From c5a0f55e7045ee5dfa12677de20c9107727d91df Mon Sep 17 00:00:00 2001
From: 7000pctAUTO <lukems3823@gmail.com>
Date: Wed, 4 Feb 2026 14:56:29 +0000
Subject: [PATCH] Add package manager parsers (npm, pip, go, cargo)

---
 src/depcheck/parsers/__init__.py | 72 ++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 src/depcheck/parsers/__init__.py

diff --git a/src/depcheck/parsers/__init__.py b/src/depcheck/parsers/__init__.py
new file mode 100644
index 0000000..04ba980
--- /dev/null
+++ b/src/depcheck/parsers/__init__.py
@@ -0,0 +1,72 @@
+"""Base parser class and parser registry."""
+
+from abc import ABC, abstractmethod
+from pathlib import Path
+from typing import Optional
+
+from depcheck.models import Dependency, PackageManager
+
+
+class Parser(ABC):
+    """Base class for package dependency parsers."""
+
+    package_manager: PackageManager = PackageManager.PIP
+
+    @abstractmethod
+    def parse(self, file_path: Path) -> list[Dependency]:
+        """Parse a dependency file and return list of dependencies."""
+        pass
+
+    @abstractmethod
+    def supports_file(self, file_path: Path) -> bool:
+        """Check if this parser supports the given file."""
+        pass
+
+    def get_file_patterns(self) -> list[str]:
+        """Get file patterns this parser handles."""
+        return []
+
+
+class ParserRegistry:
+    """Registry of available parsers."""
+
+    def __init__(self):
+        self._parsers: list[Parser] = []
+
+    def register(self, parser: Parser) -> None:
+        """Register a parser."""
+        self._parsers.append(parser)
+
+    def get_parser(self, file_path: Path) -> Optional[Parser]:
+        """Get parser for a specific file."""
+        for parser in self._parsers:
+            if parser.supports_file(file_path):
+                return parser
+        return None
+
+    def get_all_parsers(self) -> list[Parser]:
+        """Get all registered parsers."""
+        return self._parsers
+
+    def detect_package_manager(self, directory: Path) -> Optional[PackageManager]:
+        """Detect package manager based on file existence."""
+        for parser in self._parsers:
+            for pattern in parser.get_file_patterns():
+                if (directory / pattern).exists():
+                    return parser.package_manager
+        return None
+
+
+def create_parser_registry() -> ParserRegistry:
+    """Create and register all available parsers."""
+    from depcheck.parsers.npm import NpmParser
+    from depcheck.parsers.pip import PipParser
+    from depcheck.parsers.go import GoParser
+    from depcheck.parsers.cargo import CargoParser
+
+    registry = ParserRegistry()
+    registry.register(NpmParser())
+    registry.register(PipParser())
+    registry.register(GoParser())
+    registry.register(CargoParser())
+    return registry