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lean_ctx/core/property_graph/
mod.rs

1//! Property Graph Engine — SQLite-backed code knowledge graph.
2//!
3//! Stores nodes (File, Symbol, Module) and edges (imports, calls, defines,
4//! exports) extracted by `deep_queries` + `import_resolver`.  Provides
5//! efficient traversal queries for impact analysis, architecture discovery,
6//! and graph-driven context loading.
7
8mod cross_source;
9mod edge;
10pub mod file_catalog;
11mod meta;
12mod node;
13mod queries;
14mod schema;
15pub mod snapshot;
16mod sync;
17
18pub use edge::{Edge, EdgeKind};
19pub use file_catalog::FileCatalogEntry;
20pub use meta::{PropertyGraphMetaV1, load_meta, meta_path, write_meta};
21pub use node::{Node, NodeKind};
22pub use queries::{
23    DependencyChain, GraphQuery, ImpactResult, edge_weight, file_connectivity, related_files,
24};
25pub use sync::{mirror_index, parse_symbol_metadata, populate_from_project_index};
26
27use rusqlite::Connection;
28use std::path::{Path, PathBuf};
29
30/// Resolve the directory for graph.db and graph.meta.json.
31///
32/// Uses `$LEAN_CTX_DATA_DIR/graphs/<project_hash>/` (consistent with
33/// `ProjectIndex::index_dir`).  Falls back to `<project>/.lean-ctx/`
34/// only when the global data directory cannot be resolved.
35pub fn graph_dir(project_root: &str) -> PathBuf {
36    if let Ok(data_dir) = crate::core::data_dir::lean_ctx_data_dir() {
37        let normalized = crate::core::graph_index::normalize_project_root(project_root);
38        let hash = crate::core::project_hash::hash_project_root(&normalized);
39        data_dir.join("graphs").join(hash)
40    } else {
41        Path::new(project_root).join(".lean-ctx")
42    }
43}
44
45/// Transparently migrate graph.db and graph.meta.json from the old
46/// per-project `.lean-ctx/` directory to the new `$DATA_DIR/graphs/` path.
47fn migrate_if_needed(project_root: &str, new_dir: &Path) {
48    let old_dir = Path::new(project_root).join(".lean-ctx");
49    if old_dir == new_dir {
50        return;
51    }
52    for file in &["graph.db", "graph.meta.json"] {
53        let old = old_dir.join(file);
54        let new = new_dir.join(file);
55        if old.exists()
56            && !new.exists()
57            && std::fs::rename(&old, &new).is_err()
58            && std::fs::copy(&old, &new).is_ok()
59        {
60            let _ = std::fs::remove_file(&old);
61        }
62    }
63}
64
65/// Property-graph engine generation. Bump whenever edge extraction changes
66/// (e.g. the `type_ref` edges that connect C#/Java same-namespace consumers to
67/// their definers, GH #398) so an existing graph built by an older engine is
68/// transparently rebuilt on the next query instead of being served without the
69/// new edges. Graphs whose `graph.meta.json` predates this stamp deserialize to
70/// engine version `0`, so the first query after an upgrade rebuilds once.
71pub const GRAPH_ENGINE_VERSION: u32 = 2;
72
73/// `true` when the persisted graph was built by an engine older than
74/// [`GRAPH_ENGINE_VERSION`] — or predates the version stamp entirely (missing or
75/// unreadable meta) — and must therefore be rebuilt before its edges can be
76/// trusted. Callers pair this with a node-count check: an empty graph is rebuilt
77/// regardless; a non-empty-but-outdated graph is rebuilt by this gate.
78pub fn engine_outdated(project_root: &str) -> bool {
79    load_meta(project_root).is_none_or(|m| m.engine_version < GRAPH_ENGINE_VERSION)
80}
81
82pub struct CodeGraph {
83    conn: Connection,
84    db_path: PathBuf,
85}
86
87impl CodeGraph {
88    pub fn open(project_root: &str) -> anyhow::Result<Self> {
89        let db_dir = graph_dir(project_root);
90        std::fs::create_dir_all(&db_dir)?;
91        migrate_if_needed(project_root, &db_dir);
92        let db_path = db_dir.join("graph.db");
93        let conn = Connection::open(&db_path)?;
94        conn.busy_timeout(std::time::Duration::from_secs(5))?;
95        schema::initialize(&conn)?;
96        Ok(Self { conn, db_path })
97    }
98
99    pub fn open_in_memory() -> anyhow::Result<Self> {
100        let conn = Connection::open_in_memory()?;
101        schema::initialize(&conn)?;
102        Ok(Self {
103            conn,
104            db_path: PathBuf::from(":memory:"),
105        })
106    }
107
108    pub fn db_path(&self) -> &Path {
109        &self.db_path
110    }
111
112    pub fn connection(&self) -> &Connection {
113        &self.conn
114    }
115
116    pub fn upsert_node(&self, node: &Node) -> anyhow::Result<i64> {
117        node::upsert(&self.conn, node)
118    }
119
120    pub fn upsert_edge(&self, edge: &Edge) -> anyhow::Result<()> {
121        edge::upsert(&self.conn, edge)
122    }
123
124    pub fn get_node_by_path(&self, file_path: &str) -> anyhow::Result<Option<Node>> {
125        node::get_by_path(&self.conn, file_path)
126    }
127
128    pub fn get_node_by_symbol(&self, name: &str, file_path: &str) -> anyhow::Result<Option<Node>> {
129        node::get_by_symbol(&self.conn, name, file_path)
130    }
131
132    pub fn remove_file_nodes(&self, file_path: &str) -> anyhow::Result<()> {
133        node::remove_by_file(&self.conn, file_path)
134    }
135
136    pub fn edges_from(&self, node_id: i64) -> anyhow::Result<Vec<Edge>> {
137        edge::from_node(&self.conn, node_id)
138    }
139
140    pub fn edges_to(&self, node_id: i64) -> anyhow::Result<Vec<Edge>> {
141        edge::to_node(&self.conn, node_id)
142    }
143
144    pub fn dependents(&self, file_path: &str) -> anyhow::Result<Vec<String>> {
145        queries::dependents(&self.conn, file_path)
146    }
147
148    pub fn dependencies(&self, file_path: &str) -> anyhow::Result<Vec<String>> {
149        queries::dependencies(&self.conn, file_path)
150    }
151
152    pub fn impact_analysis(
153        &self,
154        file_path: &str,
155        max_depth: usize,
156    ) -> anyhow::Result<ImpactResult> {
157        queries::impact_analysis(&self.conn, file_path, max_depth)
158    }
159
160    pub fn dependency_chain(
161        &self,
162        from: &str,
163        to: &str,
164    ) -> anyhow::Result<Option<DependencyChain>> {
165        queries::dependency_chain(&self.conn, from, to)
166    }
167
168    pub fn related_files(
169        &self,
170        file_path: &str,
171        limit: usize,
172    ) -> anyhow::Result<Vec<(String, f64)>> {
173        queries::related_files(&self.conn, file_path, limit)
174    }
175
176    pub fn file_connectivity(
177        &self,
178        file_path: &str,
179    ) -> anyhow::Result<std::collections::HashMap<String, (usize, usize)>> {
180        queries::file_connectivity(&self.conn, file_path)
181    }
182
183    pub fn node_count(&self) -> anyhow::Result<usize> {
184        node::count(&self.conn)
185    }
186
187    pub fn edge_count(&self) -> anyhow::Result<usize> {
188        edge::count(&self.conn)
189    }
190
191    /// Persist a cross-source edge (code file ↔ external source URI) into the
192    /// dedicated `cross_source_edges` table. Keeps the higher weight on conflict
193    /// so repeated provider ingests don't downgrade an established link (#682).
194    pub fn upsert_cross_source_edge(
195        &self,
196        from: &str,
197        to: &str,
198        kind: &str,
199        weight: f32,
200    ) -> anyhow::Result<()> {
201        cross_source::upsert(&self.conn, from, to, kind, weight)
202    }
203
204    /// All cross-source edges as `IndexEdge`s, ready for `cross_source_hints`.
205    pub fn all_cross_source_edges(&self) -> Vec<crate::core::graph_index::IndexEdge> {
206        cross_source::all(&self.conn).unwrap_or_default()
207    }
208
209    pub fn cross_source_edge_count(&self) -> anyhow::Result<usize> {
210        cross_source::count(&self.conn)
211    }
212
213    pub fn clear(&self) -> anyhow::Result<()> {
214        self.conn.execute_batch(
215            "DELETE FROM edges; DELETE FROM nodes; DELETE FROM file_catalog; \
216             DELETE FROM cross_source_edges;",
217        )?;
218        Ok(())
219    }
220
221    /// Clear only the code graph (nodes, edges, file catalog), preserving
222    /// provider `cross_source_edges`. Used by the graph_index→PG mirror (#682.1)
223    /// so rebuilding the code graph never drops lateral provider hints, which
224    /// live in their own table and are repopulated on a separate ingest cycle.
225    pub fn clear_code_graph(&self) -> anyhow::Result<()> {
226        self.conn
227            .execute_batch("DELETE FROM edges; DELETE FROM nodes; DELETE FROM file_catalog;")?;
228        Ok(())
229    }
230
231    pub fn upsert_file_catalog(&self, entry: &FileCatalogEntry) -> anyhow::Result<()> {
232        file_catalog::upsert(&self.conn, entry)
233    }
234
235    pub fn get_file_catalog(&self, path: &str) -> anyhow::Result<Option<FileCatalogEntry>> {
236        file_catalog::get(&self.conn, path)
237    }
238
239    pub fn file_catalog_count(&self) -> anyhow::Result<usize> {
240        file_catalog::count(&self.conn)
241    }
242
243    pub fn file_catalog_paths(&self) -> anyhow::Result<Vec<String>> {
244        file_catalog::all_paths(&self.conn)
245    }
246
247    pub fn find_symbols(
248        &self,
249        name: &str,
250        file_filter: Option<&str>,
251        kind_filter: Option<&str>,
252    ) -> anyhow::Result<Vec<Node>> {
253        node::find_symbols(&self.conn, name, file_filter, kind_filter)
254    }
255
256    pub fn symbol_count(&self) -> anyhow::Result<usize> {
257        node::symbol_count(&self.conn)
258    }
259
260    /// Every symbol node with its line span (unfiltered). Backend for the
261    /// call-graph symbol table after the `graph_index` teardown (#696).
262    pub fn all_symbols(&self) -> anyhow::Result<Vec<Node>> {
263        node::all_symbols(&self.conn)
264    }
265
266    pub fn all_edges_flat(&self) -> anyhow::Result<Vec<(String, String, String, f64)>> {
267        node::all_edges_flat(&self.conn)
268    }
269}
270
271#[cfg(test)]
272mod tests {
273    use super::*;
274    use crate::core::data_dir::test_env_lock;
275
276    fn test_graph() -> CodeGraph {
277        CodeGraph::open_in_memory().unwrap()
278    }
279
280    #[test]
281    fn create_and_query_nodes() {
282        let g = test_graph();
283
284        let id = g.upsert_node(&Node::file("src/main.rs")).unwrap();
285        assert!(id > 0);
286
287        let found = g.get_node_by_path("src/main.rs").unwrap();
288        assert!(found.is_some());
289        assert_eq!(found.unwrap().file_path, "src/main.rs");
290    }
291
292    #[test]
293    fn create_and_query_edges() {
294        let g = test_graph();
295
296        let a = g.upsert_node(&Node::file("src/a.rs")).unwrap();
297        let b = g.upsert_node(&Node::file("src/b.rs")).unwrap();
298
299        g.upsert_edge(&Edge::new(a, b, EdgeKind::Imports)).unwrap();
300
301        let from_a = g.edges_from(a).unwrap();
302        assert_eq!(from_a.len(), 1);
303        assert_eq!(from_a[0].target_id, b);
304
305        let to_b = g.edges_to(b).unwrap();
306        assert_eq!(to_b.len(), 1);
307        assert_eq!(to_b[0].source_id, a);
308    }
309
310    #[test]
311    fn dependents_query() {
312        let g = test_graph();
313
314        let main = g.upsert_node(&Node::file("src/main.rs")).unwrap();
315        let lib = g.upsert_node(&Node::file("src/lib.rs")).unwrap();
316        let utils = g.upsert_node(&Node::file("src/utils.rs")).unwrap();
317
318        g.upsert_edge(&Edge::new(main, lib, EdgeKind::Imports))
319            .unwrap();
320        g.upsert_edge(&Edge::new(utils, lib, EdgeKind::Imports))
321            .unwrap();
322
323        let deps = g.dependents("src/lib.rs").unwrap();
324        assert_eq!(deps.len(), 2);
325        assert!(deps.contains(&"src/main.rs".to_string()));
326        assert!(deps.contains(&"src/utils.rs".to_string()));
327    }
328
329    #[test]
330    fn dependencies_query() {
331        let g = test_graph();
332
333        let main = g.upsert_node(&Node::file("src/main.rs")).unwrap();
334        let lib = g.upsert_node(&Node::file("src/lib.rs")).unwrap();
335        let config = g.upsert_node(&Node::file("src/config.rs")).unwrap();
336
337        g.upsert_edge(&Edge::new(main, lib, EdgeKind::Imports))
338            .unwrap();
339        g.upsert_edge(&Edge::new(main, config, EdgeKind::Imports))
340            .unwrap();
341
342        let deps = g.dependencies("src/main.rs").unwrap();
343        assert_eq!(deps.len(), 2);
344    }
345
346    #[test]
347    #[allow(clippy::many_single_char_names)] // graph test nodes: a, b, c, d, e
348    fn impact_analysis_depth() {
349        let g = test_graph();
350
351        let a = g.upsert_node(&Node::file("a.rs")).unwrap();
352        let b = g.upsert_node(&Node::file("b.rs")).unwrap();
353        let c = g.upsert_node(&Node::file("c.rs")).unwrap();
354        let d = g.upsert_node(&Node::file("d.rs")).unwrap();
355
356        g.upsert_edge(&Edge::new(b, a, EdgeKind::Imports)).unwrap();
357        g.upsert_edge(&Edge::new(c, b, EdgeKind::Imports)).unwrap();
358        g.upsert_edge(&Edge::new(d, c, EdgeKind::Imports)).unwrap();
359
360        let impact = g.impact_analysis("a.rs", 2).unwrap();
361        assert!(impact.affected_files.contains(&"b.rs".to_string()));
362        assert!(impact.affected_files.contains(&"c.rs".to_string()));
363        assert!(!impact.affected_files.contains(&"d.rs".to_string()));
364
365        let deep = g.impact_analysis("a.rs", 10).unwrap();
366        assert!(deep.affected_files.contains(&"d.rs".to_string()));
367    }
368
369    #[test]
370    fn upsert_idempotent() {
371        let g = test_graph();
372
373        let id1 = g.upsert_node(&Node::file("src/main.rs")).unwrap();
374        let id2 = g.upsert_node(&Node::file("src/main.rs")).unwrap();
375        assert_eq!(id1, id2);
376        assert_eq!(g.node_count().unwrap(), 1);
377    }
378
379    #[test]
380    fn remove_file_cascades() {
381        let g = test_graph();
382
383        let a = g.upsert_node(&Node::file("src/a.rs")).unwrap();
384        let b = g.upsert_node(&Node::file("src/b.rs")).unwrap();
385        let sym = g
386            .upsert_node(&Node::symbol("MyStruct", "src/a.rs", NodeKind::Symbol))
387            .unwrap();
388
389        g.upsert_edge(&Edge::new(a, b, EdgeKind::Imports)).unwrap();
390        g.upsert_edge(&Edge::new(sym, b, EdgeKind::Calls)).unwrap();
391
392        g.remove_file_nodes("src/a.rs").unwrap();
393
394        assert!(g.get_node_by_path("src/a.rs").unwrap().is_none());
395        assert_eq!(g.edge_count().unwrap(), 0);
396    }
397
398    #[test]
399    fn dependency_chain_found() {
400        let g = test_graph();
401
402        let a = g.upsert_node(&Node::file("a.rs")).unwrap();
403        let b = g.upsert_node(&Node::file("b.rs")).unwrap();
404        let c = g.upsert_node(&Node::file("c.rs")).unwrap();
405
406        g.upsert_edge(&Edge::new(a, b, EdgeKind::Imports)).unwrap();
407        g.upsert_edge(&Edge::new(b, c, EdgeKind::Imports)).unwrap();
408
409        let chain = g.dependency_chain("a.rs", "c.rs").unwrap();
410        assert!(chain.is_some());
411        let chain = chain.unwrap();
412        assert_eq!(chain.path, vec!["a.rs", "b.rs", "c.rs"]);
413    }
414
415    #[test]
416    fn counts() {
417        let g = test_graph();
418        assert_eq!(g.node_count().unwrap(), 0);
419        assert_eq!(g.edge_count().unwrap(), 0);
420
421        let a = g.upsert_node(&Node::file("a.rs")).unwrap();
422        let b = g.upsert_node(&Node::file("b.rs")).unwrap();
423        g.upsert_edge(&Edge::new(a, b, EdgeKind::Imports)).unwrap();
424
425        assert_eq!(g.node_count().unwrap(), 2);
426        assert_eq!(g.edge_count().unwrap(), 1);
427    }
428
429    #[test]
430    fn multi_edge_dependents() {
431        let g = test_graph();
432
433        let a = g.upsert_node(&Node::file("src/a.rs")).unwrap();
434        let b = g.upsert_node(&Node::file("src/b.rs")).unwrap();
435        let c = g.upsert_node(&Node::file("src/c.rs")).unwrap();
436
437        g.upsert_edge(&Edge::new(b, a, EdgeKind::Imports)).unwrap();
438        g.upsert_edge(&Edge::new(c, a, EdgeKind::Calls)).unwrap();
439
440        let deps = g.dependents("src/a.rs").unwrap();
441        assert_eq!(deps.len(), 2);
442        assert!(deps.contains(&"src/b.rs".to_string()));
443        assert!(deps.contains(&"src/c.rs".to_string()));
444    }
445
446    #[test]
447    fn multi_edge_impact_analysis() {
448        let g = test_graph();
449
450        let a = g.upsert_node(&Node::file("a.rs")).unwrap();
451        let b = g.upsert_node(&Node::file("b.rs")).unwrap();
452        let c = g.upsert_node(&Node::file("c.rs")).unwrap();
453
454        g.upsert_edge(&Edge::new(b, a, EdgeKind::Imports)).unwrap();
455        g.upsert_edge(&Edge::new(c, b, EdgeKind::Calls)).unwrap();
456
457        let impact = g.impact_analysis("a.rs", 10).unwrap();
458        assert!(impact.affected_files.contains(&"b.rs".to_string()));
459        assert!(impact.affected_files.contains(&"c.rs".to_string()));
460    }
461
462    #[test]
463    fn related_files_scored() {
464        let g = test_graph();
465
466        let a = g.upsert_node(&Node::file("a.rs")).unwrap();
467        let b = g.upsert_node(&Node::file("b.rs")).unwrap();
468        let c = g.upsert_node(&Node::file("c.rs")).unwrap();
469
470        g.upsert_edge(&Edge::new(a, b, EdgeKind::Imports)).unwrap();
471        g.upsert_edge(&Edge::new(a, b, EdgeKind::Calls)).unwrap();
472        g.upsert_edge(&Edge::new(a, c, EdgeKind::TypeRef)).unwrap();
473
474        let related = g.related_files("a.rs", 10).unwrap();
475        assert_eq!(related.len(), 2);
476        let b_score = related.iter().find(|(p, _)| p == "b.rs").unwrap().1;
477        let c_score = related.iter().find(|(p, _)| p == "c.rs").unwrap().1;
478        assert!(
479            b_score > c_score,
480            "b.rs has imports+calls, should rank higher than c.rs with type_ref"
481        );
482    }
483
484    #[test]
485    fn graph_dir_uses_data_dir_when_set() {
486        let tmp = tempfile::tempdir().unwrap();
487        let project = tmp.path().join("myproject");
488        std::fs::create_dir_all(&project).unwrap();
489
490        let data_dir = tmp.path().join("data");
491        std::fs::create_dir_all(&data_dir).unwrap();
492
493        let _guard = test_env_lock();
494        crate::test_env::set_var("LEAN_CTX_DATA_DIR", data_dir.to_str().unwrap());
495
496        let dir = graph_dir(project.to_str().unwrap());
497        assert!(dir.starts_with(&data_dir));
498        assert!(dir.to_string_lossy().contains("graphs"));
499
500        crate::test_env::remove_var("LEAN_CTX_DATA_DIR");
501    }
502
503    #[test]
504    fn graph_dir_returns_consistent_hash_dir() {
505        let tmp = tempfile::tempdir().unwrap();
506        let project = tmp.path().join("hash_project");
507        std::fs::create_dir_all(&project).unwrap();
508
509        let data_dir = tmp.path().join("data2");
510        std::fs::create_dir_all(&data_dir).unwrap();
511
512        let _guard = test_env_lock();
513        crate::test_env::set_var("LEAN_CTX_DATA_DIR", data_dir.to_str().unwrap());
514
515        let dir1 = graph_dir(project.to_str().unwrap());
516        let dir2 = graph_dir(project.to_str().unwrap());
517        assert_eq!(dir1, dir2, "graph_dir should be deterministic");
518        assert!(dir1.to_string_lossy().contains("graphs"));
519
520        crate::test_env::remove_var("LEAN_CTX_DATA_DIR");
521    }
522
523    #[test]
524    fn migration_moves_old_files() {
525        let tmp = tempfile::tempdir().unwrap();
526        let project = tmp.path().join("migtest");
527        let old_dir = project.join(".lean-ctx");
528        std::fs::create_dir_all(&old_dir).unwrap();
529        std::fs::write(old_dir.join("graph.db"), b"old-db-content").unwrap();
530        std::fs::write(old_dir.join("graph.meta.json"), b"old-meta").unwrap();
531
532        let new_dir = tmp.path().join("newloc");
533        std::fs::create_dir_all(&new_dir).unwrap();
534
535        migrate_if_needed(project.to_str().unwrap(), &new_dir);
536
537        assert!(new_dir.join("graph.db").exists());
538        assert!(new_dir.join("graph.meta.json").exists());
539        assert!(!old_dir.join("graph.db").exists());
540        assert!(!old_dir.join("graph.meta.json").exists());
541        assert_eq!(
542            std::fs::read_to_string(new_dir.join("graph.db")).unwrap(),
543            "old-db-content"
544        );
545    }
546
547    #[test]
548    fn migration_skips_when_new_exists() {
549        let tmp = tempfile::tempdir().unwrap();
550        let project = tmp.path().join("skiptest");
551        let old_dir = project.join(".lean-ctx");
552        std::fs::create_dir_all(&old_dir).unwrap();
553        std::fs::write(old_dir.join("graph.db"), b"old").unwrap();
554
555        let new_dir = tmp.path().join("newloc2");
556        std::fs::create_dir_all(&new_dir).unwrap();
557        std::fs::write(new_dir.join("graph.db"), b"already-there").unwrap();
558
559        migrate_if_needed(project.to_str().unwrap(), &new_dir);
560
561        assert_eq!(
562            std::fs::read_to_string(new_dir.join("graph.db")).unwrap(),
563            "already-there"
564        );
565        assert!(old_dir.join("graph.db").exists());
566    }
567
568    #[test]
569    fn open_with_data_dir() {
570        let tmp = tempfile::tempdir().unwrap();
571        let project = tmp.path().join("opentest");
572        std::fs::create_dir_all(&project).unwrap();
573
574        let data_dir = tmp.path().join("xdata");
575        std::fs::create_dir_all(&data_dir).unwrap();
576
577        let _guard = test_env_lock();
578        crate::test_env::set_var("LEAN_CTX_DATA_DIR", data_dir.to_str().unwrap());
579
580        let g = CodeGraph::open(project.to_str().unwrap()).unwrap();
581        assert!(g.db_path().starts_with(&data_dir));
582        assert!(g.db_path().to_string_lossy().contains("graph.db"));
583
584        crate::test_env::remove_var("LEAN_CTX_DATA_DIR");
585    }
586
587    #[test]
588    fn meta_path_uses_graph_dir() {
589        let tmp = tempfile::tempdir().unwrap();
590        let project = tmp.path().join("metatest");
591        std::fs::create_dir_all(&project).unwrap();
592
593        let data_dir = tmp.path().join("mdata");
594        std::fs::create_dir_all(&data_dir).unwrap();
595
596        let _guard = test_env_lock();
597        crate::test_env::set_var("LEAN_CTX_DATA_DIR", data_dir.to_str().unwrap());
598
599        let mp = meta::meta_path(project.to_str().unwrap());
600        assert!(mp.starts_with(&data_dir));
601        assert!(mp.to_string_lossy().contains("graph.meta.json"));
602
603        crate::test_env::remove_var("LEAN_CTX_DATA_DIR");
604    }
605
606    #[test]
607    fn engine_outdated_flags_old_and_missing_meta() {
608        let _iso = crate::core::data_dir::isolated_data_dir();
609        let proj = tempfile::tempdir().unwrap();
610        let root = proj.path().to_str().unwrap();
611
612        // No meta on disk yet -> outdated (an unbuilt graph forces a build).
613        assert!(engine_outdated(root), "missing meta must read as outdated");
614
615        // Meta from an engine generation before the version stamp -> outdated.
616        let mut meta = PropertyGraphMetaV1 {
617            built_at: "2026-01-01T00:00:00Z".to_string(),
618            engine_version: 0,
619            ..Default::default()
620        };
621        write_meta(root, &meta).unwrap();
622        assert!(
623            engine_outdated(root),
624            "engine_version 0 must read as outdated"
625        );
626
627        // Meta stamped with the current engine -> up to date.
628        meta.engine_version = GRAPH_ENGINE_VERSION;
629        write_meta(root, &meta).unwrap();
630        assert!(
631            !engine_outdated(root),
632            "current engine_version must read as up to date"
633        );
634    }
635}