fix(parser) parsers were able to share state unexpectedly

Signed-off-by: Paul Horton <phorton@sonatype.com>

Author: madpah

cyclonedx/parser/__init__.py

@@ -23,6 +23,9 @@
 class BaseParser(ABC):
     _components: List[Component] = []
 
+    def __init__(self):
+        self._components.clear()
+
     def component_count(self) -> int:
         return len(self._components)
 

cyclonedx/parser/environment.py

@@ -37,6 +37,8 @@ class EnvironmentParser(BaseParser):
     """
 
     def __init__(self):
+        super().__init__()
+
         import pkg_resources
 
         i: pkg_resources.DistInfoDistribution

cyclonedx/parser/requirements.py

@@ -26,6 +26,8 @@
 class RequirementsParser(BaseParser):
 
     def __init__(self, requirements_content: str):
+        super().__init__()
+
         requirements = pkg_resources.parse_requirements(requirements_content)
         for requirement in requirements:
             """