nextest_runner/reporter/

events.rs

// Copyright (c) The nextest Contributors
// SPDX-License-Identifier: MIT OR Apache-2.0

//! Events for the reporter.
//!
//! These types form the interface between the test runner and the test
//! reporter. The root structure for all events is [`TestEvent`].

use super::{FinalStatusLevel, StatusLevel, TestOutputDisplay};
use crate::{
    config::{elements::LeakTimeoutResult, scripts::ScriptId},
    list::{TestInstance, TestInstanceId, TestList},
    runner::{StressCondition, StressCount},
    test_output::ChildExecutionOutput,
};
use chrono::{DateTime, FixedOffset};
use nextest_metadata::MismatchReason;
use quick_junit::ReportUuid;
use std::{collections::BTreeMap, fmt, num::NonZero, process::ExitStatus, time::Duration};

/// A test event.
///
/// Events are produced by a [`TestRunner`](crate::runner::TestRunner) and
/// consumed by a [`Reporter`](crate::reporter::Reporter).
#[derive(Clone, Debug)]
pub struct TestEvent<'a> {
    /// The time at which the event was generated, including the offset from UTC.
    pub timestamp: DateTime<FixedOffset>,

    /// The amount of time elapsed since the start of the test run.
    pub elapsed: Duration,

    /// The kind of test event this is.
    pub kind: TestEventKind<'a>,
}

/// The kind of test event this is.
///
/// Forms part of [`TestEvent`].
#[derive(Clone, Debug)]
pub enum TestEventKind<'a> {
    /// The test run started.
    RunStarted {
        /// The list of tests that will be run.
        ///
        /// The methods on the test list indicate the number of tests that will be run.
        test_list: &'a TestList<'a>,

        /// The UUID for this run.
        run_id: ReportUuid,

        /// The nextest profile chosen for this run.
        profile_name: String,

        /// The command-line arguments for the process.
        cli_args: Vec<String>,

        /// The stress condition for this run, if any.
        stress_condition: Option<StressCondition>,
    },

    /// When running stress tests serially, a sub-run started.
    StressSubRunStarted {
        /// The amount of progress completed so far.
        progress: StressProgress,
    },

    /// A setup script started.
    SetupScriptStarted {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The setup script index.
        index: usize,

        /// The total number of setup scripts.
        total: usize,

        /// The script ID.
        script_id: ScriptId,

        /// The program to run.
        program: String,

        /// The arguments to the program.
        args: &'a [String],

        /// True if some output from the setup script is being passed through.
        no_capture: bool,
    },

    /// A setup script was slow.
    SetupScriptSlow {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The script ID.
        script_id: ScriptId,

        /// The program to run.
        program: String,

        /// The arguments to the program.
        args: &'a [String],

        /// The amount of time elapsed since the start of execution.
        elapsed: Duration,

        /// True if the script has hit its timeout and is about to be terminated.
        will_terminate: bool,
    },

    /// A setup script completed execution.
    SetupScriptFinished {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The setup script index.
        index: usize,

        /// The total number of setup scripts.
        total: usize,

        /// The script ID.
        script_id: ScriptId,

        /// The program to run.
        program: String,

        /// The arguments to the program.
        args: &'a [String],

        /// Whether the JUnit report should store success output for this script.
        junit_store_success_output: bool,

        /// Whether the JUnit report should store failure output for this script.
        junit_store_failure_output: bool,

        /// True if some output from the setup script was passed through.
        no_capture: bool,

        /// The execution status of the setup script.
        run_status: SetupScriptExecuteStatus,
    },

    // TODO: add events for BinaryStarted and BinaryFinished? May want a slightly different way to
    // do things, maybe a couple of reporter traits (one for the run as a whole and one for each
    // binary).
    /// A test started running.
    TestStarted {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that was started.
        test_instance: TestInstance<'a>,

        /// Current run statistics so far.
        current_stats: RunStats,

        /// The number of tests currently running, including this one.
        running: usize,
    },

    /// Show test-specific progress.
    ///
    /// This event is emitted shortly after a test starts running, and is used
    /// as a trigger to show test-related progress. This is to prevent many very
    /// short-lived tests from overwhelming the display code.
    TestShowProgress {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// Retry data.
        retry_data: RetryData,

        /// The test instance that was started.
        test_instance: TestInstance<'a>,
    },

    /// A test was slower than a configured soft timeout.
    TestSlow {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that was slow.
        test_instance: TestInstance<'a>,

        /// Retry data.
        retry_data: RetryData,

        /// The amount of time that has elapsed since the beginning of the test.
        elapsed: Duration,

        /// True if the test has hit its timeout and is about to be terminated.
        will_terminate: bool,
    },

    /// A test attempt failed and will be retried in the future.
    ///
    /// This event does not occur on the final run of a failing test.
    TestAttemptFailedWillRetry {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that is being retried.
        test_instance: TestInstance<'a>,

        /// The status of this attempt to run the test. Will never be success.
        run_status: ExecuteStatus,

        /// The delay before the next attempt to run the test.
        delay_before_next_attempt: Duration,

        /// Whether failure outputs are printed out.
        failure_output: TestOutputDisplay,
    },

    /// A retry has started.
    TestRetryStarted {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that is being retried.
        test_instance: TestInstance<'a>,

        /// Data related to retries.
        retry_data: RetryData,
    },

    /// A test finished running.
    TestFinished {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that finished running.
        test_instance: TestInstance<'a>,

        /// Test setting for success output.
        success_output: TestOutputDisplay,

        /// Test setting for failure output.
        failure_output: TestOutputDisplay,

        /// Whether the JUnit report should store success output for this test.
        junit_store_success_output: bool,

        /// Whether the JUnit report should store failure output for this test.
        junit_store_failure_output: bool,

        /// Information about all the runs for this test.
        run_statuses: ExecutionStatuses,

        /// Current statistics for number of tests so far.
        current_stats: RunStats,

        /// The number of tests that are currently running, excluding this one.
        running: usize,
    },

    /// A test was skipped.
    TestSkipped {
        /// If a stress test is being run, the stress index, starting from 0.
        stress_index: Option<StressIndex>,

        /// The test instance that was skipped.
        test_instance: TestInstance<'a>,

        /// The reason this test was skipped.
        reason: MismatchReason,
    },

    /// An information request was received.
    InfoStarted {
        /// The number of tasks currently running. This is the same as the
        /// number of expected responses.
        total: usize,

        /// Statistics for the run.
        run_stats: RunStats,
    },

    /// Information about a script or test was received.
    InfoResponse {
        /// The index of the response, starting from 0.
        index: usize,

        /// The total number of responses expected.
        total: usize,

        /// The response itself.
        response: InfoResponse<'a>,
    },

    /// An information request was completed.
    InfoFinished {
        /// The number of responses that were not received. In most cases, this
        /// is 0.
        missing: usize,
    },

    /// `Enter` was pressed. Either a newline or a progress bar snapshot needs
    /// to be printed.
    InputEnter {
        /// Current statistics for number of tests so far.
        current_stats: RunStats,

        /// The number of tests running.
        running: usize,
    },

    /// A cancellation notice was received.
    RunBeginCancel {
        /// The number of setup scripts still running.
        setup_scripts_running: usize,

        /// Current statistics for number of tests so far.
        ///
        /// `current_stats.cancel_reason` is set to `Some`.
        current_stats: RunStats,

        /// The number of tests still running.
        running: usize,
    },

    /// A forcible kill was requested due to receiving a signal.
    RunBeginKill {
        /// The number of setup scripts still running.
        setup_scripts_running: usize,

        /// Current statistics for number of tests so far.
        ///
        /// `current_stats.cancel_reason` is set to `Some`.
        current_stats: RunStats,

        /// The number of tests still running.
        running: usize,
    },

    /// A SIGTSTP event was received and the run was paused.
    RunPaused {
        /// The number of setup scripts running.
        setup_scripts_running: usize,

        /// The number of tests currently running.
        running: usize,
    },

    /// A SIGCONT event was received and the run is being continued.
    RunContinued {
        /// The number of setup scripts that will be started up again.
        setup_scripts_running: usize,

        /// The number of tests that will be started up again.
        running: usize,
    },

    /// When running stress tests serially, a sub-run finished.
    StressSubRunFinished {
        /// The amount of progress completed so far.
        progress: StressProgress,

        /// The amount of time it took for this sub-run to complete.
        sub_elapsed: Duration,

        /// Statistics for the sub-run.
        sub_stats: RunStats,
    },

    /// The test run finished.
    RunFinished {
        /// The unique ID for this run.
        run_id: ReportUuid,

        /// The time at which the run was started.
        start_time: DateTime<FixedOffset>,

        /// The amount of time it took for the tests to run.
        elapsed: Duration,

        /// Statistics for the run, or overall statistics for stress tests.
        run_stats: RunFinishedStats,
    },
}

/// Progress for a stress test.
#[derive(Clone, Debug)]
pub enum StressProgress {
    /// This is a count-based stress run.
    Count {
        /// The total number of stress runs.
        total: StressCount,

        /// The total time that has elapsed across all stress runs so far.
        elapsed: Duration,

        /// The number of stress runs that have been completed.
        completed: u32,
    },

    /// This is a time-based stress run.
    Time {
        /// The total time for the stress run.
        total: Duration,

        /// The total time that has elapsed across all stress runs so far.
        elapsed: Duration,

        /// The number of stress runs that have been completed.
        completed: u32,
    },
}

impl StressProgress {
    /// Returns the remaining amount of work if the progress indicates there's
    /// still more to do, otherwise `None`.
    pub fn remaining(&self) -> Option<StressRemaining> {
        match self {
            Self::Count {
                total: StressCount::Count(total),
                elapsed: _,
                completed,
            } => total
                .get()
                .checked_sub(*completed)
                .and_then(|remaining| NonZero::try_from(remaining).ok())
                .map(StressRemaining::Count),
            Self::Count {
                total: StressCount::Infinite,
                ..
            } => Some(StressRemaining::Infinite),
            Self::Time {
                total,
                elapsed,
                completed: _,
            } => total.checked_sub(*elapsed).map(StressRemaining::Time),
        }
    }

    /// Returns a unique ID for this stress sub-run, consisting of the run ID and stress index.
    pub fn unique_id(&self, run_id: ReportUuid) -> String {
        let stress_current = match self {
            Self::Count { completed, .. } | Self::Time { completed, .. } => *completed,
        };
        format!("{}:@stress-{}", run_id, stress_current)
    }
}

/// For a stress test, the amount of time or number of stress runs remaining.
#[derive(Clone, Debug)]
pub enum StressRemaining {
    /// The number of stress runs remaining, guaranteed to be non-zero.
    Count(NonZero<u32>),

    /// Infinite number of stress runs remaining.
    Infinite,

    /// The amount of time remaining.
    Time(Duration),
}

/// The index of the current stress run.
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct StressIndex {
    /// The 0-indexed index.
    pub current: u32,

    /// The total number of stress runs, if that is available.
    pub total: Option<NonZero<u32>>,
}

/// Statistics for a completed test run or stress run.
#[derive(Clone, Debug)]
pub enum RunFinishedStats {
    /// A single test run was completed.
    Single(RunStats),

    /// A stress run was completed.
    Stress(StressRunStats),
}

impl RunFinishedStats {
    /// For a single run, returns a summary of statistics as an enum. For a
    /// stress run, returns a summary for the last sub-run.
    pub fn final_stats(&self) -> FinalRunStats {
        match self {
            Self::Single(stats) => stats.summarize_final(),
            Self::Stress(stats) => stats.last_final_stats,
        }
    }
}

/// Statistics for a test run.
#[derive(Copy, Clone, Default, Debug, Eq, PartialEq)]
pub struct RunStats {
    /// The total number of tests that were expected to be run at the beginning.
    ///
    /// If the test run is cancelled, this will be more than `finished_count` at the end.
    pub initial_run_count: usize,

    /// The total number of tests that finished running.
    pub finished_count: usize,

    /// The total number of setup scripts that were expected to be run at the beginning.
    ///
    /// If the test run is cancelled, this will be more than `finished_count` at the end.
    pub setup_scripts_initial_count: usize,

    /// The total number of setup scripts that finished running.
    pub setup_scripts_finished_count: usize,

    /// The number of setup scripts that passed.
    pub setup_scripts_passed: usize,

    /// The number of setup scripts that failed.
    pub setup_scripts_failed: usize,

    /// The number of setup scripts that encountered an execution failure.
    pub setup_scripts_exec_failed: usize,

    /// The number of setup scripts that timed out.
    pub setup_scripts_timed_out: usize,

    /// The number of tests that passed. Includes `passed_slow`, `flaky` and `leaky`.
    pub passed: usize,

    /// The number of slow tests that passed.
    pub passed_slow: usize,

    /// The number of tests that passed on retry.
    pub flaky: usize,

    /// The number of tests that failed.
    pub failed: usize,

    /// The number of failed tests that were slow.
    pub failed_slow: usize,

    /// The number of tests that timed out.
    pub timed_out: usize,

    /// The number of tests that passed but leaked handles.
    pub leaky: usize,

    /// The number of tests that otherwise passed, but leaked handles and were
    /// treated as failed as a result.
    pub leaky_failed: usize,

    /// The number of tests that encountered an execution failure.
    pub exec_failed: usize,

    /// The number of tests that were skipped.
    pub skipped: usize,

    /// If the run is cancelled, the reason the cancellation is happening.
    pub cancel_reason: Option<CancelReason>,
}

impl RunStats {
    /// Returns true if there are any failures recorded in the stats.
    pub fn has_failures(&self) -> bool {
        self.failed_setup_script_count() > 0 || self.failed_count() > 0
    }

    /// Returns count of setup scripts that did not pass.
    pub fn failed_setup_script_count(&self) -> usize {
        self.setup_scripts_failed + self.setup_scripts_exec_failed + self.setup_scripts_timed_out
    }

    /// Returns count of tests that did not pass.
    pub fn failed_count(&self) -> usize {
        self.failed + self.exec_failed + self.timed_out
    }

    /// Summarizes the stats as an enum at the end of a test run.
    pub fn summarize_final(&self) -> FinalRunStats {
        // Check for failures first. The order of setup scripts vs tests should
        // not be important, though we don't assert that here.
        if self.failed_setup_script_count() > 0 {
            // Is this related to a cancellation other than one directly caused
            // by the failure?
            if self.cancel_reason > Some(CancelReason::TestFailure) {
                FinalRunStats::Cancelled {
                    reason: self.cancel_reason,
                    kind: RunStatsFailureKind::SetupScript,
                }
            } else {
                FinalRunStats::Failed(RunStatsFailureKind::SetupScript)
            }
        } else if self.setup_scripts_initial_count > self.setup_scripts_finished_count {
            FinalRunStats::Cancelled {
                reason: self.cancel_reason,
                kind: RunStatsFailureKind::SetupScript,
            }
        } else if self.failed_count() > 0 {
            let kind = RunStatsFailureKind::Test {
                initial_run_count: self.initial_run_count,
                not_run: self.initial_run_count.saturating_sub(self.finished_count),
            };

            // Is this related to a cancellation other than one directly caused
            // by the failure?
            if self.cancel_reason > Some(CancelReason::TestFailure) {
                FinalRunStats::Cancelled {
                    reason: self.cancel_reason,
                    kind,
                }
            } else {
                FinalRunStats::Failed(kind)
            }
        } else if self.initial_run_count > self.finished_count {
            FinalRunStats::Cancelled {
                reason: self.cancel_reason,
                kind: RunStatsFailureKind::Test {
                    initial_run_count: self.initial_run_count,
                    not_run: self.initial_run_count.saturating_sub(self.finished_count),
                },
            }
        } else if self.finished_count == 0 {
            FinalRunStats::NoTestsRun
        } else {
            FinalRunStats::Success
        }
    }

    pub(crate) fn on_setup_script_finished(&mut self, status: &SetupScriptExecuteStatus) {
        self.setup_scripts_finished_count += 1;

        match status.result {
            ExecutionResult::Pass
            | ExecutionResult::Leak {
                result: LeakTimeoutResult::Pass,
            } => {
                self.setup_scripts_passed += 1;
            }
            ExecutionResult::Fail { .. }
            | ExecutionResult::Leak {
                result: LeakTimeoutResult::Fail,
            } => {
                self.setup_scripts_failed += 1;
            }
            ExecutionResult::ExecFail => {
                self.setup_scripts_exec_failed += 1;
            }
            ExecutionResult::Timeout => {
                self.setup_scripts_timed_out += 1;
            }
        }
    }

    pub(crate) fn on_test_finished(&mut self, run_statuses: &ExecutionStatuses) {
        self.finished_count += 1;
        // run_statuses is guaranteed to have at least one element.
        // * If the last element is success, treat it as success (and possibly flaky).
        // * If the last element is a failure, use it to determine fail/exec fail.
        // Note that this is different from what Maven Surefire does (use the first failure):
        // https://maven.apache.org/surefire/maven-surefire-plugin/examples/rerun-failing-tests.html
        //
        // This is not likely to matter much in practice since failures are likely to be of the
        // same type.
        let last_status = run_statuses.last_status();
        match last_status.result {
            ExecutionResult::Pass => {
                self.passed += 1;
                if last_status.is_slow {
                    self.passed_slow += 1;
                }
                if run_statuses.len() > 1 {
                    self.flaky += 1;
                }
            }
            ExecutionResult::Leak {
                result: LeakTimeoutResult::Pass,
            } => {
                self.passed += 1;
                self.leaky += 1;
                if last_status.is_slow {
                    self.passed_slow += 1;
                }
                if run_statuses.len() > 1 {
                    self.flaky += 1;
                }
            }
            ExecutionResult::Leak {
                result: LeakTimeoutResult::Fail,
            } => {
                self.failed += 1;
                self.leaky_failed += 1;
                if last_status.is_slow {
                    self.failed_slow += 1;
                }
            }
            ExecutionResult::Fail { .. } => {
                self.failed += 1;
                if last_status.is_slow {
                    self.failed_slow += 1;
                }
            }
            ExecutionResult::Timeout => self.timed_out += 1,
            ExecutionResult::ExecFail => self.exec_failed += 1,
        }
    }
}

/// A type summarizing the possible outcomes of a test run.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum FinalRunStats {
    /// The test run was successful, or is successful so far.
    Success,

    /// The test run was successful, or is successful so far, but no tests were selected to run.
    NoTestsRun,

    /// The test run was cancelled.
    Cancelled {
        /// The reason for cancellation, if available.
        ///
        /// This should generally be available, but may be None if some tests
        /// that were selected to run were not executed.
        reason: Option<CancelReason>,

        /// The kind of failure that occurred.
        kind: RunStatsFailureKind,
    },

    /// At least one test failed.
    Failed(RunStatsFailureKind),
}

/// Statistics for a stress run.
#[derive(Clone, Debug)]
pub struct StressRunStats {
    /// The number of stress runs completed.
    pub completed: StressIndex,

    /// The number of stress runs that succeeded.
    pub success_count: u32,

    /// The number of stress runs that failed.
    pub failed_count: u32,

    /// The last stress run's `FinalRunStats`.
    pub last_final_stats: FinalRunStats,
}

impl StressRunStats {
    /// Summarizes the stats as an enum at the end of a test run.
    pub fn summarize_final(&self) -> StressFinalRunStats {
        if self.failed_count > 0 {
            StressFinalRunStats::Failed
        } else if matches!(self.last_final_stats, FinalRunStats::Cancelled { .. }) {
            StressFinalRunStats::Cancelled
        } else if matches!(self.last_final_stats, FinalRunStats::NoTestsRun) {
            StressFinalRunStats::NoTestsRun
        } else {
            StressFinalRunStats::Success
        }
    }
}

/// A summary of final statistics for a stress run.
pub enum StressFinalRunStats {
    /// The stress run was successful.
    Success,

    /// No tests were run.
    NoTestsRun,

    /// The stress run was cancelled.
    Cancelled,

    /// At least one stress run failed.
    Failed,
}

/// A type summarizing the step at which a test run failed.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum RunStatsFailureKind {
    /// The run was interrupted during setup script execution.
    SetupScript,

    /// The run was interrupted during test execution.
    Test {
        /// The total number of tests scheduled.
        initial_run_count: usize,

        /// The number of tests not run, or for a currently-executing test the number queued up to
        /// run.
        not_run: usize,
    },
}

/// Information about executions of a test, including retries.
#[derive(Clone, Debug)]
pub struct ExecutionStatuses {
    /// This is guaranteed to be non-empty.
    statuses: Vec<ExecuteStatus>,
}

#[expect(clippy::len_without_is_empty)] // RunStatuses is never empty
impl ExecutionStatuses {
    pub(crate) fn new(statuses: Vec<ExecuteStatus>) -> Self {
        Self { statuses }
    }

    /// Returns the last execution status.
    ///
    /// This status is typically used as the final result.
    pub fn last_status(&self) -> &ExecuteStatus {
        self.statuses
            .last()
            .expect("execution statuses is non-empty")
    }

    /// Iterates over all the statuses.
    pub fn iter(&self) -> impl DoubleEndedIterator<Item = &'_ ExecuteStatus> + '_ {
        self.statuses.iter()
    }

    /// Returns the number of times the test was executed.
    pub fn len(&self) -> usize {
        self.statuses.len()
    }

    /// Returns a description of self.
    pub fn describe(&self) -> ExecutionDescription<'_> {
        let last_status = self.last_status();
        if last_status.result.is_success() {
            if self.statuses.len() > 1 {
                ExecutionDescription::Flaky {
                    last_status,
                    prior_statuses: &self.statuses[..self.statuses.len() - 1],
                }
            } else {
                ExecutionDescription::Success {
                    single_status: last_status,
                }
            }
        } else {
            let first_status = self
                .statuses
                .first()
                .expect("execution statuses is non-empty");
            let retries = &self.statuses[1..];
            ExecutionDescription::Failure {
                first_status,
                last_status,
                retries,
            }
        }
    }
}

/// A description of test executions obtained from `ExecuteStatuses`.
///
/// This can be used to quickly determine whether a test passed, failed or was flaky.
#[derive(Copy, Clone, Debug)]
pub enum ExecutionDescription<'a> {
    /// The test was run once and was successful.
    Success {
        /// The status of the test.
        single_status: &'a ExecuteStatus,
    },

    /// The test was run more than once. The final result was successful.
    Flaky {
        /// The last, successful status.
        last_status: &'a ExecuteStatus,

        /// Previous statuses, none of which are successes.
        prior_statuses: &'a [ExecuteStatus],
    },

    /// The test was run once, or possibly multiple times. All runs failed.
    Failure {
        /// The first, failing status.
        first_status: &'a ExecuteStatus,

        /// The last, failing status. Same as the first status if no retries were performed.
        last_status: &'a ExecuteStatus,

        /// Any retries that were performed. All of these runs failed.
        ///
        /// May be empty.
        retries: &'a [ExecuteStatus],
    },
}

impl<'a> ExecutionDescription<'a> {
    /// Returns the status level for this `ExecutionDescription`.
    pub fn status_level(&self) -> StatusLevel {
        match self {
            ExecutionDescription::Success { single_status } => match single_status.result {
                ExecutionResult::Leak {
                    result: LeakTimeoutResult::Pass,
                } => StatusLevel::Leak,
                ExecutionResult::Pass => StatusLevel::Pass,
                other => unreachable!("Success only permits Pass or Leak Pass, found {other:?}"),
            },
            // A flaky test implies that we print out retry information for it.
            ExecutionDescription::Flaky { .. } => StatusLevel::Retry,
            ExecutionDescription::Failure { .. } => StatusLevel::Fail,
        }
    }

    /// Returns the final status level for this `ExecutionDescription`.
    pub fn final_status_level(&self) -> FinalStatusLevel {
        match self {
            ExecutionDescription::Success { single_status, .. } => {
                // Slow is higher priority than leaky, so return slow first here.
                if single_status.is_slow {
                    FinalStatusLevel::Slow
                } else {
                    match single_status.result {
                        ExecutionResult::Pass => FinalStatusLevel::Pass,
                        ExecutionResult::Leak {
                            result: LeakTimeoutResult::Pass,
                        } => FinalStatusLevel::Leak,
                        other => {
                            unreachable!("Success only permits Pass or Leak Pass, found {other:?}")
                        }
                    }
                }
            }
            // A flaky test implies that we print out retry information for it.
            ExecutionDescription::Flaky { .. } => FinalStatusLevel::Flaky,
            ExecutionDescription::Failure { .. } => FinalStatusLevel::Fail,
        }
    }

    /// Returns the last run status.
    pub fn last_status(&self) -> &'a ExecuteStatus {
        match self {
            ExecutionDescription::Success {
                single_status: last_status,
            }
            | ExecutionDescription::Flaky { last_status, .. }
            | ExecutionDescription::Failure { last_status, .. } => last_status,
        }
    }
}

/// Information about a single execution of a test.
#[derive(Clone, Debug)]
pub struct ExecuteStatus {
    /// Retry-related data.
    pub retry_data: RetryData,
    /// The stdout and stderr output for this test.
    pub output: ChildExecutionOutput,
    /// The execution result for this test: pass, fail or execution error.
    pub result: ExecutionResult,
    /// The time at which the test started.
    pub start_time: DateTime<FixedOffset>,
    /// The time it took for the test to run.
    pub time_taken: Duration,
    /// Whether this test counts as slow.
    pub is_slow: bool,
    /// The delay will be non-zero if this is a retry and delay was specified.
    pub delay_before_start: Duration,
}

/// Information about the execution of a setup script.
#[derive(Clone, Debug)]
pub struct SetupScriptExecuteStatus {
    /// Output for this setup script.
    pub output: ChildExecutionOutput,

    /// The execution result for this setup script: pass, fail or execution error.
    pub result: ExecutionResult,

    /// The time at which the script started.
    pub start_time: DateTime<FixedOffset>,

    /// The time it took for the script to run.
    pub time_taken: Duration,

    /// Whether this script counts as slow.
    pub is_slow: bool,

    /// The map of environment variables that were set by this script.
    ///
    /// `None` if an error occurred while running the script or reading the
    /// environment map.
    pub env_map: Option<SetupScriptEnvMap>,
}

/// A map of environment variables set by a setup script.
///
/// Part of [`SetupScriptExecuteStatus`].
#[derive(Clone, Debug)]
pub struct SetupScriptEnvMap {
    /// The map of environment variables set by the script.
    pub env_map: BTreeMap<String, String>,
}

/// Data related to retries for a test.
#[derive(Clone, Copy, Debug, Eq, PartialEq, PartialOrd, Ord)]
pub struct RetryData {
    /// The current attempt. In the range `[1, total_attempts]`.
    pub attempt: u32,

    /// The total number of times this test can be run. Equal to `1 + retries`.
    pub total_attempts: u32,
}

impl RetryData {
    /// Returns true if there are no more attempts after this.
    pub fn is_last_attempt(&self) -> bool {
        self.attempt >= self.total_attempts
    }
}

/// Whether a test passed, failed or an error occurred while executing the test.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum ExecutionResult {
    /// The test passed.
    Pass,
    /// The test passed but leaked handles. This usually indicates that
    /// a subprocess that inherit standard IO was created, but it didn't shut down when
    /// the test failed.
    Leak {
        /// Whether this leak was treated as a failure.
        ///
        /// Note the difference between `Fail { leaked: true }` and `Leak {
        /// failed: true }`. In the former case, the test failed and also leaked
        /// handles. In the latter case, the test passed but leaked handles, and
        /// configuration indicated that this is a failure.
        result: LeakTimeoutResult,
    },
    /// The test failed.
    Fail {
        /// The abort status of the test, if any (for example, the signal on Unix).
        failure_status: FailureStatus,

        /// Whether a test leaked handles. If set to true, this usually indicates that
        /// a subprocess that inherit standard IO was created, but it didn't shut down when
        /// the test failed.
        leaked: bool,
    },
    /// An error occurred while executing the test.
    ExecFail,
    /// The test was terminated due to a timeout.
    Timeout,
}

impl ExecutionResult {
    /// Returns true if the test was successful.
    pub fn is_success(self) -> bool {
        match self {
            ExecutionResult::Pass
            | ExecutionResult::Leak {
                result: LeakTimeoutResult::Pass,
            } => true,
            ExecutionResult::Leak {
                result: LeakTimeoutResult::Fail,
            }
            | ExecutionResult::Fail { .. }
            | ExecutionResult::ExecFail
            | ExecutionResult::Timeout => false,
        }
    }

    /// Returns a static string representation of the result.
    pub fn as_static_str(&self) -> &'static str {
        match self {
            ExecutionResult::Pass => "pass",
            ExecutionResult::Leak { .. } => "leak",
            ExecutionResult::Fail { .. } => "fail",
            ExecutionResult::ExecFail => "exec-fail",
            ExecutionResult::Timeout => "timeout",
        }
    }
}

/// Failure status: either an exit code or an abort status.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum FailureStatus {
    /// The test exited with a non-zero exit code.
    ExitCode(i32),

    /// The test aborted.
    Abort(AbortStatus),
}

impl FailureStatus {
    /// Extract the failure status from an `ExitStatus`.
    pub fn extract(exit_status: ExitStatus) -> Self {
        if let Some(abort_status) = AbortStatus::extract(exit_status) {
            FailureStatus::Abort(abort_status)
        } else {
            FailureStatus::ExitCode(
                exit_status
                    .code()
                    .expect("if abort_status is None, then code must be present"),
            )
        }
    }
}

/// A regular exit code or Windows NT abort status for a test.
///
/// Returned as part of the [`ExecutionResult::Fail`] variant.
#[derive(Copy, Clone, Eq, PartialEq)]
pub enum AbortStatus {
    /// The test was aborted due to a signal on Unix.
    #[cfg(unix)]
    UnixSignal(i32),

    /// The test was determined to have aborted because the high bit was set on Windows.
    #[cfg(windows)]
    WindowsNtStatus(windows_sys::Win32::Foundation::NTSTATUS),

    /// The test was terminated via job object on Windows.
    #[cfg(windows)]
    JobObject,
}

impl AbortStatus {
    /// Extract the abort status from an [`ExitStatus`].
    pub fn extract(exit_status: ExitStatus) -> Option<Self> {
        cfg_if::cfg_if! {
            if #[cfg(unix)] {
                // On Unix, extract the signal if it's found.
                use std::os::unix::process::ExitStatusExt;
                exit_status.signal().map(AbortStatus::UnixSignal)
            } else if #[cfg(windows)] {
                exit_status.code().and_then(|code| {
                    (code < 0).then_some(AbortStatus::WindowsNtStatus(code))
                })
            } else {
                None
            }
        }
    }
}

impl fmt::Debug for AbortStatus {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            #[cfg(unix)]
            AbortStatus::UnixSignal(signal) => write!(f, "UnixSignal({signal})"),
            #[cfg(windows)]
            AbortStatus::WindowsNtStatus(status) => write!(f, "WindowsNtStatus({status:x})"),
            #[cfg(windows)]
            AbortStatus::JobObject => write!(f, "JobObject"),
        }
    }
}

// Note: the order here matters -- it indicates severity of cancellation
/// The reason why a test run is being cancelled.
#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
#[cfg_attr(test, derive(test_strategy::Arbitrary))]
pub enum CancelReason {
    /// A setup script failed.
    SetupScriptFailure,

    /// A test failed and --no-fail-fast wasn't specified.
    TestFailure,

    /// An error occurred while reporting results.
    ReportError,

    /// The global timeout was exceeded.
    GlobalTimeout,

    /// A termination signal (on Unix, SIGTERM or SIGHUP) was received.
    Signal,

    /// An interrupt (on Unix, Ctrl-C) was received.
    Interrupt,

    /// A second signal was received, and the run is being forcibly killed.
    SecondSignal,
}

impl CancelReason {
    pub(crate) fn to_static_str(self) -> &'static str {
        match self {
            CancelReason::SetupScriptFailure => "setup script failure",
            CancelReason::TestFailure => "test failure",
            CancelReason::ReportError => "reporting error",
            CancelReason::GlobalTimeout => "global timeout",
            CancelReason::Signal => "signal",
            CancelReason::Interrupt => "interrupt",
            CancelReason::SecondSignal => "second signal",
        }
    }
}
/// The kind of unit of work that nextest is executing.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum UnitKind {
    /// A test.
    Test,

    /// A script (e.g. a setup script).
    Script,
}

impl UnitKind {
    pub(crate) const WAITING_ON_TEST_MESSAGE: &str = "waiting on test process";
    pub(crate) const WAITING_ON_SCRIPT_MESSAGE: &str = "waiting on script process";

    pub(crate) const EXECUTING_TEST_MESSAGE: &str = "executing test";
    pub(crate) const EXECUTING_SCRIPT_MESSAGE: &str = "executing script";

    pub(crate) fn waiting_on_message(&self) -> &'static str {
        match self {
            UnitKind::Test => Self::WAITING_ON_TEST_MESSAGE,
            UnitKind::Script => Self::WAITING_ON_SCRIPT_MESSAGE,
        }
    }

    pub(crate) fn executing_message(&self) -> &'static str {
        match self {
            UnitKind::Test => Self::EXECUTING_TEST_MESSAGE,
            UnitKind::Script => Self::EXECUTING_SCRIPT_MESSAGE,
        }
    }
}

impl fmt::Display for UnitKind {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            UnitKind::Script => write!(f, "script"),
            UnitKind::Test => write!(f, "test"),
        }
    }
}

/// A response to an information request.
#[derive(Clone, Debug)]
pub enum InfoResponse<'a> {
    /// A setup script's response.
    SetupScript(SetupScriptInfoResponse<'a>),

    /// A test's response.
    Test(TestInfoResponse<'a>),
}

/// A setup script's response to an information request.
#[derive(Clone, Debug)]
pub struct SetupScriptInfoResponse<'a> {
    /// The stress index of the setup script.
    pub stress_index: Option<StressIndex>,

    /// The identifier of the setup script instance.
    pub script_id: ScriptId,

    /// The program to run.
    pub program: String,

    /// The list of arguments to the program.
    pub args: &'a [String],

    /// The state of the setup script.
    pub state: UnitState,

    /// Output obtained from the setup script.
    pub output: ChildExecutionOutput,
}

/// A test's response to an information request.
#[derive(Clone, Debug)]
pub struct TestInfoResponse<'a> {
    /// The stress index of the test.
    pub stress_index: Option<StressIndex>,

    /// The test instance that the information is about.
    pub test_instance: TestInstanceId<'a>,

    /// Information about retries.
    pub retry_data: RetryData,

    /// The state of the test.
    pub state: UnitState,

    /// Output obtained from the test.
    pub output: ChildExecutionOutput,
}

/// The current state of a test or script process: running, exiting, or
/// terminating.
///
/// Part of information response requests.
#[derive(Clone, Debug)]
pub enum UnitState {
    /// The unit is currently running.
    Running {
        /// The process ID.
        pid: u32,

        /// The amount of time the unit has been running.
        time_taken: Duration,

        /// `Some` if the test is marked as slow, along with the duration after
        /// which it was marked as slow.
        slow_after: Option<Duration>,
    },

    /// The test has finished running, and is currently in the process of
    /// exiting.
    Exiting {
        /// The process ID.
        pid: u32,

        /// The amount of time the unit ran for.
        time_taken: Duration,

        /// `Some` if the unit is marked as slow, along with the duration after
        /// which it was marked as slow.
        slow_after: Option<Duration>,

        /// The tentative execution result before leaked status is determined.
        ///
        /// None means that the exit status could not be read, and should be
        /// treated as a failure.
        tentative_result: Option<ExecutionResult>,

        /// How long has been spent waiting for the process to exit.
        waiting_duration: Duration,

        /// How much longer nextest will wait until the test is marked leaky.
        remaining: Duration,
    },

    /// The child process is being terminated by nextest.
    Terminating(UnitTerminatingState),

    /// The unit has finished running and the process has exited.
    Exited {
        /// The result of executing the unit.
        result: ExecutionResult,

        /// The amount of time the unit ran for.
        time_taken: Duration,

        /// `Some` if the unit is marked as slow, along with the duration after
        /// which it was marked as slow.
        slow_after: Option<Duration>,
    },

    /// A delay is being waited out before the next attempt of the test is
    /// started. (Only relevant for tests.)
    DelayBeforeNextAttempt {
        /// The previous execution result.
        previous_result: ExecutionResult,

        /// Whether the previous attempt was marked as slow.
        previous_slow: bool,

        /// How long has been spent waiting so far.
        waiting_duration: Duration,

        /// How much longer nextest will wait until retrying the test.
        remaining: Duration,
    },
}

impl UnitState {
    /// Returns true if the state has a valid output attached to it.
    pub fn has_valid_output(&self) -> bool {
        match self {
            UnitState::Running { .. }
            | UnitState::Exiting { .. }
            | UnitState::Terminating(_)
            | UnitState::Exited { .. } => true,
            UnitState::DelayBeforeNextAttempt { .. } => false,
        }
    }
}

/// The current terminating state of a test or script process.
///
/// Part of [`UnitState::Terminating`].
#[derive(Clone, Debug)]
pub struct UnitTerminatingState {
    /// The process ID.
    pub pid: u32,

    /// The amount of time the unit ran for.
    pub time_taken: Duration,

    /// The reason for the termination.
    pub reason: UnitTerminateReason,

    /// The method by which the process is being terminated.
    pub method: UnitTerminateMethod,

    /// How long has been spent waiting for the process to exit.
    pub waiting_duration: Duration,

    /// How much longer nextest will wait until a kill command is sent to the process.
    pub remaining: Duration,
}

/// The reason for a script or test being forcibly terminated by nextest.
///
/// Part of information response requests.
#[derive(Clone, Copy, Debug)]
pub enum UnitTerminateReason {
    /// The unit is being terminated due to a test timeout being hit.
    Timeout,

    /// The unit is being terminated due to nextest receiving a signal.
    Signal,

    /// The unit is being terminated due to an interrupt (i.e. Ctrl-C).
    Interrupt,
}

impl fmt::Display for UnitTerminateReason {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            UnitTerminateReason::Timeout => write!(f, "timeout"),
            UnitTerminateReason::Signal => write!(f, "signal"),
            UnitTerminateReason::Interrupt => write!(f, "interrupt"),
        }
    }
}

/// The way in which a script or test is being forcibly terminated by nextest.
#[derive(Clone, Copy, Debug)]
pub enum UnitTerminateMethod {
    /// The unit is being terminated by sending a signal.
    #[cfg(unix)]
    Signal(UnitTerminateSignal),

    /// The unit is being terminated by terminating the Windows job object.
    #[cfg(windows)]
    JobObject,

    /// The unit is being waited on to exit. A termination signal will be sent
    /// if it doesn't exit within the grace period.
    ///
    /// On Windows, this occurs when nextest receives Ctrl-C. In that case, it
    /// is assumed that tests will also receive Ctrl-C and exit on their own. If
    /// tests do not exit within the grace period configured for them, their
    /// corresponding job objects will be terminated.
    #[cfg(windows)]
    Wait,

    /// A fake method used for testing.
    #[cfg(test)]
    Fake,
}

#[cfg(unix)]
/// The signal that is or was sent to terminate a script or test.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum UnitTerminateSignal {
    /// The unit is being terminated by sending a SIGINT.
    Interrupt,

    /// The unit is being terminated by sending a SIGTERM signal.
    Term,

    /// The unit is being terminated by sending a SIGHUP signal.
    Hangup,

    /// The unit is being terminated by sending a SIGQUIT signal.
    Quit,

    /// The unit is being terminated by sending a SIGKILL signal.
    Kill,
}

#[cfg(unix)]
impl fmt::Display for UnitTerminateSignal {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            UnitTerminateSignal::Interrupt => write!(f, "SIGINT"),
            UnitTerminateSignal::Term => write!(f, "SIGTERM"),
            UnitTerminateSignal::Hangup => write!(f, "SIGHUP"),
            UnitTerminateSignal::Quit => write!(f, "SIGQUIT"),
            UnitTerminateSignal::Kill => write!(f, "SIGKILL"),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_is_success() {
        assert_eq!(
            RunStats::default().summarize_final(),
            FinalRunStats::NoTestsRun,
            "empty run => no tests run"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 42,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Success,
            "initial run count = final run count => success"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 41,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Cancelled {
                reason: None,
                kind: RunStatsFailureKind::Test {
                    initial_run_count: 42,
                    not_run: 1
                }
            },
            "initial run count > final run count => cancelled"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 42,
                failed: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::Test {
                initial_run_count: 42,
                not_run: 0
            }),
            "failed => failure"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 42,
                exec_failed: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::Test {
                initial_run_count: 42,
                not_run: 0
            }),
            "exec failed => failure"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 42,
                timed_out: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::Test {
                initial_run_count: 42,
                not_run: 0
            }),
            "timed out => failure"
        );
        assert_eq!(
            RunStats {
                initial_run_count: 42,
                finished_count: 42,
                skipped: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Success,
            "skipped => not considered a failure"
        );

        assert_eq!(
            RunStats {
                setup_scripts_initial_count: 2,
                setup_scripts_finished_count: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Cancelled {
                reason: None,
                kind: RunStatsFailureKind::SetupScript,
            },
            "setup script failed => failure"
        );

        assert_eq!(
            RunStats {
                setup_scripts_initial_count: 2,
                setup_scripts_finished_count: 2,
                setup_scripts_failed: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::SetupScript),
            "setup script failed => failure"
        );
        assert_eq!(
            RunStats {
                setup_scripts_initial_count: 2,
                setup_scripts_finished_count: 2,
                setup_scripts_exec_failed: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::SetupScript),
            "setup script exec failed => failure"
        );
        assert_eq!(
            RunStats {
                setup_scripts_initial_count: 2,
                setup_scripts_finished_count: 2,
                setup_scripts_timed_out: 1,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::Failed(RunStatsFailureKind::SetupScript),
            "setup script timed out => failure"
        );
        assert_eq!(
            RunStats {
                setup_scripts_initial_count: 2,
                setup_scripts_finished_count: 2,
                setup_scripts_passed: 2,
                ..RunStats::default()
            }
            .summarize_final(),
            FinalRunStats::NoTestsRun,
            "setup scripts passed => success, but no tests run"
        );
    }
}