util.rs

   1pub mod arc_cow;
   2pub mod archive;
   3pub mod command;
   4pub mod fs;
   5pub mod markdown;
   6pub mod paths;
   7pub mod redact;
   8pub mod rel_path;
   9pub mod schemars;
  10pub mod serde;
  11pub mod shell;
  12pub mod shell_builder;
  13pub mod shell_env;
  14pub mod size;
  15#[cfg(any(test, feature = "test-support"))]
  16pub mod test;
  17pub mod time;
  18
  19use anyhow::{Context as _, Result};
  20use futures::Future;
  21use itertools::Either;
  22use paths::PathExt;
  23use regex::Regex;
  24use std::path::PathBuf;
  25use std::sync::{LazyLock, OnceLock};
  26use std::{
  27    borrow::Cow,
  28    cmp::{self, Ordering},
  29    env,
  30    ops::{AddAssign, Range, RangeInclusive},
  31    panic::Location,
  32    pin::Pin,
  33    task::{Context, Poll},
  34    time::Instant,
  35};
  36use unicase::UniCase;
  37
  38pub use take_until::*;
  39#[cfg(any(test, feature = "test-support"))]
  40pub use util_macros::{line_endings, path, uri};
  41
  42#[macro_export]
  43macro_rules! debug_panic {
  44    ( $($fmt_arg:tt)* ) => {
  45        if cfg!(debug_assertions) {
  46            panic!( $($fmt_arg)* );
  47        } else {
  48            let backtrace = std::backtrace::Backtrace::capture();
  49            log::error!("{}\n{:?}", format_args!($($fmt_arg)*), backtrace);
  50        }
  51    };
  52}
  53
  54#[inline]
  55pub const fn is_utf8_char_boundary(u8: u8) -> bool {
  56    // This is bit magic equivalent to: b < 128 || b >= 192
  57    (u8 as i8) >= -0x40
  58}
  59
  60pub fn truncate(s: &str, max_chars: usize) -> &str {
  61    match s.char_indices().nth(max_chars) {
  62        None => s,
  63        Some((idx, _)) => &s[..idx],
  64    }
  65}
  66
  67/// Removes characters from the end of the string if its length is greater than `max_chars` and
  68/// appends "..." to the string. Returns string unchanged if its length is smaller than max_chars.
  69pub fn truncate_and_trailoff(s: &str, max_chars: usize) -> String {
  70    debug_assert!(max_chars >= 5);
  71
  72    // If the string's byte length is <= max_chars, walking the string can be skipped since the
  73    // number of chars is <= the number of bytes.
  74    if s.len() <= max_chars {
  75        return s.to_string();
  76    }
  77    let truncation_ix = s.char_indices().map(|(i, _)| i).nth(max_chars);
  78    match truncation_ix {
  79        Some(index) => s[..index].to_string() + "…",
  80        _ => s.to_string(),
  81    }
  82}
  83
  84/// Removes characters from the front of the string if its length is greater than `max_chars` and
  85/// prepends the string with "...". Returns string unchanged if its length is smaller than max_chars.
  86pub fn truncate_and_remove_front(s: &str, max_chars: usize) -> String {
  87    debug_assert!(max_chars >= 5);
  88
  89    // If the string's byte length is <= max_chars, walking the string can be skipped since the
  90    // number of chars is <= the number of bytes.
  91    if s.len() <= max_chars {
  92        return s.to_string();
  93    }
  94    let suffix_char_length = max_chars.saturating_sub(1);
  95    let truncation_ix = s
  96        .char_indices()
  97        .map(|(i, _)| i)
  98        .nth_back(suffix_char_length);
  99    match truncation_ix {
 100        Some(index) if index > 0 => "…".to_string() + &s[index..],
 101        _ => s.to_string(),
 102    }
 103}
 104
 105/// Takes only `max_lines` from the string and, if there were more than `max_lines-1`, appends a
 106/// a newline and "..." to the string, so that `max_lines` are returned.
 107/// Returns string unchanged if its length is smaller than max_lines.
 108pub fn truncate_lines_and_trailoff(s: &str, max_lines: usize) -> String {
 109    let mut lines = s.lines().take(max_lines).collect::<Vec<_>>();
 110    if lines.len() > max_lines - 1 {
 111        lines.pop();
 112        lines.join("\n") + "\n…"
 113    } else {
 114        lines.join("\n")
 115    }
 116}
 117
 118/// Truncates the string at a character boundary, such that the result is less than `max_bytes` in
 119/// length.
 120pub fn truncate_to_byte_limit(s: &str, max_bytes: usize) -> &str {
 121    if s.len() < max_bytes {
 122        return s;
 123    }
 124
 125    for i in (0..max_bytes).rev() {
 126        if s.is_char_boundary(i) {
 127            return &s[..i];
 128        }
 129    }
 130
 131    ""
 132}
 133
 134/// Takes a prefix of complete lines which fit within the byte limit. If the first line is longer
 135/// than the limit, truncates at a character boundary.
 136pub fn truncate_lines_to_byte_limit(s: &str, max_bytes: usize) -> &str {
 137    if s.len() < max_bytes {
 138        return s;
 139    }
 140
 141    for i in (0..max_bytes).rev() {
 142        if s.is_char_boundary(i) && s.as_bytes()[i] == b'\n' {
 143            // Since the i-th character is \n, valid to slice at i + 1.
 144            return &s[..i + 1];
 145        }
 146    }
 147
 148    truncate_to_byte_limit(s, max_bytes)
 149}
 150
 151#[test]
 152fn test_truncate_lines_to_byte_limit() {
 153    let text = "Line 1\nLine 2\nLine 3\nLine 4";
 154
 155    // Limit that includes all lines
 156    assert_eq!(truncate_lines_to_byte_limit(text, 100), text);
 157
 158    // Exactly the first line
 159    assert_eq!(truncate_lines_to_byte_limit(text, 7), "Line 1\n");
 160
 161    // Limit between lines
 162    assert_eq!(truncate_lines_to_byte_limit(text, 13), "Line 1\n");
 163    assert_eq!(truncate_lines_to_byte_limit(text, 20), "Line 1\nLine 2\n");
 164
 165    // Limit before first newline
 166    assert_eq!(truncate_lines_to_byte_limit(text, 6), "Line ");
 167
 168    // Test with non-ASCII characters
 169    let text_utf8 = "Line 1\nLΓ­ne 2\nLine 3";
 170    assert_eq!(
 171        truncate_lines_to_byte_limit(text_utf8, 15),
 172        "Line 1\nLΓ­ne 2\n"
 173    );
 174}
 175
 176pub fn post_inc<T: From<u8> + AddAssign<T> + Copy>(value: &mut T) -> T {
 177    let prev = *value;
 178    *value += T::from(1);
 179    prev
 180}
 181
 182/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
 183/// enforcing a maximum length. This also de-duplicates items. Sort the items according to the given callback. Before calling this,
 184/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
 185pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
 186where
 187    I: IntoIterator<Item = T>,
 188    F: FnMut(&T, &T) -> Ordering,
 189{
 190    let mut start_index = 0;
 191    for new_item in new_items {
 192        if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
 193            let index = start_index + i;
 194            if vec.len() < limit {
 195                vec.insert(index, new_item);
 196            } else if index < vec.len() {
 197                vec.pop();
 198                vec.insert(index, new_item);
 199            }
 200            start_index = index;
 201        }
 202    }
 203}
 204
 205pub fn truncate_to_bottom_n_sorted_by<T, F>(items: &mut Vec<T>, limit: usize, compare: &F)
 206where
 207    F: Fn(&T, &T) -> Ordering,
 208{
 209    if limit == 0 {
 210        items.truncate(0);
 211    }
 212    if items.len() <= limit {
 213        items.sort_by(compare);
 214        return;
 215    }
 216    // When limit is near to items.len() it may be more efficient to sort the whole list and
 217    // truncate, rather than always doing selection first as is done below. It's hard to analyze
 218    // where the threshold for this should be since the quickselect style algorithm used by
 219    // `select_nth_unstable_by` makes the prefix partially sorted, and so its work is not wasted -
 220    // the expected number of comparisons needed by `sort_by` is less than it is for some arbitrary
 221    // unsorted input.
 222    items.select_nth_unstable_by(limit, compare);
 223    items.truncate(limit);
 224    items.sort_by(compare);
 225}
 226
 227/// Prevents execution of the application with root privileges on Unix systems.
 228///
 229/// This function checks if the current process is running with root privileges
 230/// and terminates the program with an error message unless explicitly allowed via the
 231/// `ZED_ALLOW_ROOT` environment variable.
 232#[cfg(unix)]
 233pub fn prevent_root_execution() {
 234    let is_root = nix::unistd::geteuid().is_root();
 235    let allow_root = std::env::var("ZED_ALLOW_ROOT").is_ok_and(|val| val == "true");
 236
 237    if is_root && !allow_root {
 238        eprintln!(
 239            "\
 240Error: Running Zed as root or via sudo is unsupported.
 241       Doing so (even once) may subtly break things for all subsequent non-root usage of Zed.
 242       It is untested and not recommended, don't complain when things break.
 243       If you wish to proceed anyways, set `ZED_ALLOW_ROOT=true` in your environment."
 244        );
 245        std::process::exit(1);
 246    }
 247}
 248
 249#[cfg(unix)]
 250fn load_shell_from_passwd() -> Result<()> {
 251    let buflen = match unsafe { libc::sysconf(libc::_SC_GETPW_R_SIZE_MAX) } {
 252        n if n < 0 => 1024,
 253        n => n as usize,
 254    };
 255    let mut buffer = Vec::with_capacity(buflen);
 256
 257    let mut pwd: std::mem::MaybeUninit<libc::passwd> = std::mem::MaybeUninit::uninit();
 258    let mut result: *mut libc::passwd = std::ptr::null_mut();
 259
 260    let uid = unsafe { libc::getuid() };
 261    let status = unsafe {
 262        libc::getpwuid_r(
 263            uid,
 264            pwd.as_mut_ptr(),
 265            buffer.as_mut_ptr() as *mut libc::c_char,
 266            buflen,
 267            &mut result,
 268        )
 269    };
 270    anyhow::ensure!(!result.is_null(), "passwd entry for uid {} not found", uid);
 271
 272    // SAFETY: If `getpwuid_r` doesn't error, we have the entry here.
 273    let entry = unsafe { pwd.assume_init() };
 274
 275    anyhow::ensure!(
 276        status == 0,
 277        "call to getpwuid_r failed. uid: {}, status: {}",
 278        uid,
 279        status
 280    );
 281    anyhow::ensure!(
 282        entry.pw_uid == uid,
 283        "passwd entry has different uid ({}) than getuid ({}) returned",
 284        entry.pw_uid,
 285        uid,
 286    );
 287
 288    let shell = unsafe { std::ffi::CStr::from_ptr(entry.pw_shell).to_str().unwrap() };
 289    let should_set_shell = env::var("SHELL").map_or(true, |shell_env| {
 290        shell_env != shell && !std::path::Path::new(&shell_env).exists()
 291    });
 292
 293    if should_set_shell {
 294        log::info!(
 295            "updating SHELL environment variable to value from passwd entry: {:?}",
 296            shell,
 297        );
 298        unsafe { env::set_var("SHELL", shell) };
 299    }
 300
 301    Ok(())
 302}
 303
 304/// Returns a shell escaped path for the current zed executable
 305pub fn get_shell_safe_zed_path(shell_kind: shell::ShellKind) -> anyhow::Result<String> {
 306    let zed_path =
 307        std::env::current_exe().context("Failed to determine current zed executable path.")?;
 308
 309    zed_path
 310        .try_shell_safe(shell_kind)
 311        .context("Failed to shell-escape Zed executable path.")
 312}
 313
 314/// Returns a path for the zed cli executable, this function
 315/// should be called from the zed executable, not zed-cli.
 316pub fn get_zed_cli_path() -> Result<PathBuf> {
 317    let zed_path =
 318        std::env::current_exe().context("Failed to determine current zed executable path.")?;
 319    let parent = zed_path
 320        .parent()
 321        .context("Failed to determine parent directory of zed executable path.")?;
 322
 323    let possible_locations: &[&str] = if cfg!(target_os = "macos") {
 324        // On macOS, the zed executable and zed-cli are inside the app bundle,
 325        // so here ./cli is for both installed and development builds.
 326        &["./cli"]
 327    } else if cfg!(target_os = "windows") {
 328        // bin/zed.exe is for installed builds, ./cli.exe is for development builds.
 329        &["bin/zed.exe", "./cli.exe"]
 330    } else if cfg!(target_os = "linux") || cfg!(target_os = "freebsd") {
 331        // bin is the standard, ./cli is for the target directory in development builds.
 332        &["../bin/zed", "./cli"]
 333    } else {
 334        anyhow::bail!("unsupported platform for determining zed-cli path");
 335    };
 336
 337    possible_locations
 338        .iter()
 339        .find_map(|p| {
 340            parent
 341                .join(p)
 342                .canonicalize()
 343                .ok()
 344                .filter(|p| p != &zed_path)
 345        })
 346        .with_context(|| {
 347            format!(
 348                "could not find zed-cli from any of: {}",
 349                possible_locations.join(", ")
 350            )
 351        })
 352}
 353
 354#[cfg(unix)]
 355pub async fn load_login_shell_environment() -> Result<()> {
 356    load_shell_from_passwd().log_err();
 357
 358    // If possible, we want to `cd` in the user's `$HOME` to trigger programs
 359    // such as direnv, asdf, mise, ... to adjust the PATH. These tools often hook
 360    // into shell's `cd` command (and hooks) to manipulate env.
 361    // We do this so that we get the env a user would have when spawning a shell
 362    // in home directory.
 363    for (name, value) in shell_env::capture(get_system_shell(), &[], paths::home_dir())
 364        .await
 365        .with_context(|| format!("capturing environment with {:?}", get_system_shell()))?
 366    {
 367        unsafe { env::set_var(&name, &value) };
 368    }
 369
 370    log::info!(
 371        "set environment variables from shell:{}, path:{}",
 372        std::env::var("SHELL").unwrap_or_default(),
 373        std::env::var("PATH").unwrap_or_default(),
 374    );
 375
 376    Ok(())
 377}
 378
 379/// Configures the process to start a new session, to prevent interactive shells from taking control
 380/// of the terminal.
 381///
 382/// For more details: <https://registerspill.thorstenball.com/p/how-to-lose-control-of-your-shell>
 383pub fn set_pre_exec_to_start_new_session(
 384    command: &mut std::process::Command,
 385) -> &mut std::process::Command {
 386    // safety: code in pre_exec should be signal safe.
 387    // https://man7.org/linux/man-pages/man7/signal-safety.7.html
 388    #[cfg(not(target_os = "windows"))]
 389    unsafe {
 390        use std::os::unix::process::CommandExt;
 391        command.pre_exec(|| {
 392            libc::setsid();
 393            Ok(())
 394        });
 395    };
 396    command
 397}
 398
 399pub fn merge_json_lenient_value_into(
 400    source: serde_json_lenient::Value,
 401    target: &mut serde_json_lenient::Value,
 402) {
 403    match (source, target) {
 404        (serde_json_lenient::Value::Object(source), serde_json_lenient::Value::Object(target)) => {
 405            for (key, value) in source {
 406                if let Some(target) = target.get_mut(&key) {
 407                    merge_json_lenient_value_into(value, target);
 408                } else {
 409                    target.insert(key, value);
 410                }
 411            }
 412        }
 413
 414        (serde_json_lenient::Value::Array(source), serde_json_lenient::Value::Array(target)) => {
 415            for value in source {
 416                target.push(value);
 417            }
 418        }
 419
 420        (source, target) => *target = source,
 421    }
 422}
 423
 424pub fn merge_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
 425    use serde_json::Value;
 426
 427    match (source, target) {
 428        (Value::Object(source), Value::Object(target)) => {
 429            for (key, value) in source {
 430                if let Some(target) = target.get_mut(&key) {
 431                    merge_json_value_into(value, target);
 432                } else {
 433                    target.insert(key, value);
 434                }
 435            }
 436        }
 437
 438        (Value::Array(source), Value::Array(target)) => {
 439            for value in source {
 440                target.push(value);
 441            }
 442        }
 443
 444        (source, target) => *target = source,
 445    }
 446}
 447
 448pub fn merge_non_null_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
 449    use serde_json::Value;
 450    if let Value::Object(source_object) = source {
 451        let target_object = if let Value::Object(target) = target {
 452            target
 453        } else {
 454            *target = Value::Object(Default::default());
 455            target.as_object_mut().unwrap()
 456        };
 457        for (key, value) in source_object {
 458            if let Some(target) = target_object.get_mut(&key) {
 459                merge_non_null_json_value_into(value, target);
 460            } else if !value.is_null() {
 461                target_object.insert(key, value);
 462            }
 463        }
 464    } else if !source.is_null() {
 465        *target = source
 466    }
 467}
 468
 469pub fn measure<R>(label: &str, f: impl FnOnce() -> R) -> R {
 470    static ZED_MEASUREMENTS: OnceLock<bool> = OnceLock::new();
 471    let zed_measurements = ZED_MEASUREMENTS.get_or_init(|| {
 472        env::var("ZED_MEASUREMENTS")
 473            .map(|measurements| measurements == "1" || measurements == "true")
 474            .unwrap_or(false)
 475    });
 476
 477    if *zed_measurements {
 478        let start = Instant::now();
 479        let result = f();
 480        let elapsed = start.elapsed();
 481        eprintln!("{}: {:?}", label, elapsed);
 482        result
 483    } else {
 484        f()
 485    }
 486}
 487
 488pub fn expanded_and_wrapped_usize_range(
 489    range: Range<usize>,
 490    additional_before: usize,
 491    additional_after: usize,
 492    wrap_length: usize,
 493) -> impl Iterator<Item = usize> {
 494    let start_wraps = range.start < additional_before;
 495    let end_wraps = wrap_length < range.end + additional_after;
 496    if start_wraps && end_wraps {
 497        Either::Left(0..wrap_length)
 498    } else if start_wraps {
 499        let wrapped_start = (range.start + wrap_length).saturating_sub(additional_before);
 500        if wrapped_start <= range.end {
 501            Either::Left(0..wrap_length)
 502        } else {
 503            Either::Right((0..range.end + additional_after).chain(wrapped_start..wrap_length))
 504        }
 505    } else if end_wraps {
 506        let wrapped_end = range.end + additional_after - wrap_length;
 507        if range.start <= wrapped_end {
 508            Either::Left(0..wrap_length)
 509        } else {
 510            Either::Right((0..wrapped_end).chain(range.start - additional_before..wrap_length))
 511        }
 512    } else {
 513        Either::Left((range.start - additional_before)..(range.end + additional_after))
 514    }
 515}
 516
 517/// Yields `[i, i + 1, i - 1, i + 2, ..]`, each modulo `wrap_length` and bounded by
 518/// `additional_before` and `additional_after`. If the wrapping causes overlap, duplicates are not
 519/// emitted. If wrap_length is 0, nothing is yielded.
 520pub fn wrapped_usize_outward_from(
 521    start: usize,
 522    additional_before: usize,
 523    additional_after: usize,
 524    wrap_length: usize,
 525) -> impl Iterator<Item = usize> {
 526    let mut count = 0;
 527    let mut after_offset = 1;
 528    let mut before_offset = 1;
 529
 530    std::iter::from_fn(move || {
 531        count += 1;
 532        if count > wrap_length {
 533            None
 534        } else if count == 1 {
 535            Some(start % wrap_length)
 536        } else if after_offset <= additional_after && after_offset <= before_offset {
 537            let value = (start + after_offset) % wrap_length;
 538            after_offset += 1;
 539            Some(value)
 540        } else if before_offset <= additional_before {
 541            let value = (start + wrap_length - before_offset) % wrap_length;
 542            before_offset += 1;
 543            Some(value)
 544        } else if after_offset <= additional_after {
 545            let value = (start + after_offset) % wrap_length;
 546            after_offset += 1;
 547            Some(value)
 548        } else {
 549            None
 550        }
 551    })
 552}
 553
 554pub trait ResultExt<E> {
 555    type Ok;
 556
 557    fn log_err(self) -> Option<Self::Ok>;
 558    /// Assert that this result should never be an error in development or tests.
 559    fn debug_assert_ok(self, reason: &str) -> Self;
 560    fn warn_on_err(self) -> Option<Self::Ok>;
 561    fn log_with_level(self, level: log::Level) -> Option<Self::Ok>;
 562    fn anyhow(self) -> anyhow::Result<Self::Ok>
 563    where
 564        E: Into<anyhow::Error>;
 565}
 566
 567impl<T, E> ResultExt<E> for Result<T, E>
 568where
 569    E: std::fmt::Debug,
 570{
 571    type Ok = T;
 572
 573    #[track_caller]
 574    fn log_err(self) -> Option<T> {
 575        self.log_with_level(log::Level::Error)
 576    }
 577
 578    #[track_caller]
 579    fn debug_assert_ok(self, reason: &str) -> Self {
 580        if let Err(error) = &self {
 581            debug_panic!("{reason} - {error:?}");
 582        }
 583        self
 584    }
 585
 586    #[track_caller]
 587    fn warn_on_err(self) -> Option<T> {
 588        self.log_with_level(log::Level::Warn)
 589    }
 590
 591    #[track_caller]
 592    fn log_with_level(self, level: log::Level) -> Option<T> {
 593        match self {
 594            Ok(value) => Some(value),
 595            Err(error) => {
 596                log_error_with_caller(*Location::caller(), error, level);
 597                None
 598            }
 599        }
 600    }
 601
 602    fn anyhow(self) -> anyhow::Result<T>
 603    where
 604        E: Into<anyhow::Error>,
 605    {
 606        self.map_err(Into::into)
 607    }
 608}
 609
 610fn log_error_with_caller<E>(caller: core::panic::Location<'_>, error: E, level: log::Level)
 611where
 612    E: std::fmt::Debug,
 613{
 614    #[cfg(not(target_os = "windows"))]
 615    let file = caller.file();
 616    #[cfg(target_os = "windows")]
 617    let file = caller.file().replace('\\', "/");
 618    // In this codebase all crates reside in a `crates` directory,
 619    // so discard the prefix up to that segment to find the crate name
 620    let file = file.split_once("crates/");
 621    let target = file.as_ref().and_then(|(_, s)| s.split_once("/src/"));
 622
 623    let module_path = target.map(|(krate, module)| {
 624        if module.starts_with(krate) {
 625            module.trim_end_matches(".rs").replace('/', "::")
 626        } else {
 627            krate.to_owned() + "::" + &module.trim_end_matches(".rs").replace('/', "::")
 628        }
 629    });
 630    let file = file.map(|(_, file)| format!("crates/{file}"));
 631    log::logger().log(
 632        &log::Record::builder()
 633            .target(module_path.as_deref().unwrap_or(""))
 634            .module_path(file.as_deref())
 635            .args(format_args!("{:?}", error))
 636            .file(Some(caller.file()))
 637            .line(Some(caller.line()))
 638            .level(level)
 639            .build(),
 640    );
 641}
 642
 643pub fn log_err<E: std::fmt::Debug>(error: &E) {
 644    log_error_with_caller(*Location::caller(), error, log::Level::Error);
 645}
 646
 647pub trait TryFutureExt {
 648    fn log_err(self) -> LogErrorFuture<Self>
 649    where
 650        Self: Sized;
 651
 652    fn log_tracked_err(self, location: core::panic::Location<'static>) -> LogErrorFuture<Self>
 653    where
 654        Self: Sized;
 655
 656    fn warn_on_err(self) -> LogErrorFuture<Self>
 657    where
 658        Self: Sized;
 659    fn unwrap(self) -> UnwrapFuture<Self>
 660    where
 661        Self: Sized;
 662}
 663
 664impl<F, T, E> TryFutureExt for F
 665where
 666    F: Future<Output = Result<T, E>>,
 667    E: std::fmt::Debug,
 668{
 669    #[track_caller]
 670    fn log_err(self) -> LogErrorFuture<Self>
 671    where
 672        Self: Sized,
 673    {
 674        let location = Location::caller();
 675        LogErrorFuture(self, log::Level::Error, *location)
 676    }
 677
 678    fn log_tracked_err(self, location: core::panic::Location<'static>) -> LogErrorFuture<Self>
 679    where
 680        Self: Sized,
 681    {
 682        LogErrorFuture(self, log::Level::Error, location)
 683    }
 684
 685    #[track_caller]
 686    fn warn_on_err(self) -> LogErrorFuture<Self>
 687    where
 688        Self: Sized,
 689    {
 690        let location = Location::caller();
 691        LogErrorFuture(self, log::Level::Warn, *location)
 692    }
 693
 694    fn unwrap(self) -> UnwrapFuture<Self>
 695    where
 696        Self: Sized,
 697    {
 698        UnwrapFuture(self)
 699    }
 700}
 701
 702#[must_use]
 703pub struct LogErrorFuture<F>(F, log::Level, core::panic::Location<'static>);
 704
 705impl<F, T, E> Future for LogErrorFuture<F>
 706where
 707    F: Future<Output = Result<T, E>>,
 708    E: std::fmt::Debug,
 709{
 710    type Output = Option<T>;
 711
 712    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
 713        let level = self.1;
 714        let location = self.2;
 715        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
 716        match inner.poll(cx) {
 717            Poll::Ready(output) => Poll::Ready(match output {
 718                Ok(output) => Some(output),
 719                Err(error) => {
 720                    log_error_with_caller(location, error, level);
 721                    None
 722                }
 723            }),
 724            Poll::Pending => Poll::Pending,
 725        }
 726    }
 727}
 728
 729pub struct UnwrapFuture<F>(F);
 730
 731impl<F, T, E> Future for UnwrapFuture<F>
 732where
 733    F: Future<Output = Result<T, E>>,
 734    E: std::fmt::Debug,
 735{
 736    type Output = T;
 737
 738    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
 739        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
 740        match inner.poll(cx) {
 741            Poll::Ready(result) => Poll::Ready(result.unwrap()),
 742            Poll::Pending => Poll::Pending,
 743        }
 744    }
 745}
 746
 747pub struct Deferred<F: FnOnce()>(Option<F>);
 748
 749impl<F: FnOnce()> Deferred<F> {
 750    /// Drop without running the deferred function.
 751    pub fn abort(mut self) {
 752        self.0.take();
 753    }
 754}
 755
 756impl<F: FnOnce()> Drop for Deferred<F> {
 757    fn drop(&mut self) {
 758        if let Some(f) = self.0.take() {
 759            f()
 760        }
 761    }
 762}
 763
 764/// Run the given function when the returned value is dropped (unless it's cancelled).
 765#[must_use]
 766pub fn defer<F: FnOnce()>(f: F) -> Deferred<F> {
 767    Deferred(Some(f))
 768}
 769
 770#[cfg(any(test, feature = "test-support"))]
 771mod rng {
 772    use rand::prelude::*;
 773
 774    pub struct RandomCharIter<T: Rng> {
 775        rng: T,
 776        simple_text: bool,
 777    }
 778
 779    impl<T: Rng> RandomCharIter<T> {
 780        pub fn new(rng: T) -> Self {
 781            Self {
 782                rng,
 783                simple_text: std::env::var("SIMPLE_TEXT").is_ok_and(|v| !v.is_empty()),
 784            }
 785        }
 786
 787        pub fn with_simple_text(mut self) -> Self {
 788            self.simple_text = true;
 789            self
 790        }
 791    }
 792
 793    impl<T: Rng> Iterator for RandomCharIter<T> {
 794        type Item = char;
 795
 796        fn next(&mut self) -> Option<Self::Item> {
 797            if self.simple_text {
 798                return if self.rng.random_range(0..100) < 5 {
 799                    Some('\n')
 800                } else {
 801                    Some(self.rng.random_range(b'a'..b'z' + 1).into())
 802                };
 803            }
 804
 805            match self.rng.random_range(0..100) {
 806                // whitespace
 807                0..=19 => [' ', '\n', '\r', '\t'].choose(&mut self.rng).copied(),
 808                // two-byte greek letters
 809                20..=32 => char::from_u32(self.rng.random_range(('Ξ±' as u32)..('Ο‰' as u32 + 1))),
 810                // // three-byte characters
 811                33..=45 => ['βœ‹', 'βœ…', '❌', '❎', '⭐']
 812                    .choose(&mut self.rng)
 813                    .copied(),
 814                // // four-byte characters
 815                46..=58 => ['🍐', 'πŸ€', 'πŸ—', 'πŸŽ‰'].choose(&mut self.rng).copied(),
 816                // ascii letters
 817                _ => Some(self.rng.random_range(b'a'..b'z' + 1).into()),
 818            }
 819        }
 820    }
 821}
 822#[cfg(any(test, feature = "test-support"))]
 823pub use rng::RandomCharIter;
 824
 825/// Get an embedded file as a string.
 826pub fn asset_str<A: rust_embed::RustEmbed>(path: &str) -> Cow<'static, str> {
 827    match A::get(path).expect(path).data {
 828        Cow::Borrowed(bytes) => Cow::Borrowed(std::str::from_utf8(bytes).unwrap()),
 829        Cow::Owned(bytes) => Cow::Owned(String::from_utf8(bytes).unwrap()),
 830    }
 831}
 832
 833/// Expands to an immediately-invoked function expression. Good for using the ? operator
 834/// in functions which do not return an Option or Result.
 835///
 836/// Accepts a normal block, an async block, or an async move block.
 837#[macro_export]
 838macro_rules! maybe {
 839    ($block:block) => {
 840        (|| $block)()
 841    };
 842    (async $block:block) => {
 843        (async || $block)()
 844    };
 845    (async move $block:block) => {
 846        (async move || $block)()
 847    };
 848}
 849
 850pub trait RangeExt<T> {
 851    fn sorted(&self) -> Self;
 852    fn to_inclusive(&self) -> RangeInclusive<T>;
 853    fn overlaps(&self, other: &Range<T>) -> bool;
 854    fn contains_inclusive(&self, other: &Range<T>) -> bool;
 855}
 856
 857impl<T: Ord + Clone> RangeExt<T> for Range<T> {
 858    fn sorted(&self) -> Self {
 859        cmp::min(&self.start, &self.end).clone()..cmp::max(&self.start, &self.end).clone()
 860    }
 861
 862    fn to_inclusive(&self) -> RangeInclusive<T> {
 863        self.start.clone()..=self.end.clone()
 864    }
 865
 866    fn overlaps(&self, other: &Range<T>) -> bool {
 867        self.start < other.end && other.start < self.end
 868    }
 869
 870    fn contains_inclusive(&self, other: &Range<T>) -> bool {
 871        self.start <= other.start && other.end <= self.end
 872    }
 873}
 874
 875impl<T: Ord + Clone> RangeExt<T> for RangeInclusive<T> {
 876    fn sorted(&self) -> Self {
 877        cmp::min(self.start(), self.end()).clone()..=cmp::max(self.start(), self.end()).clone()
 878    }
 879
 880    fn to_inclusive(&self) -> RangeInclusive<T> {
 881        self.clone()
 882    }
 883
 884    fn overlaps(&self, other: &Range<T>) -> bool {
 885        self.start() < &other.end && &other.start <= self.end()
 886    }
 887
 888    fn contains_inclusive(&self, other: &Range<T>) -> bool {
 889        self.start() <= &other.start && &other.end <= self.end()
 890    }
 891}
 892
 893/// A way to sort strings with starting numbers numerically first, falling back to alphanumeric one,
 894/// case-insensitive.
 895///
 896/// This is useful for turning regular alphanumerically sorted sequences as `1-abc, 10, 11-def, .., 2, 21-abc`
 897/// into `1-abc, 2, 10, 11-def, .., 21-abc`
 898#[derive(Debug, PartialEq, Eq)]
 899pub struct NumericPrefixWithSuffix<'a>(Option<u64>, &'a str);
 900
 901impl<'a> NumericPrefixWithSuffix<'a> {
 902    pub fn from_numeric_prefixed_str(str: &'a str) -> Self {
 903        let i = str.chars().take_while(|c| c.is_ascii_digit()).count();
 904        let (prefix, remainder) = str.split_at(i);
 905
 906        let prefix = prefix.parse().ok();
 907        Self(prefix, remainder)
 908    }
 909}
 910
 911/// When dealing with equality, we need to consider the case of the strings to achieve strict equality
 912/// to handle cases like "a" < "A" instead of "a" == "A".
 913impl Ord for NumericPrefixWithSuffix<'_> {
 914    fn cmp(&self, other: &Self) -> Ordering {
 915        match (self.0, other.0) {
 916            (None, None) => UniCase::new(self.1)
 917                .cmp(&UniCase::new(other.1))
 918                .then_with(|| self.1.cmp(other.1).reverse()),
 919            (None, Some(_)) => Ordering::Greater,
 920            (Some(_), None) => Ordering::Less,
 921            (Some(a), Some(b)) => a.cmp(&b).then_with(|| {
 922                UniCase::new(self.1)
 923                    .cmp(&UniCase::new(other.1))
 924                    .then_with(|| self.1.cmp(other.1).reverse())
 925            }),
 926        }
 927    }
 928}
 929
 930impl PartialOrd for NumericPrefixWithSuffix<'_> {
 931    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
 932        Some(self.cmp(other))
 933    }
 934}
 935
 936/// Capitalizes the first character of a string.
 937///
 938/// This function takes a string slice as input and returns a new `String` with the first character
 939/// capitalized.
 940///
 941/// # Examples
 942///
 943/// ```
 944/// use util::capitalize;
 945///
 946/// assert_eq!(capitalize("hello"), "Hello");
 947/// assert_eq!(capitalize("WORLD"), "WORLD");
 948/// assert_eq!(capitalize(""), "");
 949/// ```
 950pub fn capitalize(str: &str) -> String {
 951    let mut chars = str.chars();
 952    match chars.next() {
 953        None => String::new(),
 954        Some(first_char) => first_char.to_uppercase().collect::<String>() + chars.as_str(),
 955    }
 956}
 957
 958fn emoji_regex() -> &'static Regex {
 959    static EMOJI_REGEX: LazyLock<Regex> =
 960        LazyLock::new(|| Regex::new("(\\p{Emoji}|\u{200D})").unwrap());
 961    &EMOJI_REGEX
 962}
 963
 964/// Returns true if the given string consists of emojis only.
 965/// E.g. "πŸ‘¨β€πŸ‘©β€πŸ‘§β€πŸ‘§πŸ‘‹" will return true, but "πŸ‘‹!" will return false.
 966pub fn word_consists_of_emojis(s: &str) -> bool {
 967    let mut prev_end = 0;
 968    for capture in emoji_regex().find_iter(s) {
 969        if capture.start() != prev_end {
 970            return false;
 971        }
 972        prev_end = capture.end();
 973    }
 974    prev_end == s.len()
 975}
 976
 977/// Similar to `str::split`, but also provides byte-offset ranges of the results. Unlike
 978/// `str::split`, this is not generic on pattern types and does not return an `Iterator`.
 979pub fn split_str_with_ranges(s: &str, pat: impl Fn(char) -> bool) -> Vec<(Range<usize>, &str)> {
 980    let mut result = Vec::new();
 981    let mut start = 0;
 982
 983    for (i, ch) in s.char_indices() {
 984        if pat(ch) {
 985            if i > start {
 986                result.push((start..i, &s[start..i]));
 987            }
 988            start = i + ch.len_utf8();
 989        }
 990    }
 991
 992    if s.len() > start {
 993        result.push((start..s.len(), &s[start..s.len()]));
 994    }
 995
 996    result
 997}
 998
 999pub fn default<D: Default>() -> D {
1000    Default::default()
1001}
1002
1003pub use self::shell::{
1004    get_default_system_shell, get_default_system_shell_preferring_bash, get_system_shell,
1005};
1006
1007#[derive(Debug)]
1008pub enum ConnectionResult<O> {
1009    Timeout,
1010    ConnectionReset,
1011    Result(anyhow::Result<O>),
1012}
1013
1014impl<O> ConnectionResult<O> {
1015    pub fn into_response(self) -> anyhow::Result<O> {
1016        match self {
1017            ConnectionResult::Timeout => anyhow::bail!("Request timed out"),
1018            ConnectionResult::ConnectionReset => anyhow::bail!("Server reset the connection"),
1019            ConnectionResult::Result(r) => r,
1020        }
1021    }
1022}
1023
1024impl<O> From<anyhow::Result<O>> for ConnectionResult<O> {
1025    fn from(result: anyhow::Result<O>) -> Self {
1026        ConnectionResult::Result(result)
1027    }
1028}
1029
1030#[track_caller]
1031pub fn some_or_debug_panic<T>(option: Option<T>) -> Option<T> {
1032    #[cfg(debug_assertions)]
1033    if option.is_none() {
1034        panic!("Unexpected None");
1035    }
1036    option
1037}
1038
1039#[cfg(test)]
1040mod tests {
1041    use super::*;
1042
1043    #[test]
1044    fn test_extend_sorted() {
1045        let mut vec = vec![];
1046
1047        extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
1048        assert_eq!(vec, &[21, 17, 13, 8, 1]);
1049
1050        extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
1051        assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
1052
1053        extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
1054        assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
1055    }
1056
1057    #[test]
1058    fn test_truncate_to_bottom_n_sorted_by() {
1059        let mut vec: Vec<u32> = vec![5, 2, 3, 4, 1];
1060        truncate_to_bottom_n_sorted_by(&mut vec, 10, &u32::cmp);
1061        assert_eq!(vec, &[1, 2, 3, 4, 5]);
1062
1063        vec = vec![5, 2, 3, 4, 1];
1064        truncate_to_bottom_n_sorted_by(&mut vec, 5, &u32::cmp);
1065        assert_eq!(vec, &[1, 2, 3, 4, 5]);
1066
1067        vec = vec![5, 2, 3, 4, 1];
1068        truncate_to_bottom_n_sorted_by(&mut vec, 4, &u32::cmp);
1069        assert_eq!(vec, &[1, 2, 3, 4]);
1070
1071        vec = vec![5, 2, 3, 4, 1];
1072        truncate_to_bottom_n_sorted_by(&mut vec, 1, &u32::cmp);
1073        assert_eq!(vec, &[1]);
1074
1075        vec = vec![5, 2, 3, 4, 1];
1076        truncate_to_bottom_n_sorted_by(&mut vec, 0, &u32::cmp);
1077        assert!(vec.is_empty());
1078    }
1079
1080    #[test]
1081    fn test_iife() {
1082        fn option_returning_function() -> Option<()> {
1083            None
1084        }
1085
1086        let foo = maybe!({
1087            option_returning_function()?;
1088            Some(())
1089        });
1090
1091        assert_eq!(foo, None);
1092    }
1093
1094    #[test]
1095    fn test_truncate_and_trailoff() {
1096        assert_eq!(truncate_and_trailoff("", 5), "");
1097        assert_eq!(truncate_and_trailoff("aaaaaa", 7), "aaaaaa");
1098        assert_eq!(truncate_and_trailoff("aaaaaa", 6), "aaaaaa");
1099        assert_eq!(truncate_and_trailoff("aaaaaa", 5), "aaaaa…");
1100        assert_eq!(truncate_and_trailoff("èèèèèè", 7), "èèèèèè");
1101        assert_eq!(truncate_and_trailoff("èèèèèè", 6), "èèèèèè");
1102        assert_eq!(truncate_and_trailoff("èèèèèè", 5), "èèèèè…");
1103    }
1104
1105    #[test]
1106    fn test_truncate_and_remove_front() {
1107        assert_eq!(truncate_and_remove_front("", 5), "");
1108        assert_eq!(truncate_and_remove_front("aaaaaa", 7), "aaaaaa");
1109        assert_eq!(truncate_and_remove_front("aaaaaa", 6), "aaaaaa");
1110        assert_eq!(truncate_and_remove_front("aaaaaa", 5), "…aaaaa");
1111        assert_eq!(truncate_and_remove_front("èèèèèè", 7), "èèèèèè");
1112        assert_eq!(truncate_and_remove_front("èèèèèè", 6), "èèèèèè");
1113        assert_eq!(truncate_and_remove_front("èèèèèè", 5), "…èèèèè");
1114    }
1115
1116    #[test]
1117    fn test_numeric_prefix_str_method() {
1118        let target = "1a";
1119        assert_eq!(
1120            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1121            NumericPrefixWithSuffix(Some(1), "a")
1122        );
1123
1124        let target = "12ab";
1125        assert_eq!(
1126            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1127            NumericPrefixWithSuffix(Some(12), "ab")
1128        );
1129
1130        let target = "12_ab";
1131        assert_eq!(
1132            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1133            NumericPrefixWithSuffix(Some(12), "_ab")
1134        );
1135
1136        let target = "1_2ab";
1137        assert_eq!(
1138            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1139            NumericPrefixWithSuffix(Some(1), "_2ab")
1140        );
1141
1142        let target = "1.2";
1143        assert_eq!(
1144            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1145            NumericPrefixWithSuffix(Some(1), ".2")
1146        );
1147
1148        let target = "1.2_a";
1149        assert_eq!(
1150            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1151            NumericPrefixWithSuffix(Some(1), ".2_a")
1152        );
1153
1154        let target = "12.2_a";
1155        assert_eq!(
1156            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1157            NumericPrefixWithSuffix(Some(12), ".2_a")
1158        );
1159
1160        let target = "12a.2_a";
1161        assert_eq!(
1162            NumericPrefixWithSuffix::from_numeric_prefixed_str(target),
1163            NumericPrefixWithSuffix(Some(12), "a.2_a")
1164        );
1165    }
1166
1167    #[test]
1168    fn test_numeric_prefix_with_suffix() {
1169        let mut sorted = vec!["1-abc", "10", "11def", "2", "21-abc"];
1170        sorted.sort_by_key(|s| NumericPrefixWithSuffix::from_numeric_prefixed_str(s));
1171        assert_eq!(sorted, ["1-abc", "2", "10", "11def", "21-abc"]);
1172
1173        for numeric_prefix_less in ["numeric_prefix_less", "aaa", "~β„’Β£"] {
1174            assert_eq!(
1175                NumericPrefixWithSuffix::from_numeric_prefixed_str(numeric_prefix_less),
1176                NumericPrefixWithSuffix(None, numeric_prefix_less),
1177                "String without numeric prefix `{numeric_prefix_less}` should not be converted into NumericPrefixWithSuffix"
1178            )
1179        }
1180    }
1181
1182    #[test]
1183    fn test_word_consists_of_emojis() {
1184        let words_to_test = vec![
1185            ("πŸ‘¨β€πŸ‘©β€πŸ‘§β€πŸ‘§πŸ‘‹πŸ₯’", true),
1186            ("πŸ‘‹", true),
1187            ("!πŸ‘‹", false),
1188            ("πŸ‘‹!", false),
1189            ("πŸ‘‹ ", false),
1190            (" πŸ‘‹", false),
1191            ("Test", false),
1192        ];
1193
1194        for (text, expected_result) in words_to_test {
1195            assert_eq!(word_consists_of_emojis(text), expected_result);
1196        }
1197    }
1198
1199    #[test]
1200    fn test_truncate_lines_and_trailoff() {
1201        let text = r#"Line 1
1202Line 2
1203Line 3"#;
1204
1205        assert_eq!(
1206            truncate_lines_and_trailoff(text, 2),
1207            r#"Line 1
1208…"#
1209        );
1210
1211        assert_eq!(
1212            truncate_lines_and_trailoff(text, 3),
1213            r#"Line 1
1214Line 2
1215…"#
1216        );
1217
1218        assert_eq!(
1219            truncate_lines_and_trailoff(text, 4),
1220            r#"Line 1
1221Line 2
1222Line 3"#
1223        );
1224    }
1225
1226    #[test]
1227    fn test_expanded_and_wrapped_usize_range() {
1228        // Neither wrap
1229        assert_eq!(
1230            expanded_and_wrapped_usize_range(2..4, 1, 1, 8).collect::<Vec<usize>>(),
1231            (1..5).collect::<Vec<usize>>()
1232        );
1233        // Start wraps
1234        assert_eq!(
1235            expanded_and_wrapped_usize_range(2..4, 3, 1, 8).collect::<Vec<usize>>(),
1236            ((0..5).chain(7..8)).collect::<Vec<usize>>()
1237        );
1238        // Start wraps all the way around
1239        assert_eq!(
1240            expanded_and_wrapped_usize_range(2..4, 5, 1, 8).collect::<Vec<usize>>(),
1241            (0..8).collect::<Vec<usize>>()
1242        );
1243        // Start wraps all the way around and past 0
1244        assert_eq!(
1245            expanded_and_wrapped_usize_range(2..4, 10, 1, 8).collect::<Vec<usize>>(),
1246            (0..8).collect::<Vec<usize>>()
1247        );
1248        // End wraps
1249        assert_eq!(
1250            expanded_and_wrapped_usize_range(3..5, 1, 4, 8).collect::<Vec<usize>>(),
1251            (0..1).chain(2..8).collect::<Vec<usize>>()
1252        );
1253        // End wraps all the way around
1254        assert_eq!(
1255            expanded_and_wrapped_usize_range(3..5, 1, 5, 8).collect::<Vec<usize>>(),
1256            (0..8).collect::<Vec<usize>>()
1257        );
1258        // End wraps all the way around and past the end
1259        assert_eq!(
1260            expanded_and_wrapped_usize_range(3..5, 1, 10, 8).collect::<Vec<usize>>(),
1261            (0..8).collect::<Vec<usize>>()
1262        );
1263        // Both start and end wrap
1264        assert_eq!(
1265            expanded_and_wrapped_usize_range(3..5, 4, 4, 8).collect::<Vec<usize>>(),
1266            (0..8).collect::<Vec<usize>>()
1267        );
1268    }
1269
1270    #[test]
1271    fn test_wrapped_usize_outward_from() {
1272        // No wrapping
1273        assert_eq!(
1274            wrapped_usize_outward_from(4, 2, 2, 10).collect::<Vec<usize>>(),
1275            vec![4, 5, 3, 6, 2]
1276        );
1277        // Wrapping at end
1278        assert_eq!(
1279            wrapped_usize_outward_from(8, 2, 3, 10).collect::<Vec<usize>>(),
1280            vec![8, 9, 7, 0, 6, 1]
1281        );
1282        // Wrapping at start
1283        assert_eq!(
1284            wrapped_usize_outward_from(1, 3, 2, 10).collect::<Vec<usize>>(),
1285            vec![1, 2, 0, 3, 9, 8]
1286        );
1287        // All values wrap around
1288        assert_eq!(
1289            wrapped_usize_outward_from(5, 10, 10, 8).collect::<Vec<usize>>(),
1290            vec![5, 6, 4, 7, 3, 0, 2, 1]
1291        );
1292        // None before / after
1293        assert_eq!(
1294            wrapped_usize_outward_from(3, 0, 0, 8).collect::<Vec<usize>>(),
1295            vec![3]
1296        );
1297        // Starting point already wrapped
1298        assert_eq!(
1299            wrapped_usize_outward_from(15, 2, 2, 10).collect::<Vec<usize>>(),
1300            vec![5, 6, 4, 7, 3]
1301        );
1302        // wrap_length of 0
1303        assert_eq!(
1304            wrapped_usize_outward_from(4, 2, 2, 0).collect::<Vec<usize>>(),
1305            Vec::<usize>::new()
1306        );
1307    }
1308
1309    #[test]
1310    fn test_split_with_ranges() {
1311        let input = "hi";
1312        let result = split_str_with_ranges(input, |c| c == ' ');
1313
1314        assert_eq!(result.len(), 1);
1315        assert_eq!(result[0], (0..2, "hi"));
1316
1317        let input = "hΓ©lloπŸ¦€world";
1318        let result = split_str_with_ranges(input, |c| c == 'πŸ¦€');
1319
1320        assert_eq!(result.len(), 2);
1321        assert_eq!(result[0], (0..6, "hΓ©llo")); // 'Γ©' is 2 bytes
1322        assert_eq!(result[1], (10..15, "world")); // 'πŸ¦€' is 4 bytes
1323    }
1324}