fs.rs

   1use anyhow::{anyhow, Result};
   2use fsevent::EventStream;
   3use futures::{future::BoxFuture, Stream, StreamExt};
   4use language::LineEnding;
   5use smol::io::{AsyncReadExt, AsyncWriteExt};
   6use std::{
   7    io,
   8    os::unix::fs::MetadataExt,
   9    path::{Component, Path, PathBuf},
  10    pin::Pin,
  11    time::{Duration, SystemTime},
  12};
  13use text::Rope;
  14
  15#[cfg(any(test, feature = "test-support"))]
  16use collections::{btree_map, BTreeMap};
  17#[cfg(any(test, feature = "test-support"))]
  18use futures::lock::Mutex;
  19#[cfg(any(test, feature = "test-support"))]
  20use std::sync::{Arc, Weak};
  21
  22#[async_trait::async_trait]
  23pub trait Fs: Send + Sync {
  24    async fn create_dir(&self, path: &Path) -> Result<()>;
  25    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()>;
  26    async fn copy_file(&self, source: &Path, target: &Path, options: CopyOptions) -> Result<()>;
  27    async fn rename(&self, source: &Path, target: &Path, options: RenameOptions) -> Result<()>;
  28    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()>;
  29    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()>;
  30    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>>;
  31    async fn load(&self, path: &Path) -> Result<String>;
  32    async fn save(&self, path: &Path, text: &Rope, line_ending: LineEnding) -> Result<()>;
  33    async fn canonicalize(&self, path: &Path) -> Result<PathBuf>;
  34    async fn is_file(&self, path: &Path) -> bool;
  35    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>>;
  36    async fn read_dir(
  37        &self,
  38        path: &Path,
  39    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>>;
  40    async fn watch(
  41        &self,
  42        path: &Path,
  43        latency: Duration,
  44    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>>;
  45    fn is_fake(&self) -> bool;
  46    #[cfg(any(test, feature = "test-support"))]
  47    fn as_fake(&self) -> &FakeFs;
  48}
  49
  50#[derive(Copy, Clone, Default)]
  51pub struct CreateOptions {
  52    pub overwrite: bool,
  53    pub ignore_if_exists: bool,
  54}
  55
  56#[derive(Copy, Clone, Default)]
  57pub struct CopyOptions {
  58    pub overwrite: bool,
  59    pub ignore_if_exists: bool,
  60}
  61
  62#[derive(Copy, Clone, Default)]
  63pub struct RenameOptions {
  64    pub overwrite: bool,
  65    pub ignore_if_exists: bool,
  66}
  67
  68#[derive(Copy, Clone, Default)]
  69pub struct RemoveOptions {
  70    pub recursive: bool,
  71    pub ignore_if_not_exists: bool,
  72}
  73
  74#[derive(Clone, Debug)]
  75pub struct Metadata {
  76    pub inode: u64,
  77    pub mtime: SystemTime,
  78    pub is_symlink: bool,
  79    pub is_dir: bool,
  80}
  81
  82pub struct RealFs;
  83
  84#[async_trait::async_trait]
  85impl Fs for RealFs {
  86    async fn create_dir(&self, path: &Path) -> Result<()> {
  87        Ok(smol::fs::create_dir_all(path).await?)
  88    }
  89
  90    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()> {
  91        let mut open_options = smol::fs::OpenOptions::new();
  92        open_options.write(true).create(true);
  93        if options.overwrite {
  94            open_options.truncate(true);
  95        } else if !options.ignore_if_exists {
  96            open_options.create_new(true);
  97        }
  98        open_options.open(path).await?;
  99        Ok(())
 100    }
 101
 102    async fn copy_file(&self, source: &Path, target: &Path, options: CopyOptions) -> Result<()> {
 103        if !options.overwrite && smol::fs::metadata(target).await.is_ok() {
 104            if options.ignore_if_exists {
 105                return Ok(());
 106            } else {
 107                return Err(anyhow!("{target:?} already exists"));
 108            }
 109        }
 110
 111        smol::fs::copy(source, target).await?;
 112        Ok(())
 113    }
 114
 115    async fn rename(&self, source: &Path, target: &Path, options: RenameOptions) -> Result<()> {
 116        if !options.overwrite && smol::fs::metadata(target).await.is_ok() {
 117            if options.ignore_if_exists {
 118                return Ok(());
 119            } else {
 120                return Err(anyhow!("{target:?} already exists"));
 121            }
 122        }
 123
 124        smol::fs::rename(source, target).await?;
 125        Ok(())
 126    }
 127
 128    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()> {
 129        let result = if options.recursive {
 130            smol::fs::remove_dir_all(path).await
 131        } else {
 132            smol::fs::remove_dir(path).await
 133        };
 134        match result {
 135            Ok(()) => Ok(()),
 136            Err(err) if err.kind() == io::ErrorKind::NotFound && options.ignore_if_not_exists => {
 137                Ok(())
 138            }
 139            Err(err) => Err(err)?,
 140        }
 141    }
 142
 143    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()> {
 144        match smol::fs::remove_file(path).await {
 145            Ok(()) => Ok(()),
 146            Err(err) if err.kind() == io::ErrorKind::NotFound && options.ignore_if_not_exists => {
 147                Ok(())
 148            }
 149            Err(err) => Err(err)?,
 150        }
 151    }
 152
 153    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
 154        Ok(Box::new(std::fs::File::open(path)?))
 155    }
 156
 157    async fn load(&self, path: &Path) -> Result<String> {
 158        let mut file = smol::fs::File::open(path).await?;
 159        let mut text = String::new();
 160        file.read_to_string(&mut text).await?;
 161        Ok(text)
 162    }
 163
 164    async fn save(&self, path: &Path, text: &Rope, line_ending: LineEnding) -> Result<()> {
 165        let buffer_size = text.summary().bytes.min(10 * 1024);
 166        let file = smol::fs::File::create(path).await?;
 167        let mut writer = smol::io::BufWriter::with_capacity(buffer_size, file);
 168        for chunk in chunks(text, line_ending) {
 169            writer.write_all(chunk.as_bytes()).await?;
 170        }
 171        writer.flush().await?;
 172        Ok(())
 173    }
 174
 175    async fn canonicalize(&self, path: &Path) -> Result<PathBuf> {
 176        Ok(smol::fs::canonicalize(path).await?)
 177    }
 178
 179    async fn is_file(&self, path: &Path) -> bool {
 180        smol::fs::metadata(path)
 181            .await
 182            .map_or(false, |metadata| metadata.is_file())
 183    }
 184
 185    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>> {
 186        let symlink_metadata = match smol::fs::symlink_metadata(path).await {
 187            Ok(metadata) => metadata,
 188            Err(err) => {
 189                return match (err.kind(), err.raw_os_error()) {
 190                    (io::ErrorKind::NotFound, _) => Ok(None),
 191                    (io::ErrorKind::Other, Some(libc::ENOTDIR)) => Ok(None),
 192                    _ => Err(anyhow::Error::new(err)),
 193                }
 194            }
 195        };
 196
 197        let is_symlink = symlink_metadata.file_type().is_symlink();
 198        let metadata = if is_symlink {
 199            smol::fs::metadata(path).await?
 200        } else {
 201            symlink_metadata
 202        };
 203        Ok(Some(Metadata {
 204            inode: metadata.ino(),
 205            mtime: metadata.modified().unwrap(),
 206            is_symlink,
 207            is_dir: metadata.file_type().is_dir(),
 208        }))
 209    }
 210
 211    async fn read_dir(
 212        &self,
 213        path: &Path,
 214    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>> {
 215        let result = smol::fs::read_dir(path).await?.map(|entry| match entry {
 216            Ok(entry) => Ok(entry.path()),
 217            Err(error) => Err(anyhow!("failed to read dir entry {:?}", error)),
 218        });
 219        Ok(Box::pin(result))
 220    }
 221
 222    async fn watch(
 223        &self,
 224        path: &Path,
 225        latency: Duration,
 226    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>> {
 227        let (tx, rx) = smol::channel::unbounded();
 228        let (stream, handle) = EventStream::new(&[path], latency);
 229        std::mem::forget(handle);
 230        std::thread::spawn(move || {
 231            stream.run(move |events| smol::block_on(tx.send(events)).is_ok());
 232        });
 233        Box::pin(rx)
 234    }
 235
 236    fn is_fake(&self) -> bool {
 237        false
 238    }
 239    #[cfg(any(test, feature = "test-support"))]
 240    fn as_fake(&self) -> &FakeFs {
 241        panic!("called `RealFs::as_fake`")
 242    }
 243}
 244
 245#[cfg(any(test, feature = "test-support"))]
 246pub struct FakeFs {
 247    // Use an unfair lock to ensure tests are deterministic.
 248    state: Mutex<FakeFsState>,
 249    executor: Weak<gpui::executor::Background>,
 250}
 251
 252#[cfg(any(test, feature = "test-support"))]
 253struct FakeFsState {
 254    root: Arc<Mutex<FakeFsEntry>>,
 255    next_inode: u64,
 256    event_txs: Vec<smol::channel::Sender<Vec<fsevent::Event>>>,
 257}
 258
 259#[cfg(any(test, feature = "test-support"))]
 260#[derive(Debug)]
 261enum FakeFsEntry {
 262    File {
 263        inode: u64,
 264        mtime: SystemTime,
 265        content: String,
 266    },
 267    Dir {
 268        inode: u64,
 269        mtime: SystemTime,
 270        entries: BTreeMap<String, Arc<Mutex<FakeFsEntry>>>,
 271    },
 272    Symlink {
 273        target: PathBuf,
 274    },
 275}
 276
 277#[cfg(any(test, feature = "test-support"))]
 278impl FakeFsState {
 279    async fn read_path<'a>(&'a self, target: &Path) -> Result<Arc<Mutex<FakeFsEntry>>> {
 280        Ok(self
 281            .try_read_path(target)
 282            .await
 283            .ok_or_else(|| anyhow!("path does not exist: {}", target.display()))?
 284            .0)
 285    }
 286
 287    async fn try_read_path<'a>(
 288        &'a self,
 289        target: &Path,
 290    ) -> Option<(Arc<Mutex<FakeFsEntry>>, PathBuf)> {
 291        let mut path = target.to_path_buf();
 292        let mut real_path = PathBuf::new();
 293        let mut entry_stack = Vec::new();
 294        'outer: loop {
 295            let mut path_components = path.components().collect::<collections::VecDeque<_>>();
 296            while let Some(component) = path_components.pop_front() {
 297                match component {
 298                    Component::Prefix(_) => panic!("prefix paths aren't supported"),
 299                    Component::RootDir => {
 300                        entry_stack.clear();
 301                        entry_stack.push(self.root.clone());
 302                        real_path.clear();
 303                        real_path.push("/");
 304                    }
 305                    Component::CurDir => {}
 306                    Component::ParentDir => {
 307                        entry_stack.pop()?;
 308                        real_path.pop();
 309                    }
 310                    Component::Normal(name) => {
 311                        let current_entry = entry_stack.last().cloned()?;
 312                        let current_entry = current_entry.lock().await;
 313                        if let FakeFsEntry::Dir { entries, .. } = &*current_entry {
 314                            let entry = entries.get(name.to_str().unwrap()).cloned()?;
 315                            let _entry = entry.lock().await;
 316                            if let FakeFsEntry::Symlink { target, .. } = &*_entry {
 317                                let mut target = target.clone();
 318                                target.extend(path_components);
 319                                path = target;
 320                                continue 'outer;
 321                            } else {
 322                                entry_stack.push(entry.clone());
 323                                real_path.push(name);
 324                            }
 325                        } else {
 326                            return None;
 327                        }
 328                    }
 329                }
 330            }
 331            break;
 332        }
 333        entry_stack.pop().map(|entry| (entry, real_path))
 334    }
 335
 336    async fn write_path<Fn, T>(&self, path: &Path, callback: Fn) -> Result<T>
 337    where
 338        Fn: FnOnce(btree_map::Entry<String, Arc<Mutex<FakeFsEntry>>>) -> Result<T>,
 339    {
 340        let path = normalize_path(path);
 341        let filename = path
 342            .file_name()
 343            .ok_or_else(|| anyhow!("cannot overwrite the root"))?;
 344        let parent_path = path.parent().unwrap();
 345
 346        let parent = self.read_path(parent_path).await?;
 347        let mut parent = parent.lock().await;
 348        let new_entry = parent
 349            .dir_entries(parent_path)?
 350            .entry(filename.to_str().unwrap().into());
 351        callback(new_entry)
 352    }
 353
 354    fn emit_event<I, T>(&mut self, paths: I)
 355    where
 356        I: IntoIterator<Item = T>,
 357        T: Into<PathBuf>,
 358    {
 359        let events = paths
 360            .into_iter()
 361            .map(|path| fsevent::Event {
 362                event_id: 0,
 363                flags: fsevent::StreamFlags::empty(),
 364                path: path.into(),
 365            })
 366            .collect::<Vec<_>>();
 367
 368        self.event_txs.retain(|tx| {
 369            let _ = tx.try_send(events.clone());
 370            !tx.is_closed()
 371        });
 372    }
 373}
 374
 375#[cfg(any(test, feature = "test-support"))]
 376impl FakeFs {
 377    pub fn new(executor: Arc<gpui::executor::Background>) -> Arc<Self> {
 378        Arc::new(Self {
 379            executor: Arc::downgrade(&executor),
 380            state: Mutex::new(FakeFsState {
 381                root: Arc::new(Mutex::new(FakeFsEntry::Dir {
 382                    inode: 0,
 383                    mtime: SystemTime::now(),
 384                    entries: Default::default(),
 385                })),
 386                next_inode: 1,
 387                event_txs: Default::default(),
 388            }),
 389        })
 390    }
 391
 392    pub async fn insert_file(&self, path: impl AsRef<Path>, content: String) {
 393        let mut state = self.state.lock().await;
 394        let path = path.as_ref();
 395        let inode = state.next_inode;
 396        state.next_inode += 1;
 397        let file = Arc::new(Mutex::new(FakeFsEntry::File {
 398            inode,
 399            mtime: SystemTime::now(),
 400            content,
 401        }));
 402        state
 403            .write_path(path, move |entry| {
 404                match entry {
 405                    btree_map::Entry::Vacant(e) => {
 406                        e.insert(file);
 407                    }
 408                    btree_map::Entry::Occupied(mut e) => {
 409                        *e.get_mut() = file;
 410                    }
 411                }
 412                Ok(())
 413            })
 414            .await
 415            .unwrap();
 416        state.emit_event(&[path]);
 417    }
 418
 419    pub async fn insert_symlink(&self, path: impl AsRef<Path>, target: PathBuf) {
 420        let mut state = self.state.lock().await;
 421        let path = path.as_ref();
 422        let file = Arc::new(Mutex::new(FakeFsEntry::Symlink { target }));
 423        state
 424            .write_path(path.as_ref(), move |e| match e {
 425                btree_map::Entry::Vacant(e) => {
 426                    e.insert(file);
 427                    Ok(())
 428                }
 429                btree_map::Entry::Occupied(mut e) => {
 430                    *e.get_mut() = file;
 431                    Ok(())
 432                }
 433            })
 434            .await
 435            .unwrap();
 436        state.emit_event(&[path]);
 437    }
 438
 439    #[must_use]
 440    pub fn insert_tree<'a>(
 441        &'a self,
 442        path: impl 'a + AsRef<Path> + Send,
 443        tree: serde_json::Value,
 444    ) -> futures::future::BoxFuture<'a, ()> {
 445        use futures::FutureExt as _;
 446        use serde_json::Value::*;
 447
 448        async move {
 449            let path = path.as_ref();
 450
 451            match tree {
 452                Object(map) => {
 453                    self.create_dir(path).await.unwrap();
 454                    for (name, contents) in map {
 455                        let mut path = PathBuf::from(path);
 456                        path.push(name);
 457                        self.insert_tree(&path, contents).await;
 458                    }
 459                }
 460                Null => {
 461                    self.create_dir(&path).await.unwrap();
 462                }
 463                String(contents) => {
 464                    self.insert_file(&path, contents).await;
 465                }
 466                _ => {
 467                    panic!("JSON object must contain only objects, strings, or null");
 468                }
 469            }
 470        }
 471        .boxed()
 472    }
 473
 474    pub async fn files(&self) -> Vec<PathBuf> {
 475        let mut result = Vec::new();
 476        let mut queue = collections::VecDeque::new();
 477        queue.push_back((PathBuf::from("/"), self.state.lock().await.root.clone()));
 478        while let Some((path, entry)) = queue.pop_front() {
 479            let e = entry.lock().await;
 480            match &*e {
 481                FakeFsEntry::File { .. } => result.push(path),
 482                FakeFsEntry::Dir { entries, .. } => {
 483                    for (name, entry) in entries {
 484                        queue.push_back((path.join(name), entry.clone()));
 485                    }
 486                }
 487                FakeFsEntry::Symlink { .. } => {}
 488            }
 489        }
 490        result
 491    }
 492
 493    async fn simulate_random_delay(&self) {
 494        self.executor
 495            .upgrade()
 496            .expect("executor has been dropped")
 497            .simulate_random_delay()
 498            .await;
 499    }
 500}
 501
 502#[cfg(any(test, feature = "test-support"))]
 503impl FakeFsEntry {
 504    fn is_file(&self) -> bool {
 505        matches!(self, Self::File { .. })
 506    }
 507
 508    fn file_content(&self, path: &Path) -> Result<&String> {
 509        if let Self::File { content, .. } = self {
 510            Ok(content)
 511        } else {
 512            Err(anyhow!("not a file: {}", path.display()))
 513        }
 514    }
 515
 516    fn set_file_content(&mut self, path: &Path, new_content: String) -> Result<()> {
 517        if let Self::File { content, mtime, .. } = self {
 518            *mtime = SystemTime::now();
 519            *content = new_content;
 520            Ok(())
 521        } else {
 522            Err(anyhow!("not a file: {}", path.display()))
 523        }
 524    }
 525
 526    fn dir_entries(
 527        &mut self,
 528        path: &Path,
 529    ) -> Result<&mut BTreeMap<String, Arc<Mutex<FakeFsEntry>>>> {
 530        if let Self::Dir { entries, .. } = self {
 531            Ok(entries)
 532        } else {
 533            Err(anyhow!("not a directory: {}", path.display()))
 534        }
 535    }
 536}
 537
 538#[cfg(any(test, feature = "test-support"))]
 539#[async_trait::async_trait]
 540impl Fs for FakeFs {
 541    async fn create_dir(&self, path: &Path) -> Result<()> {
 542        self.simulate_random_delay().await;
 543        let mut state = self.state.lock().await;
 544
 545        let mut created_dirs = Vec::new();
 546        let mut cur_path = PathBuf::new();
 547        for component in path.components() {
 548            cur_path.push(component);
 549            if cur_path == Path::new("/") {
 550                continue;
 551            }
 552
 553            let inode = state.next_inode;
 554            state.next_inode += 1;
 555            state
 556                .write_path(&cur_path, |entry| {
 557                    entry.or_insert(Arc::new(Mutex::new(FakeFsEntry::Dir {
 558                        inode,
 559                        mtime: SystemTime::now(),
 560                        entries: Default::default(),
 561                    })));
 562                    created_dirs.push(cur_path.clone());
 563                    Ok(())
 564                })
 565                .await?;
 566        }
 567
 568        state.emit_event(&created_dirs);
 569        Ok(())
 570    }
 571
 572    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()> {
 573        self.simulate_random_delay().await;
 574        let mut state = self.state.lock().await;
 575        let inode = state.next_inode;
 576        state.next_inode += 1;
 577        let file = Arc::new(Mutex::new(FakeFsEntry::File {
 578            inode,
 579            mtime: SystemTime::now(),
 580            content: String::new(),
 581        }));
 582        state
 583            .write_path(path, |entry| {
 584                match entry {
 585                    btree_map::Entry::Occupied(mut e) => {
 586                        if options.overwrite {
 587                            *e.get_mut() = file;
 588                        } else if !options.ignore_if_exists {
 589                            return Err(anyhow!("path already exists: {}", path.display()));
 590                        }
 591                    }
 592                    btree_map::Entry::Vacant(e) => {
 593                        e.insert(file);
 594                    }
 595                }
 596                Ok(())
 597            })
 598            .await?;
 599        state.emit_event(&[path]);
 600        Ok(())
 601    }
 602
 603    async fn rename(&self, old_path: &Path, new_path: &Path, options: RenameOptions) -> Result<()> {
 604        let old_path = normalize_path(old_path);
 605        let new_path = normalize_path(new_path);
 606        let mut state = self.state.lock().await;
 607        let moved_entry = state
 608            .write_path(&old_path, |e| {
 609                if let btree_map::Entry::Occupied(e) = e {
 610                    Ok(e.remove())
 611                } else {
 612                    Err(anyhow!("path does not exist: {}", &old_path.display()))
 613                }
 614            })
 615            .await?;
 616        state
 617            .write_path(&new_path, |e| {
 618                match e {
 619                    btree_map::Entry::Occupied(mut e) => {
 620                        if options.overwrite {
 621                            *e.get_mut() = moved_entry;
 622                        } else if !options.ignore_if_exists {
 623                            return Err(anyhow!("path already exists: {}", new_path.display()));
 624                        }
 625                    }
 626                    btree_map::Entry::Vacant(e) => {
 627                        e.insert(moved_entry);
 628                    }
 629                }
 630                Ok(())
 631            })
 632            .await?;
 633        state.emit_event(&[old_path, new_path]);
 634        Ok(())
 635    }
 636
 637    async fn copy_file(&self, source: &Path, target: &Path, options: CopyOptions) -> Result<()> {
 638        let source = normalize_path(source);
 639        let target = normalize_path(target);
 640        let mut state = self.state.lock().await;
 641        let source_entry = state.read_path(&source).await?;
 642        let content = source_entry.lock().await.file_content(&source)?.clone();
 643        let entry = state
 644            .write_path(&target, |e| match e {
 645                btree_map::Entry::Occupied(e) => {
 646                    if options.overwrite {
 647                        Ok(Some(e.get().clone()))
 648                    } else if !options.ignore_if_exists {
 649                        return Err(anyhow!("{target:?} already exists"));
 650                    } else {
 651                        Ok(None)
 652                    }
 653                }
 654                btree_map::Entry::Vacant(e) => Ok(Some(
 655                    e.insert(Arc::new(Mutex::new(FakeFsEntry::File {
 656                        inode: 0,
 657                        mtime: SystemTime::now(),
 658                        content: String::new(),
 659                    })))
 660                    .clone(),
 661                )),
 662            })
 663            .await?;
 664        if let Some(entry) = entry {
 665            entry.lock().await.set_file_content(&target, content)?;
 666        }
 667        state.emit_event(&[target]);
 668        Ok(())
 669    }
 670
 671    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()> {
 672        let path = normalize_path(path);
 673        let parent_path = path
 674            .parent()
 675            .ok_or_else(|| anyhow!("cannot remove the root"))?;
 676        let base_name = path.file_name().unwrap();
 677
 678        let state = self.state.lock().await;
 679        let parent_entry = state.read_path(parent_path).await?;
 680        let mut parent_entry = parent_entry.lock().await;
 681        let entry = parent_entry
 682            .dir_entries(parent_path)?
 683            .entry(base_name.to_str().unwrap().into());
 684
 685        match entry {
 686            btree_map::Entry::Vacant(_) => {
 687                if !options.ignore_if_not_exists {
 688                    return Err(anyhow!("{path:?} does not exist"));
 689                }
 690            }
 691            btree_map::Entry::Occupied(e) => {
 692                {
 693                    let mut entry = e.get().lock().await;
 694                    let children = entry.dir_entries(&path)?;
 695                    if !options.recursive && !children.is_empty() {
 696                        return Err(anyhow!("{path:?} is not empty"));
 697                    }
 698                }
 699                e.remove();
 700            }
 701        }
 702
 703        Ok(())
 704    }
 705
 706    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()> {
 707        let path = normalize_path(path);
 708        let parent_path = path
 709            .parent()
 710            .ok_or_else(|| anyhow!("cannot remove the root"))?;
 711        let base_name = path.file_name().unwrap();
 712        let mut state = self.state.lock().await;
 713        let parent_entry = state.read_path(parent_path).await?;
 714        let mut parent_entry = parent_entry.lock().await;
 715        let entry = parent_entry
 716            .dir_entries(parent_path)?
 717            .entry(base_name.to_str().unwrap().into());
 718        match entry {
 719            btree_map::Entry::Vacant(_) => {
 720                if !options.ignore_if_not_exists {
 721                    return Err(anyhow!("{path:?} does not exist"));
 722                }
 723            }
 724            btree_map::Entry::Occupied(e) => {
 725                e.get().lock().await.file_content(&path)?;
 726                e.remove();
 727            }
 728        }
 729        state.emit_event(&[path]);
 730        Ok(())
 731    }
 732
 733    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
 734        let text = self.load(path).await?;
 735        Ok(Box::new(io::Cursor::new(text)))
 736    }
 737
 738    async fn load(&self, path: &Path) -> Result<String> {
 739        let path = normalize_path(path);
 740        self.simulate_random_delay().await;
 741        let state = self.state.lock().await;
 742        let entry = state.read_path(&path).await?;
 743        let entry = entry.lock().await;
 744        entry.file_content(&path).cloned()
 745    }
 746
 747    async fn save(&self, path: &Path, text: &Rope, line_ending: LineEnding) -> Result<()> {
 748        self.simulate_random_delay().await;
 749        let path = normalize_path(path);
 750        let content = chunks(text, line_ending).collect();
 751        self.insert_file(path, content).await;
 752        Ok(())
 753    }
 754
 755    async fn canonicalize(&self, path: &Path) -> Result<PathBuf> {
 756        let path = normalize_path(path);
 757        self.simulate_random_delay().await;
 758        let state = self.state.lock().await;
 759        if let Some((_, real_path)) = state.try_read_path(&path).await {
 760            Ok(real_path)
 761        } else {
 762            Err(anyhow!("path does not exist: {}", path.display()))
 763        }
 764    }
 765
 766    async fn is_file(&self, path: &Path) -> bool {
 767        let path = normalize_path(path);
 768        self.simulate_random_delay().await;
 769        let state = self.state.lock().await;
 770        if let Some((entry, _)) = state.try_read_path(&path).await {
 771            entry.lock().await.is_file()
 772        } else {
 773            false
 774        }
 775    }
 776
 777    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>> {
 778        self.simulate_random_delay().await;
 779        let path = normalize_path(path);
 780        let state = self.state.lock().await;
 781        if let Some((entry, real_path)) = state.try_read_path(&path).await {
 782            let entry = entry.lock().await;
 783            let is_symlink = real_path != path;
 784
 785            Ok(Some(match &*entry {
 786                FakeFsEntry::File { inode, mtime, .. } => Metadata {
 787                    inode: *inode,
 788                    mtime: *mtime,
 789                    is_dir: false,
 790                    is_symlink,
 791                },
 792                FakeFsEntry::Dir { inode, mtime, .. } => Metadata {
 793                    inode: *inode,
 794                    mtime: *mtime,
 795                    is_dir: true,
 796                    is_symlink,
 797                },
 798                FakeFsEntry::Symlink { .. } => unreachable!(),
 799            }))
 800        } else {
 801            Ok(None)
 802        }
 803    }
 804
 805    async fn read_dir(
 806        &self,
 807        path: &Path,
 808    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>> {
 809        self.simulate_random_delay().await;
 810        let path = normalize_path(path);
 811        let state = self.state.lock().await;
 812        let entry = state.read_path(&path).await?;
 813        let mut entry = entry.lock().await;
 814        let children = entry.dir_entries(&path)?;
 815        let paths = children
 816            .keys()
 817            .map(|file_name| Ok(path.join(file_name)))
 818            .collect::<Vec<_>>();
 819        Ok(Box::pin(futures::stream::iter(paths)))
 820    }
 821
 822    async fn watch(
 823        &self,
 824        path: &Path,
 825        _: Duration,
 826    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>> {
 827        let mut state = self.state.lock().await;
 828        self.simulate_random_delay().await;
 829        let (tx, rx) = smol::channel::unbounded();
 830        state.event_txs.push(tx);
 831        let path = path.to_path_buf();
 832        let executor = self.executor.clone();
 833        Box::pin(futures::StreamExt::filter(rx, move |events| {
 834            let result = events.iter().any(|event| event.path.starts_with(&path));
 835            let executor = executor.clone();
 836            async move {
 837                if let Some(executor) = executor.clone().upgrade() {
 838                    executor.simulate_random_delay().await;
 839                }
 840                result
 841            }
 842        }))
 843    }
 844
 845    fn is_fake(&self) -> bool {
 846        true
 847    }
 848
 849    #[cfg(any(test, feature = "test-support"))]
 850    fn as_fake(&self) -> &FakeFs {
 851        self
 852    }
 853}
 854
 855fn chunks(rope: &Rope, line_ending: LineEnding) -> impl Iterator<Item = &str> {
 856    rope.chunks().flat_map(move |chunk| {
 857        let mut newline = false;
 858        chunk.split('\n').flat_map(move |line| {
 859            let ending = if newline {
 860                Some(line_ending.as_str())
 861            } else {
 862                None
 863            };
 864            newline = true;
 865            ending.into_iter().chain([line])
 866        })
 867    })
 868}
 869
 870pub fn normalize_path(path: &Path) -> PathBuf {
 871    let mut components = path.components().peekable();
 872    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
 873        components.next();
 874        PathBuf::from(c.as_os_str())
 875    } else {
 876        PathBuf::new()
 877    };
 878
 879    for component in components {
 880        match component {
 881            Component::Prefix(..) => unreachable!(),
 882            Component::RootDir => {
 883                ret.push(component.as_os_str());
 884            }
 885            Component::CurDir => {}
 886            Component::ParentDir => {
 887                ret.pop();
 888            }
 889            Component::Normal(c) => {
 890                ret.push(c);
 891            }
 892        }
 893    }
 894    ret
 895}
 896
 897pub fn copy_recursive<'a>(
 898    fs: &'a dyn Fs,
 899    source: &'a Path,
 900    target: &'a Path,
 901    options: CopyOptions,
 902) -> BoxFuture<'a, Result<()>> {
 903    use futures::future::FutureExt;
 904
 905    async move {
 906        let metadata = fs
 907            .metadata(source)
 908            .await?
 909            .ok_or_else(|| anyhow!("path does not exist: {}", source.display()))?;
 910        if metadata.is_dir {
 911            if !options.overwrite && fs.metadata(target).await.is_ok() {
 912                if options.ignore_if_exists {
 913                    return Ok(());
 914                } else {
 915                    return Err(anyhow!("{target:?} already exists"));
 916                }
 917            }
 918
 919            let _ = fs
 920                .remove_dir(
 921                    target,
 922                    RemoveOptions {
 923                        recursive: true,
 924                        ignore_if_not_exists: true,
 925                    },
 926                )
 927                .await;
 928            fs.create_dir(target).await?;
 929            let mut children = fs.read_dir(source).await?;
 930            while let Some(child_path) = children.next().await {
 931                if let Ok(child_path) = child_path {
 932                    if let Some(file_name) = child_path.file_name() {
 933                        let child_target_path = target.join(file_name);
 934                        copy_recursive(fs, &child_path, &child_target_path, options).await?;
 935                    }
 936                }
 937            }
 938
 939            Ok(())
 940        } else {
 941            fs.copy_file(source, target, options).await
 942        }
 943    }
 944    .boxed()
 945}
 946
 947#[cfg(test)]
 948mod tests {
 949    use super::*;
 950    use gpui::TestAppContext;
 951    use serde_json::json;
 952
 953    #[gpui::test]
 954    async fn test_fake_fs(cx: &mut TestAppContext) {
 955        let fs = FakeFs::new(cx.background());
 956
 957        fs.insert_tree(
 958            "/root",
 959            json!({
 960                "dir1": {
 961                    "a": "A",
 962                    "b": "B"
 963                },
 964                "dir2": {
 965                    "c": "C",
 966                    "dir3": {
 967                        "d": "D"
 968                    }
 969                }
 970            }),
 971        )
 972        .await;
 973
 974        assert_eq!(
 975            fs.files().await,
 976            vec![
 977                PathBuf::from("/root/dir1/a"),
 978                PathBuf::from("/root/dir1/b"),
 979                PathBuf::from("/root/dir2/c"),
 980                PathBuf::from("/root/dir2/dir3/d"),
 981            ]
 982        );
 983
 984        fs.insert_symlink("/root/dir2/link-to-dir3", "./dir3".into())
 985            .await;
 986
 987        assert_eq!(
 988            fs.canonicalize("/root/dir2/link-to-dir3".as_ref())
 989                .await
 990                .unwrap(),
 991            PathBuf::from("/root/dir2/dir3"),
 992        );
 993        assert_eq!(
 994            fs.canonicalize("/root/dir2/link-to-dir3/d".as_ref())
 995                .await
 996                .unwrap(),
 997            PathBuf::from("/root/dir2/dir3/d"),
 998        );
 999        assert_eq!(
1000            fs.load("/root/dir2/link-to-dir3/d".as_ref()).await.unwrap(),
1001            "D",
1002        );
1003    }
1004}