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    //! Routines for comparing and diffing output.
    //!
    //! # Deprecated comparisons
    //!
    //! Cargo's tests are in transition from internal-only pattern and normalization routines used in
    //! asserts like [`crate::Execs::with_stdout`] to [`assert_e2e`] and [`assert_ui`].
    //!
    //! ## Patterns
    //!
    //! Many of these functions support special markup to assist with comparing
    //! text that may vary or is otherwise uninteresting for the test at hand. The
    //! supported patterns are:
    //!
    //! - `[..]` is a wildcard that matches 0 or more characters on the same line
    //!   (similar to `.*` in a regex). It is non-greedy.
    //! - `[EXE]` optionally adds `.exe` on Windows (empty string on other
    //!   platforms).
    //! - `[ROOT]` is the path to the test directory's root.
    //! - `[CWD]` is the working directory of the process that was run.
    //! - There is a wide range of substitutions (such as `[COMPILING]` or
    //!   `[WARNING]`) to match cargo's "status" output and allows you to ignore
    //!   the alignment. See the source of `substitute_macros` for a complete list
    //!   of substitutions.
    //! - `[DIRTY-MSVC]` (only when the line starts with it) would be replaced by
    //!   `[DIRTY]` when `cfg(target_env = "msvc")` or the line will be ignored otherwise.
    //!   Tests that work around [issue 7358](https://github.com/rust-lang/cargo/issues/7358)
    //!   can use this to avoid duplicating the `with_stderr` call like:
    //!   `if cfg!(target_env = "msvc") {e.with_stderr("...[DIRTY]...");} else {e.with_stderr("...");}`.
    //!
    //! ## Normalization
    //!
    //! In addition to the patterns described above, the strings are normalized
    //! in such a way to avoid unwanted differences. The normalizations are:
    //!
    //! - Raw tab characters are converted to the string `<tab>`. This is helpful
    //!   so that raw tabs do not need to be written in the expected string, and
    //!   to avoid confusion of tabs vs spaces.
    //! - Backslashes are converted to forward slashes to deal with Windows paths.
    //!   This helps so that all tests can be written assuming forward slashes.
    //!   Other heuristics are applied to try to ensure Windows-style paths aren't
    //!   a problem.
    //! - Carriage returns are removed, which can help when running on Windows.

    use crate::cross_compile::try_alternate;
    use crate::paths;
    use crate::{diff, rustc_host};
    use anyhow::{bail, Context, Result};
    use serde_json::Value;
    use std::fmt;
    use std::path::Path;
    use std::str;
    use url::Url;

    /// This makes it easier to write regex replacements that are guaranteed to only
    /// get compiled once
    macro_rules! regex {
        ($re:literal $(,)?) => {{
            static RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
            RE.get_or_init(|| regex::Regex::new($re).unwrap())
        }};
    }

    /// Assertion policy for UI tests
    ///
    /// This emphasizes showing as much content as possible at the cost of more brittleness
    ///
    /// # Snapshots
    ///
    /// Updating of snapshots is controlled with the `SNAPSHOTS` environment variable:
    ///
    /// - `skip`: do not run the tests
    /// - `ignore`: run the tests but ignore their failure
    /// - `verify`: run the tests
    /// - `overwrite`: update the snapshots based on the output of the tests
    ///
    /// # Patterns
    ///
    /// - `[..]` is a character wildcard, stopping at line breaks
    /// - `\n...\n` is a multi-line wildcard
    /// - `[EXE]` matches the exe suffix for the current platform
    /// - `[ROOT]` matches [`paths::root()`][crate::paths::root]
    /// - `[ROOTURL]` matches [`paths::root()`][crate::paths::root] as a URL
    ///
    /// # Normalization
    ///
    /// In addition to the patterns described above, text is normalized
    /// in such a way to avoid unwanted differences. The normalizations are:
    ///
    /// - Backslashes are converted to forward slashes to deal with Windows paths.
    ///   This helps so that all tests can be written assuming forward slashes.
    ///   Other heuristics are applied to try to ensure Windows-style paths aren't
    ///   a problem.
    /// - Carriage returns are removed, which can help when running on Windows.
    ///
    /// # Example
    ///
    /// ```no_run
    /// # use cargo_test_support::compare::assert_e2e;
    /// # use cargo_test_support::file;
    /// # let p = cargo_test_support::project().build();
    /// # let stdout = "";
    /// assert_e2e().eq(stdout, file!["stderr.term.svg"]);
    /// ```
    /// ```console
    /// $ SNAPSHOTS=overwrite cargo test
    /// ```
    pub fn assert_ui() -> snapbox::Assert {
        let mut subs = snapbox::Redactions::new();
        subs.extend(MIN_LITERAL_REDACTIONS.into_iter().cloned())
            .unwrap();
        add_test_support_redactions(&mut subs);
        add_regex_redactions(&mut subs);

        snapbox::Assert::new()
            .action_env(snapbox::assert::DEFAULT_ACTION_ENV)
            .redact_with(subs)
    }

    /// Assertion policy for functional end-to-end tests
    ///
    /// This emphasizes showing as much content as possible at the cost of more brittleness
    ///
    /// # Snapshots
    ///
    /// Updating of snapshots is controlled with the `SNAPSHOTS` environment variable:
    ///
    /// - `skip`: do not run the tests
    /// - `ignore`: run the tests but ignore their failure
    /// - `verify`: run the tests
    /// - `overwrite`: update the snapshots based on the output of the tests
    ///
    /// # Patterns
    ///
    /// - `[..]` is a character wildcard, stopping at line breaks
    /// - `\n...\n` is a multi-line wildcard
    /// - `[EXE]` matches the exe suffix for the current platform
    /// - `[ROOT]` matches [`paths::root()`][crate::paths::root]
    /// - `[ROOTURL]` matches [`paths::root()`][crate::paths::root] as a URL
    ///
    /// # Normalization
    ///
    /// In addition to the patterns described above, text is normalized
    /// in such a way to avoid unwanted differences. The normalizations are:
    ///
    /// - Backslashes are converted to forward slashes to deal with Windows paths.
    ///   This helps so that all tests can be written assuming forward slashes.
    ///   Other heuristics are applied to try to ensure Windows-style paths aren't
    ///   a problem.
    /// - Carriage returns are removed, which can help when running on Windows.
    ///
    /// # Example
    ///
    /// ```no_run
    /// # use cargo_test_support::compare::assert_e2e;
    /// # use cargo_test_support::str;
    /// # let p = cargo_test_support::project().build();
    /// assert_e2e().eq(p.read_lockfile(), str![]);
    /// ```
    /// ```console
    /// $ SNAPSHOTS=overwrite cargo test
    /// ```
    pub fn assert_e2e() -> snapbox::Assert {
        let mut subs = snapbox::Redactions::new();
        subs.extend(MIN_LITERAL_REDACTIONS.into_iter().cloned())
            .unwrap();
        subs.extend(E2E_LITERAL_REDACTIONS.into_iter().cloned())
            .unwrap();
        add_test_support_redactions(&mut subs);
        add_regex_redactions(&mut subs);

        snapbox::Assert::new()
            .action_env(snapbox::assert::DEFAULT_ACTION_ENV)
            .redact_with(subs)
    }

    fn add_test_support_redactions(subs: &mut snapbox::Redactions) {
        let root = paths::root();
        // Use `from_file_path` instead of `from_dir_path` so the trailing slash is
        // put in the users output, rather than hidden in the variable
        let root_url = url::Url::from_file_path(&root).unwrap().to_string();

        subs.insert("[ROOT]", root).unwrap();
        subs.insert("[ROOTURL]", root_url).unwrap();
        subs.insert("[HOST_TARGET]", rustc_host()).unwrap();
        if let Some(alt_target) = try_alternate() {
            subs.insert("[ALT_TARGET]", alt_target).unwrap();
        }
    }

    fn add_regex_redactions(subs: &mut snapbox::Redactions) {
        // For e2e tests
        subs.insert(
            "[ELAPSED]",
            regex!(r"\[FINISHED\].*in (?<redacted>[0-9]+(\.[0-9]+)?(m [0-9]+)?)s"),
        )
        .unwrap();
        // for UI tests
        subs.insert(
            "[ELAPSED]",
            regex!(r"Finished.*in (?<redacted>[0-9]+(\.[0-9]+)?(m [0-9]+)?)s"),
        )
        .unwrap();
        // output from libtest
        subs.insert(
            "[ELAPSED]",
            regex!(r"; finished in (?<redacted>[0-9]+(\.[0-9]+)?(m [0-9]+)?)s"),
        )
        .unwrap();
        subs.insert(
            "[FILE_NUM]",
            regex!(r"\[(REMOVED|SUMMARY)\] (?<redacted>[0-9]+) files"),
        )
        .unwrap();
        subs.insert(
            "[FILE_SIZE]",
            regex!(r"(?<redacted>[0-9]+(\.[0-9]+)?([a-zA-Z]i)?)B\s"),
        )
        .unwrap();
        subs.insert(
            "[HASH]",
            regex!(r"home/\.cargo/registry/(cache|index|src)/-(?<redacted>[a-z0-9]+)"),
        )
        .unwrap();
        subs.insert(
            "[HASH]",
            regex!(r"\.cargo/target/(?<redacted>[0-9a-f]{2}/[0-9a-f]{14})"),
        )
        .unwrap();
        subs.insert("[HASH]", regex!(r"/[a-z0-9\-_]+-(?<redacted>[0-9a-f]{16})"))
            .unwrap();
        subs.insert(
            "[AVG_ELAPSED]",
            regex!(r"(?<redacted>[0-9]+(\.[0-9]+)?) ns/iter"),
        )
        .unwrap();
        subs.insert(
            "[JITTER]",
            regex!(r"ns/iter \(\+/- (?<redacted>[0-9]+(\.[0-9]+)?)\)"),
        )
        .unwrap();

        // Following 3 subs redact:
        //   "1719325877.527949100s, 61549498ns after last build at 1719325877.466399602s"
        //   "1719503592.218193216s, 1h 1s after last build at 1719499991.982681034s"
        // into "[DIRTY_REASON_NEW_TIME], [DIRTY_REASON_DIFF] after last build at [DIRTY_REASON_OLD_TIME]"
        subs.insert(
            "[TIME_DIFF_AFTER_LAST_BUILD]",
            regex!(r"(?<redacted>[0-9]+(\.[0-9]+)?s, (\s?[0-9]+(\.[0-9]+)?(s|ns|h))+ after last build at [0-9]+(\.[0-9]+)?s)"),
           )
           .unwrap();
    }

    static MIN_LITERAL_REDACTIONS: &[(&str, &str)] = &[
        ("[EXE]", std::env::consts::EXE_SUFFIX),
        ("[BROKEN_PIPE]", "Broken pipe (os error 32)"),
        ("[BROKEN_PIPE]", "The pipe is being closed. (os error 232)"),
        // Unix message for an entity was not found
        ("[NOT_FOUND]", "No such file or directory (os error 2)"),
        // Windows message for an entity was not found
        (
            "[NOT_FOUND]",
            "The system cannot find the file specified. (os error 2)",
        ),
        (
            "[NOT_FOUND]",
            "The system cannot find the path specified. (os error 3)",
        ),
        ("[NOT_FOUND]", "Access is denied. (os error 5)"),
        ("[NOT_FOUND]", "program not found"),
        // Unix message for exit status
        ("[EXIT_STATUS]", "exit status"),
        // Windows message for exit status
        ("[EXIT_STATUS]", "exit code"),
    ];
    static E2E_LITERAL_REDACTIONS: &[(&str, &str)] = &[
        ("[RUNNING]", "     Running"),
        ("[COMPILING]", "   Compiling"),
        ("[CHECKING]", "    Checking"),
        ("[COMPLETED]", "   Completed"),
        ("[CREATED]", "     Created"),
        ("[CREATING]", "    Creating"),
        ("[CREDENTIAL]", "  Credential"),
        ("[DOWNGRADING]", " Downgrading"),
        ("[FINISHED]", "    Finished"),
        ("[ERROR]", "error:"),
        ("[WARNING]", "warning:"),
        ("[NOTE]", "note:"),
        ("[HELP]", "help:"),
        ("[DOCUMENTING]", " Documenting"),
        ("[SCRAPING]", "    Scraping"),
        ("[FRESH]", "       Fresh"),
        ("[DIRTY]", "       Dirty"),
        ("[LOCKING]", "     Locking"),
        ("[UPDATING]", "    Updating"),
        ("[UPGRADING]", "   Upgrading"),
        ("[ADDING]", "      Adding"),
        ("[REMOVING]", "    Removing"),
        ("[REMOVED]", "     Removed"),
        ("[UNCHANGED]", "   Unchanged"),
        ("[DOCTEST]", "   Doc-tests"),
        ("[PACKAGING]", "   Packaging"),
        ("[PACKAGED]", "    Packaged"),
        ("[DOWNLOADING]", " Downloading"),
        ("[DOWNLOADED]", "  Downloaded"),
        ("[UPLOADING]", "   Uploading"),
        ("[UPLOADED]", "    Uploaded"),
        ("[VERIFYING]", "   Verifying"),
        ("[ARCHIVING]", "   Archiving"),
        ("[INSTALLING]", "  Installing"),
        ("[REPLACING]", "   Replacing"),
        ("[UNPACKING]", "   Unpacking"),
        ("[SUMMARY]", "     Summary"),
        ("[FIXED]", "       Fixed"),
        ("[FIXING]", "      Fixing"),
        ("[IGNORED]", "     Ignored"),
        ("[INSTALLED]", "   Installed"),
        ("[REPLACED]", "    Replaced"),
        ("[BUILDING]", "    Building"),
        ("[LOGIN]", "       Login"),
        ("[LOGOUT]", "      Logout"),
        ("[YANK]", "        Yank"),
        ("[OWNER]", "       Owner"),
        ("[MIGRATING]", "   Migrating"),
        ("[EXECUTABLE]", "  Executable"),
        ("[SKIPPING]", "    Skipping"),
        ("[WAITING]", "     Waiting"),
        ("[PUBLISHED]", "   Published"),
        ("[BLOCKING]", "    Blocking"),
        ("[GENERATED]", "   Generated"),
        ("[OPENING]", "     Opening"),
    ];

    /// Normalizes the output so that it can be compared against the expected value.
    fn normalize_actual(actual: &str, cwd: Option<&Path>) -> String {
        // It's easier to read tabs in outputs if they don't show up as literal
        // hidden characters
        let actual = actual.replace('\t', "<tab>");
        if cfg!(windows) {
            // Let's not deal with \r\n vs \n on windows...
            let actual = actual.replace('\r', "");
            normalize_windows(&actual, cwd)
        } else {
            actual
        }
    }

    /// Normalizes the expected string so that it can be compared against the actual output.
    fn normalize_expected(expected: &str, cwd: Option<&Path>) -> String {
        let expected = replace_dirty_msvc(expected);
        let expected = substitute_macros(&expected);

        if cfg!(windows) {
            normalize_windows(&expected, cwd)
        } else {
            let expected = match cwd {
                None => expected,
                Some(cwd) => expected.replace("[CWD]", &cwd.display().to_string()),
            };
            let expected = expected.replace("[ROOT]", &paths::root().display().to_string());
            expected
        }
    }

    fn replace_dirty_msvc_impl(s: &str, is_msvc: bool) -> String {
        if is_msvc {
            s.replace("[DIRTY-MSVC]", "[DIRTY]")
        } else {
            use itertools::Itertools;

            let mut new = s
                .lines()
                .filter(|it| !it.starts_with("[DIRTY-MSVC]"))
                .join("\n");

            if s.ends_with("\n") {
                new.push_str("\n");
            }

            new
        }
    }

    fn replace_dirty_msvc(s: &str) -> String {
        replace_dirty_msvc_impl(s, cfg!(target_env = "msvc"))
    }

    /// Normalizes text for both actual and expected strings on Windows.
    fn normalize_windows(text: &str, cwd: Option<&Path>) -> String {
        // Let's not deal with / vs \ (windows...)
        let text = text.replace('\\', "/");

        // Weirdness for paths on Windows extends beyond `/` vs `\` apparently.
        // Namely paths like `c:\` and `C:\` are equivalent and that can cause
        // issues. The return value of `env::current_dir()` may return a
        // lowercase drive name, but we round-trip a lot of values through `Url`
        // which will auto-uppercase the drive name. To just ignore this
        // distinction we try to canonicalize as much as possible, taking all
        // forms of a path and canonicalizing them to one.
        let replace_path = |s: &str, path: &Path, with: &str| {
            let path_through_url = Url::from_file_path(path).unwrap().to_file_path().unwrap();
            let path1 = path.display().to_string().replace('\\', "/");
            let path2 = path_through_url.display().to_string().replace('\\', "/");
            s.replace(&path1, with)
                .replace(&path2, with)
                .replace(with, &path1)
        };

        let text = match cwd {
            None => text,
            Some(p) => replace_path(&text, p, "[CWD]"),
        };

        // Similar to cwd above, perform similar treatment to the root path
        // which in theory all of our paths should otherwise get rooted at.
        let root = paths::root();
        let text = replace_path(&text, &root, "[ROOT]");

        text
    }

    fn substitute_macros(input: &str) -> String {
        let mut result = input.to_owned();
        for &(pat, subst) in MIN_LITERAL_REDACTIONS {
            result = result.replace(pat, subst)
        }
        for &(pat, subst) in E2E_LITERAL_REDACTIONS {
            result = result.replace(pat, subst)
        }
        result
    }

    /// Compares one string against another, checking that they both match.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    ///
    /// - `description` explains where the output is from (usually "stdout" or "stderr").
    /// - `other_output` is other output to display in the error (usually stdout or stderr).
    pub(crate) fn match_exact(
        expected: &str,
        actual: &str,
        description: &str,
        other_output: &str,
        cwd: Option<&Path>,
    ) -> Result<()> {
        let expected = normalize_expected(expected, cwd);
        let actual = normalize_actual(actual, cwd);
        let e: Vec<_> = expected.lines().map(WildStr::new).collect();
        let a: Vec<_> = actual.lines().map(WildStr::new).collect();
        if e == a {
            return Ok(());
        }
        let diff = diff::colored_diff(&e, &a);
        bail!(
            "{} did not match:\n\
             {}\n\n\
             other output:\n\
             {}\n",
            description,
            diff,
            other_output,
        );
    }

    /// Convenience wrapper around [`match_exact`] which will panic on error.
    #[track_caller]
    pub(crate) fn assert_match_exact(expected: &str, actual: &str) {
        if let Err(e) = match_exact(expected, actual, "", "", None) {
            crate::panic_error("", e);
        }
    }

    /// Checks that the given string contains the given lines, ignoring the order
    /// of the lines.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    pub(crate) fn match_unordered(expected: &str, actual: &str, cwd: Option<&Path>) -> Result<()> {
        let expected = normalize_expected(expected, cwd);
        let actual = normalize_actual(actual, cwd);
        let e: Vec<_> = expected.lines().map(|line| WildStr::new(line)).collect();
        let mut a: Vec<_> = actual.lines().map(|line| WildStr::new(line)).collect();
        // match more-constrained lines first, although in theory we'll
        // need some sort of recursive match here. This handles the case
        // that you expect "a\n[..]b" and two lines are printed out,
        // "ab\n"a", where technically we do match unordered but a naive
        // search fails to find this. This simple sort at least gets the
        // test suite to pass for now, but we may need to get more fancy
        // if tests start failing again.
        a.sort_by_key(|s| s.line.len());
        let mut changes = Vec::new();
        let mut a_index = 0;
        let mut failure = false;

        use crate::diff::Change;
        for (e_i, e_line) in e.into_iter().enumerate() {
            match a.iter().position(|a_line| e_line == *a_line) {
                Some(index) => {
                    let a_line = a.remove(index);
                    changes.push(Change::Keep(e_i, index, a_line));
                    a_index += 1;
                }
                None => {
                    failure = true;
                    changes.push(Change::Remove(e_i, e_line));
                }
            }
        }
        for unmatched in a {
            failure = true;
            changes.push(Change::Add(a_index, unmatched));
            a_index += 1;
        }
        if failure {
            bail!(
                "Expected lines did not match (ignoring order):\n{}\n",
                diff::render_colored_changes(&changes)
            );
        } else {
            Ok(())
        }
    }

    /// Checks that the given string contains the given contiguous lines
    /// somewhere.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    pub(crate) fn match_contains(expected: &str, actual: &str, cwd: Option<&Path>) -> Result<()> {
        let expected = normalize_expected(expected, cwd);
        let actual = normalize_actual(actual, cwd);
        let e: Vec<_> = expected.lines().map(|line| WildStr::new(line)).collect();
        let a: Vec<_> = actual.lines().map(|line| WildStr::new(line)).collect();
        if e.len() == 0 {
            bail!("expected length must not be zero");
        }
        for window in a.windows(e.len()) {
            if window == e {
                return Ok(());
            }
        }
        bail!(
            "expected to find:\n\
             {}\n\n\
             did not find in output:\n\
             {}",
            expected,
            actual
        );
    }

    /// Checks that the given string does not contain the given contiguous lines
    /// anywhere.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    pub(crate) fn match_does_not_contain(
        expected: &str,
        actual: &str,
        cwd: Option<&Path>,
    ) -> Result<()> {
        if match_contains(expected, actual, cwd).is_ok() {
            bail!(
                "expected not to find:\n\
                 {}\n\n\
                 but found in output:\n\
                 {}",
                expected,
                actual
            );
        } else {
            Ok(())
        }
    }

    /// Checks that the given string contains the given contiguous lines
    /// somewhere, and should be repeated `number` times.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    pub(crate) fn match_contains_n(
        expected: &str,
        number: usize,
        actual: &str,
        cwd: Option<&Path>,
    ) -> Result<()> {
        let expected = normalize_expected(expected, cwd);
        let actual = normalize_actual(actual, cwd);
        let e: Vec<_> = expected.lines().map(|line| WildStr::new(line)).collect();
        let a: Vec<_> = actual.lines().map(|line| WildStr::new(line)).collect();
        if e.len() == 0 {
            bail!("expected length must not be zero");
        }
        let matches = a.windows(e.len()).filter(|window| *window == e).count();
        if matches == number {
            Ok(())
        } else {
            bail!(
                "expected to find {} occurrences of:\n\
                 {}\n\n\
                 but found {} matches in the output:\n\
                 {}",
                number,
                expected,
                matches,
                actual
            )
        }
    }

    /// Checks that the given string has a line that contains the given patterns,
    /// and that line also does not contain the `without` patterns.
    ///
    /// See [Patterns](index.html#patterns) for more information on pattern matching.
    ///
    /// See [`crate::Execs::with_stderr_line_without`] for an example and cautions
    /// against using.
    pub(crate) fn match_with_without(
        actual: &str,
        with: &[String],
        without: &[String],
        cwd: Option<&Path>,
    ) -> Result<()> {
        let actual = normalize_actual(actual, cwd);
        let norm = |s: &String| format!("[..]{}[..]", normalize_expected(s, cwd));
        let with: Vec<_> = with.iter().map(norm).collect();
        let without: Vec<_> = without.iter().map(norm).collect();
        let with_wild: Vec<_> = with.iter().map(|w| WildStr::new(w)).collect();
        let without_wild: Vec<_> = without.iter().map(|w| WildStr::new(w)).collect();

        let matches: Vec<_> = actual
            .lines()
            .map(WildStr::new)
            .filter(|line| with_wild.iter().all(|with| with == line))
            .filter(|line| !without_wild.iter().any(|without| without == line))
            .collect();
        match matches.len() {
            0 => bail!(
                "Could not find expected line in output.\n\
                 With contents: {:?}\n\
                 Without contents: {:?}\n\
                 Actual stderr:\n\
                 {}\n",
                with,
                without,
                actual
            ),
            1 => Ok(()),
            _ => bail!(
                "Found multiple matching lines, but only expected one.\n\
                 With contents: {:?}\n\
                 Without contents: {:?}\n\
                 Matching lines:\n\
                 {}\n",
                with,
                without,
                itertools::join(matches, "\n")
            ),
        }
    }

    /// Checks that the given string of JSON objects match the given set of
    /// expected JSON objects.
    ///
    /// See [`crate::Execs::with_json`] for more details.
    pub(crate) fn match_json(expected: &str, actual: &str, cwd: Option<&Path>) -> Result<()> {
        let (exp_objs, act_objs) = collect_json_objects(expected, actual)?;
        if exp_objs.len() != act_objs.len() {
            bail!(
                "expected {} json lines, got {}, stdout:\n{}",
                exp_objs.len(),
                act_objs.len(),
                actual
            );
        }
        for (exp_obj, act_obj) in exp_objs.iter().zip(act_objs) {
            find_json_mismatch(exp_obj, &act_obj, cwd)?;
        }
        Ok(())
    }

    /// Checks that the given string of JSON objects match the given set of
    /// expected JSON objects, ignoring their order.
    ///
    /// See [`crate::Execs::with_json_contains_unordered`] for more details and
    /// cautions when using.
    pub(crate) fn match_json_contains_unordered(
        expected: &str,
        actual: &str,
        cwd: Option<&Path>,
    ) -> Result<()> {
        let (exp_objs, mut act_objs) = collect_json_objects(expected, actual)?;
        for exp_obj in exp_objs {
            match act_objs
                .iter()
                .position(|act_obj| find_json_mismatch(&exp_obj, act_obj, cwd).is_ok())
            {
                Some(index) => act_objs.remove(index),
                None => {
                    bail!(
                        "Did not find expected JSON:\n\
                         {}\n\
                         Remaining available output:\n\
                         {}\n",
                        serde_json::to_string_pretty(&exp_obj).unwrap(),
                        itertools::join(
                            act_objs.iter().map(|o| serde_json::to_string(o).unwrap()),
                            "\n"
                        )
                    );
                }
            };
        }
        Ok(())
    }

    fn collect_json_objects(
        expected: &str,
        actual: &str,
    ) -> Result<(Vec<serde_json::Value>, Vec<serde_json::Value>)> {
        let expected_objs: Vec<_> = expected
            .split("\n\n")
            .map(|expect| {
                expect
                    .parse()
                    .with_context(|| format!("failed to parse expected JSON object:\n{}", expect))
            })
            .collect::<Result<_>>()?;
        let actual_objs: Vec<_> = actual
            .lines()
            .filter(|line| line.starts_with('{'))
            .map(|line| {
                line.parse()
                    .with_context(|| format!("failed to parse JSON object:\n{}", line))
            })
            .collect::<Result<_>>()?;
        Ok((expected_objs, actual_objs))
    }

    /// Compares JSON object for approximate equality.
    /// You can use `[..]` wildcard in strings (useful for OS-dependent things such
    /// as paths). You can use a `"{...}"` string literal as a wildcard for
    /// arbitrary nested JSON (useful for parts of object emitted by other programs
    /// (e.g., rustc) rather than Cargo itself).
    pub(crate) fn find_json_mismatch(
        expected: &Value,
        actual: &Value,
        cwd: Option<&Path>,
    ) -> Result<()> {
        match find_json_mismatch_r(expected, actual, cwd) {
            Some((expected_part, actual_part)) => bail!(
                "JSON mismatch\nExpected:\n{}\nWas:\n{}\nExpected part:\n{}\nActual part:\n{}\n",
                serde_json::to_string_pretty(expected).unwrap(),
                serde_json::to_string_pretty(&actual).unwrap(),
                serde_json::to_string_pretty(expected_part).unwrap(),
                serde_json::to_string_pretty(actual_part).unwrap(),
            ),
            None => Ok(()),
        }
    }

    fn find_json_mismatch_r<'a>(
        expected: &'a Value,
        actual: &'a Value,
        cwd: Option<&Path>,
    ) -> Option<(&'a Value, &'a Value)> {
        use serde_json::Value::*;
        match (expected, actual) {
            (&Number(ref l), &Number(ref r)) if l == r => None,
            (&Bool(l), &Bool(r)) if l == r => None,
            (&String(ref l), _) if l == "{...}" => None,
            (&String(ref l), &String(ref r)) => {
                if match_exact(l, r, "", "", cwd).is_err() {
                    Some((expected, actual))
                } else {
                    None
                }
            }
            (&Array(ref l), &Array(ref r)) => {
                if l.len() != r.len() {
                    return Some((expected, actual));
                }

                l.iter()
                    .zip(r.iter())
                    .filter_map(|(l, r)| find_json_mismatch_r(l, r, cwd))
                    .next()
            }
            (&Object(ref l), &Object(ref r)) => {
                let mut expected_entries = l.iter();
                let mut actual_entries = r.iter();

                loop {
                    match (expected_entries.next(), actual_entries.next()) {
                        (None, None) => return None,
                        (Some((expected_key, expected_value)), Some((actual_key, actual_value)))
                            if expected_key == actual_key =>
                        {
                            if let mismatch @ Some(_) =
                                find_json_mismatch_r(expected_value, actual_value, cwd)
                            {
                                return mismatch;
                            }
                        }
                        _ => return Some((expected, actual)),
                    }
                }
            }
            (&Null, &Null) => None,
            // Magic string literal `"{...}"` acts as wildcard for any sub-JSON.
            _ => Some((expected, actual)),
        }
    }

    /// A single line string that supports `[..]` wildcard matching.
    pub(crate) struct WildStr<'a> {
        has_meta: bool,
        line: &'a str,
    }

    impl<'a> WildStr<'a> {
        pub fn new(line: &'a str) -> WildStr<'a> {
            WildStr {
                has_meta: line.contains("[..]"),
                line,
            }
        }
    }

    impl<'a> PartialEq for WildStr<'a> {
        fn eq(&self, other: &Self) -> bool {
            match (self.has_meta, other.has_meta) {
                (false, false) => self.line == other.line,
                (true, false) => meta_cmp(self.line, other.line),
                (false, true) => meta_cmp(other.line, self.line),
                (true, true) => panic!("both lines cannot have [..]"),
            }
        }
    }

    fn meta_cmp(a: &str, mut b: &str) -> bool {
        for (i, part) in a.split("[..]").enumerate() {
            match b.find(part) {
                Some(j) => {
                    if i == 0 && j != 0 {
                        return false;
                    }
                    b = &b[j + part.len()..];
                }
                None => return false,
            }
        }
        b.is_empty() || a.ends_with("[..]")
    }

    impl fmt::Display for WildStr<'_> {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            f.write_str(&self.line)
        }
    }

    impl fmt::Debug for WildStr<'_> {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            write!(f, "{:?}", self.line)
        }
    }

    #[cfg(test)]
    mod test {
        use snapbox::assert_data_eq;
        use snapbox::prelude::*;
        use snapbox::str;

        use super::*;

        #[test]
        fn wild_str_cmp() {
            for (a, b) in &[
                ("a b", "a b"),
                ("a[..]b", "a b"),
                ("a[..]", "a b"),
                ("[..]", "a b"),
                ("[..]b", "a b"),
            ] {
                assert_eq!(WildStr::new(a), WildStr::new(b));
            }
            for (a, b) in &[("[..]b", "c"), ("b", "c"), ("b", "cb")] {
                assert_ne!(WildStr::new(a), WildStr::new(b));
            }
        }

        #[test]
        fn dirty_msvc() {
            let case = |expected: &str, wild: &str, msvc: bool| {
                assert_eq!(expected, &replace_dirty_msvc_impl(wild, msvc));
            };

            // no replacements
            case("aa", "aa", false);
            case("aa", "aa", true);

            // with replacements
            case(
                "\
    [DIRTY] a",
                "\
    [DIRTY-MSVC] a",
                true,
            );
            case(
                "",
                "\
    [DIRTY-MSVC] a",
                false,
            );
            case(
                "\
    [DIRTY] a
    [COMPILING] a",
                "\
    [DIRTY-MSVC] a
    [COMPILING] a",
                true,
            );
            case(
                "\
    [COMPILING] a",
                "\
    [DIRTY-MSVC] a
    [COMPILING] a",
                false,
            );

            // test trailing newline behavior
            case(
                "\
    A
    B
    ", "\
    A
    B
    ", true,
            );

            case(
                "\
    A
    B
    ", "\
    A
    B
    ", false,
            );

            case(
                "\
    A
    B", "\
    A
    B", true,
            );

            case(
                "\
    A
    B", "\
    A
    B", false,
            );

            case(
                "\
    [DIRTY] a
    ",
                "\
    [DIRTY-MSVC] a
    ",
                true,
            );
            case(
                "\n",
                "\
    [DIRTY-MSVC] a
    ",
                false,
            );

            case(
                "\
    [DIRTY] a",
                "\
    [DIRTY-MSVC] a",
                true,
            );
            case(
                "",
                "\
    [DIRTY-MSVC] a",
                false,
            );
        }

        #[test]
        fn redact_elapsed_time() {
            let mut subs = snapbox::Redactions::new();
            add_regex_redactions(&mut subs);

            assert_data_eq!(
                subs.redact("[FINISHED] `release` profile [optimized] target(s) in 5.5s"),
                str!["[FINISHED] `release` profile [optimized] target(s) in [ELAPSED]s"].raw()
            );
            assert_data_eq!(
                subs.redact("[FINISHED] `release` profile [optimized] target(s) in 1m 05s"),
                str!["[FINISHED] `release` profile [optimized] target(s) in [ELAPSED]s"].raw()
            );
        }
    }