chore: import upstream snapshot with attribution

tests/test_merge_graphs_cli.py

@@ -0,0 +1,94 @@
+"""`graphify merge-graphs` tolerates inputs that disagree on graph type (#1606).
+
+Per-repo graph.json files written by different extract paths at different times
+don't always agree on the `directed` / `multigraph` flags. compose requires one
+uniform type, so a mixed set used to crash with an unhandled NetworkXError. The
+handler now normalizes every input to a plain undirected Graph before composing.
+"""
+from __future__ import annotations
+
+import json
+import subprocess
+import sys
+from pathlib import Path
+
+PYTHON = sys.executable
+
+
+def _run(args, cwd):
+    return subprocess.run([PYTHON, "-m", "graphify"] + args, cwd=cwd,
+                          capture_output=True, text=True)
+
+
+def _write(p: Path, directed: bool, multigraph: bool, node_id: str):
+    p.parent.mkdir(parents=True, exist_ok=True)
+    p.write_text(json.dumps({
+        "directed": directed, "multigraph": multigraph, "graph": {},
+        "nodes": [{"id": node_id}], "links": [],
+    }))
+
+
+def test_merge_graphs_mixed_directed_and_multigraph(tmp_path):
+    a = tmp_path / "r1" / "graphify-out" / "graph.json"
+    b = tmp_path / "r2" / "graphify-out" / "graph.json"
+    c = tmp_path / "r3" / "graphify-out" / "graph.json"
+    _write(a, directed=True, multigraph=False, node_id="x")    # DiGraph
+    _write(b, directed=False, multigraph=False, node_id="y")   # Graph
+    _write(c, directed=False, multigraph=True, node_id="z")    # MultiGraph
+    out = tmp_path / "merged.json"
+
+    r = _run(["merge-graphs", str(a), str(b), str(c), "--out", str(out)], tmp_path)
+    assert r.returncode == 0, f"merge crashed: {r.stderr}"
+    assert out.exists()
+    data = json.loads(out.read_text())
+    ids = {n["id"] for n in data["nodes"]}
+    # every input's node survives, normalized into one undirected simple graph
+    assert {"r1::x", "r2::y", "r3::z"} <= ids or len(ids) == 3
+    assert data.get("directed") is False
+    assert data.get("multigraph") is False
+
+
+def test_merge_graphs_same_named_repo_dirs_do_not_collapse(tmp_path):
+    # #1729: two graphs under a same-named repo dir (src/graphify-out and
+    # frontend/src/graphify-out both → tag "src") share the `src::` prefix, so a
+    # bare `app` node from each collapsed into one — silently merging unrelated
+    # entities and inventing cross-runtime edges. Distinct tags must keep them apart.
+    a = tmp_path / "src" / "graphify-out" / "graph.json"
+    b = tmp_path / "frontend" / "src" / "graphify-out" / "graph.json"
+    a.parent.mkdir(parents=True, exist_ok=True)
+    b.parent.mkdir(parents=True, exist_ok=True)
+    a.write_text(json.dumps({"directed": False, "multigraph": False, "nodes": [
+        {"id": "app", "label": "app.js", "source_file": "app.js"}], "links": []}))
+    b.write_text(json.dumps({"directed": False, "multigraph": False, "nodes": [
+        {"id": "app", "label": "App.jsx", "source_file": "App.jsx"}], "links": []}))
+    out = tmp_path / "merged.json"
+
+    r = _run(["merge-graphs", str(a), str(b), "--out", str(out)], tmp_path)
+    assert r.returncode == 0, r.stderr
+    data = json.loads(out.read_text())
+    app_nodes = [n for n in data["nodes"] if n["id"].endswith("::app")]
+    assert len(app_nodes) == 2, f"both app nodes must survive; got {[n['id'] for n in app_nodes]}"
+    labels = {n.get("label") for n in app_nodes}
+    assert labels == {"app.js", "App.jsx"}, f"both entities preserved; got {labels}"
+
+
+def test_distinct_repo_tags_unit(tmp_path):
+    from graphify.build import distinct_repo_tags
+    # distinct repo dirs pass through unchanged
+    assert distinct_repo_tags([
+        Path("backend/graphify-out/graph.json"),
+        Path("web/graphify-out/graph.json"),
+    ]) == ["backend", "web"]
+    # same-named repo dirs are widened to stay distinct
+    tags = distinct_repo_tags([
+        Path("proj/src/graphify-out/graph.json"),
+        Path("proj/frontend/src/graphify-out/graph.json"),
+    ])
+    assert len(set(tags)) == 2, tags
+    # a repeated dir name triple still yields all-distinct tags (index fallback)
+    tags3 = distinct_repo_tags([
+        Path("a/src/graphify-out/graph.json"),
+        Path("b/src/graphify-out/graph.json"),
+        Path("c/src/graphify-out/graph.json"),
+    ])
+    assert len(set(tags3)) == 3, tags3