test(node): guard that every repo-scoped handler is visibility-gated

crates/gitlawb-node/src/api/mod.rs

@@ -239,4 +239,322 @@ mod authz_guard {
             "a marker present only in a comment must not count as an enforced gate"
         );
     }
+
+    /// All `pub async fn` / `pub(crate) async fn` handler names declared in `src`.
+    /// Verb-agnostic on purpose: a repo-scoped read of any name is in scope, so a
+    /// handler named `fetch_*` / `replicate_*` / `info_refs` cannot escape the gate
+    /// check by not being called `list_*` / `get_*`.
+    fn handler_names(src: &str) -> Vec<String> {
+        ["pub async fn ", "pub(crate) async fn "]
+            .iter()
+            .flat_map(|decl| {
+                src.match_indices(decl).map(move |(i, _)| {
+                    src[i + decl.len()..]
+                        .chars()
+                        .take_while(|c| c.is_alphanumeric() || *c == '_')
+                        .collect::<String>()
+                })
+            })
+            .collect()
+    }
+
+    /// True when the handler's signature takes an owner+repo path
+    /// (`Path<(String, String...)>`), i.e. it is a repo-scoped read rather than a
+    /// node-wide aggregate (`/stats`, `/ipfs/pins`, the global feeds).
+    fn is_repo_scoped(body: &str) -> bool {
+        let header = &body[..body.find('{').unwrap_or(body.len())];
+        header.contains("Path<(String, String")
+    }
+
+    /// True when at least one gate marker runs for EVERY service — i.e. some
+    /// marker sits outside any `if service == ...` discriminator block. A gate
+    /// that appears ONLY inside such a block (as the info/refs advertisement gate
+    /// did before #119: `visibility_check` ran under `if service ==
+    /// "git-upload-pack"`, leaving `git-receive-pack` ungated) covers a subset of
+    /// services and must NOT count as a full gate. Other handlers carry no
+    /// `service ==` discriminator, so for them this matches the plain
+    /// substring check. NOTE: only `if service ==` is detected — a
+    /// `match service { .. }` discriminator is NOT tracked and a gate inside one
+    /// arm would pass as full; avoid that shape, or extend the span loop below.
+    fn gate_runs_unconditionally(body: &str, markers: &[&str]) -> bool {
+        // Brace-matched spans of each `if service == ...` block.
+        let mut cond_spans: Vec<(usize, usize)> = Vec::new();
+        let mut search = 0;
+        while let Some(rel) = body[search..].find("if service ==") {
+            let cond_start = search + rel;
+            let Some(brace_rel) = body[cond_start..].find('{') else {
+                break;
+            };
+            let open = cond_start + brace_rel;
+            let mut depth = 0i32;
+            let mut end = body.len();
+            for (i, c) in body[open..].char_indices() {
+                match c {
+                    '{' => depth += 1,
+                    '}' => {
+                        depth -= 1;
+                        if depth == 0 {
+                            end = open + i;
+                            break;
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            cond_spans.push((open, end));
+            // On an unclosed block `end` stays at body.len() (the fail-safe
+            // direction: treat the rest as conditional rather than mask a gate);
+            // clamp so the next slice can't index past the end and panic.
+            search = (end + 1).min(body.len());
+        }
+        markers.iter().any(|m| {
+            body.match_indices(m)
+                .any(|(pos, _)| !cond_spans.iter().any(|(s, e)| pos >= *s && pos <= *e))
+        })
+    }
+
+    /// Egress gate guard: every repo-scoped handler (`Path<(String, String..)>`)
+    /// must carry an authz marker — a read gate (`authorize_repo_read` /
+    /// `visibility_check`), or a write gate (`require_repo_owner` / `require_owner`
+    /// / `did_matches` / a `&auth.0` self-binding) — or be listed in KNOWN_UNGATED
+    /// (the tracked, ungated reads). A new ungated handler of ANY verb trips this,
+    /// and a completeness scan over `src/api/` trips it for a whole new module that
+    /// adds a repo-scoped handler without being wired into `sources`. Mutations are
+    /// also checked precisely, per handler, by the mutation guard above; here they
+    /// only need *some* binding so the net stays verb-agnostic.
+    ///
+    /// Scope and limits (this is a source scrape; the runtime route guard covers
+    /// behaviour):
+    /// - It proves a gate is CALLED, not that it runs on the requested path: a
+    ///   content handler gating `"/"` instead of the subtree still passes here.
+    /// - It sees handlers taking the owner+repo tuple `Path<(String, String..)>`; a
+    ///   repo identified by a struct/custom extractor would be missed (the helper
+    ///   unit tests pin these boundaries).
+    /// - KNOWN_UNGATED entries need a real open issue and review; the staleness
+    ///   assert removes one only once its gate lands.
+    #[test]
+    fn every_repo_scoped_handler_is_gated() {
+        let sources: &[(&str, &str)] = &[
+            (include_str!("bounties.rs"), "bounties.rs"),
+            (include_str!("certs.rs"), "certs.rs"),
+            (include_str!("changelog.rs"), "changelog.rs"),
+            (include_str!("encrypted.rs"), "encrypted.rs"),
+            (include_str!("events.rs"), "events.rs"),
+            (include_str!("issues.rs"), "issues.rs"),
+            (include_str!("labels.rs"), "labels.rs"),
+            (include_str!("protect.rs"), "protect.rs"),
+            (include_str!("pulls.rs"), "pulls.rs"),
+            (include_str!("replicas.rs"), "replicas.rs"),
+            (include_str!("repos.rs"), "repos.rs"),
+            (include_str!("stars.rs"), "stars.rs"),
+            (include_str!("visibility.rs"), "visibility.rs"),
+            (include_str!("webhooks.rs"), "webhooks.rs"),
+        ];
+        let listed: std::collections::HashSet<&str> = sources.iter().map(|(_, f)| *f).collect();
+        assert!(!listed.is_empty(), "read-guard `sources` is empty");
+
+        // Completeness: every api/*.rs NOT already in `sources` must declare no
+        // repo-scoped handler, so a brand-new module cannot add an ungated handler
+        // the scrape never looks at. Reads the directory at test time (so the list
+        // cannot silently drift from the filesystem) and only inspects unlisted
+        // files — listed files are covered by the per-handler loop below.
+        let api_dir = concat!(env!("CARGO_MANIFEST_DIR"), "/src/api");
+        for (_, f) in sources {
+            assert!(
+                std::path::Path::new(api_dir).join(f).exists(),
+                "read-guard `sources` lists {f} but the file does not exist"
+            );
+        }
+        for entry in std::fs::read_dir(api_dir).expect("read src/api") {
+            let path = entry.expect("dir entry").path();
+            let fname = path.file_name().unwrap().to_string_lossy().into_owned();
+            if !fname.ends_with(".rs") || fname == "mod.rs" || listed.contains(fname.as_str()) {
+                continue;
+            }
+            let src = std::fs::read_to_string(&path).expect("read api file");
+            let has_repo_handler = handler_names(&src)
+                .iter()
+                .any(|n| is_repo_scoped(&fn_body(&src, n)));
+            assert!(
+                !has_repo_handler,
+                "api/{fname} declares a repo-scoped handler but is not in the egress \
+                 guard `sources` list — add it so its handlers are gate-checked"
+            );
+        }
+
+        // Repo-scoped reads known to be ungated today, each tracked by an issue.
+        // Remove an entry the moment its gate lands (the staleness assert enforces it).
+        let known_ungated: &[(&str, &str)] = &[
+            // info/refs gates only git-upload-pack today; git-receive-pack
+            // advertisement is ungated until #119 makes the gate unconditional.
+            ("git_info_refs", "#119"),
+            ("list_certs", "#120"),
+            ("get_cert", "#120"),
+            ("list_issues", "#120"),
+            ("get_issue", "#120"),
+            ("list_issue_comments", "#120"),
+            ("list_labels", "#120"),
+            ("list_repo_bounties", "#120"),
+            ("get_star_status", "#120"),
+            ("list_repo_events", "#94 (PR #113)"),
+            ("list_webhooks", "#94 (PR #113)"),
+            ("list_replicas", "PR #113"),
+            ("list_protected_branches", "PR #113"),
+        ];
+        let is_known = |n: &str| known_ungated.iter().any(|(k, _)| *k == n);
+        // Any one of these = the handler binds the caller to an authz decision: the
+        // first two are read gates, the rest are the write/owner/self-binding forms.
+        // A repo-scoped mutation passes here on its write gate; the mutation guard
+        // above additionally verifies the exact gate type per handler. NOTE: a local
+        // rename of `caller`/`replica_did` must be paired with a marker update here.
+        let markers = [
+            "authorize_repo_read(",
+            "visibility_check(",
+            "require_repo_owner(",
+            "require_owner(",
+            "did_matches(",
+            "caller = &auth.0",
+            "replica_did = &auth.0",
+        ];
+
+        // Every KNOWN_UNGATED name must be a real handler (catch typos / renames).
+        let all: std::collections::HashSet<String> =
+            sources.iter().flat_map(|(s, _)| handler_names(s)).collect();
+        for (n, _) in known_ungated {
+            assert!(
+                all.contains(*n),
+                "KNOWN_UNGATED lists `{n}`, which is not a real handler (renamed or removed?)"
+            );
+        }
+
+        let mut checked = 0usize;
+        for (src, file) in sources {
+            for name in handler_names(src) {
+                let body = fn_body(src, &name);
+                if !is_repo_scoped(&body) {
+                    continue; // node-wide aggregate, not a repo-scoped surface
+                }
+                checked += 1;
+                let gated = gate_runs_unconditionally(&body, &markers);
+                assert!(
+                    gated || is_known(&name),
+                    "repo-scoped handler `{name}` ({file}) has no authz gate and is \
+                     not in KNOWN_UNGATED — add the visibility/owner gate with the \
+                     caller, or track it there"
+                );
+                assert!(
+                    !(gated && is_known(&name)),
+                    "handler `{name}` ({file}) is now gated — remove it from \
+                     KNOWN_UNGATED so the allowlist stays an accurate gap list"
+                );
+            }
+        }
+        // Tripwire: if the scrape silently stopped finding handlers (e.g. a parser
+        // regression in handler_names/is_repo_scoped), this floor fails loudly
+        // instead of the guard passing vacuously. Current count is ~54 repo-scoped
+        // handlers; 20 is a deliberate floor that trips only on a gross regression.
+        assert!(
+            checked >= 20,
+            "egress guard only checked {checked} repo-scoped handlers — the scrape likely broke"
+        );
+    }
+
+    /// Pins the `handler_names` boundary: it collects every `pub`/`pub(crate)
+    /// async fn` regardless of verb (so a `fetch_*` read cannot escape), and skips
+    /// private `async fn` and sync `fn` helpers.
+    #[test]
+    fn handler_names_finds_all_pub_async_and_skips_others() {
+        let src = "pub async fn list_things() {}\n\
+                   pub async fn fetch_thing() {}\n\
+                   pub(crate) async fn get_crate_thing() {}\n\
+                   async fn private_helper() {}\n\
+                   fn sync_helper() {}\n";
+        let names = handler_names(src);
+        // Verb-agnostic: a non-list/get read verb is still seen.
+        assert!(names.contains(&"list_things".to_string()));
+        assert!(names.contains(&"fetch_thing".to_string()));
+        // pub(crate) routed handlers are in scope too.
+        assert!(names.contains(&"get_crate_thing".to_string()));
+        // Private/sync helpers are not routed handlers and are skipped.
+        assert!(!names
+            .iter()
+            .any(|n| n == "private_helper" || n == "sync_helper"));
+    }
+
+    /// Pins the `is_repo_scoped` boundary: an owner+repo tuple Path is repo-scoped;
+    /// a single-segment or absent Path is a node-wide aggregate.
+    #[test]
+    fn is_repo_scoped_requires_owner_repo_path() {
+        let repo =
+            "fn get_x(s: State, Path((owner, name)): Path<(String, String)>) {\n  body();\n}";
+        let three = "fn get_y(Path((o, n, id)): Path<(String, String, String)>) {\n  body();\n}";
+        let node_wide = "fn list_z(s: State<AppState>) {\n  body();\n}";
+        let single = "fn get_w(Path(cid): Path<String>) {\n  body();\n}";
+        assert!(is_repo_scoped(repo), "owner+repo tuple is repo-scoped");
+        assert!(is_repo_scoped(three), "owner+repo+id tuple is repo-scoped");
+        assert!(!is_repo_scoped(node_wide), "no Path is node-wide");
+        assert!(
+            !is_repo_scoped(single),
+            "single-segment Path is not repo-scoped"
+        );
+    }
+
+    /// Pins `gate_runs_unconditionally`: a gate nested only inside an
+    /// `if service == ...` block is conditional (does NOT count), while the same
+    /// gate at the top level — or an additional unconditional one — does.
+    #[test]
+    fn conditional_service_gate_is_not_a_full_gate() {
+        let markers = ["visibility_check("];
+        // Gate runs only for one service: not a full gate.
+        let conditional = "fn f() {\n  \
+            if service == \"git-upload-pack\" {\n    \
+                visibility_check(rules, caller);\n  \
+            }\n  \
+            if service == \"git-receive-pack\" { acquire_fresh(); }\n}";
+        assert!(
+            !gate_runs_unconditionally(conditional, &markers),
+            "a gate only inside `if service ==` covers a subset of services"
+        );
+        // Same gate at top level: full gate.
+        let unconditional = "fn f() {\n  \
+            visibility_check(rules, caller);\n  \
+            if service == \"git-receive-pack\" { acquire_fresh(); }\n}";
+        assert!(
+            gate_runs_unconditionally(unconditional, &markers),
+            "an unconditional gate runs for every service"
+        );
+        // A gate inside EACH of two service blocks, none outside: still a
+        // subset (no service clears it unconditionally), so not a full gate.
+        let both_conditional = "fn f() {\n  \
+            if service == \"git-upload-pack\" { visibility_check(a); }\n  \
+            if service == \"git-receive-pack\" { visibility_check(b); }\n}";
+        assert!(
+            !gate_runs_unconditionally(both_conditional, &markers),
+            "a gate inside every service block is still conditional"
+        );
+        // A marker inside one block AND again unconditionally: the
+        // unconditional occurrence makes it a full gate (exercises the
+        // match_indices scan past the in-block hit).
+        let inside_and_outside = "fn f() {\n  \
+            if service == \"git-upload-pack\" { visibility_check(a); }\n  \
+            visibility_check(b);\n}";
+        assert!(
+            gate_runs_unconditionally(inside_and_outside, &markers),
+            "an unconditional occurrence counts even when another is conditional"
+        );
+        // No marker at all: not gated.
+        assert!(!gate_runs_unconditionally(
+            "fn f() { do_thing(); }",
+            &markers
+        ));
+        // An unclosed `if service ==` block (e.g. phantom brace from a string
+        // literal) must not panic on the slice advance; the span runs to EOF, so
+        // the in-block marker reads as conditional. Real Rust source is balanced,
+        // so this only guards the scraper against a future pathological body.
+        let unclosed = "fn f() { if service == \"x\" { visibility_check(a);";
+        assert!(
+            !gate_runs_unconditionally(unclosed, &markers),
+            "an unclosed service block must not panic and stays conditional"
+        );
+    }
 }