car-server-core 0.52.1

//! File [`DurableFixProposal`]s as issues on the releases repo — the
//! **reporting** half of self-correction.
//!
//! [`super::ab_learnings`] already does the hard part: it folds a dogfooding
//! round's losses into ranked, evidence-backed proposals that name which CAR
//! component to change and on what evidence. Until this module existed, that
//! output was `println!`'d and written to `learnings-<unix>.md`, where nobody
//! read it unless they had already gone looking — which defeats the purpose of
//! an automated round.
//!
//! ## Why this is a sibling of [`super::merge`] and not an extension of it
//!
//! [`super::merge::GitHubApi`] resolves its repository from the checkout's
//! `origin` remote, because a pull request must land where the branch was
//! pushed. A defect report must NOT: it belongs on the releases repo, which is
//! reachable from any deployment that has telemetry, with or without a source
//! checkout. Folding issue filing into that trait would inherit exactly the
//! repo-resolution rule that is wrong here, so the seam is separate and the
//! repository is always an explicit argument.
//!
//! That split is the whole reason reporting and correcting can live in
//! different places: filing needs no source, fixing does.
//!
//! ## Idempotence
//!
//! Every body carries `<!-- car-fix-signature: <hex> -->`, a hash over the
//! proposal's *stable identity* — its target component and failure pattern.
//! Deliberately not the title (wording drifts) and not `evidence_tasks` (those
//! change every round, which would make each re-run a fresh duplicate).
//!
//! The search is scoped to **open** issues. A signature whose issue was closed
//! and then recurs gets a new report, and that is the intended behaviour rather
//! than an oversight: recurrence after a fix is a real signal that the fix did
//! not hold, and silently swallowing it would hide the most interesting case.
//!
//! ## The marker is a dedup id, and the report target is public
//!
//! `Parslee-ai/car-releases` is world-writable: anyone with a GitHub account
//! can open an issue on it. The signature marker is plain text in that public
//! repository, so anyone can paste one into an issue of their own — which used
//! to be enough to make this module see `AlreadyOpen` and suppress a real
//! defect report indefinitely. Deduplication therefore honours a marker only
//! on an issue that [`super::provenance::resolve_tier`] puts at
//! [`ProvenanceTier::Runtime`]: filed by the account this runtime
//! authenticates as, carrying a signature recomputed here from a proposal held
//! in memory. A marker on anyone else's issue is recorded and ignored
//! (`Parslee-ai/car#1081`).

use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};

use std::time::SystemTime;

use super::ab_learnings::{Confidence, DurableFixProposal};
use super::merge::GhError;
use super::provenance::{
    resolve_tier, LocalSignatures, PermissionOracle, ProvenanceRecord, ProvenanceTier, RawIssue,
};

/// The default report target. Not the source repo: see the module docs.
pub const DEFAULT_REPORT_REPO: &str = "Parslee-ai/car-releases";

/// A tentative proposal must have recurred at least this many times before it
/// is worth a human's attention. A one-off tentative signal is noise, and a
/// tracker that fills with noise stops being read at all.
const TENTATIVE_MIN_EVIDENCE: usize = 2;

/// The GitHub issue operations reporting needs, behind a seam.
///
/// Same idiom as [`super::merge::GitHubApi`] and
/// [`super::contract::derive_contract`]: the interesting behaviour here is
/// deduplication and the noise gate, and neither is testable against a live
/// tracker.
pub trait IssueApi: Send + Sync {
    /// Every **open** issue on `repo`, as the tracker returned it.
    ///
    /// Returns [`RawIssue`], which carries no accessor for its text: matching a
    /// marker is a predicate, and reading a body requires a resolved trust
    /// tier. See [`super::provenance`].
    fn list_open_issues(&self, repo: &str) -> Result<Vec<RawIssue>, GhError>;

    /// Open an issue and return its number.
    fn create_issue(
        &self,
        repo: &str,
        title: &str,
        body: &str,
        labels: &[String],
    ) -> Result<u64, GhError>;
}

/// The stable identity of a proposed fix: what to change, and what pattern
/// motivated it. See the module docs for what is deliberately excluded.
pub fn proposal_signature(proposal: &DurableFixProposal) -> String {
    let mut hasher = Sha256::new();
    hasher.update(proposal.target_component.trim().to_lowercase().as_bytes());
    // A NUL separator, so ("ab", "c") and ("a", "bc") cannot collide.
    hasher.update([0u8]);
    hasher.update(proposal.pattern.trim().to_lowercase().as_bytes());
    format!("{:x}", hasher.finalize())[..16].to_string()
}

/// The machine-readable handle embedded in every body.
pub fn signature_marker(signature: &str) -> String {
    format!("<!-- car-fix-signature: {signature} -->")
}

/// The signature carried by `body`, if it carries exactly one well-formed
/// marker.
///
/// Strict about the shape — hex only — so a body cannot smuggle other text
/// through the field, and so the value compared against locally recomputed
/// signatures is the same alphabet [`proposal_signature`] produces.
pub fn parse_signature_marker(body: &str) -> Option<&str> {
    const OPEN: &str = "<!-- car-fix-signature: ";
    const CLOSE: &str = " -->";
    // Every occurrence, not just the first. `render_issue_body` interpolates
    // model-authored prose ahead of the marker, so a proposal whose text
    // happens to contain the literal opener would otherwise void the real
    // marker underneath it and re-file that report every round.
    let mut rest = body;
    while let Some(open) = rest.find(OPEN) {
        let after = &rest[open + OPEN.len()..];
        if let Some(end) = after.find(CLOSE) {
            let signature = &after[..end];
            if !signature.is_empty() && signature.chars().all(|c| c.is_ascii_hexdigit()) {
                return Some(signature);
            }
        }
        rest = &rest[open + OPEN.len()..];
    }
    None
}

/// Whether this proposal clears the bar for filing.
///
/// [`Confidence::Strong`] means a recurring, diagnosable pattern already
/// mapped to a component — that is a defect report on its own. `Tentative`
/// means the specific fix still needs a human reading the failures, which is
/// only worth filing once the pattern has actually repeated.
pub fn clears_reporting_bar(proposal: &DurableFixProposal) -> bool {
    match proposal.confidence {
        Confidence::Strong => true,
        Confidence::Tentative => proposal.evidence_count >= TENTATIVE_MIN_EVIDENCE,
    }
}

/// Render one proposal as an issue body, marker included.
pub fn render_issue_body(proposal: &DurableFixProposal, signature: &str) -> String {
    let mut body = String::new();
    body.push_str("_Filed automatically by `car coder-ab` from a dogfooding round._\n\n");

    body.push_str("## Pattern\n\n");
    body.push_str(proposal.pattern.trim());
    body.push_str("\n\n## Where to look\n\n");
    body.push_str(&format!("- **Component**: {}\n", proposal.target_component));
    body.push_str(&format!(
        "- **Hint**: {} _(best-effort — verify before editing)_\n",
        proposal.target_hint
    ));

    body.push_str("\n## Proposed change\n\n");
    body.push_str(proposal.proposed_change.trim());

    body.push_str("\n\n## Evidence\n\n");
    body.push_str(&format!(
        "{} occurrence(s), confidence {:?}, kind {:?}, priority {}.\n",
        proposal.evidence_count, proposal.confidence, proposal.kind, proposal.priority
    ));
    if !proposal.evidence_tasks.is_empty() {
        body.push_str("\nTasks evidencing this pattern:\n\n");
        for task in &proposal.evidence_tasks {
            body.push_str(&format!("- `{task}`\n"));
        }
    }

    body.push_str(
        "\n---\n\nThis is a *class* of change, not a patch — the synthesizer narrows where to \
         look, it does not invent the specific fix.\n\n",
    );
    body.push_str(&signature_marker(signature));
    body.push('\n');
    body
}

/// What one proposal's report attempt did.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case", tag = "outcome")]
pub enum ReportOutcome {
    /// A new issue was opened.
    Filed { number: u64 },
    /// An open issue already carries this signature.
    AlreadyOpen { number: u64 },
    /// Below the reporting bar; see [`clears_reporting_bar`].
    BelowBar,
    /// The tracker call failed. Reporting is best-effort: one failure must not
    /// abort the round, and it must not be silent either.
    Failed { error: String },
}

/// One proposal and what happened to it.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct ReportRecord {
    pub title: String,
    pub signature: String,
    #[serde(flatten)]
    pub outcome: ReportOutcome,
    /// The trust tier resolved for every open issue that carried this
    /// signature. Empty when nothing did.
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub provenance: Vec<ProvenanceRecord>,
    /// Issues that carried this signature and resolved to
    /// [`ProvenanceTier::Public`] — a stranger's issue wearing our marker. They
    /// do not suppress the report, and they are not silent either.
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub public_marker_carriers: Vec<u64>,
}

/// How many marker-carrying issues one proposal will resolve a tier for.
///
/// Each non-runtime resolution costs a live permission lookup, so an attacker
/// who papered the tracker with copies of one marker would otherwise turn each
/// reporting round into hundreds of API calls. Runtime-authored candidates are
/// checked first and cost nothing, so this cap cannot hide our own issue behind
/// a pile of forgeries.
const MAX_MARKER_CARRIERS: usize = 5;

/// File every proposal that clears the bar, skipping signatures already open on
/// an issue this runtime actually filed.
///
/// Best-effort by construction: a tracker failure is recorded against that
/// proposal and the rest still go. A dogfooding round that produced real
/// findings must not lose them because the tracker was briefly unreachable.
pub fn report_proposals(
    api: &dyn IssueApi,
    oracle: &dyn PermissionOracle,
    repo: &str,
    proposals: &[DurableFixProposal],
    labels: &[String],
) -> Vec<ReportRecord> {
    // Recomputed here, from proposals held in memory. This set is the whole
    // content of the `runtime` tier: a marker matches only if we just derived
    // the same hex ourselves.
    let local = LocalSignatures::from_proposals(proposals);
    // One listing for the whole round. It used to be one per proposal, which
    // fetched up to `SCAN_LIMIT` bodies again for every finding.
    let open = api.list_open_issues(repo);
    // The account we authenticate as, resolved once per round at read time. It
    // is this process's own identity, not a revocable grant on someone else's
    // account, so ordering candidates by it is safe.
    //
    // A failure here is fatal to the round for the same reason a failed listing
    // is: without it nothing can reach the `runtime` tier, so every proposal
    // would re-file. Filing blind duplicates is worse than saying we could not
    // check.
    let viewer = oracle.viewer_login();

    proposals
        .iter()
        .map(|proposal| {
            let signature = proposal_signature(proposal);
            let mut record = ReportRecord {
                title: proposal.title.clone(),
                signature: signature.clone(),
                outcome: ReportOutcome::BelowBar,
                provenance: Vec::new(),
                public_marker_carriers: Vec::new(),
            };
            if !clears_reporting_bar(proposal) {
                return record;
            }
            // If we cannot tell whether it is already open, filing blind would
            // duplicate — whether the gap is the listing or our own identity.
            let rows = match (&open, &viewer) {
                (Ok(rows), Ok(_)) => rows,
                (Err(e), _) | (_, Err(e)) => {
                    record.outcome = ReportOutcome::Failed {
                        error: e.to_string(),
                    };
                    return record;
                }
            };
            let already_open = resolve_marker_carriers(
                rows,
                &signature,
                oracle,
                &local,
                viewer.as_deref().ok(),
                &mut record,
            );
            if let Some(number) = already_open {
                record.outcome = ReportOutcome::AlreadyOpen { number };
                return record;
            }
            let body = render_issue_body(proposal, &signature);
            record.outcome = match api.create_issue(repo, &proposal.title, &body, labels) {
                Ok(number) => ReportOutcome::Filed { number },
                Err(e) => ReportOutcome::Failed {
                    error: e.to_string(),
                },
            };
            record
        })
        .collect()
}

/// Resolve a tier for the issues carrying `signature` and return the number of
/// the first one whose author has write access, recording every decision.
fn resolve_marker_carriers(
    rows: &[RawIssue],
    signature: &str,
    oracle: &dyn PermissionOracle,
    local: &LocalSignatures,
    viewer: Option<&str>,
    record: &mut ReportRecord,
) -> Option<u64> {
    let mut carriers: Vec<&RawIssue> = rows
        .iter()
        .filter(|row| row.carries_marker(signature))
        .collect();
    // Ours first, so the cap below can only ever drop forgeries.
    carriers.sort_by_key(|row| match viewer {
        Some(v) if v.eq_ignore_ascii_case(row.author_login()) => 0,
        _ => 1,
    });

    for row in carriers.into_iter().take(MAX_MARKER_CARRIERS) {
        let tiered = resolve_tier((*row).clone(), oracle, local, SystemTime::now());
        record.provenance.push(tiered.record().clone());
        if tiered.tier() == ProvenanceTier::Public {
            record.public_marker_carriers.push(tiered.number());
            continue;
        }
        // Write access to the tracker. Stop here: further lookups cost live
        // `gh` calls and cannot change the answer.
        return Some(tiered.number());
    }
    None
}

/// A one-line-per-proposal summary for the round's stdout.
pub fn render_report(records: &[ReportRecord], repo: &str) -> String {
    if records.is_empty() {
        return "issue reporting: no proposals to report".to_string();
    }
    let mut out = format!("issue reporting → {repo}\n");
    for record in records {
        let line = match &record.outcome {
            ReportOutcome::Filed { number } => format!("filed #{number}"),
            ReportOutcome::AlreadyOpen { number } => format!("already open as #{number}"),
            ReportOutcome::BelowBar => "skipped (below reporting bar)".to_string(),
            ReportOutcome::Failed { error } => format!("FAILED: {error}"),
        };
        out.push_str(&format!("  {} — {}\n", record.title, line));
        if !record.public_marker_carriers.is_empty() {
            // Not a failure, and not silent: someone else's issue is wearing
            // this runtime's dedup marker, which is exactly what a marker read
            // as an auth token would have honoured.
            out.push_str(&format!(
                "    note: signature also appears on issue(s) {} filed by accounts with no write \
                 access to the tracker — ignored for deduplication\n",
                record
                    .public_marker_carriers
                    .iter()
                    .map(|n| format!("#{n}"))
                    .collect::<Vec<_>>()
                    .join(", ")
            ));
        }
    }
    out
}

// ---------------------------------------------------------------------------
// The real `gh` CLI
// ---------------------------------------------------------------------------

/// How many open issues to scan when looking for an existing signature.
///
/// Bounded because the scan is a full body fetch. A tracker with more than this
/// many open issues carrying auto-filed signatures is itself the problem.
const SCAN_LIMIT: usize = 200;

/// [`IssueApi`] over the real GitHub CLI.
pub struct GhIssues;

impl IssueApi for GhIssues {
    /// Deliberately a bounded **list and local match**, not `--search`.
    ///
    /// GitHub's search index is eventually consistent: an issue filed seconds
    /// ago does not reliably appear in `--search` results yet. Two rounds in
    /// quick succession would each search, each find nothing, and each file —
    /// which is precisely the duplicate deduplication exists to prevent.
    /// Listing open issues and matching the marker in the body we already
    /// fetched has no such window.
    ///
    /// The author is fetched with the body because provenance comes from the
    /// account, and an issue whose author is unknown cannot be tiered.
    fn list_open_issues(&self, repo: &str) -> Result<Vec<RawIssue>, GhError> {
        let args: Vec<String> = vec![
            "issue".into(),
            "list".into(),
            "--repo".into(),
            repo.into(),
            "--state".into(),
            "open".into(),
            "--limit".into(),
            SCAN_LIMIT.to_string(),
            "--json".into(),
            "number,title,body,author".into(),
        ];
        let out = super::merge::gh(std::path::Path::new("."), &args)?;
        let rows: Vec<IssueRow> = serde_json::from_str(&out).map_err(|e| GhError {
            message: format!("could not parse `gh issue list` output: {e}"),
            stderr: String::new(),
        })?;
        Ok(rows
            .into_iter()
            .map(|row| {
                let login = row.author.map(|a| a.login).unwrap_or_default();
                RawIssue::new(repo, row.number, login, row.title, row.body)
            })
            .collect())
    }

    fn create_issue(
        &self,
        repo: &str,
        title: &str,
        body: &str,
        labels: &[String],
    ) -> Result<u64, GhError> {
        let mut args: Vec<String> = vec![
            "issue".into(),
            "create".into(),
            "--repo".into(),
            repo.into(),
            "--title".into(),
            title.into(),
            "--body".into(),
            body.into(),
        ];
        for label in labels {
            args.push("--label".into());
            args.push(label.clone());
        }
        let out = super::merge::gh(std::path::Path::new("."), &args)?;
        parse_issue_number(&out).ok_or_else(|| GhError {
            message: "`gh issue create` succeeded but printed no issue URL".to_string(),
            stderr: String::new(),
        })
    }
}

#[derive(Deserialize)]
struct IssueRow {
    number: u64,
    title: String,
    body: String,
    /// `null` for a ghost (deleted) account, and the report target is a public
    /// repo where one such issue anywhere in the scan would otherwise fail the
    /// whole parse and turn every proposal in the round into `Failed`. An issue
    /// with no author cannot be tiered above `public`, which an empty login
    /// already is.
    #[serde(default)]
    author: Option<IssueAuthor>,
}

#[derive(Deserialize)]
struct IssueAuthor {
    #[serde(default)]
    login: String,
}

/// `gh issue create` prints the issue URL; the number is its last path segment.
fn parse_issue_number(output: &str) -> Option<u64> {
    output
        .split_whitespace()
        .last()?
        .rsplit('/')
        .next()?
        .parse()
        .ok()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::coder::ab_learnings::ProposalKind;
    use crate::coder::provenance::RepoPermission;
    use std::sync::Mutex;

    fn proposal(
        component: &str,
        pattern: &str,
        confidence: Confidence,
        evidence: usize,
    ) -> DurableFixProposal {
        DurableFixProposal {
            title: format!("fix {component}"),
            pattern: pattern.to_string(),
            target_component: component.to_string(),
            target_hint: "coder/native_loop.rs".to_string(),
            proposed_change: "widen the guard".to_string(),
            evidence_tasks: vec!["task-1".to_string()],
            evidence_count: evidence,
            kind: ProposalKind::HarnessAddressable,
            confidence,
            priority: 10,
        }
    }

    /// The account this runtime files as, in tests.
    const BOT: &str = "car-bot";

    #[derive(Default)]
    struct FakeIssues {
        /// Open issues as (number, author login, body).
        open: Vec<(u64, String, String)>,
        created: Mutex<Vec<(String, String, String)>>,
        fail_list: bool,
        fail_create: bool,
    }

    struct FakeOracle {
        viewer: String,
        maintainers: Vec<String>,
        fail_identity: bool,
    }

    impl Default for FakeOracle {
        fn default() -> Self {
            Self {
                viewer: BOT.to_string(),
                maintainers: Vec::new(),
                fail_identity: false,
            }
        }
    }

    impl PermissionOracle for FakeOracle {
        fn viewer_login(&self) -> Result<String, GhError> {
            if self.fail_identity {
                return Err(GhError {
                    message: "gh api user failed".into(),
                    stderr: String::new(),
                });
            }
            Ok(self.viewer.clone())
        }

        fn permission(&self, _repo: &str, login: &str) -> Result<RepoPermission, GhError> {
            Ok(if self.maintainers.iter().any(|m| m == login) {
                RepoPermission::Write
            } else {
                RepoPermission::None
            })
        }
    }

    impl IssueApi for FakeIssues {
        fn list_open_issues(&self, repo: &str) -> Result<Vec<RawIssue>, GhError> {
            if self.fail_list {
                return Err(GhError {
                    message: "list exploded".into(),
                    stderr: String::new(),
                });
            }
            Ok(self
                .open
                .iter()
                .map(|(number, author, body)| {
                    RawIssue::new(repo, *number, author, "an open issue", body)
                })
                .collect())
        }

        fn create_issue(
            &self,
            repo: &str,
            title: &str,
            body: &str,
            _labels: &[String],
        ) -> Result<u64, GhError> {
            if self.fail_create {
                return Err(GhError {
                    message: "create exploded".into(),
                    stderr: String::new(),
                });
            }
            let mut created = self.created.lock().unwrap();
            created.push((repo.to_string(), title.to_string(), body.to_string()));
            Ok(900 + created.len() as u64)
        }
    }

    #[test]
    fn signature_is_stable_across_calls() {
        let p = proposal(
            "native_loop",
            "tool results never returned",
            Confidence::Strong,
            3,
        );
        assert_eq!(proposal_signature(&p), proposal_signature(&p));
    }

    #[test]
    fn signature_ignores_volatile_fields() {
        // Title wording and per-round evidence must NOT change identity, or every
        // re-run files a duplicate.
        let mut a = proposal(
            "native_loop",
            "tool results never returned",
            Confidence::Strong,
            3,
        );
        let mut b = a.clone();
        b.title = "completely different wording".into();
        b.evidence_tasks = vec!["task-9".into(), "task-12".into()];
        b.evidence_count = 11;
        b.priority = 1;
        assert_eq!(proposal_signature(&a), proposal_signature(&b));

        // But the identity fields do change it.
        a.target_component = "contract".into();
        assert_ne!(proposal_signature(&a), proposal_signature(&b));
    }

    #[test]
    fn separator_prevents_field_boundary_collision() {
        let a = proposal("ab", "c", Confidence::Strong, 1);
        let b = proposal("a", "bc", Confidence::Strong, 1);
        assert_ne!(proposal_signature(&a), proposal_signature(&b));
    }

    #[test]
    fn strong_always_clears_tentative_needs_recurrence() {
        assert!(clears_reporting_bar(&proposal(
            "c",
            "p",
            Confidence::Strong,
            1
        )));
        assert!(!clears_reporting_bar(&proposal(
            "c",
            "p",
            Confidence::Tentative,
            1
        )));
        assert!(clears_reporting_bar(&proposal(
            "c",
            "p",
            Confidence::Tentative,
            2
        )));
    }

    #[test]
    fn body_carries_the_marker_that_dedupe_reads() {
        let p = proposal("native_loop", "thrash", Confidence::Strong, 3);
        let sig = proposal_signature(&p);
        let body = render_issue_body(&p, &sig);
        assert!(body.contains(&signature_marker(&sig)));
        // The dedupe path matches on the bare signature, so that must appear too.
        assert!(body.contains(&sig));
        assert!(body.contains("native_loop"));
        assert!(body.contains("widen the guard"));
    }

    #[test]
    fn files_new_proposals_and_skips_already_open_ones() {
        let already = proposal("contract", "derivation drifts", Confidence::Strong, 4);
        let sig = proposal_signature(&already);
        let api = FakeIssues {
            open: vec![(
                77,
                BOT.to_string(),
                format!("stale text {}", signature_marker(&sig)),
            )],
            ..Default::default()
        };
        let fresh = proposal("native_loop", "thrash", Confidence::Strong, 2);
        let noise = proposal("router", "maybe", Confidence::Tentative, 1);

        let records = report_proposals(
            &api,
            &FakeOracle::default(),
            "acme/releases",
            &[already, fresh, noise],
            &[],
        );

        assert_eq!(
            records[0].outcome,
            ReportOutcome::AlreadyOpen { number: 77 }
        );
        assert_eq!(records[1].outcome, ReportOutcome::Filed { number: 901 });
        assert_eq!(records[2].outcome, ReportOutcome::BelowBar);
        // Exactly one create call, and it went to the named repo.
        let created = api.created.lock().unwrap();
        assert_eq!(created.len(), 1);
        assert_eq!(created[0].0, "acme/releases");
    }

    #[test]
    fn a_tracker_failure_is_recorded_and_does_not_abort_the_round() {
        let api = FakeIssues {
            fail_create: true,
            ..Default::default()
        };
        let records = report_proposals(
            &api,
            &FakeOracle::default(),
            "acme/releases",
            &[
                proposal("a", "one", Confidence::Strong, 2),
                proposal("b", "two", Confidence::Strong, 2),
            ],
            &[],
        );
        // Both were attempted — the first failure did not stop the second.
        assert_eq!(records.len(), 2);
        assert!(matches!(records[0].outcome, ReportOutcome::Failed { .. }));
        assert!(matches!(records[1].outcome, ReportOutcome::Failed { .. }));
    }

    #[test]
    fn a_lookup_failure_does_not_file_blind() {
        // If we cannot tell whether it is already open, filing would duplicate.
        let api = FakeIssues {
            fail_list: true,
            ..Default::default()
        };
        let records = report_proposals(
            &api,
            &FakeOracle::default(),
            "acme/releases",
            &[proposal("a", "one", Confidence::Strong, 2)],
            &[],
        );
        assert!(matches!(records[0].outcome, ReportOutcome::Failed { .. }));
        assert!(api.created.lock().unwrap().is_empty());
    }

    #[test]
    fn a_stranger_wearing_our_marker_cannot_suppress_a_real_report() {
        // The report target is world-writable and the marker is plain text in
        // it. Before provenance, this pasted marker made the round say
        // "already open" and the defect was never reported.
        let p = proposal("contract", "derivation drifts", Confidence::Strong, 4);
        let sig = proposal_signature(&p);
        let api = FakeIssues {
            open: vec![(
                4242,
                "drive-by".to_string(),
                format!("unrelated rant {}", signature_marker(&sig)),
            )],
            ..Default::default()
        };

        let records = report_proposals(&api, &FakeOracle::default(), "acme/releases", &[p], &[]);

        assert_eq!(records[0].outcome, ReportOutcome::Filed { number: 901 });
        assert_eq!(records[0].public_marker_carriers, vec![4242]);
        // The tier decision is recorded, not just acted on.
        assert_eq!(records[0].provenance.len(), 1);
        assert_eq!(records[0].provenance[0].tier, ProvenanceTier::Public);
        // And it is said out loud in the round's summary.
        let rendered = render_report(&records, "acme/releases");
        assert!(rendered.contains("#4242"));
        assert!(rendered.contains("ignored for deduplication"));
    }

    #[test]
    fn a_teammates_report_still_dedupes() {
        // There is no dedicated bot account: `runtime` is whoever ran
        // `gh auth login`. If only that account's issues counted, the next
        // operator's round would re-file every report the last one filed and
        // announce their legitimate issues as forgeries.
        let p = proposal("contract", "derivation drifts", Confidence::Strong, 4);
        let sig = proposal_signature(&p);
        let api = FakeIssues {
            open: vec![(50, "a-maintainer".to_string(), signature_marker(&sig))],
            ..Default::default()
        };
        let oracle = FakeOracle {
            maintainers: vec!["a-maintainer".to_string()],
            ..Default::default()
        };

        let records = report_proposals(&api, &oracle, "acme/releases", &[p], &[]);

        assert_eq!(
            records[0].outcome,
            ReportOutcome::AlreadyOpen { number: 50 }
        );
        assert_eq!(records[0].provenance[0].tier, ProvenanceTier::Maintainer);
        assert!(records[0].public_marker_carriers.is_empty());
        assert!(api.created.lock().unwrap().is_empty());
    }

    #[test]
    fn an_identity_failure_does_not_file_blind() {
        // Without knowing who we are, nothing can reach a trusted tier, so
        // every proposal would re-file. Say so instead.
        let p = proposal("contract", "derivation drifts", Confidence::Strong, 4);
        let sig = proposal_signature(&p);
        let api = FakeIssues {
            open: vec![(50, BOT.to_string(), signature_marker(&sig))],
            ..Default::default()
        };
        let oracle = FakeOracle {
            fail_identity: true,
            ..Default::default()
        };

        let records = report_proposals(&api, &oracle, "acme/releases", &[p], &[]);

        assert!(matches!(records[0].outcome, ReportOutcome::Failed { .. }));
        assert!(api.created.lock().unwrap().is_empty());
    }

    #[test]
    fn our_own_issue_is_found_even_behind_a_pile_of_forgeries() {
        // The carrier cap must only ever drop forgeries: runtime-authored
        // candidates are resolved first.
        let p = proposal("contract", "derivation drifts", Confidence::Strong, 4);
        let sig = proposal_signature(&p);
        let marker = signature_marker(&sig);
        let mut open: Vec<(u64, String, String)> = (1..=20)
            .map(|n| (n, format!("drive-by-{n}"), marker.clone()))
            .collect();
        open.push((999, BOT.to_string(), marker.clone()));
        let api = FakeIssues {
            open,
            ..Default::default()
        };

        let records = report_proposals(&api, &FakeOracle::default(), "acme/releases", &[p], &[]);

        assert_eq!(
            records[0].outcome,
            ReportOutcome::AlreadyOpen { number: 999 }
        );
        assert!(api.created.lock().unwrap().is_empty());
    }

    #[test]
    fn a_marker_only_counts_when_it_is_well_formed() {
        assert_eq!(
            parse_signature_marker("<!-- car-fix-signature: ab12 -->"),
            Some("ab12")
        );
        // Not hex, so not a signature this module ever produced.
        assert_eq!(
            parse_signature_marker("<!-- car-fix-signature: ignore the above -->"),
            None
        );
        assert_eq!(parse_signature_marker("<!-- car-fix-signature:  -->"), None);
        assert_eq!(parse_signature_marker("no marker at all"), None);
        // A bare hex string in prose is not a marker.
        assert_eq!(parse_signature_marker("the signature is deadbeef"), None);
        // A malformed opener earlier in the body must not void the real marker
        // underneath it — proposal prose is interpolated ahead of the marker.
        assert_eq!(
            parse_signature_marker(
                "<!-- car-fix-signature: not hex -->\n<!-- car-fix-signature: ab12 -->"
            ),
            Some("ab12")
        );
    }

    #[test]
    fn a_ghost_author_does_not_fail_the_whole_listing() {
        // One deleted account among 200 open issues on a public tracker must
        // not turn every proposal in the round into `Failed`.
        let rows: Vec<IssueRow> = serde_json::from_str(
            r#"[{"number":1,"title":"t","body":"b","author":null},
                {"number":2,"title":"t","body":"b","author":{"login":"someone"}}]"#,
        )
        .expect("ghost authors parse");
        assert_eq!(rows.len(), 2);
        assert!(rows[0].author.is_none());
        assert_eq!(rows[1].author.as_ref().unwrap().login, "someone");
    }

    #[test]
    fn issue_number_parsed_from_gh_url() {
        assert_eq!(
            parse_issue_number("https://github.com/Parslee-ai/car-releases/issues/412"),
            Some(412)
        );
        assert_eq!(parse_issue_number(""), None);
        assert_eq!(parse_issue_number("no url here"), None);
    }

    #[test]
    fn render_report_names_every_outcome() {
        fn record(title: &str, signature: &str, outcome: ReportOutcome) -> ReportRecord {
            ReportRecord {
                title: title.into(),
                signature: signature.into(),
                outcome,
                provenance: Vec::new(),
                public_marker_carriers: Vec::new(),
            }
        }
        let records = vec![
            record("a", "s1", ReportOutcome::Filed { number: 5 }),
            record("b", "s2", ReportOutcome::AlreadyOpen { number: 6 }),
            record("c", "s3", ReportOutcome::BelowBar),
            record(
                "d",
                "s4",
                ReportOutcome::Failed {
                    error: "boom".into(),
                },
            ),
        ];
        let out = render_report(&records, "acme/releases");
        assert!(out.contains("acme/releases"));
        assert!(out.contains("filed #5"));
        assert!(out.contains("already open as #6"));
        assert!(out.contains("below reporting bar"));
        assert!(out.contains("FAILED: boom"));
    }
}