fix: match Go edge section behavior, update test

Author: blackwell-systems

src/gcf/encode.py

@@ -56,9 +56,8 @@ def encode(p: Payload) -> str:
             if e.status and e.status != "unchanged":
                 line += f" {e.status}"
             edge_lines.append(line)
-        if edge_lines:
-            parts.append("## edges")
-            parts.extend(edge_lines)
+        parts.append("## edges")
+        parts.extend(edge_lines)
 
     return "\n".join(parts) + "\n"
 

tests/test_encode.py

@@ -163,7 +163,7 @@ def test_encode_edge_unchanged_status_omitted():
 
 
 def test_encode_skips_edges_with_missing_symbols():
-    """Edges referencing symbols not in the payload are skipped."""
+    """Edges referencing unknown symbols are skipped, but section header emitted."""
     p = Payload(
         tool="test",
         symbols=[
@@ -174,7 +174,10 @@ def test_encode_skips_edges_with_missing_symbols():
         ],
     )
     output = encode(p)
-    assert "## edges" not in output
+    # Section header is emitted (matches Go), but no edge lines beneath it
+    assert "## edges" in output
+    lines_after_edges = output.split("## edges\n")[1]
+    assert lines_after_edges.strip() == ""
 
 
 def test_encode_empty_payload():