perfgate_export/

lib.rs

//! Export formats for perfgate benchmarks.
//!
//! This crate provides functionality for exporting run and compare receipts
//! to various formats suitable for trend analysis and time-series ingestion.
//!
//! # Supported Formats
//!
//! - **CSV**: RFC 4180 compliant CSV with header row
//! - **JSONL**: JSON Lines format (one JSON object per line)
//! - **HTML**: HTML summary table
//! - **Prometheus**: Prometheus text exposition format
//!
//! # Example
//!
//! ```
//! use perfgate_export::{ExportFormat, ExportUseCase};
//! use perfgate_types::*;
//! use std::collections::BTreeMap;
//!
//! let receipt = RunReceipt {
//!     schema: RUN_SCHEMA_V1.to_string(),
//!     tool: ToolInfo { name: "perfgate".into(), version: "0.1.0".into() },
//!     run: RunMeta {
//!         id: "r1".into(),
//!         started_at: "2024-01-01T00:00:00Z".into(),
//!         ended_at: "2024-01-01T00:00:01Z".into(),
//!         host: HostInfo { os: "linux".into(), arch: "x86_64".into(),
//!             cpu_count: None, memory_bytes: None, hostname_hash: None },
//!     },
//!     bench: BenchMeta {
//!         name: "bench".into(), cwd: None,
//!         command: vec!["echo".into()], repeat: 1, warmup: 0,
//!         work_units: None, timeout_ms: None,
//!     },
//!     samples: vec![Sample {
//!         wall_ms: 42, exit_code: 0, warmup: false, timed_out: false,
//!         cpu_ms: None, page_faults: None, ctx_switches: None,
//!         max_rss_kb: None, binary_bytes: None, stdout: None, stderr: None,
//!     }],
//!     stats: Stats {
//!         wall_ms: U64Summary { median: 42, min: 42, max: 42 },
//!         cpu_ms: None, page_faults: None, ctx_switches: None,
//!         max_rss_kb: None, binary_bytes: None, throughput_per_s: None,
//!     },
//! };
//!
//! // Export a run receipt to CSV
//! let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
//! assert!(csv.contains("bench"));
//! ```

use perfgate_types::{CompareReceipt, Metric, MetricStatus, RunReceipt};

/// Supported export formats.
///
/// # Examples
///
/// ```
/// use perfgate_export::ExportFormat;
///
/// let fmt = ExportFormat::Csv;
/// assert_eq!(ExportFormat::parse("csv"), Some(fmt));
/// assert_eq!(ExportFormat::parse("unknown"), None);
/// ```
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ExportFormat {
    /// RFC 4180 compliant CSV with header row.
    Csv,
    /// JSON Lines format (one JSON object per line).
    Jsonl,
    /// HTML summary table.
    Html,
    /// Prometheus text exposition format.
    Prometheus,
}

impl ExportFormat {
    /// Parse format from string.
    ///
    /// ```
    /// use perfgate_export::ExportFormat;
    ///
    /// assert_eq!(ExportFormat::parse("csv"), Some(ExportFormat::Csv));
    /// assert_eq!(ExportFormat::parse("jsonl"), Some(ExportFormat::Jsonl));
    /// assert_eq!(ExportFormat::parse("prometheus"), Some(ExportFormat::Prometheus));
    /// assert_eq!(ExportFormat::parse("unknown"), None);
    /// ```
    pub fn parse(s: &str) -> Option<Self> {
        s.parse().ok()
    }
}

impl std::str::FromStr for ExportFormat {
    type Err = ();

    /// Parse an [`ExportFormat`] from a string.
    ///
    /// # Examples
    ///
    /// ```
    /// use perfgate_export::ExportFormat;
    ///
    /// let fmt: ExportFormat = "jsonl".parse().unwrap();
    /// assert_eq!(fmt, ExportFormat::Jsonl);
    ///
    /// let bad: Result<ExportFormat, _> = "nope".parse();
    /// assert!(bad.is_err());
    /// ```
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s.to_lowercase().as_str() {
            "csv" => Ok(ExportFormat::Csv),
            "jsonl" => Ok(ExportFormat::Jsonl),
            "html" => Ok(ExportFormat::Html),
            "prometheus" | "prom" => Ok(ExportFormat::Prometheus),
            _ => Err(()),
        }
    }
}

/// Row structure for RunReceipt export.
///
/// # Examples
///
/// ```
/// use perfgate_export::RunExportRow;
///
/// let row = RunExportRow {
///     bench_name: "my-bench".into(),
///     wall_ms_median: 42,
///     wall_ms_min: 40,
///     wall_ms_max: 44,
///     binary_bytes_median: None,
///     cpu_ms_median: Some(20),
///     ctx_switches_median: None,
///     max_rss_kb_median: None,
///     page_faults_median: None,
///     throughput_median: None,
///     sample_count: 5,
///     timestamp: "2024-01-01T00:00:00Z".into(),
/// };
/// assert_eq!(row.bench_name, "my-bench");
/// assert_eq!(row.sample_count, 5);
/// ```
#[derive(Debug, Clone, serde::Serialize)]
pub struct RunExportRow {
    pub bench_name: String,
    pub wall_ms_median: u64,
    pub wall_ms_min: u64,
    pub wall_ms_max: u64,
    pub binary_bytes_median: Option<u64>,
    pub cpu_ms_median: Option<u64>,
    pub ctx_switches_median: Option<u64>,
    pub max_rss_kb_median: Option<u64>,
    pub page_faults_median: Option<u64>,
    pub throughput_median: Option<f64>,
    pub sample_count: usize,
    pub timestamp: String,
}

/// Row structure for CompareReceipt export.
///
/// # Examples
///
/// ```
/// use perfgate_export::CompareExportRow;
///
/// let row = CompareExportRow {
///     bench_name: "my-bench".into(),
///     metric: "wall_ms".into(),
///     baseline_value: 100.0,
///     current_value: 110.0,
///     regression_pct: 10.0,
///     status: "pass".into(),
///     threshold: 20.0,
/// };
/// assert_eq!(row.metric, "wall_ms");
/// assert_eq!(row.status, "pass");
/// ```
#[derive(Debug, Clone, serde::Serialize)]
pub struct CompareExportRow {
    pub bench_name: String,
    pub metric: String,
    pub baseline_value: f64,
    pub current_value: f64,
    pub regression_pct: f64,
    pub status: String,
    pub threshold: f64,
}

/// Use case for exporting receipts to different formats.
pub struct ExportUseCase;

impl ExportUseCase {
    /// Export a [`RunReceipt`] to the specified format.
    ///
    /// ```
    /// # use std::collections::BTreeMap;
    /// # use perfgate_types::*;
    /// # use perfgate_export::{ExportFormat, ExportUseCase};
    /// let receipt = RunReceipt {
    ///     schema: RUN_SCHEMA_V1.to_string(),
    ///     tool: ToolInfo { name: "perfgate".into(), version: "0.1.0".into() },
    ///     run: RunMeta {
    ///         id: "r1".into(),
    ///         started_at: "2024-01-01T00:00:00Z".into(),
    ///         ended_at: "2024-01-01T00:00:01Z".into(),
    ///         host: HostInfo { os: "linux".into(), arch: "x86_64".into(),
    ///             cpu_count: None, memory_bytes: None, hostname_hash: None },
    ///     },
    ///     bench: BenchMeta {
    ///         name: "bench".into(), cwd: None,
    ///         command: vec!["echo".into()], repeat: 1, warmup: 0,
    ///         work_units: None, timeout_ms: None,
    ///     },
    ///     samples: vec![Sample {
    ///         wall_ms: 42, exit_code: 0, warmup: false, timed_out: false,
    ///         cpu_ms: None, page_faults: None, ctx_switches: None,
    ///         max_rss_kb: None, binary_bytes: None, stdout: None, stderr: None,
    ///     }],
    ///     stats: Stats {
    ///         wall_ms: U64Summary { median: 42, min: 42, max: 42 },
    ///         cpu_ms: None, page_faults: None, ctx_switches: None,
    ///         max_rss_kb: None, binary_bytes: None, throughput_per_s: None,
    ///     },
    /// };
    /// let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
    /// assert!(csv.contains("bench"));
    /// assert!(csv.contains("42"));
    /// ```
    pub fn export_run(receipt: &RunReceipt, format: ExportFormat) -> anyhow::Result<String> {
        let row = Self::run_to_row(receipt);

        match format {
            ExportFormat::Csv => Self::run_row_to_csv(&row),
            ExportFormat::Jsonl => Self::run_row_to_jsonl(&row),
            ExportFormat::Html => Self::run_row_to_html(&row),
            ExportFormat::Prometheus => Self::run_row_to_prometheus(&row),
        }
    }

    /// Export a [`CompareReceipt`] to the specified format.
    ///
    /// ```
    /// # use std::collections::BTreeMap;
    /// # use perfgate_types::*;
    /// # use perfgate_export::{ExportFormat, ExportUseCase};
    /// let receipt = CompareReceipt {
    ///     schema: COMPARE_SCHEMA_V1.to_string(),
    ///     tool: ToolInfo { name: "perfgate".into(), version: "0.1.0".into() },
    ///     bench: BenchMeta {
    ///         name: "bench".into(), cwd: None,
    ///         command: vec!["echo".into()], repeat: 1, warmup: 0,
    ///         work_units: None, timeout_ms: None,
    ///     },
    ///     baseline_ref: CompareRef { path: None, run_id: None },
    ///     current_ref: CompareRef { path: None, run_id: None },
    ///     budgets: BTreeMap::new(),
    ///     deltas: BTreeMap::from([(Metric::WallMs, Delta {
    ///         baseline: 100.0, current: 105.0, ratio: 1.05, pct: 0.05,
    ///         regression: 0.05, statistic: MetricStatistic::Median,
    ///         significance: None, status: MetricStatus::Pass,
    ///     })]),
    ///     verdict: Verdict {
    ///         status: VerdictStatus::Pass,
    ///         counts: VerdictCounts { pass: 1, warn: 0, fail: 0 },
    ///         reasons: vec![],
    ///     },
    /// };
    /// let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();
    /// assert!(csv.contains("wall_ms"));
    /// assert!(csv.contains("100"));
    /// ```
    pub fn export_compare(
        receipt: &CompareReceipt,
        format: ExportFormat,
    ) -> anyhow::Result<String> {
        let rows = Self::compare_to_rows(receipt);

        match format {
            ExportFormat::Csv => Self::compare_rows_to_csv(&rows),
            ExportFormat::Jsonl => Self::compare_rows_to_jsonl(&rows),
            ExportFormat::Html => Self::compare_rows_to_html(&rows),
            ExportFormat::Prometheus => Self::compare_rows_to_prometheus(&rows),
        }
    }

    /// Convert RunReceipt to exportable row.
    fn run_to_row(receipt: &RunReceipt) -> RunExportRow {
        let sample_count = receipt.samples.iter().filter(|s| !s.warmup).count();

        RunExportRow {
            bench_name: receipt.bench.name.clone(),
            wall_ms_median: receipt.stats.wall_ms.median,
            wall_ms_min: receipt.stats.wall_ms.min,
            wall_ms_max: receipt.stats.wall_ms.max,
            binary_bytes_median: receipt.stats.binary_bytes.as_ref().map(|s| s.median),
            cpu_ms_median: receipt.stats.cpu_ms.as_ref().map(|s| s.median),
            ctx_switches_median: receipt.stats.ctx_switches.as_ref().map(|s| s.median),
            max_rss_kb_median: receipt.stats.max_rss_kb.as_ref().map(|s| s.median),
            page_faults_median: receipt.stats.page_faults.as_ref().map(|s| s.median),
            throughput_median: receipt.stats.throughput_per_s.as_ref().map(|s| s.median),
            sample_count,
            timestamp: receipt.run.started_at.clone(),
        }
    }

    /// Convert CompareReceipt to exportable rows (one per metric, sorted by metric name).
    fn compare_to_rows(receipt: &CompareReceipt) -> Vec<CompareExportRow> {
        let mut rows: Vec<CompareExportRow> = receipt
            .deltas
            .iter()
            .map(|(metric, delta)| {
                let threshold = receipt
                    .budgets
                    .get(metric)
                    .map(|b| b.threshold)
                    .unwrap_or(0.0);

                CompareExportRow {
                    bench_name: receipt.bench.name.clone(),
                    metric: metric_to_string(*metric),
                    baseline_value: delta.baseline,
                    current_value: delta.current,
                    regression_pct: delta.pct * 100.0,
                    status: status_to_string(delta.status),
                    threshold: threshold * 100.0,
                }
            })
            .collect();

        rows.sort_by(|a, b| a.metric.cmp(&b.metric));
        rows
    }

    /// Format RunExportRow as CSV (RFC 4180).
    fn run_row_to_csv(row: &RunExportRow) -> anyhow::Result<String> {
        let mut output = String::new();

        output.push_str("bench_name,wall_ms_median,wall_ms_min,wall_ms_max,binary_bytes_median,cpu_ms_median,ctx_switches_median,max_rss_kb_median,page_faults_median,throughput_median,sample_count,timestamp\n");

        output.push_str(&csv_escape(&row.bench_name));
        output.push(',');
        output.push_str(&row.wall_ms_median.to_string());
        output.push(',');
        output.push_str(&row.wall_ms_min.to_string());
        output.push(',');
        output.push_str(&row.wall_ms_max.to_string());
        output.push(',');
        output.push_str(
            &row.binary_bytes_median
                .map_or(String::new(), |v| v.to_string()),
        );
        output.push(',');
        output.push_str(&row.cpu_ms_median.map_or(String::new(), |v| v.to_string()));
        output.push(',');
        output.push_str(
            &row.ctx_switches_median
                .map_or(String::new(), |v| v.to_string()),
        );
        output.push(',');
        output.push_str(
            &row.max_rss_kb_median
                .map_or(String::new(), |v| v.to_string()),
        );
        output.push(',');
        output.push_str(
            &row.page_faults_median
                .map_or(String::new(), |v| v.to_string()),
        );
        output.push(',');
        output.push_str(
            &row.throughput_median
                .map_or(String::new(), |v| format!("{:.6}", v)),
        );
        output.push(',');
        output.push_str(&row.sample_count.to_string());
        output.push(',');
        output.push_str(&csv_escape(&row.timestamp));
        output.push('\n');

        Ok(output)
    }

    /// Format RunExportRow as JSONL.
    fn run_row_to_jsonl(row: &RunExportRow) -> anyhow::Result<String> {
        let json = serde_json::to_string(row)?;
        Ok(format!("{}\n", json))
    }

    /// Format CompareExportRows as CSV (RFC 4180).
    fn compare_rows_to_csv(rows: &[CompareExportRow]) -> anyhow::Result<String> {
        let mut output = String::new();

        output.push_str(
            "bench_name,metric,baseline_value,current_value,regression_pct,status,threshold\n",
        );

        for row in rows {
            output.push_str(&csv_escape(&row.bench_name));
            output.push(',');
            output.push_str(&csv_escape(&row.metric));
            output.push(',');
            output.push_str(&format!("{:.6}", row.baseline_value));
            output.push(',');
            output.push_str(&format!("{:.6}", row.current_value));
            output.push(',');
            output.push_str(&format!("{:.6}", row.regression_pct));
            output.push(',');
            output.push_str(&csv_escape(&row.status));
            output.push(',');
            output.push_str(&format!("{:.6}", row.threshold));
            output.push('\n');
        }

        Ok(output)
    }

    /// Format CompareExportRows as JSONL.
    fn compare_rows_to_jsonl(rows: &[CompareExportRow]) -> anyhow::Result<String> {
        let mut output = String::new();

        for row in rows {
            let json = serde_json::to_string(row)?;
            output.push_str(&json);
            output.push('\n');
        }

        Ok(output)
    }

    fn run_row_to_html(row: &RunExportRow) -> anyhow::Result<String> {
        let html = format!(
            "<!doctype html><html><head><meta charset=\"utf-8\"><title>perfgate run export</title></head><body>\
             <h1>perfgate run export</h1>\
             <table border=\"1\">\
             <thead><tr><th>bench_name</th><th>wall_ms_median</th><th>wall_ms_min</th><th>wall_ms_max</th><th>binary_bytes_median</th><th>cpu_ms_median</th><th>ctx_switches_median</th><th>max_rss_kb_median</th><th>page_faults_median</th><th>throughput_median</th><th>sample_count</th><th>timestamp</th></tr></thead>\
             <tbody><tr><td>{bench}</td><td>{wall_med}</td><td>{wall_min}</td><td>{wall_max}</td><td>{binary}</td><td>{cpu}</td><td>{ctx}</td><td>{rss}</td><td>{pf}</td><td>{throughput}</td><td>{sample_count}</td><td>{timestamp}</td></tr></tbody>\
             </table></body></html>\n",
            bench = html_escape(&row.bench_name),
            wall_med = row.wall_ms_median,
            wall_min = row.wall_ms_min,
            wall_max = row.wall_ms_max,
            binary = row
                .binary_bytes_median
                .map_or(String::new(), |v| v.to_string()),
            cpu = row.cpu_ms_median.map_or(String::new(), |v| v.to_string()),
            ctx = row
                .ctx_switches_median
                .map_or(String::new(), |v| v.to_string()),
            rss = row
                .max_rss_kb_median
                .map_or(String::new(), |v| v.to_string()),
            pf = row
                .page_faults_median
                .map_or(String::new(), |v| v.to_string()),
            throughput = row
                .throughput_median
                .map_or(String::new(), |v| format!("{:.6}", v)),
            sample_count = row.sample_count,
            timestamp = html_escape(&row.timestamp),
        );
        Ok(html)
    }

    fn compare_rows_to_html(rows: &[CompareExportRow]) -> anyhow::Result<String> {
        let mut out = String::from(
            "<!doctype html><html><head><meta charset=\"utf-8\"><title>perfgate compare export</title></head><body><h1>perfgate compare export</h1><table border=\"1\"><thead><tr><th>bench_name</th><th>metric</th><th>baseline_value</th><th>current_value</th><th>regression_pct</th><th>status</th><th>threshold</th></tr></thead><tbody>",
        );

        for row in rows {
            out.push_str(&format!(
                "<tr><td>{}</td><td>{}</td><td>{:.6}</td><td>{:.6}</td><td>{:.6}</td><td>{}</td><td>{:.6}</td></tr>",
                html_escape(&row.bench_name),
                html_escape(&row.metric),
                row.baseline_value,
                row.current_value,
                row.regression_pct,
                html_escape(&row.status),
                row.threshold
            ));
        }

        out.push_str("</tbody></table></body></html>\n");
        Ok(out)
    }

    fn run_row_to_prometheus(row: &RunExportRow) -> anyhow::Result<String> {
        let bench = prometheus_escape_label_value(&row.bench_name);
        let mut out = String::new();
        out.push_str(&format!(
            "perfgate_run_wall_ms_median{{bench=\"{}\"}} {}\n",
            bench, row.wall_ms_median
        ));
        out.push_str(&format!(
            "perfgate_run_wall_ms_min{{bench=\"{}\"}} {}\n",
            bench, row.wall_ms_min
        ));
        out.push_str(&format!(
            "perfgate_run_wall_ms_max{{bench=\"{}\"}} {}\n",
            bench, row.wall_ms_max
        ));
        if let Some(v) = row.binary_bytes_median {
            out.push_str(&format!(
                "perfgate_run_binary_bytes_median{{bench=\"{}\"}} {}\n",
                bench, v
            ));
        }
        if let Some(v) = row.cpu_ms_median {
            out.push_str(&format!(
                "perfgate_run_cpu_ms_median{{bench=\"{}\"}} {}\n",
                bench, v
            ));
        }
        if let Some(v) = row.ctx_switches_median {
            out.push_str(&format!(
                "perfgate_run_ctx_switches_median{{bench=\"{}\"}} {}\n",
                bench, v
            ));
        }
        if let Some(v) = row.max_rss_kb_median {
            out.push_str(&format!(
                "perfgate_run_max_rss_kb_median{{bench=\"{}\"}} {}\n",
                bench, v
            ));
        }
        if let Some(v) = row.page_faults_median {
            out.push_str(&format!(
                "perfgate_run_page_faults_median{{bench=\"{}\"}} {}\n",
                bench, v
            ));
        }
        if let Some(v) = row.throughput_median {
            out.push_str(&format!(
                "perfgate_run_throughput_per_s_median{{bench=\"{}\"}} {:.6}\n",
                bench, v
            ));
        }
        out.push_str(&format!(
            "perfgate_run_sample_count{{bench=\"{}\"}} {}\n",
            bench, row.sample_count
        ));
        Ok(out)
    }

    fn compare_rows_to_prometheus(rows: &[CompareExportRow]) -> anyhow::Result<String> {
        let mut out = String::new();
        for row in rows {
            let bench = prometheus_escape_label_value(&row.bench_name);
            let metric = prometheus_escape_label_value(&row.metric);
            out.push_str(&format!(
                "perfgate_compare_baseline_value{{bench=\"{}\",metric=\"{}\"}} {:.6}\n",
                bench, metric, row.baseline_value
            ));
            out.push_str(&format!(
                "perfgate_compare_current_value{{bench=\"{}\",metric=\"{}\"}} {:.6}\n",
                bench, metric, row.current_value
            ));
            out.push_str(&format!(
                "perfgate_compare_regression_pct{{bench=\"{}\",metric=\"{}\"}} {:.6}\n",
                bench, metric, row.regression_pct
            ));
            out.push_str(&format!(
                "perfgate_compare_threshold_pct{{bench=\"{}\",metric=\"{}\"}} {:.6}\n",
                bench, metric, row.threshold
            ));

            let status_code = match row.status.as_str() {
                "pass" => 0,
                "warn" => 1,
                "fail" => 2,
                _ => -1,
            };
            out.push_str(&format!(
                "perfgate_compare_status{{bench=\"{}\",metric=\"{}\",status=\"{}\"}} {}\n",
                bench,
                metric,
                prometheus_escape_label_value(&row.status),
                status_code
            ));
        }
        Ok(out)
    }
}

/// Convert Metric enum to snake_case string.
fn metric_to_string(metric: Metric) -> String {
    metric.as_str().to_string()
}

/// Convert MetricStatus enum to lowercase string.
fn status_to_string(status: MetricStatus) -> String {
    match status {
        MetricStatus::Pass => "pass".to_string(),
        MetricStatus::Warn => "warn".to_string(),
        MetricStatus::Fail => "fail".to_string(),
    }
}

/// Escape a string for CSV per RFC 4180.
/// If the string contains comma, double quote, or newline, wrap in quotes and escape quotes.
///
/// # Examples
///
/// ```
/// use perfgate_export::csv_escape;
///
/// assert_eq!(csv_escape("hello"), "hello");
/// assert_eq!(csv_escape("has,comma"), "\"has,comma\"");
/// assert_eq!(csv_escape("has\"quote"), "\"has\"\"quote\"");
/// ```
pub fn csv_escape(s: &str) -> String {
    if s.contains(',') || s.contains('"') || s.contains('\n') || s.contains('\r') {
        format!("\"{}\"", s.replace('"', "\"\""))
    } else {
        s.to_string()
    }
}

fn html_escape(s: &str) -> String {
    s.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
}

fn prometheus_escape_label_value(s: &str) -> String {
    s.replace('\\', "\\\\").replace('"', "\\\"")
}

#[cfg(test)]
mod tests {
    use super::*;
    use perfgate_types::{
        BenchMeta, Budget, COMPARE_SCHEMA_V1, CompareRef, Delta, Direction, F64Summary, HostInfo,
        Metric, MetricStatistic, MetricStatus, RUN_SCHEMA_V1, RunMeta, Sample, Stats, ToolInfo,
        U64Summary, Verdict, VerdictCounts, VerdictStatus,
    };
    use std::collections::BTreeMap;

    fn create_test_run_receipt() -> RunReceipt {
        RunReceipt {
            schema: RUN_SCHEMA_V1.to_string(),
            tool: ToolInfo {
                name: "perfgate".to_string(),
                version: "0.1.0".to_string(),
            },
            run: RunMeta {
                id: "test-run-001".to_string(),
                started_at: "2024-01-15T10:00:00Z".to_string(),
                ended_at: "2024-01-15T10:00:05Z".to_string(),
                host: HostInfo {
                    os: "linux".to_string(),
                    arch: "x86_64".to_string(),
                    cpu_count: None,
                    memory_bytes: None,
                    hostname_hash: None,
                },
            },
            bench: BenchMeta {
                name: "test-benchmark".to_string(),
                cwd: None,
                command: vec!["echo".to_string(), "hello".to_string()],
                repeat: 5,
                warmup: 0,
                work_units: None,
                timeout_ms: None,
            },
            samples: vec![
                Sample {
                    wall_ms: 100,
                    exit_code: 0,
                    warmup: false,
                    timed_out: false,
                    cpu_ms: Some(50),
                    page_faults: None,
                    ctx_switches: None,
                    max_rss_kb: Some(1024),
                    binary_bytes: None,
                    stdout: None,
                    stderr: None,
                },
                Sample {
                    wall_ms: 102,
                    exit_code: 0,
                    warmup: false,
                    timed_out: false,
                    cpu_ms: Some(52),
                    page_faults: None,
                    ctx_switches: None,
                    max_rss_kb: Some(1028),
                    binary_bytes: None,
                    stdout: None,
                    stderr: None,
                },
            ],
            stats: Stats {
                wall_ms: U64Summary {
                    median: 100,
                    min: 98,
                    max: 102,
                },
                cpu_ms: Some(U64Summary {
                    median: 50,
                    min: 48,
                    max: 52,
                }),
                page_faults: None,
                ctx_switches: None,
                max_rss_kb: Some(U64Summary {
                    median: 1024,
                    min: 1020,
                    max: 1028,
                }),
                binary_bytes: None,
                throughput_per_s: None,
            },
        }
    }

    fn create_test_compare_receipt() -> CompareReceipt {
        let mut budgets = BTreeMap::new();
        budgets.insert(
            Metric::WallMs,
            Budget {
                threshold: 0.2,
                warn_threshold: 0.18,
                direction: Direction::Lower,
            },
        );
        budgets.insert(
            Metric::MaxRssKb,
            Budget {
                threshold: 0.15,
                warn_threshold: 0.135,
                direction: Direction::Lower,
            },
        );

        let mut deltas = BTreeMap::new();
        deltas.insert(
            Metric::WallMs,
            Delta {
                baseline: 100.0,
                current: 110.0,
                ratio: 1.1,
                pct: 0.1,
                regression: 0.1,
                statistic: MetricStatistic::Median,
                significance: None,
                status: MetricStatus::Pass,
            },
        );
        deltas.insert(
            Metric::MaxRssKb,
            Delta {
                baseline: 1024.0,
                current: 1280.0,
                ratio: 1.25,
                pct: 0.25,
                regression: 0.25,
                statistic: MetricStatistic::Median,
                significance: None,
                status: MetricStatus::Fail,
            },
        );

        CompareReceipt {
            schema: COMPARE_SCHEMA_V1.to_string(),
            tool: ToolInfo {
                name: "perfgate".to_string(),
                version: "0.1.0".to_string(),
            },
            bench: BenchMeta {
                name: "alpha-bench".to_string(),
                cwd: None,
                command: vec!["test".to_string()],
                repeat: 5,
                warmup: 0,
                work_units: None,
                timeout_ms: None,
            },
            baseline_ref: CompareRef {
                path: Some("baseline.json".to_string()),
                run_id: Some("baseline-001".to_string()),
            },
            current_ref: CompareRef {
                path: Some("current.json".to_string()),
                run_id: Some("current-001".to_string()),
            },
            budgets,
            deltas,
            verdict: Verdict {
                status: VerdictStatus::Fail,
                counts: VerdictCounts {
                    pass: 1,
                    warn: 0,
                    fail: 1,
                },
                reasons: vec!["max_rss_kb_fail".to_string()],
            },
        }
    }

    #[test]
    fn test_run_export_csv() {
        let receipt = create_test_run_receipt();
        let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();

        assert!(csv.starts_with("bench_name,wall_ms_median,"));
        assert!(csv.contains("test-benchmark"));
        assert!(csv.contains("100,98,102"));
        assert!(csv.contains("1024"));
        assert!(csv.contains("2024-01-15T10:00:00Z"));
    }

    #[test]
    fn test_run_export_jsonl() {
        let receipt = create_test_run_receipt();
        let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();

        let lines: Vec<&str> = jsonl.trim().split('\n').collect();
        assert_eq!(lines.len(), 1);

        let parsed: serde_json::Value = serde_json::from_str(lines[0]).unwrap();
        assert_eq!(parsed["bench_name"], "test-benchmark");
        assert_eq!(parsed["wall_ms_median"], 100);
    }

    #[test]
    fn test_compare_export_csv() {
        let receipt = create_test_compare_receipt();
        let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();

        assert!(csv.starts_with("bench_name,metric,baseline_value,"));
        assert!(csv.contains("alpha-bench"));
        assert!(csv.contains("max_rss_kb"));
        assert!(csv.contains("wall_ms"));
        let max_rss_pos = csv.find("max_rss_kb").unwrap();
        let wall_ms_pos = csv.find("wall_ms").unwrap();
        assert!(max_rss_pos < wall_ms_pos);
    }

    #[test]
    fn test_compare_export_jsonl() {
        let receipt = create_test_compare_receipt();
        let jsonl = ExportUseCase::export_compare(&receipt, ExportFormat::Jsonl).unwrap();

        let lines: Vec<&str> = jsonl.trim().split('\n').collect();
        assert_eq!(lines.len(), 2);

        for line in &lines {
            let _: serde_json::Value = serde_json::from_str(line).unwrap();
        }

        let first: serde_json::Value = serde_json::from_str(lines[0]).unwrap();
        assert_eq!(first["metric"], "max_rss_kb");
    }

    #[test]
    fn test_csv_escape() {
        assert_eq!(csv_escape("simple"), "simple");
        assert_eq!(csv_escape("has,comma"), "\"has,comma\"");
        assert_eq!(csv_escape("has\"quote"), "\"has\"\"quote\"");
        assert_eq!(csv_escape("has\nnewline"), "\"has\nnewline\"");
    }

    #[test]
    fn test_stable_ordering_across_runs() {
        let receipt = create_test_compare_receipt();

        let csv1 = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();
        let csv2 = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();

        assert_eq!(csv1, csv2, "CSV output should be deterministic");
    }

    #[test]
    fn test_export_format_from_str() {
        assert_eq!(ExportFormat::parse("csv"), Some(ExportFormat::Csv));
        assert_eq!(ExportFormat::parse("CSV"), Some(ExportFormat::Csv));
        assert_eq!(ExportFormat::parse("jsonl"), Some(ExportFormat::Jsonl));
        assert_eq!(ExportFormat::parse("JSONL"), Some(ExportFormat::Jsonl));
        assert_eq!(ExportFormat::parse("html"), Some(ExportFormat::Html));
        assert_eq!(
            ExportFormat::parse("prometheus"),
            Some(ExportFormat::Prometheus)
        );
        assert_eq!(ExportFormat::parse("invalid"), None);
    }

    #[test]
    fn test_run_export_html_and_prometheus() {
        let receipt = create_test_run_receipt();

        let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
        assert!(html.contains("<table"), "html output should contain table");
        assert!(html.contains("test-benchmark"));

        let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
        assert!(prom.contains("perfgate_run_wall_ms_median"));
        assert!(prom.contains("bench=\"test-benchmark\""));
    }

    #[test]
    fn test_compare_export_html_and_prometheus() {
        let receipt = create_test_compare_receipt();

        let html = ExportUseCase::export_compare(&receipt, ExportFormat::Html).unwrap();
        assert!(html.contains("<table"), "html output should contain table");
        assert!(html.contains("max_rss_kb"));

        let prom = ExportUseCase::export_compare(&receipt, ExportFormat::Prometheus).unwrap();
        assert!(prom.contains("perfgate_compare_regression_pct"));
        assert!(prom.contains("metric=\"max_rss_kb\""));
    }

    #[test]
    fn test_html_escape() {
        assert_eq!(html_escape("simple"), "simple");
        assert_eq!(html_escape("<script>"), "&lt;script&gt;");
        assert_eq!(html_escape("a&b"), "a&amp;b");
        assert_eq!(html_escape("\"quoted\""), "&quot;quoted&quot;");
    }

    #[test]
    fn test_prometheus_escape() {
        assert_eq!(prometheus_escape_label_value("simple"), "simple");
        assert_eq!(prometheus_escape_label_value("has\"quote"), "has\\\"quote");
        assert_eq!(
            prometheus_escape_label_value("has\\backslash"),
            "has\\\\backslash"
        );
    }

    mod snapshot_tests {
        use super::*;
        use insta::assert_snapshot;

        #[test]
        fn test_run_html_snapshot() {
            let receipt = create_test_run_receipt();
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert_snapshot!("run_html", html);
        }

        #[test]
        fn test_run_prometheus_snapshot() {
            let receipt = create_test_run_receipt();
            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert_snapshot!("run_prometheus", prom);
        }

        #[test]
        fn test_compare_html_snapshot() {
            let receipt = create_test_compare_receipt();
            let html = ExportUseCase::export_compare(&receipt, ExportFormat::Html).unwrap();
            assert_snapshot!("compare_html", html);
        }

        #[test]
        fn test_compare_prometheus_snapshot() {
            let receipt = create_test_compare_receipt();
            let prom = ExportUseCase::export_compare(&receipt, ExportFormat::Prometheus).unwrap();
            assert_snapshot!("compare_prometheus", prom);
        }
    }

    mod edge_case_tests {
        use super::*;

        fn create_empty_run_receipt() -> RunReceipt {
            RunReceipt {
                schema: RUN_SCHEMA_V1.to_string(),
                tool: ToolInfo {
                    name: "perfgate".to_string(),
                    version: "0.1.0".to_string(),
                },
                run: RunMeta {
                    id: "empty-run".to_string(),
                    started_at: "2024-01-01T00:00:00Z".to_string(),
                    ended_at: "2024-01-01T00:00:01Z".to_string(),
                    host: HostInfo {
                        os: "linux".to_string(),
                        arch: "x86_64".to_string(),
                        cpu_count: None,
                        memory_bytes: None,
                        hostname_hash: None,
                    },
                },
                bench: BenchMeta {
                    name: "empty-bench".to_string(),
                    cwd: None,
                    command: vec!["true".to_string()],
                    repeat: 0,
                    warmup: 0,
                    work_units: None,
                    timeout_ms: None,
                },
                samples: vec![],
                stats: Stats {
                    wall_ms: U64Summary {
                        median: 0,
                        min: 0,
                        max: 0,
                    },
                    cpu_ms: None,
                    page_faults: None,
                    ctx_switches: None,
                    max_rss_kb: None,
                    binary_bytes: None,
                    throughput_per_s: None,
                },
            }
        }

        fn create_empty_compare_receipt() -> CompareReceipt {
            CompareReceipt {
                schema: COMPARE_SCHEMA_V1.to_string(),
                tool: ToolInfo {
                    name: "perfgate".to_string(),
                    version: "0.1.0".to_string(),
                },
                bench: BenchMeta {
                    name: "empty-bench".to_string(),
                    cwd: None,
                    command: vec!["true".to_string()],
                    repeat: 0,
                    warmup: 0,
                    work_units: None,
                    timeout_ms: None,
                },
                baseline_ref: CompareRef {
                    path: None,
                    run_id: None,
                },
                current_ref: CompareRef {
                    path: None,
                    run_id: None,
                },
                budgets: BTreeMap::new(),
                deltas: BTreeMap::new(),
                verdict: Verdict {
                    status: VerdictStatus::Pass,
                    counts: VerdictCounts {
                        pass: 0,
                        warn: 0,
                        fail: 0,
                    },
                    reasons: vec![],
                },
            }
        }

        fn create_run_receipt_with_bench_name(name: &str) -> RunReceipt {
            let mut receipt = create_empty_run_receipt();
            receipt.bench.name = name.to_string();
            receipt.samples.push(Sample {
                wall_ms: 42,
                exit_code: 0,
                warmup: false,
                timed_out: false,
                cpu_ms: None,
                page_faults: None,
                ctx_switches: None,
                max_rss_kb: None,
                binary_bytes: None,
                stdout: None,
                stderr: None,
            });
            receipt.stats.wall_ms = U64Summary {
                median: 42,
                min: 42,
                max: 42,
            };
            receipt
        }

        // --- Empty receipt tests ---

        #[test]
        fn empty_run_receipt_csv_has_header_and_one_row() {
            let receipt = create_empty_run_receipt();
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            let lines: Vec<&str> = csv.trim().split('\n').collect();
            assert_eq!(lines.len(), 2, "should have header + 1 data row");
            assert!(lines[0].starts_with("bench_name,"));
            assert!(csv.contains("empty-bench"));
        }

        #[test]
        fn empty_run_receipt_jsonl_is_valid() {
            let receipt = create_empty_run_receipt();
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["bench_name"], "empty-bench");
            assert_eq!(parsed["sample_count"], 0);
        }

        #[test]
        fn empty_run_receipt_html_is_valid() {
            let receipt = create_empty_run_receipt();
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.starts_with("<!doctype html>"));
            assert!(html.contains("<table"));
            assert!(html.contains("</table>"));
            assert!(html.contains("empty-bench"));
        }

        #[test]
        fn empty_run_receipt_prometheus_is_valid() {
            let receipt = create_empty_run_receipt();
            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("perfgate_run_wall_ms_median"));
            assert!(prom.contains("bench=\"empty-bench\""));
            assert!(prom.contains("perfgate_run_sample_count"));
        }

        #[test]
        fn empty_compare_receipt_csv_has_header_only() {
            let receipt = create_empty_compare_receipt();
            let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();
            let lines: Vec<&str> = csv.trim().split('\n').collect();
            assert_eq!(lines.len(), 1, "should have header only with no deltas");
            assert!(lines[0].starts_with("bench_name,metric,"));
        }

        #[test]
        fn empty_compare_receipt_jsonl_is_empty() {
            let receipt = create_empty_compare_receipt();
            let jsonl = ExportUseCase::export_compare(&receipt, ExportFormat::Jsonl).unwrap();
            assert!(
                jsonl.trim().is_empty(),
                "JSONL should be empty for no deltas"
            );
        }

        #[test]
        fn empty_compare_receipt_html_has_valid_structure() {
            let receipt = create_empty_compare_receipt();
            let html = ExportUseCase::export_compare(&receipt, ExportFormat::Html).unwrap();
            assert!(html.starts_with("<!doctype html>"));
            assert!(html.contains("<table"));
            assert!(html.contains("</table>"));
            assert!(html.contains("<thead>"));
            assert!(html.contains("</tbody>"));
        }

        #[test]
        fn empty_compare_receipt_prometheus_is_empty() {
            let receipt = create_empty_compare_receipt();
            let prom = ExportUseCase::export_compare(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(
                prom.trim().is_empty(),
                "Prometheus output should be empty for no deltas"
            );
        }

        // --- CSV special characters tests ---

        #[test]
        fn csv_bench_name_with_comma() {
            let receipt = create_run_receipt_with_bench_name("bench,with,commas");
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(
                csv.contains("\"bench,with,commas\""),
                "comma-containing bench name should be quoted"
            );
            let lines: Vec<&str> = csv.trim().split('\n').collect();
            assert_eq!(lines.len(), 2, "should still have exactly 2 lines");
        }

        #[test]
        fn csv_bench_name_with_quotes() {
            let receipt = create_run_receipt_with_bench_name("bench\"quoted\"name");
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(
                csv.contains("\"bench\"\"quoted\"\"name\""),
                "quotes should be escaped as double-quotes in CSV"
            );
        }

        #[test]
        fn csv_bench_name_with_newline() {
            let receipt = create_run_receipt_with_bench_name("bench\nwith\nnewlines");
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(
                csv.contains("\"bench\nwith\nnewlines\""),
                "newline-containing bench name should be quoted"
            );
        }

        #[test]
        fn csv_bench_name_with_commas_and_quotes() {
            let receipt = create_run_receipt_with_bench_name("a,\"b\",c");
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            // Must be properly escaped per RFC 4180
            assert!(csv.contains("\"a,\"\"b\"\",c\""));
        }

        // --- JSONL unicode tests ---

        #[test]
        fn jsonl_bench_name_with_unicode() {
            let receipt = create_run_receipt_with_bench_name("ベンチマーク-速度");
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["bench_name"], "ベンチマーク-速度");
        }

        #[test]
        fn jsonl_bench_name_with_emoji() {
            let receipt = create_run_receipt_with_bench_name("bench-🚀-fast");
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["bench_name"], "bench-🚀-fast");
        }

        #[test]
        fn jsonl_bench_name_with_special_json_chars() {
            let receipt = create_run_receipt_with_bench_name("bench\\with\"special\tchars");
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["bench_name"], "bench\\with\"special\tchars");
        }

        // --- HTML empty data tests ---

        #[test]
        fn html_run_with_all_optional_metrics_none() {
            let receipt = create_empty_run_receipt();
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains("<html>"));
            assert!(html.contains("</html>"));
            // Should not panic or error even with all None optional metrics
            assert!(html.contains("empty-bench"));
        }

        #[test]
        fn html_bench_name_with_html_chars() {
            let receipt = create_run_receipt_with_bench_name("<script>alert('xss')</script>");
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(
                !html.contains("<script>"),
                "HTML special chars should be escaped"
            );
            assert!(html.contains("&lt;script&gt;"));
        }

        // --- Prometheus metric name tests ---

        #[test]
        fn prometheus_bench_name_with_quotes() {
            let receipt = create_run_receipt_with_bench_name("bench\"name");
            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(
                prom.contains("bench="),
                "Prometheus output should have bench label"
            );
            assert!(
                !prom.contains("bench=\"bench\"name\""),
                "raw quotes should be escaped"
            );
            assert!(prom.contains("bench=\"bench\\\"name\""));
        }

        #[test]
        fn prometheus_bench_name_with_backslash() {
            let receipt = create_run_receipt_with_bench_name("bench\\path");
            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("bench=\"bench\\\\path\""));
        }

        #[test]
        fn prometheus_compare_with_all_metric_types() {
            let mut receipt = create_empty_compare_receipt();
            receipt.bench.name = "full-metrics".to_string();
            receipt.deltas.insert(
                Metric::WallMs,
                Delta {
                    baseline: 100.0,
                    current: 110.0,
                    ratio: 1.1,
                    pct: 0.1,
                    regression: 0.1,
                    statistic: MetricStatistic::Median,
                    significance: None,
                    status: MetricStatus::Pass,
                },
            );
            receipt.deltas.insert(
                Metric::MaxRssKb,
                Delta {
                    baseline: 1024.0,
                    current: 1024.0,
                    ratio: 1.0,
                    pct: 0.0,
                    regression: 0.0,
                    statistic: MetricStatistic::Median,
                    significance: None,
                    status: MetricStatus::Pass,
                },
            );
            let prom = ExportUseCase::export_compare(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("metric=\"wall_ms\""));
            assert!(prom.contains("metric=\"max_rss_kb\""));
            assert!(prom.contains("perfgate_compare_baseline_value"));
            assert!(prom.contains("perfgate_compare_current_value"));
            assert!(prom.contains("perfgate_compare_status"));
        }

        // --- Single-sample run receipt ---

        #[test]
        fn single_sample_run_exports_all_formats() {
            let receipt = create_run_receipt_with_bench_name("single");

            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(csv.contains("single"));
            assert_eq!(csv.trim().lines().count(), 2);

            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["sample_count"], 1);

            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains("<td>single</td>"));

            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("perfgate_run_sample_count{bench=\"single\"} 1"));
        }

        // --- Huge values ---

        #[test]
        fn huge_values_run_receipt() {
            let mut receipt = create_empty_run_receipt();
            receipt.bench.name = "huge".to_string();
            receipt.stats.wall_ms = U64Summary {
                median: u64::MAX,
                min: u64::MAX - 1,
                max: u64::MAX,
            };
            receipt.stats.max_rss_kb = Some(U64Summary {
                median: u64::MAX,
                min: u64::MAX,
                max: u64::MAX,
            });

            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(csv.contains(&u64::MAX.to_string()));

            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["wall_ms_median"], u64::MAX);

            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains(&u64::MAX.to_string()));

            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains(&u64::MAX.to_string()));
        }

        // --- Warmup-only samples yield sample_count == 0 ---

        #[test]
        fn warmup_only_samples_count_zero() {
            let mut receipt = create_empty_run_receipt();
            receipt.samples = vec![
                Sample {
                    wall_ms: 10,
                    exit_code: 0,
                    warmup: true,
                    timed_out: false,
                    cpu_ms: None,
                    page_faults: None,
                    ctx_switches: None,
                    max_rss_kb: None,
                    binary_bytes: None,
                    stdout: None,
                    stderr: None,
                },
                Sample {
                    wall_ms: 11,
                    exit_code: 0,
                    warmup: true,
                    timed_out: false,
                    cpu_ms: None,
                    page_faults: None,
                    ctx_switches: None,
                    max_rss_kb: None,
                    binary_bytes: None,
                    stdout: None,
                    stderr: None,
                },
            ];

            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["sample_count"], 0);

            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            // sample_count column is second-to-last; verify 0
            let data_line = csv.lines().nth(1).unwrap();
            assert!(
                data_line.contains(",0,"),
                "warmup-only should yield sample_count 0"
            );
        }

        // --- CSV with carriage return ---

        #[test]
        fn csv_bench_name_with_carriage_return() {
            let receipt = create_run_receipt_with_bench_name("bench\rwith\rcr");
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(
                csv.contains("\"bench\rwith\rcr\""),
                "carriage-return-containing bench name should be quoted"
            );
        }

        // --- CSV compare with special chars in bench name ---

        #[test]
        fn csv_compare_special_chars_in_bench_name() {
            let mut receipt = create_empty_compare_receipt();
            receipt.bench.name = "bench,\"special\"\nname".to_string();
            receipt.deltas.insert(
                Metric::WallMs,
                Delta {
                    baseline: 100.0,
                    current: 105.0,
                    ratio: 1.05,
                    pct: 0.05,
                    regression: 0.05,
                    statistic: MetricStatistic::Median,
                    significance: None,
                    status: MetricStatus::Pass,
                },
            );
            let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();
            // RFC 4180: commas/quotes/newlines inside must be quoted, quotes doubled
            assert!(csv.contains("\"bench,\"\"special\"\"\nname\""));
        }

        // --- Unicode bench name across all formats ---

        #[test]
        fn unicode_bench_name_all_formats() {
            let name = "日本語ベンチ_αβγ_🚀";
            let receipt = create_run_receipt_with_bench_name(name);

            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            assert!(csv.contains(name));

            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();
            assert_eq!(parsed["bench_name"], name);

            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains(name));

            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains(name));
        }

        // --- HTML compare with mixed statuses ---

        #[test]
        fn html_compare_mixed_statuses() {
            let mut receipt = create_empty_compare_receipt();
            receipt.bench.name = "mixed".to_string();
            for (metric, status) in [
                (Metric::WallMs, MetricStatus::Pass),
                (Metric::CpuMs, MetricStatus::Warn),
                (Metric::MaxRssKb, MetricStatus::Fail),
            ] {
                receipt.deltas.insert(
                    metric,
                    Delta {
                        baseline: 100.0,
                        current: 120.0,
                        ratio: 1.2,
                        pct: 0.2,
                        regression: 0.2,
                        statistic: MetricStatistic::Median,
                        significance: None,
                        status,
                    },
                );
            }
            let html = ExportUseCase::export_compare(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains("<td>pass</td>"));
            assert!(html.contains("<td>warn</td>"));
            assert!(html.contains("<td>fail</td>"));
            // 3 data rows
            assert_eq!(html.matches("<tr><td>").count(), 3);
        }

        // --- HTML empty bench name ---

        #[test]
        fn html_empty_bench_name() {
            let receipt = create_run_receipt_with_bench_name("");
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains("<td></td>"));
            assert!(html.contains("<html>"));
        }

        // --- Prometheus run with all optional metrics present ---

        #[test]
        fn prometheus_run_all_optional_metrics_present() {
            let mut receipt = create_empty_run_receipt();
            receipt.bench.name = "full".to_string();
            receipt.stats.cpu_ms = Some(U64Summary {
                median: 50,
                min: 48,
                max: 52,
            });
            receipt.stats.page_faults = Some(U64Summary {
                median: 10,
                min: 8,
                max: 12,
            });
            receipt.stats.ctx_switches = Some(U64Summary {
                median: 5,
                min: 3,
                max: 7,
            });
            receipt.stats.max_rss_kb = Some(U64Summary {
                median: 2048,
                min: 2000,
                max: 2100,
            });
            receipt.stats.binary_bytes = Some(U64Summary {
                median: 100000,
                min: 99000,
                max: 101000,
            });
            receipt.stats.throughput_per_s = Some(F64Summary {
                median: 1234.567890,
                min: 1200.0,
                max: 1300.0,
            });

            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("perfgate_run_cpu_ms_median{bench=\"full\"} 50"));
            assert!(prom.contains("perfgate_run_page_faults_median{bench=\"full\"} 10"));
            assert!(prom.contains("perfgate_run_ctx_switches_median{bench=\"full\"} 5"));
            assert!(prom.contains("perfgate_run_max_rss_kb_median{bench=\"full\"} 2048"));
            assert!(prom.contains("perfgate_run_binary_bytes_median{bench=\"full\"} 100000"));
            assert!(
                prom.contains("perfgate_run_throughput_per_s_median{bench=\"full\"} 1234.567890")
            );
        }

        // --- Prometheus compare status code mapping ---

        #[test]
        fn prometheus_compare_status_codes() {
            let mut receipt = create_empty_compare_receipt();
            receipt.bench.name = "status-test".to_string();
            for (metric, status, expected_code) in [
                (Metric::WallMs, MetricStatus::Pass, "0"),
                (Metric::CpuMs, MetricStatus::Warn, "1"),
                (Metric::MaxRssKb, MetricStatus::Fail, "2"),
            ] {
                receipt.deltas.insert(
                    metric,
                    Delta {
                        baseline: 100.0,
                        current: 110.0,
                        ratio: 1.1,
                        pct: 0.1,
                        regression: 0.1,
                        statistic: MetricStatistic::Median,
                        significance: None,
                        status,
                    },
                );
                receipt.budgets.insert(
                    metric,
                    Budget {
                        threshold: 0.2,
                        warn_threshold: 0.15,
                        direction: Direction::Lower,
                    },
                );
                let _ = expected_code; // used below
            }

            let prom = ExportUseCase::export_compare(&receipt, ExportFormat::Prometheus).unwrap();
            assert!(prom.contains("status=\"pass\"} 0"));
            assert!(prom.contains("status=\"warn\"} 1"));
            assert!(prom.contains("status=\"fail\"} 2"));
        }

        // --- JSONL compare round-trip field validation ---

        #[test]
        fn jsonl_compare_fields_match_receipt() {
            let receipt = create_test_compare_receipt();
            let jsonl = ExportUseCase::export_compare(&receipt, ExportFormat::Jsonl).unwrap();

            let lines: Vec<&str> = jsonl.trim().lines().collect();
            assert_eq!(lines.len(), receipt.deltas.len());

            for line in lines {
                let parsed: serde_json::Value = serde_json::from_str(line).unwrap();
                assert_eq!(parsed["bench_name"], "alpha-bench");
                let metric_name = parsed["metric"].as_str().unwrap();
                assert!(
                    ["wall_ms", "max_rss_kb"].contains(&metric_name),
                    "unexpected metric: {}",
                    metric_name
                );
                assert!(parsed["baseline_value"].as_f64().unwrap() > 0.0);
                assert!(parsed["current_value"].as_f64().unwrap() > 0.0);
                let status = parsed["status"].as_str().unwrap();
                assert!(
                    ["pass", "warn", "fail"].contains(&status),
                    "unexpected status: {}",
                    status
                );
            }
        }

        // --- JSONL run round-trip ---

        #[test]
        fn jsonl_run_round_trip() {
            let receipt = create_test_run_receipt();
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let parsed: serde_json::Value = serde_json::from_str(jsonl.trim()).unwrap();

            assert_eq!(parsed["bench_name"], receipt.bench.name);
            assert_eq!(parsed["wall_ms_median"], receipt.stats.wall_ms.median);
            assert_eq!(parsed["wall_ms_min"], receipt.stats.wall_ms.min);
            assert_eq!(parsed["wall_ms_max"], receipt.stats.wall_ms.max);
            assert_eq!(
                parsed["cpu_ms_median"],
                receipt.stats.cpu_ms.as_ref().unwrap().median
            );
            assert_eq!(
                parsed["max_rss_kb_median"],
                receipt.stats.max_rss_kb.as_ref().unwrap().median
            );
            assert_eq!(
                parsed["sample_count"],
                receipt.samples.iter().filter(|s| !s.warmup).count()
            );
            assert_eq!(parsed["timestamp"], receipt.run.started_at);
        }

        // --- HTML structure tests ---

        #[test]
        fn html_run_all_optional_metrics_present() {
            let mut receipt = create_empty_run_receipt();
            receipt.bench.name = "full-html".to_string();
            receipt.stats.cpu_ms = Some(U64Summary {
                median: 50,
                min: 48,
                max: 52,
            });
            receipt.stats.throughput_per_s = Some(F64Summary {
                median: 999.123456,
                min: 900.0,
                max: 1100.0,
            });

            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();
            assert!(html.contains("<td>50</td>"));
            assert!(html.contains("999.123456"));
            assert!(html.contains("full-html"));
        }

        // --- CSV escape edge cases ---

        #[test]
        fn csv_escape_empty_string() {
            assert_eq!(csv_escape(""), "");
        }

        #[test]
        fn csv_escape_only_quotes() {
            assert_eq!(csv_escape("\"\"\""), "\"\"\"\"\"\"\"\"");
        }

        #[test]
        fn csv_escape_no_special_chars() {
            assert_eq!(csv_escape("plain-bench_name.v2"), "plain-bench_name.v2");
        }

        // --- Prometheus escape edge cases ---

        #[test]
        fn prometheus_escape_newline_preserved() {
            // Newlines are not escaped by prometheus_escape_label_value
            // (the function only escapes backslash and double-quote)
            let result = prometheus_escape_label_value("a\nb");
            assert_eq!(result, "a\nb");
        }

        #[test]
        fn prometheus_escape_empty() {
            assert_eq!(prometheus_escape_label_value(""), "");
        }

        // --- HTML escape edge cases ---

        #[test]
        fn html_escape_all_special_chars_combined() {
            assert_eq!(
                html_escape("<tag attr=\"val\">&</tag>"),
                "&lt;tag attr=&quot;val&quot;&gt;&amp;&lt;/tag&gt;"
            );
        }

        #[test]
        fn html_escape_empty() {
            assert_eq!(html_escape(""), "");
        }

        // --- ExportFormat::parse edge cases ---

        #[test]
        fn format_parse_prom_alias() {
            assert_eq!(ExportFormat::parse("prom"), Some(ExportFormat::Prometheus));
            assert_eq!(ExportFormat::parse("PROM"), Some(ExportFormat::Prometheus));
        }

        #[test]
        fn format_parse_empty_string() {
            assert_eq!(ExportFormat::parse(""), None);
        }

        // --- Compare CSV threshold values ---

        #[test]
        fn compare_csv_threshold_percentage() {
            let receipt = create_test_compare_receipt();
            let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();
            // Budget threshold 0.2 → exported as 20.000000
            assert!(csv.contains("20.000000"));
            // Budget threshold 0.15 → exported as 15.000000
            assert!(csv.contains("15.000000"));
        }

        // --- Compare regression_pct is percentage ---

        #[test]
        fn compare_regression_pct_is_percentage() {
            let receipt = create_test_compare_receipt();
            let jsonl = ExportUseCase::export_compare(&receipt, ExportFormat::Jsonl).unwrap();

            for line in jsonl.trim().lines() {
                let parsed: serde_json::Value = serde_json::from_str(line).unwrap();
                let metric = parsed["metric"].as_str().unwrap();
                let regression_pct = parsed["regression_pct"].as_f64().unwrap();
                match metric {
                    "wall_ms" => {
                        // pct=0.1 → regression_pct=10.0
                        assert!((regression_pct - 10.0).abs() < 0.01);
                    }
                    "max_rss_kb" => {
                        // pct=0.25 → regression_pct=25.0
                        assert!((regression_pct - 25.0).abs() < 0.01);
                    }
                    _ => panic!("unexpected metric: {}", metric),
                }
            }
        }
    }
}

#[cfg(test)]
mod property_tests {
    use super::*;
    use perfgate_types::{
        BenchMeta, Budget, COMPARE_SCHEMA_V1, CompareRef, Delta, Direction, F64Summary, HostInfo,
        Metric, MetricStatistic, MetricStatus, RUN_SCHEMA_V1, RunMeta, Sample, Stats, ToolInfo,
        U64Summary, Verdict, VerdictCounts, VerdictStatus,
    };
    use proptest::prelude::*;
    use std::collections::BTreeMap;

    fn non_empty_string() -> impl Strategy<Value = String> {
        "[a-zA-Z0-9_-]{1,20}".prop_map(|s| s)
    }

    fn rfc3339_timestamp() -> impl Strategy<Value = String> {
        (
            2020u32..2030,
            1u32..13,
            1u32..29,
            0u32..24,
            0u32..60,
            0u32..60,
        )
            .prop_map(|(year, month, day, hour, min, sec)| {
                format!(
                    "{:04}-{:02}-{:02}T{:02}:{:02}:{:02}Z",
                    year, month, day, hour, min, sec
                )
            })
    }

    fn tool_info_strategy() -> impl Strategy<Value = ToolInfo> {
        (non_empty_string(), non_empty_string())
            .prop_map(|(name, version)| ToolInfo { name, version })
    }

    fn host_info_strategy() -> impl Strategy<Value = HostInfo> {
        (non_empty_string(), non_empty_string()).prop_map(|(os, arch)| HostInfo {
            os,
            arch,
            cpu_count: None,
            memory_bytes: None,
            hostname_hash: None,
        })
    }

    fn run_meta_strategy() -> impl Strategy<Value = RunMeta> {
        (
            non_empty_string(),
            rfc3339_timestamp(),
            rfc3339_timestamp(),
            host_info_strategy(),
        )
            .prop_map(|(id, started_at, ended_at, host)| RunMeta {
                id,
                started_at,
                ended_at,
                host,
            })
    }

    fn bench_meta_strategy() -> impl Strategy<Value = BenchMeta> {
        (
            non_empty_string(),
            proptest::option::of(non_empty_string()),
            proptest::collection::vec(non_empty_string(), 1..5),
            1u32..100,
            0u32..10,
            proptest::option::of(1u64..10000),
            proptest::option::of(100u64..60000),
        )
            .prop_map(
                |(name, cwd, command, repeat, warmup, work_units, timeout_ms)| BenchMeta {
                    name,
                    cwd,
                    command,
                    repeat,
                    warmup,
                    work_units,
                    timeout_ms,
                },
            )
    }

    fn sample_strategy() -> impl Strategy<Value = Sample> {
        (
            0u64..100000,
            -128i32..128,
            any::<bool>(),
            any::<bool>(),
            proptest::option::of(0u64..1000000),
            proptest::option::of(0u64..1000000),
            proptest::option::of(0u64..1000000),
            proptest::option::of(0u64..1000000),
            proptest::option::of(0u64..100000000),
        )
            .prop_map(
                |(
                    wall_ms,
                    exit_code,
                    warmup,
                    timed_out,
                    cpu_ms,
                    page_faults,
                    ctx_switches,
                    max_rss_kb,
                    binary_bytes,
                )| Sample {
                    wall_ms,
                    exit_code,
                    warmup,
                    timed_out,
                    cpu_ms,
                    page_faults,
                    ctx_switches,
                    max_rss_kb,
                    binary_bytes,
                    stdout: None,
                    stderr: None,
                },
            )
    }

    fn u64_summary_strategy() -> impl Strategy<Value = U64Summary> {
        (0u64..1000000, 0u64..1000000, 0u64..1000000).prop_map(|(a, b, c)| {
            let mut vals = [a, b, c];
            vals.sort();
            U64Summary {
                min: vals[0],
                median: vals[1],
                max: vals[2],
            }
        })
    }

    fn f64_summary_strategy() -> impl Strategy<Value = F64Summary> {
        (0.0f64..1000000.0, 0.0f64..1000000.0, 0.0f64..1000000.0).prop_map(|(a, b, c)| {
            let mut vals = [a, b, c];
            vals.sort_by(|x, y| x.partial_cmp(y).unwrap());
            F64Summary {
                min: vals[0],
                median: vals[1],
                max: vals[2],
            }
        })
    }

    fn stats_strategy() -> impl Strategy<Value = Stats> {
        (
            u64_summary_strategy(),
            proptest::option::of(u64_summary_strategy()),
            proptest::option::of(u64_summary_strategy()),
            proptest::option::of(u64_summary_strategy()),
            proptest::option::of(u64_summary_strategy()),
            proptest::option::of(u64_summary_strategy()),
            proptest::option::of(f64_summary_strategy()),
        )
            .prop_map(
                |(
                    wall_ms,
                    cpu_ms,
                    page_faults,
                    ctx_switches,
                    max_rss_kb,
                    binary_bytes,
                    throughput_per_s,
                )| Stats {
                    wall_ms,
                    cpu_ms,
                    page_faults,
                    ctx_switches,
                    max_rss_kb,
                    binary_bytes,
                    throughput_per_s,
                },
            )
    }

    fn run_receipt_strategy() -> impl Strategy<Value = RunReceipt> {
        (
            tool_info_strategy(),
            run_meta_strategy(),
            bench_meta_strategy(),
            proptest::collection::vec(sample_strategy(), 1..10),
            stats_strategy(),
        )
            .prop_map(|(tool, run, bench, samples, stats)| RunReceipt {
                schema: RUN_SCHEMA_V1.to_string(),
                tool,
                run,
                bench,
                samples,
                stats,
            })
    }

    fn direction_strategy() -> impl Strategy<Value = Direction> {
        prop_oneof![Just(Direction::Lower), Just(Direction::Higher),]
    }

    fn budget_strategy() -> impl Strategy<Value = Budget> {
        (0.01f64..1.0, 0.01f64..1.0, direction_strategy()).prop_map(
            |(threshold, warn_factor, direction)| {
                let warn_threshold = threshold * warn_factor;
                Budget {
                    threshold,
                    warn_threshold,
                    direction,
                }
            },
        )
    }

    fn metric_status_strategy() -> impl Strategy<Value = MetricStatus> {
        prop_oneof![
            Just(MetricStatus::Pass),
            Just(MetricStatus::Warn),
            Just(MetricStatus::Fail),
        ]
    }

    fn delta_strategy() -> impl Strategy<Value = Delta> {
        (0.1f64..10000.0, 0.1f64..10000.0, metric_status_strategy()).prop_map(
            |(baseline, current, status)| {
                let ratio = current / baseline;
                let pct = (current - baseline) / baseline;
                let regression = if pct > 0.0 { pct } else { 0.0 };
                Delta {
                    baseline,
                    current,
                    ratio,
                    pct,
                    regression,
                    statistic: MetricStatistic::Median,
                    significance: None,
                    status,
                }
            },
        )
    }

    fn verdict_status_strategy() -> impl Strategy<Value = VerdictStatus> {
        prop_oneof![
            Just(VerdictStatus::Pass),
            Just(VerdictStatus::Warn),
            Just(VerdictStatus::Fail),
        ]
    }

    fn verdict_counts_strategy() -> impl Strategy<Value = VerdictCounts> {
        (0u32..10, 0u32..10, 0u32..10).prop_map(|(pass, warn, fail)| VerdictCounts {
            pass,
            warn,
            fail,
        })
    }

    fn verdict_strategy() -> impl Strategy<Value = Verdict> {
        (
            verdict_status_strategy(),
            verdict_counts_strategy(),
            proptest::collection::vec("[a-zA-Z0-9 ]{1,50}", 0..5),
        )
            .prop_map(|(status, counts, reasons)| Verdict {
                status,
                counts,
                reasons,
            })
    }

    fn metric_strategy() -> impl Strategy<Value = Metric> {
        prop_oneof![
            Just(Metric::BinaryBytes),
            Just(Metric::CpuMs),
            Just(Metric::CtxSwitches),
            Just(Metric::MaxRssKb),
            Just(Metric::PageFaults),
            Just(Metric::ThroughputPerS),
            Just(Metric::WallMs),
        ]
    }

    fn budgets_map_strategy() -> impl Strategy<Value = BTreeMap<Metric, Budget>> {
        proptest::collection::btree_map(metric_strategy(), budget_strategy(), 1..8)
    }

    fn deltas_map_strategy() -> impl Strategy<Value = BTreeMap<Metric, Delta>> {
        proptest::collection::btree_map(metric_strategy(), delta_strategy(), 1..8)
    }

    fn compare_ref_strategy() -> impl Strategy<Value = CompareRef> {
        (
            proptest::option::of(non_empty_string()),
            proptest::option::of(non_empty_string()),
        )
            .prop_map(|(path, run_id)| CompareRef { path, run_id })
    }

    fn compare_receipt_strategy() -> impl Strategy<Value = CompareReceipt> {
        (
            tool_info_strategy(),
            bench_meta_strategy(),
            compare_ref_strategy(),
            compare_ref_strategy(),
            budgets_map_strategy(),
            deltas_map_strategy(),
            verdict_strategy(),
        )
            .prop_map(
                |(tool, bench, baseline_ref, current_ref, budgets, deltas, verdict)| {
                    CompareReceipt {
                        schema: COMPARE_SCHEMA_V1.to_string(),
                        tool,
                        bench,
                        baseline_ref,
                        current_ref,
                        budgets,
                        deltas,
                        verdict,
                    }
                },
            )
    }

    proptest! {
        #![proptest_config(ProptestConfig::with_cases(50))]

        #[test]
        fn run_export_csv_has_header_and_data(receipt in run_receipt_strategy()) {
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();

            prop_assert!(csv.starts_with("bench_name,wall_ms_median,wall_ms_min,wall_ms_max,binary_bytes_median,cpu_ms_median,ctx_switches_median,max_rss_kb_median,page_faults_median,throughput_median,sample_count,timestamp\n"));

            let lines: Vec<&str> = csv.trim().split('\n').collect();
            prop_assert_eq!(lines.len(), 2);

            let bench_in_csv = csv.contains(&receipt.bench.name) || csv.contains(&format!("\"{}\"", receipt.bench.name));
            prop_assert!(bench_in_csv, "CSV should contain bench name");
        }

        #[test]
        fn run_export_jsonl_is_valid_json(receipt in run_receipt_strategy()) {
            let jsonl = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();

            let lines: Vec<&str> = jsonl.trim().split('\n').collect();
            prop_assert_eq!(lines.len(), 1);

            let parsed: Result<serde_json::Value, _> = serde_json::from_str(lines[0]);
            prop_assert!(parsed.is_ok());

            let json = parsed.unwrap();
            prop_assert_eq!(json["bench_name"].as_str().unwrap(), receipt.bench.name);
        }

        #[test]
        fn compare_export_csv_metrics_sorted(receipt in compare_receipt_strategy()) {
            let csv = ExportUseCase::export_compare(&receipt, ExportFormat::Csv).unwrap();

            let lines: Vec<&str> = csv.trim().split('\n').skip(1).collect();

            let mut metrics: Vec<String> = vec![];
            for line in &lines {
                let parts: Vec<&str> = line.split(',').collect();
                if parts.len() > 1 {
                    metrics.push(parts[1].trim_matches('"').to_string());
                }
            }

            let mut sorted_metrics = metrics.clone();
            sorted_metrics.sort();

            prop_assert_eq!(metrics, sorted_metrics, "Metrics should be sorted alphabetically");
        }

        #[test]
        fn compare_export_jsonl_line_per_metric(receipt in compare_receipt_strategy()) {
            let jsonl = ExportUseCase::export_compare(&receipt, ExportFormat::Jsonl).unwrap();

            let lines: Vec<&str> = jsonl.trim().split('\n').filter(|s| !s.is_empty()).collect();
            prop_assert_eq!(lines.len(), receipt.deltas.len());

            for line in &lines {
                let parsed: Result<serde_json::Value, _> = serde_json::from_str(line);
                prop_assert!(parsed.is_ok());
            }
        }

        #[test]
        fn export_is_deterministic(receipt in run_receipt_strategy()) {
            let csv1 = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            let csv2 = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();
            prop_assert_eq!(csv1, csv2);

            let jsonl1 = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            let jsonl2 = ExportUseCase::export_run(&receipt, ExportFormat::Jsonl).unwrap();
            prop_assert_eq!(jsonl1, jsonl2);
        }

        #[test]
        fn html_output_contains_valid_structure(receipt in run_receipt_strategy()) {
            let html = ExportUseCase::export_run(&receipt, ExportFormat::Html).unwrap();

            prop_assert!(html.starts_with("<!doctype html>"));
            prop_assert!(html.contains("<html>"));
            prop_assert!(html.contains("</html>"));
            prop_assert!(html.contains("<table"));
            prop_assert!(html.contains("</table>"));
            prop_assert!(html.contains(&receipt.bench.name));
        }

        #[test]
        fn prometheus_output_valid_format(receipt in run_receipt_strategy()) {
            let prom = ExportUseCase::export_run(&receipt, ExportFormat::Prometheus).unwrap();

            prop_assert!(prom.contains("perfgate_run_wall_ms_median"));
            let bench_label = format!("bench=\"{}\"", receipt.bench.name);
            prop_assert!(prom.contains(&bench_label));

            for line in prom.lines() {
                if !line.is_empty() {
                    let has_open = line.chars().any(|c| c == '{');
                    let has_close = line.chars().any(|c| c == '}');
                    prop_assert!(has_open, "Prometheus line should contain opening brace");
                    prop_assert!(has_close, "Prometheus line should contain closing brace");
                }
            }
        }

        #[test]
        fn csv_escape_preserves_content(receipt in run_receipt_strategy()) {
            let csv = ExportUseCase::export_run(&receipt, ExportFormat::Csv).unwrap();

            let quoted_bench = format!("\"{}\"", receipt.bench.name);
            prop_assert!(csv.contains(&receipt.bench.name) || csv.contains(&quoted_bench));

            for line in csv.lines() {
                let quoted_count = line.matches('"').count();
                prop_assert!(quoted_count % 2 == 0, "Quotes should be balanced in CSV");
            }
        }
    }
}