Namespace-aware C# type resolution and member-call receiver inference

graphify/extractors/MIGRATION.md

@@ -12,12 +12,38 @@ written so an AI agent can execute it in a single session.
 | zig | yes |
 | elixir | yes |
 | razor | yes |
-| (40 more in extract.py) | no |
+| csharp | partial — helpers + cross-file resolver split into `extractors/csharp*.py`; config-driven `extract_csharp` entry stays (see Middle path) |
+| (39 more in extract.py) | no |
 
 Note: config-driven extractors (python, js, java, c, cpp, ruby, csharp,
 kotlin, scala, php, lua, swift, groovy) depend on the shared
-`_extract_generic` core (~1,300 lines). Do NOT port them one-by-one; the core
-must move first as its own coordinated batch. Pick a bespoke extractor.
+`_extract_generic` core (~1,300 lines). Do NOT move the config-driven
+`extract_<lang>` ENTRY POINT one-by-one; the core must move first as its own
+coordinated batch. Pick a bespoke extractor for a full port.
+
+### Middle path (config-driven helper split — the C# pattern)
+
+Even for a config-driven language you can give it a real module home *before* the
+`_extract_generic` batch: split the language-specific **helpers** (per-file
+binding / type-table / shadow model, type references, imports) and the cross-file
+**member-call resolver** into their own modules — see `extractors/csharp_extract.py`,
+`extractors/csharp_resolve.py`, and `extractors/csharp.py` — facade-re-exported
+from `extract.py`, while the thin `extract_<lang>` → `_extract_generic` entry
+point stays inline. Guardrails:
+
+- **Prove the split is behavior-preserving** with a normalized node/edge snapshot
+  over BOTH the single-file `extract_<lang>` and the multi-file `extract` entry
+  points (order-preserving — a list-sorting canonical hides a fact-order
+  regression).
+- **Lift shared config** (`LanguageConfig`) to `base.py`; keep the import
+  direction `extract.py -> extractors/` (never import `graphify.extract` here).
+- Only pull C#-only logic out of `_extract_generic` where the helper **returns
+  facts** and the core keeps emission (no `add_node`/`add_edge`/`nodes`/`seen_ids`
+  threaded in) — otherwise leave a thin inline hook.
+
+Unlike a verbatim entry-point port, a middle-path split may ship alongside a
+feature (e.g. the C# member-call resolver) with its own tests; the snapshot +
+full suite are the preservation proof.
 
 ## Invariants (non-negotiable)
 

graphify/extractors/base.py

@@ -1,7 +1,9 @@
 # DO NOT import from graphify.extract here — direction is extract.py → extractors/ only.
 from __future__ import annotations
 
+from dataclasses import dataclass
 from pathlib import Path
+from typing import Callable
 
 from graphify.ids import make_id
 
@@ -64,3 +66,49 @@ def _file_stem(path: Path) -> str:
 
 def _read_text(node, source: bytes) -> str:
     return source[node.start_byte:node.end_byte].decode("utf-8", errors="replace")
+
+
+# ── LanguageConfig dataclass ─────────────────────────────────────────────────
+
+@dataclass
+class LanguageConfig:
+    ts_module: str                                   # e.g. "tree_sitter_python"
+    ts_language_fn: str = "language"                 # attr to call: e.g. tslang.language()
+
+    class_types: frozenset = frozenset()
+    function_types: frozenset = frozenset()
+    import_types: frozenset = frozenset()
+    call_types: frozenset = frozenset()
+    static_prop_types: frozenset = frozenset()
+    helper_fn_names: frozenset = frozenset()
+    container_bind_methods: frozenset = frozenset()
+    event_listener_properties: frozenset = frozenset()
+
+    # Name extraction
+    name_field: str = "name"
+    name_fallback_child_types: tuple = ()
+
+    # Body detection
+    body_field: str = "body"
+    body_fallback_child_types: tuple = ()   # e.g. ("declaration_list", "compound_statement")
+
+    # Call name extraction
+    call_function_field: str = "function"           # field on call node for callee
+    call_accessor_node_types: frozenset = frozenset()  # member/attribute nodes
+    call_accessor_field: str = "attribute"          # field on accessor for method name
+    call_accessor_object_field: str = ""            # field on accessor for the receiver/object
+
+    # Stop recursion at these types in walk_calls
+    function_boundary_types: frozenset = frozenset()
+
+    # Import handler: called for import nodes instead of generic handling
+    import_handler: Callable | None = None
+
+    # Optional custom name resolver for functions (C, C++ declarator unwrapping)
+    resolve_function_name_fn: Callable | None = None
+
+    # Extra label formatting for functions: if True, functions get "name()" label
+    function_label_parens: bool = True
+
+    # Extra walk hook called after generic dispatch (for JS arrow functions, C# namespaces, etc.)
+    extra_walk_fn: Callable | None = None