From b9fb298cae45bcbb9c7dc2681d2c14db6630039e Mon Sep 17 00:00:00 2001
From: Bonobo <github@in9.at>
Date: Wed, 2 Sep 2026 13:22:27 +0200
Subject: [PATCH] perf(neo4j): precompute row sort keys

---
 src/build/neo4j/rows.ts          | 19 +++++++++++--------
 test/neo4j-edge-identity.test.ts | 18 ++++++++++++++++++
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/build/neo4j/rows.ts b/src/build/neo4j/rows.ts
index 35d2107..0056703 100644
--- a/src/build/neo4j/rows.ts
+++ b/src/build/neo4j/rows.ts
@@ -109,14 +109,17 @@ export class RowBuilder {
 
   finish(): GraphRows {
     for (const e of this.deferred) if (this.keys.has(e.to.value)) this.edges.push(e);
-    const nodes = [...this.nodes.values()].sort((a, b) =>
-      `${a.labels[0]}\0${a.value}`.localeCompare(`${b.labels[0]}\0${b.value}`),
-    );
-    const edges = this.edges.sort((a, b) =>
-      `${a.type}\0${a.from.value}\0${a.to.value}`.localeCompare(
-        `${b.type}\0${b.from.value}\0${b.to.value}`,
-      ),
-    );
+    const nodes = [...this.nodes.values()]
+      .map((row) => ({ row, sortKey: `${row.labels[0]}\0${row.value}` }))
+      .sort((a, b) => a.sortKey.localeCompare(b.sortKey))
+      .map(({ row }) => row);
+    const edges = this.edges
+      .map((row) => ({
+        row,
+        sortKey: `${row.type}\0${row.from.value}\0${row.to.value}`,
+      }))
+      .sort((a, b) => a.sortKey.localeCompare(b.sortKey))
+      .map(({ row }) => row);
     return { nodes, edges };
   }
 }
diff --git a/test/neo4j-edge-identity.test.ts b/test/neo4j-edge-identity.test.ts
index 0909d31..81d9491 100644
--- a/test/neo4j-edge-identity.test.ts
+++ b/test/neo4j-edge-identity.test.ts
@@ -43,3 +43,21 @@ describe("edge identity discriminant (_k)", () => {
     expect(ddg.length).toBe(2);
   });
 });
+
+test("row sorting preserves composite-key collation across prefix values", () => {
+  const builder = new RowBuilder();
+  const target = builder.node(["CanNode"], "id", "target", {});
+  const file = builder.node(["CanNode"], "id", "file", {});
+  const nested = builder.node(["CanNode"], "id", "file/<anon>", {});
+  const slash = builder.node(["CanNode"], "id", "file/x", {});
+
+  builder.edge("TS_CALLS", file, target);
+  builder.edge("TS_CALLS", nested, target);
+  builder.edge("TS_CALLS", slash, target);
+
+  expect(builder.finish().edges.map((edge) => edge.from.value)).toEqual([
+    "file/<anon>",
+    "file/x",
+    "file",
+  ]);
+});