019                None => {}
1020            }
1021        }
1022
1023        summary
1024    }
1025
1026    pub fn row_infos(&self, row: u32) -> InlayBufferRows<'_> {
1027        let mut cursor = self.transforms.cursor::<Dimensions<InlayPoint, Point>>(());
1028        let inlay_point = InlayPoint::new(row, 0);
1029        cursor.seek(&inlay_point, Bias::Left);
1030
1031        let max_buffer_row = self.buffer.max_row();
1032        let mut buffer_point = cursor.start().1;
1033        let buffer_row = if row == 0 {
1034            MultiBufferRow(0)
1035        } else {
1036            match cursor.item() {
1037                Some(Transform::Isomorphic(_)) => {
1038                    buffer_point += inlay_point.0 - cursor.start().0.0;
1039                    MultiBufferRow(buffer_point.row)
1040                }
1041                _ => cmp::min(MultiBufferRow(buffer_point.row + 1), max_buffer_row),
1042            }
1043        };
1044
1045        InlayBufferRows {
1046            transforms: cursor,
1047            inlay_row: inlay_point.row(),
1048            buffer_rows: self.buffer.row_infos(buffer_row),
1049            max_buffer_row,
1050        }
1051    }
1052
1053    pub fn line_len(&self, row: u32) -> u32 {
1054        let line_start = self.to_offset(InlayPoint::new(row, 0)).0;
1055        let line_end = if row >= self.max_point().row() {
1056            self.len().0
1057        } else {
1058            self.to_offset(InlayPoint::new(row + 1, 0)).0 - 1
1059        };
1060        (line_end - line_start) as u32
1061    }
1062
1063    pub(crate) fn chunks<'a>(
1064        &'a self,
1065        range: Range<InlayOffset>,
1066        language_aware: bool,
1067        highlights: Highlights<'a>,
1068    ) -> InlayChunks<'a> {
1069        let mut cursor = self.transforms.cursor::<Dimensions<InlayOffset, usize>>(());
1070        cursor.seek(&range.start, Bias::Right);
1071
1072        let buffer_range = self.to_buffer_offset(range.start)..self.to_buffer_offset(range.end);
1073        let buffer_chunks = CustomHighlightsChunks::new(
1074            buffer_range,
1075            language_aware,
1076            highlights.text_highlights,
1077            &self.buffer,
1078        );
1079
1080        InlayChunks {
1081            transforms: cursor,
1082            buffer_chunks,
1083            inlay_chunks: None,
1084            inlay_chunk: None,
1085            buffer_chunk: None,
1086            output_offset: range.start,
1087            max_output_offset: range.end,
1088            highlight_styles: highlights.styles,
1089            highlights,
1090            snapshot: self,
1091        }
1092    }
1093
1094    #[cfg(test)]
1095    pub fn text(&self) -> String {
1096        self.chunks(Default::default()..self.len(), false, Highlights::default())
1097            .map(|chunk| chunk.chunk.text)
1098            .collect()
1099    }
1100
1101    fn check_invariants(&self) {
1102        #[cfg(any(debug_assertions, feature = "test-support"))]
1103        {
1104            assert_eq!(self.transforms.summary().input, self.buffer.text_summary());
1105            let mut transforms = self.transforms.iter().peekable();
1106            while let Some(transform) = transforms.next() {
1107                let transform_is_isomorphic = matches!(transform, Transform::Isomorphic(_));
1108                if let Some(next_transform) = transforms.peek() {
1109                    let next_transform_is_isomorphic =
1110                        matches!(next_transform, Transform::Isomorphic(_));
1111                    assert!(
1112                        !transform_is_isomorphic || !next_transform_is_isomorphic,
1113                        "two adjacent isomorphic transforms"
1114                    );
1115                }
1116            }
1117        }
1118    }
1119}
1120
1121fn push_isomorphic(sum_tree: &mut SumTree<Transform>, summary: TextSummary) {
1122    if summary.len == 0 {
1123        return;
1124    }
1125
1126    let mut summary = Some(summary);
1127    sum_tree.update_last(
1128        |transform| {
1129            if let Transform::Isomorphic(transform) = transform {
1130                *transform += summary.take().unwrap();
1131            }
1132        },
1133        (),
1134    );
1135
1136    if let Some(summary) = summary {
1137        sum_tree.push(Transform::Isomorphic(summary), ());
1138    }
1139}
1140
1141/// Given a byte index that is NOT a UTF-8 boundary, find the next one.
1142/// Assumes: 0 < byte_index < text.len() and !text.is_char_boundary(byte_index)
1143#[inline(always)]
1144fn find_next_utf8_boundary(text: &str, byte_index: usize) -> usize {
1145    let bytes = text.as_bytes();
1146    let mut idx = byte_index + 1;
1147
1148    // Scan forward until we find a boundary
1149    while idx < text.len() {
1150        if is_utf8_char_boundary(bytes[idx]) {
1151            return idx;
1152        }
1153        idx += 1;
1154    }
1155
1156    // Hit the end, return the full length
1157    text.len()
1158}
1159
1160// Private helper function taken from Rust's core::num module (which is both Apache2 and MIT licensed)
1161const fn is_utf8_char_boundary(byte: u8) -> bool {
1162    // This is bit magic equivalent to: b < 128 || b >= 192
1163    (byte as i8) >= -0x40
1164}
1165
1166#[cfg(test)]
1167mod tests {
1168    use super::*;
1169    use crate::{
1170        MultiBuffer,
1171        display_map::{HighlightKey, InlayHighlights, TextHighlights},
1172        hover_links::InlayHighlight,
1173    };
1174    use gpui::{App, HighlightStyle};
1175    use multi_buffer::Anchor;
1176    use project::{InlayHint, InlayHintLabel, ResolveState};
1177    use rand::prelude::*;
1178    use settings::SettingsStore;
1179    use std::{any::TypeId, cmp::Reverse, env, sync::Arc};
1180    use sum_tree::TreeMap;
1181    use text::{Patch, Rope};
1182    use util::RandomCharIter;
1183    use util::post_inc;
1184
1185    #[test]
1186    fn test_inlay_properties_label_padding() {
1187        assert_eq!(
1188            Inlay::hint(
1189                InlayId::Hint(0),
1190                Anchor::min(),
1191                &InlayHint {
1192                    label: InlayHintLabel::String("a".to_string()),
1193                    position: text::Anchor::MIN,
1194                    padding_left: false,
1195                    padding_right: false,
1196                    tooltip: None,
1197                    kind: None,
1198                    resolve_state: ResolveState::Resolved,
1199                },
1200            )
1201            .text()
1202            .to_string(),
1203            "a",
1204            "Should not pad label if not requested"
1205        );
1206
1207        assert_eq!(
1208            Inlay::hint(
1209                InlayId::Hint(0),
1210                Anchor::min(),
1211                &InlayHint {
1212                    label: InlayHintLabel::String("a".to_string()),
1213                    position: text::Anchor::MIN,
1214                    padding_left: true,
1215                    padding_right: true,
1216                    tooltip: None,
1217                    kind: None,
1218                    resolve_state: ResolveState::Resolved,
1219                },
1220            )
1221            .text()
1222            .to_string(),
1223            " a ",
1224            "Should pad label for every side requested"
1225        );
1226
1227        assert_eq!(
1228            Inlay::hint(
1229                InlayId::Hint(0),
1230                Anchor::min(),
1231                &InlayHint {
1232                    label: InlayHintLabel::String(" a ".to_string()),
1233                    position: text::Anchor::MIN,
1234                    padding_left: false,
1235                    padding_right: false,
1236                    tooltip: None,
1237                    kind: None,
1238                    resolve_state: ResolveState::Resolved,
1239                },
1240            )
1241            .text()
1242            .to_string(),
1243            " a ",
1244            "Should not change already padded label"
1245        );
1246
1247        assert_eq!(
1248            Inlay::hint(
1249                InlayId::Hint(0),
1250                Anchor::min(),
1251                &InlayHint {
1252                    label: InlayHintLabel::String(" a ".to_string()),
1253                    position: text::Anchor::MIN,
1254                    padding_left: true,
1255                    padding_right: true,
1256                    tooltip: None,
1257                    kind: None,
1258                    resolve_state: ResolveState::Resolved,
1259                },
1260            )
1261            .text()
1262            .to_string(),
1263            " a ",
1264            "Should not change already padded label"
1265        );
1266    }
1267
1268    #[gpui::test]
1269    fn test_inlay_hint_padding_with_multibyte_chars() {
1270        assert_eq!(
1271            Inlay::hint(
1272                InlayId::Hint(0),
1273                Anchor::min(),
1274                &InlayHint {
1275                    label: InlayHintLabel::String("🎨".to_string()),
1276                    position: text::Anchor::MIN,
1277                    padding_left: true,
1278                    padding_right: true,
1279                    tooltip: None,
1280                    kind: None,
1281                    resolve_state: ResolveState::Resolved,
1282                },
1283            )
1284            .text()
1285            .to_string(),
1286            " 🎨 ",
1287            "Should pad single emoji correctly"
1288        );
1289    }
1290
1291    #[gpui::test]
1292    fn test_basic_inlays(cx: &mut App) {
1293        let buffer = MultiBuffer::build_simple("abcdefghi", cx);
1294        let buffer_edits = buffer.update(cx, |buffer, _| buffer.subscribe());
1295        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer.read(cx).snapshot(cx));
1296        assert_eq!(inlay_snapshot.text(), "abcdefghi");
1297        let mut next_inlay_id = 0;
1298
1299        let (inlay_snapshot, _) = inlay_map.splice(
1300            &[],
1301            vec![Inlay::mock_hint(
1302                post_inc(&mut next_inlay_id),
1303                buffer.read(cx).snapshot(cx).anchor_after(3),
1304                "|123|",
1305            )],
1306        );
1307        assert_eq!(inlay_snapshot.text(), "abc|123|defghi");
1308        assert_eq!(
1309            inlay_snapshot.to_inlay_point(Point::new(0, 0)),
1310            InlayPoint::new(0, 0)
1311        );
1312        assert_eq!(
1313            inlay_snapshot.to_inlay_point(Point::new(0, 1)),
1314            InlayPoint::new(0, 1)
1315        );
1316        assert_eq!(
1317            inlay_snapshot.to_inlay_point(Point::new(0, 2)),
1318            InlayPoint::new(0, 2)
1319        );
1320        assert_eq!(
1321            inlay_snapshot.to_inlay_point(Point::new(0, 3)),
1322            InlayPoint::new(0, 3)
1323        );
1324        assert_eq!(
1325            inlay_snapshot.to_inlay_point(Point::new(0, 4)),
1326            InlayPoint::new(0, 9)
1327        );
1328        assert_eq!(
1329            inlay_snapshot.to_inlay_point(Point::new(0, 5)),
1330            InlayPoint::new(0, 10)
1331        );
1332        assert_eq!(
1333            inlay_snapshot.clip_point(InlayPoint::new(0, 0), Bias::Left),
1334            InlayPoint::new(0, 0)
1335        );
1336        assert_eq!(
1337            inlay_snapshot.clip_point(InlayPoint::new(0, 0), Bias::Right),
1338            InlayPoint::new(0, 0)
1339        );
1340        assert_eq!(
1341            inlay_snapshot.clip_point(InlayPoint::new(0, 3), Bias::Left),
1342            InlayPoint::new(0, 3)
1343        );
1344        assert_eq!(
1345            inlay_snapshot.clip_point(InlayPoint::new(0, 3), Bias::Right),
1346            InlayPoint::new(0, 3)
1347        );
1348        assert_eq!(
1349            inlay_snapshot.clip_point(InlayPoint::new(0, 4), Bias::Left),
1350            InlayPoint::new(0, 3)
1351        );
1352        assert_eq!(
1353            inlay_snapshot.clip_point(InlayPoint::new(0, 4), Bias::Right),
1354            InlayPoint::new(0, 9)
1355        );
1356
1357        // Edits before or after the inlay should not affect it.
1358        buffer.update(cx, |buffer, cx| {
1359            buffer.edit([(2..3, "x"), (3..3, "y"), (4..4, "z")], None, cx)
1360        });
1361        let (inlay_snapshot, _) = inlay_map.sync(
1362            buffer.read(cx).snapshot(cx),
1363            buffer_edits.consume().into_inner(),
1364        );
1365        assert_eq!(inlay_snapshot.text(), "abxy|123|dzefghi");
1366
1367        // An edit surrounding the inlay should invalidate it.
1368        buffer.update(cx, |buffer, cx| buffer.edit([(4..5, "D")], None, cx));
1369        let (inlay_snapshot, _) = inlay_map.sync(
1370            buffer.read(cx).snapshot(cx),
1371            buffer_edits.consume().into_inner(),
1372        );
1373        assert_eq!(inlay_snapshot.text(), "abxyDzefghi");
1374
1375        let (inlay_snapshot, _) = inlay_map.splice(
1376            &[],
1377            vec![
1378                Inlay::mock_hint(
1379                    post_inc(&mut next_inlay_id),
1380                    buffer.read(cx).snapshot(cx).anchor_before(3),
1381                    "|123|",
1382                ),
1383                Inlay::edit_prediction(
1384                    post_inc(&mut next_inlay_id),
1385                    buffer.read(cx).snapshot(cx).anchor_after(3),
1386                    "|456|",
1387                ),
1388            ],
1389        );
1390        assert_eq!(inlay_snapshot.text(), "abx|123||456|yDzefghi");
1391
1392        // Edits ending where the inlay starts should not move it if it has a left bias.
1393        buffer.update(cx, |buffer, cx| buffer.edit([(3..3, "JKL")], None, cx));
1394        let (inlay_snapshot, _) = inlay_map.sync(
1395            buffer.read(cx).snapshot(cx),
1396            buffer_edits.consume().into_inner(),
1397        );
1398        assert_eq!(inlay_snapshot.text(), "abx|123|JKL|456|yDzefghi");
1399
1400        assert_eq!(
1401            inlay_snapshot.clip_point(InlayPoint::new(0, 0), Bias::Left),
1402            InlayPoint::new(0, 0)
1403        );
1404        assert_eq!(
1405            inlay_snapshot.clip_point(InlayPoint::new(0, 0), Bias::Right),
1406            InlayPoint::new(0, 0)
1407        );
1408
1409        assert_eq!(
1410            inlay_snapshot.clip_point(InlayPoint::new(0, 1), Bias::Left),
1411            InlayPoint::new(0, 1)
1412        );
1413        assert_eq!(
1414            inlay_snapshot.clip_point(InlayPoint::new(0, 1), Bias::Right),
1415            InlayPoint::new(0, 1)
1416        );
1417
1418        assert_eq!(
1419            inlay_snapshot.clip_point(InlayPoint::new(0, 2), Bias::Left),
1420            InlayPoint::new(0, 2)
1421        );
1422        assert_eq!(
1423            inlay_snapshot.clip_point(InlayPoint::new(0, 2), Bias::Right),
1424            InlayPoint::new(0, 2)
1425        );
1426
1427        assert_eq!(
1428            inlay_snapshot.clip_point(InlayPoint::new(0, 3), Bias::Left),
1429            InlayPoint::new(0, 2)
1430        );
1431        assert_eq!(
1432            inlay_snapshot.clip_point(InlayPoint::new(0, 3), Bias::Right),
1433            InlayPoint::new(0, 8)
1434        );
1435
1436        assert_eq!(
1437            inlay_snapshot.clip_point(InlayPoint::new(0, 4), Bias::Left),
1438            InlayPoint::new(0, 2)
1439        );
1440        assert_eq!(
1441            inlay_snapshot.clip_point(InlayPoint::new(0, 4), Bias::Right),
1442            InlayPoint::new(0, 8)
1443        );
1444
1445        assert_eq!(
1446            inlay_snapshot.clip_point(InlayPoint::new(0, 5), Bias::Left),
1447            InlayPoint::new(0, 2)
1448        );
1449        assert_eq!(
1450            inlay_snapshot.clip_point(InlayPoint::new(0, 5), Bias::Right),
1451            InlayPoint::new(0, 8)
1452        );
1453
1454        assert_eq!(
1455            inlay_snapshot.clip_point(InlayPoint::new(0, 6), Bias::Left),
1456            InlayPoint::new(0, 2)
1457        );
1458        assert_eq!(
1459            inlay_snapshot.clip_point(InlayPoint::new(0, 6), Bias::Right),
1460            InlayPoint::new(0, 8)
1461        );
1462
1463        assert_eq!(
1464            inlay_snapshot.clip_point(InlayPoint::new(0, 7), Bias::Left),
1465            InlayPoint::new(0, 2)
1466        );
1467        assert_eq!(
1468            inlay_snapshot.clip_point(InlayPoint::new(0, 7), Bias::Right),
1469            InlayPoint::new(0, 8)
1470        );
1471
1472        assert_eq!(
1473            inlay_snapshot.clip_point(InlayPoint::new(0, 8), Bias::Left),
1474            InlayPoint::new(0, 8)
1475        );
1476        assert_eq!(
1477            inlay_snapshot.clip_point(InlayPoint::new(0, 8), Bias::Right),
1478            InlayPoint::new(0, 8)
1479        );
1480
1481        assert_eq!(
1482            inlay_snapshot.clip_point(InlayPoint::new(0, 9), Bias::Left),
1483            InlayPoint::new(0, 9)
1484        );
1485        assert_eq!(
1486            inlay_snapshot.clip_point(InlayPoint::new(0, 9), Bias::Right),
1487            InlayPoint::new(0, 9)
1488        );
1489
1490        assert_eq!(
1491            inlay_snapshot.clip_point(InlayPoint::new(0, 10), Bias::Left),
1492            InlayPoint::new(0, 10)
1493        );
1494        assert_eq!(
1495            inlay_snapshot.clip_point(InlayPoint::new(0, 10), Bias::Right),
1496            InlayPoint::new(0, 10)
1497        );
1498
1499        assert_eq!(
1500            inlay_snapshot.clip_point(InlayPoint::new(0, 11), Bias::Left),
1501            InlayPoint::new(0, 11)
1502        );
1503        assert_eq!(
1504            inlay_snapshot.clip_point(InlayPoint::new(0, 11), Bias::Right),
1505            InlayPoint::new(0, 11)
1506        );
1507
1508        assert_eq!(
1509            inlay_snapshot.clip_point(InlayPoint::new(0, 12), Bias::Left),
1510            InlayPoint::new(0, 11)
1511        );
1512        assert_eq!(
1513            inlay_snapshot.clip_point(InlayPoint::new(0, 12), Bias::Right),
1514            InlayPoint::new(0, 17)
1515        );
1516
1517        assert_eq!(
1518            inlay_snapshot.clip_point(InlayPoint::new(0, 13), Bias::Left),
1519            InlayPoint::new(0, 11)
1520        );
1521        assert_eq!(
1522            inlay_snapshot.clip_point(InlayPoint::new(0, 13), Bias::Right),
1523            InlayPoint::new(0, 17)
1524        );
1525
1526        assert_eq!(
1527            inlay_snapshot.clip_point(InlayPoint::new(0, 14), Bias::Left),
1528            InlayPoint::new(0, 11)
1529        );
1530        assert_eq!(
1531            inlay_snapshot.clip_point(InlayPoint::new(0, 14), Bias::Right),
1532            InlayPoint::new(0, 17)
1533        );
1534
1535        assert_eq!(
1536            inlay_snapshot.clip_point(InlayPoint::new(0, 15), Bias::Left),
1537            InlayPoint::new(0, 11)
1538        );
1539        assert_eq!(
1540            inlay_snapshot.clip_point(InlayPoint::new(0, 15), Bias::Right),
1541            InlayPoint::new(0, 17)
1542        );
1543
1544        assert_eq!(
1545            inlay_snapshot.clip_point(InlayPoint::new(0, 16), Bias::Left),
1546            InlayPoint::new(0, 11)
1547        );
1548        assert_eq!(
1549            inlay_snapshot.clip_point(InlayPoint::new(0, 16), Bias::Right),
1550            InlayPoint::new(0, 17)
1551        );
1552
1553        assert_eq!(
1554            inlay_snapshot.clip_point(InlayPoint::new(0, 17), Bias::Left),
1555            InlayPoint::new(0, 17)
1556        );
1557        assert_eq!(
1558            inlay_snapshot.clip_point(InlayPoint::new(0, 17), Bias::Right),
1559            InlayPoint::new(0, 17)
1560        );
1561
1562        assert_eq!(
1563            inlay_snapshot.clip_point(InlayPoint::new(0, 18), Bias::Left),
1564            InlayPoint::new(0, 18)
1565        );
1566        assert_eq!(
1567            inlay_snapshot.clip_point(InlayPoint::new(0, 18), Bias::Right),
1568            InlayPoint::new(0, 18)
1569        );
1570
1571        // The inlays can be manually removed.
1572        let (inlay_snapshot, _) = inlay_map.splice(
1573            &inlay_map
1574                .inlays
1575                .iter()
1576                .map(|inlay| inlay.id)
1577                .collect::<Vec<InlayId>>(),
1578            Vec::new(),
1579        );
1580        assert_eq!(inlay_snapshot.text(), "abxJKLyDzefghi");
1581    }
1582
1583    #[gpui::test]
1584    fn test_inlay_buffer_rows(cx: &mut App) {
1585        let buffer = MultiBuffer::build_simple("abc\ndef\nghi", cx);
1586        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer.read(cx).snapshot(cx));
1587        assert_eq!(inlay_snapshot.text(), "abc\ndef\nghi");
1588        let mut next_inlay_id = 0;
1589
1590        let (inlay_snapshot, _) = inlay_map.splice(
1591            &[],
1592            vec![
1593                Inlay::mock_hint(
1594                    post_inc(&mut next_inlay_id),
1595                    buffer.read(cx).snapshot(cx).anchor_before(0),
1596                    "|123|\n",
1597                ),
1598                Inlay::mock_hint(
1599                    post_inc(&mut next_inlay_id),
1600                    buffer.read(cx).snapshot(cx).anchor_before(4),
1601                    "|456|",
1602                ),
1603                Inlay::edit_prediction(
1604                    post_inc(&mut next_inlay_id),
1605                    buffer.read(cx).snapshot(cx).anchor_before(7),
1606                    "\n|567|\n",
1607                ),
1608            ],
1609        );
1610        assert_eq!(inlay_snapshot.text(), "|123|\nabc\n|456|def\n|567|\n\nghi");
1611        assert_eq!(
1612            inlay_snapshot
1613                .row_infos(0)
1614                .map(|info| info.buffer_row)
1615                .collect::<Vec<_>>(),
1616            vec![Some(0), None, Some(1), None, None, Some(2)]
1617        );
1618    }
1619
1620    #[gpui::test(iterations = 100)]
1621    fn test_random_inlays(cx: &mut App, mut rng: StdRng) {
1622        init_test(cx);
1623
1624        let operations = env::var("OPERATIONS")
1625            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1626            .unwrap_or(10);
1627
1628        let len = rng.random_range(0..30);
1629        let buffer = if rng.random() {
1630            let text = util::RandomCharIter::new(&mut rng)
1631                .take(len)
1632                .collect::<String>();
1633            MultiBuffer::build_simple(&text, cx)
1634        } else {
1635            MultiBuffer::build_random(&mut rng, cx)
1636        };
1637        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1638        let mut next_inlay_id = 0;
1639        log::info!("buffer text: {:?}", buffer_snapshot.text());
1640        let (mut inlay_map, mut inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1641        for _ in 0..operations {
1642            let mut inlay_edits = Patch::default();
1643
1644            let mut prev_inlay_text = inlay_snapshot.text();
1645            let mut buffer_edits = Vec::new();
1646            match rng.random_range(0..=100) {
1647                0..=50 => {
1648                    let (snapshot, edits) = inlay_map.randomly_mutate(&mut next_inlay_id, &mut rng);
1649                    log::info!("mutated text: {:?}", snapshot.text());
1650                    inlay_edits = Patch::new(edits);
1651                }
1652                _ => buffer.update(cx, |buffer, cx| {
1653                    let subscription = buffer.subscribe();
1654                    let edit_count = rng.random_range(1..=5);
1655                    buffer.randomly_mutate(&mut rng, edit_count, cx);
1656                    buffer_snapshot = buffer.snapshot(cx);
1657                    let edits = subscription.consume().into_inner();
1658                    log::info!("editing {:?}", edits);
1659                    buffer_edits.extend(edits);
1660                }),
1661            };
1662
1663            let (new_inlay_snapshot, new_inlay_edits) =
1664                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1665            inlay_snapshot = new_inlay_snapshot;
1666            inlay_edits = inlay_edits.compose(new_inlay_edits);
1667
1668            log::info!("buffer text: {:?}", buffer_snapshot.text());
1669            log::info!("inlay text: {:?}", inlay_snapshot.text());
1670
1671            let inlays = inlay_map
1672                .inlays
1673                .iter()
1674                .filter(|inlay| inlay.position.is_valid(&buffer_snapshot))
1675                .map(|inlay| {
1676                    let offset = inlay.position.to_offset(&buffer_snapshot);
1677                    (offset, inlay.clone())
1678                })
1679                .collect::<Vec<_>>();
1680            let mut expected_text = Rope::from(&buffer_snapshot.text());
1681            for (offset, inlay) in inlays.iter().rev() {
1682                expected_text.replace(*offset..*offset, &inlay.text().to_string());
1683            }
1684            assert_eq!(inlay_snapshot.text(), expected_text.to_string());
1685
1686            let expected_buffer_rows = inlay_snapshot.row_infos(0).collect::<Vec<_>>();
1687            assert_eq!(
1688                expected_buffer_rows.len() as u32,
1689                expected_text.max_point().row + 1
1690            );
1691            for row_start in 0..expected_buffer_rows.len() {
1692                assert_eq!(
1693                    inlay_snapshot
1694                        .row_infos(row_start as u32)
1695                        .collect::<Vec<_>>(),
1696                    &expected_buffer_rows[row_start..],
1697                    "incorrect buffer rows starting at {}",
1698                    row_start
1699                );
1700            }
1701
1702            let mut text_highlights = TextHighlights::default();
1703            let text_highlight_count = rng.random_range(0_usize..10);
1704            let mut text_highlight_ranges = (0..text_highlight_count)
1705                .map(|_| buffer_snapshot.random_byte_range(0, &mut rng))
1706                .collect::<Vec<_>>();
1707            text_highlight_ranges.sort_by_key(|range| (range.start, Reverse(range.end)));
1708            log::info!("highlighting text ranges {text_highlight_ranges:?}");
1709            text_highlights.insert(
1710                HighlightKey::Type(TypeId::of::<()>()),
1711                Arc::new((
1712                    HighlightStyle::default(),
1713                    text_highlight_ranges
1714                        .into_iter()
1715                        .map(|range| {
1716                            buffer_snapshot.anchor_before(range.start)
1717                                ..buffer_snapshot.anchor_after(range.end)
1718                        })
1719                        .collect(),
1720                )),
1721            );
1722
1723            let mut inlay_highlights = InlayHighlights::default();
1724            if !inlays.is_empty() {
1725                let inlay_highlight_count = rng.random_range(0..inlays.len());
1726                let mut inlay_indices = BTreeSet::default();
1727                while inlay_indices.len() < inlay_highlight_count {
1728                    inlay_indices.insert(rng.random_range(0..inlays.len()));
1729                }
1730                let new_highlights = TreeMap::from_ordered_entries(
1731                    inlay_indices
1732                        .into_iter()
1733                        .filter_map(|i| {
1734                            let (_, inlay) = &inlays[i];
1735                            let inlay_text_len = inlay.text().len();
1736                            match inlay_text_len {
1737                                0 => None,
1738                                1 => Some(InlayHighlight {
1739                                    inlay: inlay.id,
1740                                    inlay_position: inlay.position,
1741                                    range: 0..1,
1742                                }),
1743                                n => {
1744                                    let inlay_text = inlay.text().to_string();
1745                                    let mut highlight_end = rng.random_range(1..n);
1746                                    let mut highlight_start = rng.random_range(0..highlight_end);
1747                                    while !inlay_text.is_char_boundary(highlight_end) {
1748                                        highlight_end += 1;
1749                                    }
1750                                    while !inlay_text.is_char_boundary(highlight_start) {
1751                                        highlight_start -= 1;
1752                                    }
1753                                    Some(InlayHighlight {
1754                                        inlay: inlay.id,
1755                                        inlay_position: inlay.position,
1756                                        range: highlight_start..highlight_end,
1757                                    })
1758                                }
1759                            }
1760                        })
1761                        .map(|highlight| (highlight.inlay, (HighlightStyle::default(), highlight))),
1762                );
1763                log::info!("highlighting inlay ranges {new_highlights:?}");
1764                inlay_highlights.insert(TypeId::of::<()>(), new_highlights);
1765            }
1766
1767            for _ in 0..5 {
1768                let mut end = rng.random_range(0..=inlay_snapshot.len().0);
1769                end = expected_text.clip_offset(end, Bias::Right);
1770                let mut start = rng.random_range(0..=end);
1771                start = expected_text.clip_offset(start, Bias::Right);
1772
1773                let range = InlayOffset(start)..InlayOffset(end);
1774                log::info!("calling inlay_snapshot.chunks({range:?})");
1775                let actual_text = inlay_snapshot
1776                    .chunks(
1777                        range,
1778                        false,
1779                        Highlights {
1780                            text_highlights: Some(&text_highlights),
1781                            inlay_highlights: Some(&inlay_highlights),
1782                            ..Highlights::default()
1783                        },
1784                    )
1785                    .map(|chunk| chunk.chunk.text)
1786                    .collect::<String>();
1787                assert_eq!(
1788                    actual_text,
1789                    expected_text.slice(start..end).to_string(),
1790                    "incorrect text in range {:?}",
1791                    start..end
1792                );
1793
1794                assert_eq!(
1795                    inlay_snapshot.text_summary_for_range(InlayOffset(start)..InlayOffset(end)),
1796                    expected_text.slice(start..end).summary()
1797                );
1798            }
1799
1800            for edit in inlay_edits {
1801                prev_inlay_text.replace_range(
1802                    edit.new.start.0..edit.new.start.0 + edit.old_len().0,
1803                    &inlay_snapshot.text()[edit.new.start.0..edit.new.end.0],
1804                );
1805            }
1806            assert_eq!(prev_inlay_text, inlay_snapshot.text());
1807
1808            assert_eq!(expected_text.max_point(), inlay_snapshot.max_point().0);
1809            assert_eq!(expected_text.len(), inlay_snapshot.len().0);
1810
1811            let mut buffer_point = Point::default();
1812            let mut inlay_point = inlay_snapshot.to_inlay_point(buffer_point);
1813            let mut buffer_chars = buffer_snapshot.chars_at(0);
1814            loop {
1815                // Ensure conversion from buffer coordinates to inlay coordinates
1816                // is consistent.
1817                let buffer_offset = buffer_snapshot.point_to_offset(buffer_point);
1818                assert_eq!(
1819                    inlay_snapshot.to_point(inlay_snapshot.to_inlay_offset(buffer_offset)),
1820                    inlay_point
1821                );
1822
1823                // No matter which bias we clip an inlay point with, it doesn't move
1824                // because it was constructed from a buffer point.
1825                assert_eq!(
1826                    inlay_snapshot.clip_point(inlay_point, Bias::Left),
1827                    inlay_point,
1828                    "invalid inlay point for buffer point {:?} when clipped left",
1829                    buffer_point
1830                );
1831                assert_eq!(
1832                    inlay_snapshot.clip_point(inlay_point, Bias::Right),
1833                    inlay_point,
1834                    "invalid inlay point for buffer point {:?} when clipped right",
1835                    buffer_point
1836                );
1837
1838                if let Some(ch) = buffer_chars.next() {
1839                    if ch == '\n' {
1840                        buffer_point += Point::new(1, 0);
1841                    } else {
1842                        buffer_point += Point::new(0, ch.len_utf8() as u32);
1843                    }
1844
1845                    // Ensure that moving forward in the buffer always moves the inlay point forward as well.
1846                    let new_inlay_point = inlay_snapshot.to_inlay_point(buffer_point);
1847                    assert!(new_inlay_point > inlay_point);
1848                    inlay_point = new_inlay_point;
1849                } else {
1850                    break;
1851                }
1852            }
1853
1854            let mut inlay_point = InlayPoint::default();
1855            let mut inlay_offset = InlayOffset::default();
1856            for ch in expected_text.chars() {
1857                assert_eq!(
1858                    inlay_snapshot.to_offset(inlay_point),
1859                    inlay_offset,
1860                    "invalid to_offset({:?})",
1861                    inlay_point
1862                );
1863                assert_eq!(
1864                    inlay_snapshot.to_point(inlay_offset),
1865                    inlay_point,
1866                    "invalid to_point({:?})",
1867                    inlay_offset
1868                );
1869
1870                let mut bytes = [0; 4];
1871                for byte in ch.encode_utf8(&mut bytes).as_bytes() {
1872                    inlay_offset.0 += 1;
1873                    if *byte == b'\n' {
1874                        inlay_point.0 += Point::new(1, 0);
1875                    } else {
1876                        inlay_point.0 += Point::new(0, 1);
1877                    }
1878
1879                    let clipped_left_point = inlay_snapshot.clip_point(inlay_point, Bias::Left);
1880                    let clipped_right_point = inlay_snapshot.clip_point(inlay_point, Bias::Right);
1881                    assert!(
1882                        clipped_left_point <= clipped_right_point,
1883                        "inlay point {:?} when clipped left is greater than when clipped right ({:?} > {:?})",
1884                        inlay_point,
1885                        clipped_left_point,
1886                        clipped_right_point
1887                    );
1888
1889                    // Ensure the clipped points are at valid text locations.
1890                    assert_eq!(
1891                        clipped_left_point.0,
1892                        expected_text.clip_point(clipped_left_point.0, Bias::Left)
1893                    );
1894                    assert_eq!(
1895                        clipped_right_point.0,
1896                        expected_text.clip_point(clipped_right_point.0, Bias::Right)
1897                    );
1898
1899                    // Ensure the clipped points never overshoot the end of the map.
1900                    assert!(clipped_left_point <= inlay_snapshot.max_point());
1901                    assert!(clipped_right_point <= inlay_snapshot.max_point());
1902
1903                    // Ensure the clipped points are at valid buffer locations.
1904                    assert_eq!(
1905                        inlay_snapshot
1906                            .to_inlay_point(inlay_snapshot.to_buffer_point(clipped_left_point)),
1907                        clipped_left_point,
1908                        "to_buffer_point({:?}) = {:?}",
1909                        clipped_left_point,
1910                        inlay_snapshot.to_buffer_point(clipped_left_point),
1911                    );
1912                    assert_eq!(
1913                        inlay_snapshot
1914                            .to_inlay_point(inlay_snapshot.to_buffer_point(clipped_right_point)),
1915                        clipped_right_point,
1916                        "to_buffer_point({:?}) = {:?}",
1917                        clipped_right_point,
1918                        inlay_snapshot.to_buffer_point(clipped_right_point),
1919                    );
1920                }
1921            }
1922        }
1923    }
1924
1925    #[gpui::test(iterations = 100)]
1926    fn test_random_chunk_bitmaps(cx: &mut gpui::App, mut rng: StdRng) {
1927        init_test(cx);
1928
1929        // Generate random buffer using existing test infrastructure
1930        let text_len = rng.random_range(0..10000);
1931        let buffer = if rng.random() {
1932            let text = RandomCharIter::new(&mut rng)
1933                .take(text_len)
1934                .collect::<String>();
1935            MultiBuffer::build_simple(&text, cx)
1936        } else {
1937            MultiBuffer::build_random(&mut rng, cx)
1938        };
1939
1940        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1941        let (mut inlay_map, _) = InlayMap::new(buffer_snapshot.clone());
1942
1943        // Perform random mutations to add inlays
1944        let mut next_inlay_id = 0;
1945        let mutation_count = rng.random_range(1..10);
1946        for _ in 0..mutation_count {
1947            inlay_map.randomly_mutate(&mut next_inlay_id, &mut rng);
1948        }
1949
1950        let (snapshot, _) = inlay_map.sync(buffer_snapshot, vec![]);
1951
1952        // Get all chunks and verify their bitmaps
1953        let chunks = snapshot.chunks(
1954            InlayOffset(0)..InlayOffset(snapshot.len().0),
1955            false,
1956            Highlights::default(),
1957        );
1958
1959        for chunk in chunks.into_iter().map(|inlay_chunk| inlay_chunk.chunk) {
1960            let chunk_text = chunk.text;
1961            let chars_bitmap = chunk.chars;
1962            let tabs_bitmap = chunk.tabs;
1963
1964            // Check empty chunks have empty bitmaps
1965            if chunk_text.is_empty() {
1966                assert_eq!(
1967                    chars_bitmap, 0,
1968                    "Empty chunk should have empty chars bitmap"
1969                );
1970                assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
1971                continue;
1972            }
1973
1974            // Verify that chunk text doesn't exceed 128 bytes
1975            assert!(
1976                chunk_text.len() <= 128,
1977                "Chunk text length {} exceeds 128 bytes",
1978                chunk_text.len()
1979            );
1980
1981            // Verify chars bitmap
1982            let char_indices = chunk_text
1983                .char_indices()
1984                .map(|(i, _)| i)
1985                .collect::<Vec<_>>();
1986
1987            for byte_idx in 0..chunk_text.len() {
1988                let should_have_bit = char_indices.contains(&byte_idx);
1989                let has_bit = chars_bitmap & (1 << byte_idx) != 0;
1990
1991                if has_bit != should_have_bit {
1992                    eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
1993                    eprintln!("Char indices: {:?}", char_indices);
1994                    eprintln!("Chars bitmap: {:#b}", chars_bitmap);
1995                    assert_eq!(
1996                        has_bit, should_have_bit,
1997                        "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
1998                        byte_idx, chunk_text, should_have_bit, has_bit
1999                    );
2000                }
2001            }
2002
2003            // Verify tabs bitmap
2004            for (byte_idx, byte) in chunk_text.bytes().enumerate() {
2005                let is_tab = byte == b'\t';
2006                let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
2007
2008                if has_bit != is_tab {
2009                    eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
2010                    eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
2011                    assert_eq!(
2012                        has_bit, is_tab,
2013                        "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
2014                        byte_idx, chunk_text, byte as char, is_tab, has_bit
2015                    );
2016                }
2017            }
2018        }
2019    }
2020
2021    fn init_test(cx: &mut App) {
2022        let store = SettingsStore::test(cx);
2023        cx.set_global(store);
2024        theme::init(theme::LoadThemes::JustBase, cx);
2025    }
2026
2027    /// Helper to create test highlights for an inlay
2028    fn create_inlay_highlights(
2029        inlay_id: InlayId,
2030        highlight_range: Range<usize>,
2031        position: Anchor,
2032    ) -> TreeMap<TypeId, TreeMap<InlayId, (HighlightStyle, InlayHighlight)>> {
2033        let mut inlay_highlights = TreeMap::default();
2034        let mut type_highlights = TreeMap::default();
2035        type_highlights.insert(
2036            inlay_id,
2037            (
2038                HighlightStyle::default(),
2039                InlayHighlight {
2040                    inlay: inlay_id,
2041                    range: highlight_range,
2042                    inlay_position: position,
2043                },
2044            ),
2045        );
2046        inlay_highlights.insert(TypeId::of::<()>(), type_highlights);
2047        inlay_highlights
2048    }
2049
2050    #[gpui::test]
2051    fn test_inlay_utf8_boundary_panic_fix(cx: &mut App) {
2052        init_test(cx);
2053
2054        // This test verifies that we handle UTF-8 character boundaries correctly
2055        // when splitting inlay text for highlighting. Previously, this would panic
2056        // when trying to split at byte 13, which is in the middle of the '…' character.
2057        //
2058        // See https://github.com/zed-industries/zed/issues/33641
2059        let buffer = MultiBuffer::build_simple("fn main() {}\n", cx);
2060        let (mut inlay_map, _) = InlayMap::new(buffer.read(cx).snapshot(cx));
2061
2062        // Create an inlay with text that contains a multi-byte character
2063        // The string "SortingDirec…" contains an ellipsis character '…' which is 3 bytes (E2 80 A6)
2064        let inlay_text = "SortingDirec…";
2065        let position = buffer.read(cx).snapshot(cx).anchor_before(Point::new(0, 5));
2066
2067        let inlay = Inlay {
2068            id: InlayId::Hint(0),
2069            position,
2070            content: InlayContent::Text(text::Rope::from(inlay_text)),
2071        };
2072
2073        let (inlay_snapshot, _) = inlay_map.splice(&[], vec![inlay]);
2074
2075        // Create highlights that request a split at byte 13, which is in the middle
2076        // of the '…' character (bytes 12..15). We include the full character.
2077        let inlay_highlights = create_inlay_highlights(InlayId::Hint(0), 0..13, position);
2078
2079        let highlights = crate::display_map::Highlights {
2080            text_highlights: None,
2081            inlay_highlights: Some(&inlay_highlights),
2082            styles: crate::display_map::HighlightStyles::default(),
2083        };
2084
2085        // Collect chunks - this previously would panic
2086        let chunks: Vec<_> = inlay_snapshot
2087            .chunks(
2088                InlayOffset(0)..InlayOffset(inlay_snapshot.len().0),
2089                false,
2090                highlights,
2091            )
2092            .collect();
2093
2094        // Verify the chunks are correct
2095        let full_text: String = chunks.iter().map(|c| c.chunk.text).collect();
2096        assert_eq!(full_text, "fn maSortingDirec…in() {}\n");
2097
2098        // Verify the highlighted portion includes the complete ellipsis character
2099        let highlighted_chunks: Vec<_> = chunks
2100            .iter()
2101            .filter(|c| c.chunk.highlight_style.is_some() && c.chunk.is_inlay)
2102            .collect();
2103
2104        assert_eq!(highlighted_chunks.len(), 1);
2105        assert_eq!(highlighted_chunks[0].chunk.text, "SortingDirec…");
2106    }
2107
2108    #[gpui::test]
2109    fn test_inlay_utf8_boundaries(cx: &mut App) {
2110        init_test(cx);
2111
2112        struct TestCase {
2113            inlay_text: &'static str,
2114            highlight_range: Range<usize>,
2115            expected_highlighted: &'static str,
2116            description: &'static str,
2117        }
2118
2119        let test_cases = vec![
2120            TestCase {
2121                inlay_text: "Hello👋World",
2122                highlight_range: 0..7,
2123                expected_highlighted: "Hello👋",
2124                description: "Emoji boundary - rounds up to include full emoji",
2125            },
2126            TestCase {
2127                inlay_text: "Test→End",
2128                highlight_range: 0..5,
2129                expected_highlighted: "Test→",
2130                description: "Arrow boundary - rounds up to include full arrow",
2131            },
2132            TestCase {
2133                inlay_text: "café",
2134                highlight_range: 0..4,
2135                expected_highlighted: "café",
2136                description: "Accented char boundary - rounds up to include full é",
2137            },
2138            TestCase {
2139                inlay_text: "🎨🎭🎪",
2140                highlight_range: 0..5,
2141                expected_highlighted: "🎨🎭",
2142                description: "Multiple emojis - partial highlight",
2143            },
2144            TestCase {
2145                inlay_text: "普通话",
2146                highlight_range: 0..4,
2147                expected_highlighted: "普通",
2148                description: "Chinese characters - partial highlight",
2149            },
2150            TestCase {
2151                inlay_text: "Hello",
2152                highlight_range: 0..2,
2153                expected_highlighted: "He",
2154                description: "ASCII only - no adjustment needed",
2155            },
2156            TestCase {
2157                inlay_text: "👋",
2158                highlight_range: 0..1,
2159                expected_highlighted: "👋",
2160                description: "Single emoji - partial byte range includes whole char",
2161            },
2162            TestCase {
2163                inlay_text: "Test",
2164                highlight_range: 0..0,
2165                expected_highlighted: "",
2166                description: "Empty range",
2167            },
2168            TestCase {
2169                inlay_text: "🎨ABC",
2170                highlight_range: 2..5,
2171                expected_highlighted: "A",
2172                description: "Range starting mid-emoji skips the emoji",
2173            },
2174        ];
2175
2176        for test_case in test_cases {
2177            let buffer = MultiBuffer::build_simple("test", cx);
2178            let (mut inlay_map, _) = InlayMap::new(buffer.read(cx).snapshot(cx));
2179            let position = buffer.read(cx).snapshot(cx).anchor_before(Point::new(0, 2));
2180
2181            let inlay = Inlay {
2182                id: InlayId::Hint(0),
2183                position,
2184                content: InlayContent::Text(text::Rope::from(test_case.inlay_text)),
2185            };
2186
2187            let (inlay_snapshot, _) = inlay_map.splice(&[], vec![inlay]);
2188            let inlay_highlights = create_inlay_highlights(
2189                InlayId::Hint(0),
2190                test_case.highlight_range.clone(),
2191                position,
2192            );
2193
2194            let highlights = crate::display_map::Highlights {
2195                text_highlights: None,
2196                inlay_highlights: Some(&inlay_highlights),
2197                styles: crate::display_map::HighlightStyles::default(),
2198            };
2199
2200            let chunks: Vec<_> = inlay_snapshot
2201                .chunks(
2202                    InlayOffset(0)..InlayOffset(inlay_snapshot.len().0),
2203                    false,
2204                    highlights,
2205                )
2206                .collect();
2207
2208            // Verify we got chunks and they total to the expected text
2209            let full_text: String = chunks.iter().map(|c| c.chunk.text).collect();
2210            assert_eq!(
2211                full_text,
2212                format!("te{}st", test_case.inlay_text),
2213                "Full text mismatch for case: {}",
2214                test_case.description
2215            );
2216
2217            // Verify that the highlighted portion matches expectations
2218            let highlighted_text: String = chunks
2219                .iter()
2220                .filter(|c| c.chunk.highlight_style.is_some() && c.chunk.is_inlay)
2221                .map(|c| c.chunk.text)
2222                .collect();
2223            assert_eq!(
2224                highlighted_text, test_case.expected_highlighted,
2225                "Highlighted text mismatch for case: {} (text: '{}', range: {:?})",
2226                test_case.description, test_case.inlay_text, test_case.highlight_range
2227            );
2228        }
2229    }
2230}