Merge pull request #1 from pixee/dry-run

Added dry-run option with tests

requirements.txt

@@ -1,3 +1,4 @@
+GitPython<4
 mock==5.1.*
 pytest==7.4.*
--e .
+-e .

src/dependency_manager/__init__.py

@@ -1 +1 @@
-from .manager import DependencyManagerAbstract
+from .manager import DependencyManagerAbstract

src/dependency_manager/manager.py

@@ -1,18 +1,19 @@
 from abc import ABC, abstractmethod
 from pathlib import Path
-import pkg_resources
 from typing import Union
+import pkg_resources
 from .singleton import Singleton
 
 
 class DependencyManagerAbstract(Singleton, ABC):
-    def init(self):
+    def init(self, dry_run=False):
         """One-time class initialization."""
         self.parent_directory = self.get_parent_dir()
         self.dependency_file = self._infer_dependency_files()
         self.dependencies = self._infer_dependencies()
         self.dependencies_changed = False
         self.dependency_file_changed = False
+        self.dry_run = dry_run
 
     @abstractmethod
     def get_parent_dir(self) -> Path:
@@ -46,16 +47,28 @@ def remove(self, dependencies: list[str]):
                 self.dependencies_changed = True
 
     def write(self):
-        if not self.dependency_file or not self.dependencies or not self.dependencies_changed:
+        """
+        Write the updated dependency files if any changes were made.
+        If the dry_run flag is set, print it to stdout instead.
+        """
+        if (
+            not self.dependency_file
+            or not self.dependencies
+            or not self.dependencies_changed
+        ):
             return
 
         dependencies = [str(req) for req in self.dependencies]
-        self._write(dependencies)
+        if self.dry_run:
+            print("\n".join(dependencies))
+        else:
+            self._write(dependencies)
         self.dependency_file_changed = True
 
     def _write(self, dependencies):
         with open(self.dependency_file, "w", encoding="utf-8") as f:
             f.writelines("\n".join(dependencies))
+
     def _infer_dependency_files(self) -> Union[Path, None]:
         try:
             # For now for simplicity only return the first file

src/dependency_manager/singleton.py

@@ -20,6 +20,7 @@ def init(self, *args, **kwds):
         Subclasses should override this method for initialization, not __init__.
         """
         pass
+
     @classmethod
     def clear_instance(cls):
         """Delete the singleton's current instance."""

tests/test_manager.py

@@ -1,13 +1,34 @@
-import os
 from pathlib import Path
+import os
 import pytest
+import git
 from dependency_manager import DependencyManagerAbstract
 
 path_with_req = Path("tests/reqs_file_inside")
+original_contents = """# file used to test dependency management
+requests==2.31.0
+black==23.7.*
+mypy~=1.4
+pylint>1
+"""
+
+
+@pytest.fixture()
+def path_with_req_with_cleanup():
+    """
+    Yields the directory with the requirements and ensures it returns to its original state after.
+    """
+    path = "tests/reqs_file_inside"
+    yield Path(path)
+    repo = git.Git(os.getcwd())
+    repo.execute(["git", "checkout", str(Path(os.getcwd()) / path)])
+
+
 class TestManager:
     def test_must_define_parent_dir(self):
         class MyUnfinishedManager(DependencyManagerAbstract):
             pass
+
         with pytest.raises(TypeError):
             MyUnfinishedManager()
 
@@ -23,14 +44,15 @@ def get_parent_dir(self):
 
     def test_no_reqs_file_doesnt_error(self):
         dir_wo_reqs = Path("tests/no_reqs_files_inside")
+
         class DependencyManager(DependencyManagerAbstract):
             def get_parent_dir(self):
                 return dir_wo_reqs
 
-        dm = DependencyManager()
-        assert dm.parent_directory == dir_wo_reqs
-        assert dm.dependency_file == None
-        assert dm.dependencies == []
+        manager = DependencyManager()
+        assert manager.parent_directory == dir_wo_reqs
+        assert manager.dependency_file is None
+        assert not manager.dependencies
 
         DependencyManager().write()
 
@@ -39,63 +61,90 @@ class DependencyManager(DependencyManagerAbstract):
             def get_parent_dir(self):
                 return path_with_req
 
-        dm = DependencyManager()
-        assert dm.dependency_file == path_with_req / "requirements.txt"
-        assert len(dm.dependencies) == 4
+        manager = DependencyManager()
+        assert manager.dependency_file == path_with_req / "requirements.txt"
+        assert len(manager.dependencies) == 4
 
     def test_add(self):
         class DependencyManager(DependencyManagerAbstract):
             def get_parent_dir(self):
                 return path_with_req
 
-        dm = DependencyManager()
-        assert dm.dependency_file == path_with_req / "requirements.txt"
-        assert len(dm.dependencies) == 4
+        manager = DependencyManager()
+        assert manager.dependency_file == path_with_req / "requirements.txt"
+        assert len(manager.dependencies) == 4
 
         DependencyManager().add(["my_pkg==1"])
-        assert len(dm.dependencies) == 5
-        my_pkg = dm.dependencies[-1]
+        assert len(manager.dependencies) == 5
+        my_pkg = manager.dependencies[-1]
         assert str(my_pkg) == "my_pkg==1"
 
         DependencyManager().add(["my_pkg_no_ver"])
-        assert len(dm.dependencies) == 6
-        my_pkg = dm.dependencies[-1]
+        assert len(manager.dependencies) == 6
+        my_pkg = manager.dependencies[-1]
         assert str(my_pkg) == "my_pkg_no_ver"
 
         # don't add already existing dep
         DependencyManager().add(["my_pkg_no_ver"])
-        assert len(dm.dependencies) == 6
+        assert len(manager.dependencies) == 6
 
     def test_cant_handle_urls(self):
         class DependencyManager(DependencyManagerAbstract):
             def get_parent_dir(self):
                 return path_with_req
 
-        dm = DependencyManager()
+        manager = DependencyManager()
 
-        assert len(dm.dependencies) == 4
+        assert len(manager.dependencies) == 4
         DependencyManager().add(["git+https://github.com/someproject/"])
-        assert len(dm.dependencies) == 4
+        assert len(manager.dependencies) == 4
+
     def test_remove(self):
         class DependencyManager(DependencyManagerAbstract):
             def get_parent_dir(self):
                 return path_with_req
 
-        dm = DependencyManager()
-        assert dm.dependency_file == path_with_req / "requirements.txt"
-        assert len(dm.dependencies) == 4
+        manager = DependencyManager()
+        assert manager.dependency_file == path_with_req / "requirements.txt"
+        assert len(manager.dependencies) == 4
 
-        first_dep = dm.dependencies[0]
-        dm.remove([str(first_dep)])
-        assert len(dm.dependencies) == 3
+        first_dep = manager.dependencies[0]
+        manager.remove([str(first_dep)])
+        assert len(manager.dependencies) == 3
 
         DependencyManager().remove(["git+https://github.com/someproject/"])
-        assert len(dm.dependencies) == 3
+        assert len(manager.dependencies) == 3
 
         # Don't remove what isn't there
         DependencyManager().remove(["my_pkg==1"])
-        assert len(dm.dependencies) == 3
+        assert len(manager.dependencies) == 3
 
-    def test_write(self):
-        # TODO:
-        pass
+    def test_dry_run(self, capsys):
+        class DependencyManager(DependencyManagerAbstract):
+            def get_parent_dir(self):
+                return path_with_req
+
+        manager = DependencyManager(dry_run=True)
+        first_dep = manager.dependencies[0]
+        manager.remove([str(first_dep)])
+        manager.write()
+        with open(manager.dependency_file, "r", encoding="utf-8") as dep_file:
+            contents = dep_file.read()
+        assert contents == original_contents
+        expected = "black==23.7.*\nmypy~=1.4\npylint>1\n"
+        captured = capsys.readouterr()
+        assert captured.out == expected
+
+    def test_write(self, path_with_req_with_cleanup):
+        class DependencyManager(DependencyManagerAbstract):
+            def get_parent_dir(self):
+                return path_with_req_with_cleanup
+
+        manager = DependencyManager()
+        first_dep = manager.dependencies[0]
+        manager.remove([str(first_dep)])
+        manager.write()
+        with open(manager.dependency_file, "r", encoding="utf-8") as dep_file:
+            contents = dep_file.read()
+        expected = "black==23.7.*\nmypy~=1.4\npylint>1"
+        assert contents == expected