feat: added PURL generation for swift parser

cve_bin_tool/parsers/swift.py

@@ -2,23 +2,80 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 import json
+import re
+from json.decoder import JSONDecodeError
+from urllib.parse import urlparse
 
 from cve_bin_tool.parsers import Parser
 
 
 class SwiftParser(Parser):
+    """
+    Parser implementation for Swift dependency files (Package.resolved).
+
+    This parser is designed to parse Swift dependencies files and generate Package URL (PURL) strings
+    based on the modules and their dependencies listed in the file.
+
+    Attributes:
+        cve_db (CVEDB): The CVE database instance used for vulnerability information.
+        logger (Logger): The logger instance for logging messages and debugging information.
+
+    Methods:
+        generate_purl(product, version, vendor):
+            Generates PURL after normalizing all components.
+        run_checker(filename):
+            Parse the Swift dependency file and yield valid PURLs for the modules listed in the file.
+
+    """
+
     def __init__(self, cve_db, logger):
         super().__init__(cve_db, logger)
+        self.purl_pkg_type = "swift"
+
+    def generate_purl(self, product, version, vendor, qualifier={}, subpath=None):
+        """Generates PURL after normalizing all components."""
+
+        product = re.sub(r"[^a-zA-Z0-9_-]", "", product)
+        version = re.sub(r"[^a-zA-Z0-9.+-]", "", version)
+
+        if not re.match(r"[a-zA-Z0-9_-]", product):
+            return
+        if not vendor:
+            vendor = "UNKNOWN"
+        if not version:
+            version = "UNKNOWN"
+
+        purl = super().generate_purl(
+            product,
+            version,
+            vendor,
+            qualifier,
+            subpath,
+        )
+
+        return purl
 
     def run_checker(self, filename):
+        """Parse the file and yield valid PURLs."""
         self.filename = filename
         with open(self.filename) as fh:
             # parse the json structure for extracting product version pairs
-            content = json.load(fh)
+            try:
+                content = json.load(fh)
+            except JSONDecodeError as e:
+                self.logger.debug(f"Error occurred while parsing {filename}: {e}")
+                return
             for package in content["object"]["pins"]:
                 product = package["package"]
                 version = package["state"]["version"]
-                vendor = self.find_vendor(product, version)
-                if vendor is not None:
-                    yield from vendor
+                repository_url = package.get("repositoryURL", None)
+                domain = None
+                if repository_url:
+                    parse = urlparse(repository_url)
+                    domain = parse.netloc
+                self.logger.debug(domain)
+
+                vendors = self.find_vendor(product, version)
+                if vendors is not None:
+                    yield from vendors
             self.logger.debug(f"Done scanning file: {self.filename}")