From a34469972b6cfb9dedf24b4931f3286af10edcdb Mon Sep 17 00:00:00 2001
From: Rahul Krishna <rkrsn@ibm.com>
Date: Tue, 7 Jul 2026 00:19:45 -0400
Subject: [PATCH] fix: emit real byte offsets on L3 body nodes so span.bytes is
 sliceable
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GraphNode carried only line/column, so spanOf() in schema/v2/dataflow.ts
hardcoded bytes:[0,0] for every L3 entry/exit/param/statement node —
module.source.slice(...) on any L3 body node returned "". Add
start_offset/end_offset (UTF-16 char offsets, matching the L1 convention)
to GraphNode, populate them at the single construction site
(dataflow/extract.ts's emitNode, from the owning ts-morph node's
getStart()/getEnd() — the whole callable for entry/exit, the param decl
for param nodes), and have spanOf() use them.
---
 src/dataflow/extract.ts   |  11 ++++++++++-
 src/schema/graphs.ts      |   3 +++
 src/schema/v2/dataflow.ts | Bin 12941 -> 12965 bytes
 test/schema-v2.test.ts    |  10 ++++++++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/dataflow/extract.ts b/src/dataflow/extract.ts
index 751ad53..d9a02f9 100644
--- a/src/dataflow/extract.ts
+++ b/src/dataflow/extract.ts
@@ -81,7 +81,16 @@ function emitNode(id: number, kind: GraphNode["kind"], ast: Node | null, build:
   const target = ast ?? build.fn; // ENTRY/EXIT carry the whole callable's span
   const s = build.sf.getLineAndColumnAtPos(target.getStart());
   const e = build.sf.getLineAndColumnAtPos(target.getEnd());
-  return { id, kind, start_line: s.line, start_column: s.column, end_line: e.line, end_column: e.column };
+  return {
+    id,
+    kind,
+    start_line: s.line,
+    start_column: s.column,
+    end_line: e.line,
+    end_column: e.column,
+    start_offset: target.getStart(),
+    end_offset: target.getEnd(),
+  };
 }
 
 function hasRestParam(build: FunctionCfgBuild): boolean {
diff --git a/src/schema/graphs.ts b/src/schema/graphs.ts
index 801eb5c..27e02a8 100644
--- a/src/schema/graphs.ts
+++ b/src/schema/graphs.ts
@@ -34,6 +34,9 @@ export interface GraphNode {
   start_column: number;
   end_line: number;
   end_column: number;
+  /** UTF-16 char offsets into the owning module's `source` (same convention as L1 `span.bytes`). */
+  start_offset: number;
+  end_offset: number;
 }
 
 // ----------------------------------------------------------------------------------------------
diff --git a/src/schema/v2/dataflow.ts b/src/schema/v2/dataflow.ts
index e5f7a22a36d99541326dbe109c7e1b26dee5c1ec..f664df9af9dda26d80c20595473825f4074f5713 100644
GIT binary patch
delta 41
rcmeB8U7EVVhfgL?uec<!s3bl=Ev-1UL`NY{FEuX(%G(^kXR87LPACsb

delta 24
fcmZ3Q+MBw;hmYMrN5LRgp?0#YUe@NTd>51fXw(RW

diff --git a/test/schema-v2.test.ts b/test/schema-v2.test.ts
index ada1509..a33584e 100644
--- a/test/schema-v2.test.ts
+++ b/test/schema-v2.test.ts
@@ -344,6 +344,16 @@ describe("schema v2 — L3 intraprocedural dataflow", () => {
   test("no dangling endpoints at L3", () => {
     expect(danglingCount(dfL3)).toBe(0);
   });
+
+  test("a sampled L3 statement node is source-sliceable (span.bytes reproduces its text)", () => {
+    const mod = dfL3.application.symbol_table["src/flow.ts"];
+    const classify = mod.functions.classify as V2Callable;
+    const stmt = classify.body["4:3"];
+    expect(stmt?.kind).toBe("statement");
+    const [s, e] = (stmt as { span: { bytes: [number, number] } }).span.bytes;
+    expect(e).toBeGreaterThan(s);
+    expect(mod.source.slice(s, e)).toBe('let label = "none";');
+  });
 });
 
 describe("schema v2 — L4 interprocedural SDG", () => {