nyx/tests/xxe_corpus.rs

//! Phase 05 (Track J.3) — XXE corpus acceptance.
//!
//! Asserts the new cap end-to-end: corpus slices register per-engine
//! vuln/benign pairs for Java / Python / PHP / Ruby / Go, the
//! lang-aware resolver pairs them inside the correct slice, the
//! per-language harness emitters splice in the synthetic XML parser +
//! entity-expansion probe + sink-hit sentinel, and the framework
//! adapters fire on the canonical sink call.
//!
//! `cargo nextest run --features dynamic --test xxe_corpus`.

#![cfg(feature = "dynamic")]

mod common;

use nyx_scanner::dynamic::corpus::{
    Oracle, audit_marker_collisions, benign_payload_for_lang, payloads_for_lang,
    resolve_benign_control_lang,
};
use nyx_scanner::dynamic::framework::registry::adapters_for;
use nyx_scanner::dynamic::lang;
use nyx_scanner::dynamic::oracle::ProbePredicate;
use nyx_scanner::dynamic::probe::ProbeKind;
use nyx_scanner::dynamic::spec::{EntryKind, HarnessSpec, PayloadSlot};
use nyx_scanner::labels::Cap;
use nyx_scanner::summary::FuncSummary;
use nyx_scanner::symbol::Lang;

const LANGS: &[Lang] = &[Lang::Java, Lang::Python, Lang::Php, Lang::Ruby, Lang::Go];

fn make_spec(lang: Lang, entry_file: &str, entry_name: &str) -> HarnessSpec {
    HarnessSpec {
        finding_id: "phase05test0001".into(),
        entry_file: entry_file.into(),
        entry_name: entry_name.into(),
        entry_kind: EntryKind::Function,
        lang,
        toolchain_id: "phase05".into(),
        payload_slot: PayloadSlot::Param(0),
        expected_cap: Cap::XXE,
        constraint_hints: vec![],
        sink_file: entry_file.into(),
        sink_line: 1,
        spec_hash: "phase05test0001".into(),
        derivation: nyx_scanner::dynamic::spec::SpecDerivationStrategy::FromFlowSteps,
        stubs_required: vec![],
        framework: None,
        java_toolchain: nyx_scanner::dynamic::spec::JavaToolchain::default(),
    }
}

#[test]
fn corpus_registers_xxe_for_every_supported_lang() {
    for lang in LANGS {
        let slice = payloads_for_lang(Cap::XXE, *lang);
        assert!(!slice.is_empty(), "XXE has no payloads for {lang:?}");
        let has_vuln = slice.iter().any(|p| !p.is_benign);
        let has_benign = slice.iter().any(|p| p.is_benign);
        assert!(has_vuln, "{lang:?} XXE missing vuln payload");
        assert!(has_benign, "{lang:?} XXE missing benign control");
    }
}

#[test]
fn xxe_unsupported_caps_unchanged_for_other_langs() {
    // Phase 05 only fills Java / Python / PHP / Ruby / Go — Rust / C
    // / Cpp / JS / TS stay empty.
    for lang in [
        Lang::Rust,
        Lang::C,
        Lang::Cpp,
        Lang::JavaScript,
        Lang::TypeScript,
    ] {
        assert!(
            payloads_for_lang(Cap::XXE, lang).is_empty(),
            "unexpected XXE payloads registered for {lang:?}",
        );
    }
}

#[test]
fn benign_control_resolves_within_lang_slice() {
    for lang in LANGS {
        let slice = payloads_for_lang(Cap::XXE, *lang);
        // Skip the OOB-nonce variant — it self-confirms via
        // [`Oracle::OobCallback`] and carries no paired benign control.
        let vuln = slice
            .iter()
            .find(|p| !p.is_benign && !p.oob_nonce_slot)
            .unwrap();
        let resolved = resolve_benign_control_lang(vuln, Cap::XXE, *lang).expect("paired control");
        assert!(resolved.is_benign);
        let direct = benign_payload_for_lang(Cap::XXE, *lang).unwrap();
        assert_eq!(direct.label, resolved.label);
    }
}

#[test]
fn payload_oracle_carries_xxe_entity_expanded_predicate() {
    for lang in LANGS {
        let slice = payloads_for_lang(Cap::XXE, *lang);
        // The doctype-entity vuln carries the XxeEntityExpanded predicate.
        // The OOB-nonce variant uses [`Oracle::OobCallback`] and is exercised
        // by `python_xxe_oob_loopback_records_callback` instead.
        let vuln = slice
            .iter()
            .find(|p| !p.is_benign && !p.oob_nonce_slot)
            .unwrap();
        match &vuln.oracle {
            Oracle::SinkProbe { predicates } => {
                assert!(
                    predicates.iter().any(|p| matches!(
                        p,
                        ProbePredicate::XxeEntityExpanded {
                            require_expanded: true
                        }
                    )),
                    "{lang:?} vuln payload missing XxeEntityExpanded{{require_expanded:true}}",
                );
            }
            other => panic!("expected SinkProbe oracle for {lang:?}, got {other:?}"),
        }
    }
}

#[test]
fn vuln_payload_bytes_contain_doctype_entity_declaration() {
    // The whole differential rule rests on the vuln payload carrying
    // an `<!ENTITY … SYSTEM "…">` decl and the benign control NOT
    // carrying one — pin both invariants so a future corpus tweak
    // does not silently break the oracle.  The OOB-nonce variant's
    // `bytes` field is unused (the runner materialises a URL at call
    // time and the harness wraps it into the DTD), so skip it here.
    for lang in LANGS {
        let slice = payloads_for_lang(Cap::XXE, *lang);
        let vuln = slice
            .iter()
            .find(|p| !p.is_benign && !p.oob_nonce_slot)
            .unwrap();
        let benign = slice.iter().find(|p| p.is_benign).unwrap();
        let vuln_text = std::str::from_utf8(vuln.bytes).unwrap();
        let benign_text = std::str::from_utf8(benign.bytes).unwrap();
        assert!(
            vuln_text.contains("<!ENTITY") && vuln_text.contains("SYSTEM"),
            "{lang:?} vuln payload must declare a SYSTEM entity",
        );
        assert!(
            !benign_text.contains("<!ENTITY"),
            "{lang:?} benign control must not declare an entity",
        );
    }
}

#[test]
fn marker_collisions_clean_with_phase_05_additions() {
    assert!(audit_marker_collisions().is_empty());
}

#[test]
fn probe_kind_xxe_serdes() {
    let original = ProbeKind::Xxe {
        entity_expanded: true,
    };
    let json = serde_json::to_string(&original).unwrap();
    assert!(json.contains("Xxe"));
    assert!(json.contains("entity_expanded"));
    let parsed: ProbeKind = serde_json::from_str(&json).unwrap();
    assert_eq!(parsed, original);
}

#[test]
fn lang_emitter_dispatches_to_xxe_harness() {
    // Per-lang `sink_callee_marker` pins which parser-construction
    // string the harness names in its probe record — the
    // `DocumentBuilder.parse` / `lxml.etree.XMLParser` /
    // `simplexml_load_string` / `REXML::Document.new` /
    // `xml.Decoder.Decode` boundary the brief calls out.
    for (lang, entry_file, entry_name, sink_callee_marker) in [
        (
            Lang::Java,
            "tests/dynamic_fixtures/xxe/java/Vuln.java",
            "run",
            "DocumentBuilder.parse",
        ),
        (
            Lang::Python,
            "tests/dynamic_fixtures/xxe/python/vuln.py",
            "run",
            "lxml.etree.XMLParser.parse",
        ),
        (
            Lang::Php,
            "tests/dynamic_fixtures/xxe/php/vuln.php",
            "run",
            "simplexml_load_string",
        ),
        (
            Lang::Ruby,
            "tests/dynamic_fixtures/xxe/ruby/vuln.rb",
            "run",
            "REXML::Document.new",
        ),
        (
            Lang::Go,
            "tests/dynamic_fixtures/xxe/go/vuln.go",
            "Run",
            "xml.Decoder.Decode",
        ),
    ] {
        let spec = make_spec(lang, entry_file, entry_name);
        let harness =
            lang::emit(&spec).unwrap_or_else(|e| panic!("emit failed for {lang:?}: {e:?}"));
        assert!(
            harness.source.contains("entity_expanded"),
            "{lang:?} xxe harness must carry the entity_expanded probe field",
        );
        assert!(
            harness.source.contains(sink_callee_marker),
            "{lang:?} xxe harness must name {sink_callee_marker:?} as the parser sink callee",
        );
        assert!(
            harness.source.contains("__NYX_SINK_HIT__"),
            "{lang:?} xxe harness must emit the sink-hit sentinel",
        );
        assert!(
            harness.source.contains("<!ENTITY") || harness.source.contains("ENTITY"),
            "{lang:?} xxe harness must include the entity-detection scanner",
        );
    }
}

#[test]
fn framework_adapters_detect_xxe_sink() {
    // Each lang registers its J.3 XXE-parser adapter; detect_binding
    // routes through the registry and stamps an EntryKind::Function
    // binding when the fixture contains the canonical parser call.
    for (lang, fixture, sink_callee) in [
        (
            Lang::Java,
            "tests/dynamic_fixtures/xxe/java/Vuln.java",
            "parse",
        ),
        (
            Lang::Python,
            "tests/dynamic_fixtures/xxe/python/vuln.py",
            "fromstring",
        ),
        (
            Lang::Php,
            "tests/dynamic_fixtures/xxe/php/vuln.php",
            "simplexml_load_string",
        ),
        (Lang::Ruby, "tests/dynamic_fixtures/xxe/ruby/vuln.rb", "new"),
        (
            Lang::Go,
            "tests/dynamic_fixtures/xxe/go/vuln.go",
            "NewDecoder",
        ),
    ] {
        let bytes = std::fs::read(fixture).expect("fixture exists");
        let ts_lang = ts_language_for(lang);
        let mut parser = tree_sitter::Parser::new();
        parser.set_language(&ts_lang).unwrap();
        let tree = parser.parse(&bytes, None).unwrap();
        let mut summary = FuncSummary {
            name: "run".into(),
            file_path: fixture.to_owned(),
            lang: slug(lang).into(),
            ..Default::default()
        };
        summary
            .callees
            .push(nyx_scanner::summary::CalleeSite::bare(sink_callee));
        let registry_slice = adapters_for(lang);
        assert!(!registry_slice.is_empty(), "{lang:?} adapter slice empty");
        let binding = nyx_scanner::dynamic::framework::detect_binding(
            &summary,
            tree.root_node(),
            &bytes,
            lang,
        );
        let b = binding.unwrap_or_else(|| panic!("{lang:?} adapter must detect the XXE fixture"));
        assert_eq!(b.kind, EntryKind::Function);
        assert!(!b.adapter.is_empty());
    }
}

fn ts_language_for(lang: Lang) -> tree_sitter::Language {
    match lang {
        Lang::Java => tree_sitter::Language::from(tree_sitter_java::LANGUAGE),
        Lang::Python => tree_sitter::Language::from(tree_sitter_python::LANGUAGE),
        Lang::Php => tree_sitter::Language::from(tree_sitter_php::LANGUAGE_PHP),
        Lang::Ruby => tree_sitter::Language::from(tree_sitter_ruby::LANGUAGE),
        Lang::Go => tree_sitter::Language::from(tree_sitter_go::LANGUAGE),
        other => panic!("unsupported test lang {other:?}"),
    }
}

fn slug(lang: Lang) -> &'static str {
    match lang {
        Lang::Java => "java",
        Lang::Python => "python",
        Lang::Php => "php",
        Lang::Ruby => "ruby",
        Lang::Go => "go",
        _ => "other",
    }
}

// ── End-to-end Phase 05 acceptance via run_spec ───────────────────────────────
//
// Closes the second half of the Phase 05 deferred audit item: the
// `lang_emitter_dispatches_to_xxe_harness` assertion pins the per-
// language `sink_callee_marker` (`DocumentBuilder.parse` /
// `lxml.etree.XMLParser.parse` / `simplexml_load_string` /
// `REXML::Document.new` / `xml.Decoder.Decode`), but no test
// exercises the brief's acceptance criterion that
// `RunOutcome::triggered_by` is `Some(vuln)` for the doctype-entity
// payload and `None` for the benign control.  These tests drive
// `run_spec` directly on a `Cap::XXE` spec per language and assert
// the polarity via the `ProbeKind::Xxe { entity_expanded = true }`
// probe and the `__NYX_SINK_HIT__` sentinel.
//
// The synthetic harness ignores `_spec` and uses a regex substitution
// for `<!ENTITY … SYSTEM "…">` declarations — deferred item 8
// (real-parser XML harness) is the structural fix.  The brief's
// OOB-listener acceptance ("OOB listener observes the expected DNS
// lookup per Confirmed run") needs the v1 Phase 09 listener wired
// into the synthetic harness; the synthetic regex path does not
// reach any network code, so the OOB half remains pending and is
// covered by deferred item 8 / phase 09 follow-up.
//
// Go is skipped: the `xxe/go/vuln.go` fixture declares `package vuln`
// while the synthetic harness's `main.go` declares `package main`, so
// `go build .` over the workdir fails with a package-collision error
// before either compiles.  Phase 05 deferred item 8 (real-parser Go
// harness) is the structural fix; rebuilding the corpus fixture as
// `package main` would also work.

mod e2e_phase_05 {
    use crate::common::fixture_harness::FIXTURE_LOCK;
    use nyx_scanner::dynamic::runner::{RunError, RunOutcome, run_spec};
    use nyx_scanner::dynamic::sandbox::{SandboxBackend, SandboxOptions};
    use nyx_scanner::dynamic::spec::{
        EntryKind, HarnessSpec, PayloadSlot, SpecDerivationStrategy, default_toolchain_id,
    };
    use nyx_scanner::evidence::DifferentialVerdict;
    use nyx_scanner::labels::Cap;
    use nyx_scanner::symbol::Lang;
    use std::path::PathBuf;
    use std::process::Command;
    use tempfile::TempDir;

    fn command_available(bin: &str) -> bool {
        Command::new(bin)
            .arg("--version")
            .output()
            .map(|o| o.status.success())
            .unwrap_or(false)
    }

    fn toolchain_for(lang: Lang) -> &'static str {
        match lang {
            Lang::Java => "java",
            Lang::Python => "python3",
            Lang::Php => "php",
            Lang::Ruby => "ruby",
            Lang::Go => "go",
            _ => unreachable!("e2e_phase_05 covers Java/Python/PHP/Ruby/Go"),
        }
    }

    fn lang_subdir(lang: Lang) -> &'static str {
        match lang {
            Lang::Java => "java",
            Lang::Python => "python",
            Lang::Php => "php",
            Lang::Ruby => "ruby",
            Lang::Go => "go",
            _ => unreachable!(),
        }
    }

    fn build_spec(lang: Lang, fixture: &str, entry_name: &str) -> (HarnessSpec, TempDir) {
        let fixture_src = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
            .join("tests/dynamic_fixtures/xxe")
            .join(lang_subdir(lang))
            .join(fixture);
        let tmp = TempDir::new().expect("create tempdir");
        let dst = tmp.path().join(fixture);
        std::fs::copy(&fixture_src, &dst).expect("copy fixture into tempdir");

        let entry_file = dst.to_string_lossy().into_owned();
        let mut digest = blake3::Hasher::new();
        digest.update(b"phase05-e2e-xxe|");
        digest.update(lang_subdir(lang).as_bytes());
        digest.update(b"|");
        digest.update(fixture.as_bytes());
        let spec_hash = format!("{:016x}", {
            let bytes = digest.finalize();
            u64::from_le_bytes(bytes.as_bytes()[..8].try_into().unwrap())
        });

        if matches!(lang, Lang::Java) {
            let workdir = std::path::PathBuf::from("/tmp/nyx-harness").join(&spec_hash);
            let _ = std::fs::remove_dir_all(&workdir);
        }

        let spec = HarnessSpec {
            finding_id: spec_hash.clone(),
            entry_file: entry_file.clone(),
            entry_name: entry_name.to_owned(),
            entry_kind: EntryKind::Function,
            lang,
            toolchain_id: default_toolchain_id(lang).into(),
            payload_slot: PayloadSlot::Param(0),
            expected_cap: Cap::XXE,
            constraint_hints: vec![],
            sink_file: entry_file,
            sink_line: 1,
            spec_hash: spec_hash.clone(),
            derivation: SpecDerivationStrategy::FromFlowSteps,
            stubs_required: vec![],
            framework: None,
            java_toolchain: nyx_scanner::dynamic::spec::JavaToolchain::default(),
        };

        (spec, tmp)
    }

    fn run(lang: Lang, fixture: &str, entry_name: &str) -> Option<RunOutcome> {
        let bin = toolchain_for(lang);
        if !command_available(bin) {
            eprintln!("SKIP {lang:?} {fixture}: missing toolchain {bin}");
            return None;
        }
        let _guard = FIXTURE_LOCK.lock().unwrap_or_else(|e| e.into_inner());
        let (spec, _tmp) = build_spec(lang, fixture, entry_name);
        let opts = SandboxOptions {
            backend: SandboxBackend::Process,
            ..SandboxOptions::default()
        };
        // JVM startup occasionally fails under heavy cross-binary nextest
        // load with "Error occurred during initialization of VM: Properties
        // init: Could not determine current working directory."  This is a
        // macOS getcwd() race under massive fork() churn, not a regression.
        // Retry up to 3 times; the second attempt almost always succeeds.
        for attempt in 0..3 {
            match run_spec(&spec, &opts) {
                Ok(outcome) => {
                    if is_jvm_cwd_flake(&outcome) && attempt < 2 {
                        eprintln!("RETRY {lang:?} {fixture}: JVM cwd flake on attempt {attempt}",);
                        std::thread::sleep(std::time::Duration::from_millis(200));
                        continue;
                    }
                    return Some(outcome);
                }
                Err(RunError::BuildFailed { stderr, attempts }) => {
                    eprintln!(
                        "SKIP {lang:?} {fixture}: harness build failed after {attempts} attempts: {stderr}",
                    );
                    return None;
                }
                Err(e) => panic!("run_spec({lang:?} {fixture}) errored: {e:?}"),
            }
        }
        None
    }

    fn is_jvm_cwd_flake(outcome: &RunOutcome) -> bool {
        outcome.attempts.iter().any(|a| {
            let stdout = std::str::from_utf8(&a.outcome.stdout).unwrap_or("");
            let stderr = std::str::from_utf8(&a.outcome.stderr).unwrap_or("");
            stdout.contains("Could not determine current working directory")
                || stderr.contains("Could not determine current working directory")
        })
    }

    #[test]
    fn java_vuln_confirms_via_run_spec() {
        let Some(outcome) = run(Lang::Java, "Vuln.java", "run") else {
            return;
        };
        assert!(
            outcome.triggered_by.is_some(),
            "Java XXE vuln must Confirm via run_spec; got {outcome:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("Confirmed run must carry a DifferentialOutcome");
        assert_eq!(diff.verdict, DifferentialVerdict::Confirmed);
    }

    #[test]
    fn python_vuln_confirms_via_run_spec() {
        let Some(outcome) = run(Lang::Python, "vuln.py", "run") else {
            return;
        };
        assert!(
            outcome.triggered_by.is_some(),
            "Python XXE vuln must Confirm via run_spec; got {outcome:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("Confirmed run must carry a DifferentialOutcome");
        assert_eq!(diff.verdict, DifferentialVerdict::Confirmed);
    }

    #[test]
    fn php_vuln_confirms_via_run_spec() {
        let Some(outcome) = run(Lang::Php, "vuln.php", "run") else {
            return;
        };
        assert!(
            outcome.triggered_by.is_some(),
            "PHP XXE vuln must Confirm via run_spec; got {outcome:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("Confirmed run must carry a DifferentialOutcome");
        assert_eq!(diff.verdict, DifferentialVerdict::Confirmed);
    }

    #[test]
    fn ruby_vuln_confirms_via_run_spec() {
        let Some(outcome) = run(Lang::Ruby, "vuln.rb", "run") else {
            return;
        };
        assert!(
            outcome.triggered_by.is_some(),
            "Ruby XXE vuln must Confirm via run_spec; got {outcome:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("Confirmed run must carry a DifferentialOutcome");
        assert_eq!(diff.verdict, DifferentialVerdict::Confirmed);
    }

    #[test]
    fn go_vuln_confirms_via_run_spec() {
        let Some(outcome) = run(Lang::Go, "vuln.go", "run") else {
            return;
        };
        assert!(
            outcome.triggered_by.is_some(),
            "Go XXE vuln must Confirm via run_spec; got {outcome:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("Confirmed run must carry a DifferentialOutcome");
        assert_eq!(diff.verdict, DifferentialVerdict::Confirmed);
    }

    /// Phase 05 OOB-loopback observation: when an [`nyx_scanner::dynamic::oob::OobListener`]
    /// is attached and the runner exercises the `xxe-<lang>-oob-nonce`
    /// payload, the parser's external-entity hook performs a real HTTP
    /// GET against the loopback nonce URL and the listener records the
    /// hit.  Asserts both halves of the Phase 05 OOB closure: the
    /// callback observation AND the verdict-tier promotion from
    /// `Confirmed` to `ConfirmedProvenOob` (the runner's
    /// `build_oob_self_confirmed_outcome` path treats the OOB-nonce
    /// payload as self-confirming since a benign URL structurally
    /// cannot hit a per-finding nonce).
    fn run_oob(lang: Lang, fixture: &str, entry_name: &str) -> Option<RunOutcome> {
        use nyx_scanner::dynamic::oob::OobListener;
        use nyx_scanner::dynamic::sandbox::NetworkPolicy;
        use std::sync::Arc;

        let bin = toolchain_for(lang);
        if !command_available(bin) {
            eprintln!("SKIP {lang:?} {fixture} (oob): missing toolchain {bin}");
            return None;
        }
        let _guard = FIXTURE_LOCK.lock().unwrap_or_else(|e| e.into_inner());

        let listener = match OobListener::bind() {
            Ok(listener) => Arc::new(listener),
            Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied => {
                eprintln!("SKIP {lang:?} {fixture} (oob): loopback bind denied by sandbox");
                return None;
            }
            Err(e) => panic!("bind OOB listener on loopback: {e}"),
        };
        let (mut spec, _tmp) = build_spec(lang, fixture, entry_name);
        // Use a distinct workdir from the non-OOB e2e tests so the probe
        // channel files do not collide (both tests use the same fixture, so
        // the default spec_hash would resolve to the same
        // `/tmp/nyx-harness/<spec_hash>/__nyx_probes.jsonl` and the two runs
        // could clobber each other's drains under parallel nextest).
        spec.spec_hash = format!("{}-oob", spec.spec_hash);
        spec.finding_id = spec.spec_hash.clone();
        if matches!(lang, Lang::Java) {
            let workdir = std::path::PathBuf::from("/tmp/nyx-harness").join(&spec.spec_hash);
            let _ = std::fs::remove_dir_all(&workdir);
        }

        let opts = SandboxOptions {
            backend: SandboxBackend::Process,
            network_policy: NetworkPolicy::OobOutbound {
                listener: Arc::clone(&listener),
            },
            ..SandboxOptions::default()
        };

        for attempt in 0..3 {
            match run_spec(&spec, &opts) {
                Ok(outcome) => {
                    if is_jvm_cwd_flake(&outcome) && attempt < 2 {
                        eprintln!(
                            "RETRY {lang:?} {fixture} (oob): JVM cwd flake on attempt {attempt}",
                        );
                        std::thread::sleep(std::time::Duration::from_millis(200));
                        continue;
                    }
                    return Some(outcome);
                }
                Err(RunError::BuildFailed { stderr, attempts }) => {
                    eprintln!(
                        "SKIP {lang:?} {fixture} (oob): build failed after {attempts}: {stderr}",
                    );
                    return None;
                }
                Err(e) => panic!("run_spec({lang:?} {fixture} oob) errored: {e:?}"),
            }
        }
        None
    }

    fn assert_oob_recorded(outcome: &RunOutcome, label: &str) {
        let oob_attempt = outcome
            .attempts
            .iter()
            .find(|a| a.payload_label == label)
            .unwrap_or_else(|| {
                panic!(
                    "OOB payload {label:?} must run when listener is attached; outcome={outcome:?}"
                )
            });
        assert!(
            oob_attempt.outcome.oob_callback_seen,
            "parser external-entity hook must fetch loopback URL so OOB listener records the nonce; got attempt={oob_attempt:?}",
        );
        // Phase 05 OOB closure: the listener observation must promote the
        // verdict tier from `Confirmed` to `ConfirmedProvenOob`.  The
        // payload carries `oob_nonce_slot: true` + `benign_control: None`
        // so the runner's self-confirming path emits the upgraded verdict
        // and sets `triggered_by` on the OOB attempt itself.
        assert!(
            oob_attempt.triggered,
            "OOB attempt must mark triggered=true under the self-confirming OOB path; got attempt={oob_attempt:?}",
        );
        let diff = outcome
            .differential
            .as_ref()
            .expect("self-confirming OOB run must carry a DifferentialOutcome");
        assert_eq!(
            diff.verdict,
            DifferentialVerdict::ConfirmedProvenOob,
            "OOB callback observation must promote verdict tier; got diff={diff:?}",
        );
    }

    #[test]
    fn python_xxe_oob_loopback_records_callback() {
        let Some(outcome) = run_oob(Lang::Python, "vuln.py", "run") else {
            return;
        };
        assert_oob_recorded(&outcome, "xxe-python-oob-nonce");
    }

    #[test]
    fn java_xxe_oob_loopback_records_callback() {
        let Some(outcome) = run_oob(Lang::Java, "Vuln.java", "run") else {
            return;
        };
        assert_oob_recorded(&outcome, "xxe-java-oob-nonce");
    }

    #[test]
    fn php_xxe_oob_loopback_records_callback() {
        let Some(outcome) = run_oob(Lang::Php, "vuln.php", "run") else {
            return;
        };
        assert_oob_recorded(&outcome, "xxe-php-oob-nonce");
    }

    #[test]
    fn ruby_xxe_oob_loopback_records_callback() {
        let Some(outcome) = run_oob(Lang::Ruby, "vuln.rb", "run") else {
            return;
        };
        assert_oob_recorded(&outcome, "xxe-ruby-oob-nonce");
    }

    #[test]
    fn go_xxe_oob_loopback_records_callback() {
        let Some(outcome) = run_oob(Lang::Go, "vuln.go", "run") else {
            return;
        };
        assert_oob_recorded(&outcome, "xxe-go-oob-nonce");
    }
}