feat(rust): add full parser support and resolution for Rust codebases

code_review_graph/parser.py

@@ -187,7 +187,7 @@ class EdgeInfo:
     "typescript": ["class_declaration", "class"],
     "tsx": ["class_declaration", "class"],
     "go": ["type_declaration"],
-    "rust": ["struct_item", "enum_item", "impl_item"],
+    "rust": ["struct_item", "enum_item", "impl_item", "trait_item"],
     "java": ["class_declaration", "interface_declaration", "enum_declaration"],
     "c": ["struct_specifier", "type_definition"],
     "cpp": ["class_specifier", "struct_specifier"],
@@ -5306,6 +5306,14 @@ def _collect_import_names(
                     if child.type == "import_clause":
                         self._collect_js_import_names(child, module, import_map)
 
+        elif language == "rust":
+            # Walk use_declaration children to find the inner import node
+            for child in node.children:
+                if child.type in ("scoped_identifier", "scoped_use_list", "use_as_clause", "use_wildcard", "identifier"):
+                    for local_name, full_path in self._parse_rust_use_node(child):
+                        if local_name != "*":
+                            import_map[local_name] = full_path
+
     def _collect_js_import_names(
         self, clause_node, module: str, import_map: dict[str, str],
     ) -> None:
@@ -5481,8 +5489,149 @@ def _do_resolve_module(
                         break
                     current = current.parent
 
+        elif language == "rust":
+            # Standardize path separator to ::
+            module_path = module.replace("::", "/")
+            segments = [seg for seg in module_path.split("/") if seg]
+            if not segments:
+                return None
+
+            # Find crate root / source root and collect all dependencies from Cargo.toml files found along the way
+            crate_root = None
+            dependencies = {}
+            current = caller_dir
+            for _ in range(20):
+                cargo_toml = current / "Cargo.toml"
+                if cargo_toml.is_file():
+                    if not crate_root:
+                        crate_root = current
+                    dependencies.update(self._find_rust_local_dependencies(cargo_toml))
+                if current.parent == current:
+                    break
+                current = current.parent
+
+            if crate_root:
+                src_root = crate_root / "src"
+                if not src_root.is_dir():
+                    src_root = crate_root
+            else:
+                src_root = caller_dir
+
+            # Determine starting directory and segments to resolve
+            start_dir = None
+            resolved_file = None
+
+            if segments[0] == "crate":
+                start_dir = src_root
+                resolved_file = src_root / "lib.rs" if (src_root / "lib.rs").is_file() else (src_root / "main.rs" if (src_root / "main.rs").is_file() else None)
+                resolve_segments = segments[1:]
+            elif segments[0] == "super":
+                super_count = 0
+                for seg in segments:
+                    if seg == "super":
+                        super_count += 1
+                    else:
+                        break
+
+                curr_file = Path(file_path)
+                for _ in range(super_count):
+                    parent_mod = self._find_rust_parent_module(curr_file)
+                    if parent_mod:
+                        curr_file = parent_mod
+                    else:
+                        curr_file = curr_file.parent
+
+                resolved_file = curr_file
+                if resolved_file.is_dir():
+                    start_dir = resolved_file
+                    resolved_file = None
+                else:
+                    start_dir = resolved_file.parent
+
+                resolve_segments = segments[super_count:]
+            elif segments[0] == "self":
+                resolved_file = Path(file_path)
+                start_dir = resolved_file.parent
+                resolve_segments = segments[1:]
+            elif segments[0] in dependencies:
+                dep_path = dependencies[segments[0]]
+                dep_src_root = dep_path / "src" if (dep_path / "src").is_dir() else dep_path
+                start_dir = dep_src_root
+                resolved_file = dep_src_root / "lib.rs" if (dep_src_root / "lib.rs").is_file() else (dep_src_root / "main.rs" if (dep_src_root / "main.rs").is_file() else None)
+                resolve_segments = segments[1:]
+            else:
+                start_dir = caller_dir
+                resolve_segments = segments
+
+            # Walk resolve segments
+            current_dir = start_dir
+            for seg in resolve_segments:
+                file_candidate = current_dir / f"{seg}.rs"
+                dir_candidate = current_dir / seg / "mod.rs"
+
+                if file_candidate.is_file():
+                    resolved_file = file_candidate
+                    current_dir = current_dir / seg
+                elif dir_candidate.is_file():
+                    resolved_file = dir_candidate
+                    current_dir = current_dir / seg
+                else:
+                    # Last segment might be a struct or function, so we keep the previous resolved file
+                    break
+
+            if resolved_file:
+                return str(resolved_file.resolve())
+
         return None
 
+    def _find_rust_parent_module(self, path: Path) -> Optional[Path]:
+        parent_dir = path.parent
+        name = path.name
+
+        if name in ("mod.rs", "lib.rs", "main.rs"):
+            gp = parent_dir.parent
+            cand = gp / f"{parent_dir.name}.rs"
+            if cand.is_file():
+                return cand
+            for name_cand in ("mod.rs", "lib.rs", "main.rs"):
+                cand = gp / name_cand
+                if cand.is_file():
+                    return cand
+        else:
+            cand = parent_dir / "mod.rs"
+            if cand.is_file():
+                return cand
+            gp = parent_dir.parent
+            cand = gp / f"{parent_dir.name}.rs"
+            if cand.is_file():
+                return cand
+            for name_cand in ("lib.rs", "main.rs"):
+                cand = parent_dir / name_cand
+                if cand.is_file():
+                    return cand
+        return None
+
+    def _find_rust_local_dependencies(self, cargo_toml_path: Path) -> dict[str, Path]:
+        deps = {}
+        if not cargo_toml_path.is_file():
+            return deps
+        try:
+            text = cargo_toml_path.read_text(encoding="utf-8", errors="replace")
+        except OSError:
+            return deps
+        # Match name = { path = "..." }
+        pattern = re.compile(r'^([\w-]+)\s*=\s*\{[^}]*path\s*=\s*"([^"]+)"', re.MULTILINE)
+        for match in pattern.finditer(text):
+            name = match.group(1).strip()
+            path_val = match.group(2).strip()
+            try:
+                resolved_path = (cargo_toml_path.parent / path_val).resolve()
+                deps[name] = resolved_path
+                deps[name.replace("-", "_")] = resolved_path
+            except (OSError, ValueError):
+                pass
+        return deps
+
     def _find_dart_pubspec_root(
         self, start: Path, pkg_name: str,
     ) -> Optional[Path]:
@@ -5514,6 +5663,48 @@ def _find_dart_pubspec_root(
         self._dart_pubspec_cache[cache_key] = None
         return None
 
+    def _resolve_rust_scoped_call(
+        self,
+        call_name: str,
+        file_path: str,
+        import_map: dict[str, str],
+        defined_names: set[str],
+    ) -> Optional[str]:
+        if "::" not in call_name:
+            return None
+
+        parts = call_name.split("::")
+        method = parts[-1]
+        type_prefix_parts = parts[:-1]
+        type_prefix = "::".join(type_prefix_parts)
+
+        # Check if type_prefix is defined in the same file
+        if type_prefix in defined_names:
+            qualified_type = self._qualify(type_prefix, file_path, None)
+            return f"{qualified_type}.{method}"
+
+        # Check if type_prefix is imported
+        if type_prefix in import_map:
+            resolved_type = self._resolve_imported_symbol(
+                type_prefix, import_map[type_prefix], file_path, "rust",
+            )
+            if resolved_type:
+                return f"{resolved_type}.{method}"
+
+        # What if type_prefix itself is a path, like `crate::db::InMemoryRepo`?
+        if type_prefix_parts[0] in ("crate", "super", "self"):
+            if len(type_prefix_parts) >= 2:
+                module_part = "::".join(type_prefix_parts[:-1])
+                type_name = type_prefix_parts[-1]
+                resolved_module_file = self._resolve_module_to_file(
+                    module_part, file_path, "rust"
+                )
+                if resolved_module_file:
+                    qualified_type = self._qualify(type_name, resolved_module_file, None)
+                    return f"{qualified_type}.{method}"
+
+        return None
+
     def _resolve_call_target(
         self,
         call_name: str,
@@ -5523,6 +5714,13 @@ def _resolve_call_target(
         defined_names: set[str],
     ) -> str:
         """Resolve a bare call name to a qualified target, with fallback."""
+        if language == "rust" and "::" in call_name:
+            resolved = self._resolve_rust_scoped_call(
+                call_name, file_path, import_map, defined_names
+            )
+            if resolved:
+                return resolved
+
         if call_name in defined_names:
             return self._qualify(call_name, file_path, None)
         if call_name in import_map:
@@ -5663,6 +5861,27 @@ def _qualify(self, name: str, file_path: str, enclosing_class: Optional[str]) ->
 
     def _get_name(self, node, language: str, kind: str) -> Optional[str]:
         """Extract the name from a class/function definition node."""
+        if language == "rust" and node.type == "impl_item":
+            # Find if there is a 'for' child
+            for_index = -1
+            type_identifiers = []
+            for i, child in enumerate(node.children):
+                if child.type == "for":
+                    for_index = i
+                elif child.type in ("type_identifier", "generic_type", "scoped_type_identifier"):
+                    type_identifiers.append((i, child))
+
+            if for_index != -1:
+                # Implementing a trait: the target struct/type is after 'for'.
+                for idx, child in type_identifiers:
+                    if idx > for_index:
+                        return self._get_rust_base_type(child)
+            else:
+                # Inherent impl: the target struct/type is the first type identifier
+                if type_identifiers:
+                    return self._get_rust_base_type(type_identifiers[0][1])
+            return None
+
         # Dart: function_signature has a return-type node before the identifier;
         # search only for 'identifier' to avoid returning the return type name.
         if language == "dart" and node.type == "function_signature":
@@ -5940,6 +6159,61 @@ def _leaf_name(qi):
                     return self._get_name(child, language, kind)
         return None
 
+    def _get_rust_base_type(self, node) -> str:
+        if node.type in ("type_identifier", "identifier"):
+            return node.text.decode("utf-8", errors="replace")
+        if node.type == "generic_type":
+            for child in node.children:
+                if child.type == "type_identifier":
+                    return self._get_rust_base_type(child)
+        if node.type == "scoped_type_identifier":
+            for child in reversed(node.children):
+                if child.type == "type_identifier":
+                    return self._get_rust_base_type(child)
+        return node.text.decode("utf-8", errors="replace")
+
+    def _parse_rust_use_node(self, node, prefix="") -> list[tuple[str, str]]:
+        results = []
+        if node.type == "identifier":
+            name = node.text.decode("utf-8", errors="replace")
+            full_path = f"{prefix}::{name}" if prefix else name
+            results.append((name, full_path))
+        elif node.type == "scoped_identifier":
+            full_path = node.text.decode("utf-8", errors="replace")
+            name = node.children[-1].text.decode("utf-8", errors="replace")
+            if prefix:
+                full_path = f"{prefix}::{full_path}"
+            results.append((name, full_path))
+        elif node.type == "scoped_use_list":
+            prefix_node = node.children[0]
+            prefix_str = prefix_node.text.decode("utf-8", errors="replace")
+            if prefix:
+                prefix_str = f"{prefix}::{prefix_str}"
+            use_list = node.children[-1]
+            if use_list.type == "use_list":
+                for child in use_list.children:
+                    if child.type in ("identifier", "scoped_identifier", "scoped_use_list", "use_as_clause", "use_wildcard"):
+                        results.extend(self._parse_rust_use_node(child, prefix_str))
+        elif node.type == "use_list":
+            for child in node.children:
+                if child.type in ("identifier", "scoped_identifier", "scoped_use_list", "use_as_clause", "use_wildcard"):
+                    results.extend(self._parse_rust_use_node(child, prefix))
+        elif node.type == "use_as_clause":
+            path_node = node.children[0]
+            alias_node = node.children[-1]
+            path_str = path_node.text.decode("utf-8", errors="replace")
+            if prefix:
+                path_str = f"{prefix}::{path_str}"
+            alias_str = alias_node.text.decode("utf-8", errors="replace")
+            results.append((alias_str, path_str))
+        elif node.type == "use_wildcard":
+            prefix_node = node.children[0]
+            prefix_str = prefix_node.text.decode("utf-8", errors="replace")
+            if prefix:
+                prefix_str = f"{prefix}::{prefix_str}"
+            results.append(("*", prefix_str))
+        return results
+
     def _get_go_receiver_type(self, node) -> Optional[str]:
         """Extract the receiver type from a Go method_declaration.
 
@@ -6151,6 +6425,21 @@ def _get_bases(self, node, language: str, source: bytes) -> list[str]:
                             bases.append(
                                 idents[0].text.decode("utf-8", errors="replace"),
                             )
+        elif language == "rust":
+            if node.type == "impl_item":
+                # Check if there's a 'for' child
+                for_index = -1
+                type_identifiers = []
+                for i, child in enumerate(node.children):
+                    if child.type == "for":
+                        for_index = i
+                    elif child.type in ("type_identifier", "generic_type", "scoped_type_identifier"):
+                        type_identifiers.append((i, child))
+
+                if for_index != -1 and type_identifiers:
+                    # The trait is the first type_identifier (before the 'for' keyword)
+                    trait_node = type_identifiers[0][1]
+                    bases.append(self._get_rust_base_type(trait_node))
         return bases
 
     def _extract_import(self, node, language: str, source: bytes) -> list[str]:
@@ -6190,8 +6479,14 @@ def _extract_import(self, node, language: str, source: bytes) -> list[str]:
                             val = s.text.decode("utf-8", errors="replace")
                             imports.append(val.strip('"'))
         elif language == "rust":
-            # use crate::module::item
-            imports.append(text.replace("use ", "").rstrip(";").strip())
+            # Walk use_declaration children to find the inner import node
+            for child in node.children:
+                if child.type in ("scoped_identifier", "scoped_use_list", "use_as_clause", "use_wildcard", "identifier"):
+                    for _, full_path in self._parse_rust_use_node(child):
+                        if full_path.endswith("::*"):
+                            imports.append(full_path[:-3])
+                        else:
+                            imports.append(full_path)
         elif language in ("c", "cpp"):
             # #include <header> or #include "header"
             for child in node.children: