Add support for dynamic dependencies

src/flake8_requirements/checker.py

@@ -20,7 +20,7 @@
 from .modules import STDLIB_PY3
 
 # NOTE: Changing this number will alter package version as well.
-__version__ = "2.1.1"
+__version__ = "2.2.0"
 __license__ = "MIT"
 
 LOG = getLogger('flake8.plugin.requirements')
@@ -560,6 +560,33 @@ def get_pyproject_toml_pep621(cls):
         cfg_pep518 = cls.get_pyproject_toml()
         return cfg_pep518.get('project', {})
 
+    @classmethod
+    def get_setuptools_dynamic_requirements(cls):
+        """Retrieve dynamic requirements defined in setuptools config."""
+        cfg = cls.get_pyproject_toml()
+        dynamic_keys = cfg.get('project', {}).get('dynamic', [])
+        dynamic_config = (
+            cfg.get('tool', {}).get('setuptools', {}).get('dynamic', {})
+        )
+        requirements = []
+        files_to_parse = []
+        if 'dependencies' in dynamic_keys:
+            files_to_parse.extend(
+                dynamic_config.get('dependencies', {}).get('file', [])
+            )
+        if 'optional-dependencies' in dynamic_keys:
+            for element in dynamic_config.get(
+                'optional-dependencies', {}
+            ).values():
+                files_to_parse.extend(element.get('file', []))
+        for file_path in files_to_parse:
+            try:
+                with open(file_path, 'r') as file:
+                    requirements.extend(parse_requirements(file))
+            except IOError as e:
+                LOG.debug("Couldn't open requirements file: %s", e)
+        return requirements
+
     @classmethod
     def get_pyproject_toml_pep621_requirements(cls):
         """Try to get PEP 621 metadata requirements."""
@@ -569,6 +596,8 @@ def get_pyproject_toml_pep621_requirements(cls):
             pep621.get("dependencies", ())))
         for r in pep621.get("optional-dependencies", {}).values():
             requirements.extend(parse_requirements(r))
+        if len(requirements) == 0:
+            requirements = cls.get_setuptools_dynamic_requirements()
         return requirements
 
     @classmethod

test/test_pep621.py

@@ -1,6 +1,9 @@
 import unittest
 from unittest import mock
 from unittest.mock import mock_open
+from unittest.mock import patch
+
+from pkg_resources import parse_requirements
 
 from flake8_requirements.checker import Flake8Checker
 from flake8_requirements.checker import ModuleSet
@@ -80,3 +83,87 @@ def test_3rd_party(self):
             checker = Flake8Checker(None, None)
             mods = checker.get_mods_3rd_party(False)
             self.assertEqual(mods, ModuleSet({"tools": {}, "dev_tools": {}}))
+
+    def test_dynamic_requirements(self):
+        requirements_content = "package1\npackage2>=2.0"
+        data = {
+            "project": {"dynamic": ["dependencies"]},
+            "tool": {
+                "setuptools": {
+                    "dynamic": {"dependencies": {"file": ["requirements.txt"]}}
+                }
+            },
+        }
+        with patch(
+            'flake8_requirements.checker.Flake8Checker.get_pyproject_toml',
+            return_value=data,
+        ):
+            with patch(
+                'builtins.open', mock_open(read_data=requirements_content)
+            ):
+                result = Flake8Checker.get_setuptools_dynamic_requirements()
+                expected_results = ['package1', 'package2>=2.0']
+                parsed_results = [str(req) for req in result]
+                self.assertEqual(parsed_results, expected_results)
+
+    def test_dynamic_optional_dependencies(self):
+        data = {
+            "project": {"dynamic": ["dependencies", "optional-dependencies"]},
+            "tool": {
+                "setuptools": {
+                    "dynamic": {
+                        "dependencies": {"file": ["requirements.txt"]},
+                        "optional-dependencies": {
+                            "test": {"file": ["optional-requirements.txt"]}
+                        },
+                    }
+                }
+            },
+        }
+        requirements_content = """
+        package1
+        package2>=2.0
+        """
+        optional_requirements_content = "package3[extra] >= 3.0"
+        with mock.patch(
+            'flake8_requirements.checker.Flake8Checker.get_pyproject_toml',
+            return_value=data,
+        ):
+            with mock.patch('builtins.open', mock.mock_open()) as mocked_file:
+                mocked_file.side_effect = [
+                    mock.mock_open(
+                        read_data=requirements_content
+                    ).return_value,
+                    mock.mock_open(
+                        read_data=optional_requirements_content
+                    ).return_value,
+                ]
+                result = Flake8Checker.get_setuptools_dynamic_requirements()
+                expected = list(parse_requirements(requirements_content))
+                expected += list(
+                    parse_requirements(optional_requirements_content)
+                )
+
+                self.assertEqual(len(result), len(expected))
+                for i in range(len(result)):
+                    self.assertEqual(result[i], expected[i])
+
+    def test_missing_requirements_file(self):
+        data = {
+            "project": {"dynamic": ["dependencies"]},
+            "tool": {
+                "setuptools": {
+                    "dynamic": {
+                        "dependencies": {
+                            "file": ["nonexistent-requirements.txt"]
+                        }
+                    }
+                }
+            },
+        }
+        with mock.patch(
+            'flake8_requirements.checker.Flake8Checker.get_pyproject_toml',
+            return_value=data,
+        ):
+            result = Flake8Checker.get_setuptools_dynamic_requirements()
+            self.assertEqual(result, [])