Dart imports are never resolved to file nodes (0/139 in a real Flutter repo) — affected is blind

[salveki]

Summary

Dart import edges are never resolved to file nodes. The edge is created, but its target is the import path as a string node with source_file: None, so nothing connects it to the file it names. Reverse traversal is therefore blind: affected returns "No affected nodes found" for a file whose importer is visible on line 5 of the source.

Measured on a real Flutter repo (76 source files, 636 nodes, 840 edges), graphify 0.9.30:

Language	internal import edges resolved to a file node
Python	696 / 696 — 100%
TypeScript	resolves (605 usable imports_from edges)
Dart	0 / 139 — 0%

Reproduce

Any Flutter/Dart project:

GRAPHIFY_FORCE=1 graphify . --code-only

import json
g = json.load(open("graphify-out/graph.json"))
idx = {n["id"]: n for n in g["nodes"]}
res = unres = 0
for e in g["links"]:
    if e.get("relation") not in ("imports", "imports_from"):
        continue
    if not (idx.get(e["source"], {}).get("source_file") or "").endswith(".dart"):
        continue
    t = idx.get(e["target"], {})
    lbl = t.get("label") or ""
    if lbl.startswith("dart:") or (lbl.startswith("package:") and "/" not in lbl):
        continue
    res += 1 if t.get("source_file") else 0
    unres += 0 if t.get("source_file") else 1
print(res, unres)

A concrete edge from the repo I measured, where grid_screen.dart line 5 is
import '../cell/cell_widget.dart';:

grid_screen.dart --imports--> "../cell/cell_widget.dart"   (source_file: None)

Cause

graphify/extractors/dart.py, section # 6. Imports and Exports:

for m in re.finditer(r"""^\s*import\s+['"]([^'"]+)['"]""", src_clean, re.MULTILINE):
    pkg = m.group(1)
    tgt_nid = _make_id(pkg)                    # id from the raw string
    add_node(tgt_nid, pkg, source_file=None)   # never linked to a file
    add_edge(file_nid, tgt_nid, "imports")

JS/TS goes through _resolve_js_import_target() in graphify/extractors/resolution.py, which returns _make_id(str(resolved_path)) — the same id the file node carries — so the edge lands on the real file. Dart has an extractor but no resolver counterpart.

Impact

Every question needing reverse traversal fails on Dart, while symbol-level relations work fine. On a 9-question battery over the same repo, the five questions requiring resolved import edges (who imports X, who instantiates Y, which file is most depended on) all failed; the three resting on inherits / implements / references all passed. Coverage itself is fine — 55/55 .dart files are in the graph.

This matters more in Flutter than the numbers suggest, because widget composition lives inside build(): "where is CellWidget constructed" is the ordinary question, and it is unanswerable without a cross-file edge to walk.

Note on #2114 and #2174

Not a criticism of either PR — just flagging that neither closes this, in case it is assumed:

• feat(extract): tree-sitter-based Dart extraction with source_location line anchors #2114 (tree-sitter Dart extraction) keeps the same import handling; the new _handle_import_export() still does tgt_nid = _make_id(pkg) / add_node(..., source_file=None). The 1038-line diff contains no reference to resolution or _resolve_. The defect is orthogonal to the extraction backend.
• fix: materialize internal import endpoints in monorepos #2174 (materialize internal import endpoints in monorepos) covers Python and JS/TS. Its "unresolved internal" endpoint classification would at least make these 139 edges visible as a diagnostic rather than silent, which seems worth having regardless.

Suggested shape

Mirroring _resolve_js_import_target, Dart needs noticeably less machinery than JS/TS — no extension inference (.dart is mandatory), no directory index convention, no path aliases:

1. raw.startswith(".") → relative to the importing file's directory, normalized.
2. package:<name>/<subpath> where <name> matches name: in the nearest pubspec.yaml → <pubspec_dir>/lib/<subpath>.
3. dart:* and other package:* → external; return the _make_id("ref", raw) namespaced id, as _resolve_js_import_target already does to avoid the Unresolved bare npm import gets aliased onto an unrelated same-named local file (cross-language phantom edge) #1638 collision.

part / part of directives are a separate concern and could stay out of a first pass.

Happy to send a PR for this if it would be useful, or to leave it to whoever is already in dart.py — say which is easier, since #2114 touches the same function.