Add package manager parsers (npm, pip, go, cargo)

src/depcheck/parsers/cargo.py

@@ -0,0 +1,68 @@
+"""Cargo Cargo.toml parser."""
+
+from pathlib import Path
+
+import toml
+
+from depcheck.models import Dependency, PackageManager
+from depcheck.parsers import Parser
+from depcheck.utils import parse_version_string
+
+
+class CargoParser(Parser):
+    """Parser for Rust Cargo.toml files."""
+
+    package_manager = PackageManager.CARGO
+
+    def supports_file(self, file_path: Path) -> bool:
+        return file_path.name == "Cargo.toml"
+
+    def get_file_patterns(self) -> list[str]:
+        return ["Cargo.toml"]
+
+    def parse(self, file_path: Path) -> list[Dependency]:
+        dependencies: list[Dependency] = []
+
+        try:
+            content = file_path.read_text()
+            data = toml.loads(content)
+        except (toml.TomlDecodeError, OSError):
+            return dependencies
+
+        sections = [
+            ("dependencies", "dependencies"),
+            ("dev-dependencies", "devDependencies"),
+            ("build-dependencies", "buildDependencies"),
+        ]
+
+        for section_key, category in sections:
+            section = data.get(section_key, {})
+            if isinstance(section, dict):
+                for name, version_info in section.items():
+                    if isinstance(version_info, str):
+                        version = parse_version_string(version_info)
+                        if version:
+                            dependencies.append(
+                                Dependency(
+                                    name=name,
+                                    current_version=version,
+                                    package_manager=self.package_manager,
+                                    category=category,
+                                    source_file=str(file_path),
+                                )
+                            )
+                    elif isinstance(version_info, dict):
+                        version = version_info.get("version", "")
+                        version = parse_version_string(str(version))
+                        if version:
+                            dependencies.append(
+                                Dependency(
+                                    name=name,
+                                    current_version=version,
+                                    package_manager=self.package_manager,
+                                    category=category,
+                                    source_file=str(file_path),
+                                )
+                            )
+
+        return dependencies