Add missing type hints - Part 2 (#4801)

* add typehints to tests.inspection * change several yield statements in fixtures to return * add typehints to tests.installation.test_chef, tests.installation.test_chooser, tests.installation.test_executor * add typehints to tests.installation.test_installer * add typehints to tests.installation.test_installer_old * add typehints to tests.installation.test_pip_installer * add typehints to tests.masonry * add typehints to tests.mixology * add typehints to tests.packages * add typehints to tests.plugins

Add missing type hints - Part 2 (#4801)
* add typehints to tests.inspection * change several yield statements in fixtures to return * add typehints to tests.installation.test_chef, tests.installation.test_chooser, tests.installation.test_executor * add typehints to tests.installation.test_installer * add typehints to tests.installation.test_installer_old * add typehints to tests.installation.test_pip_installer * add typehints to tests.masonry * add typehints to tests.mixology * add typehints to tests.packages * add typehints to tests.plugins
5c328a36 · finswimmer · GitHub · 2b92a33a · 5c328a36 · 5c328a36
Commit 5c328a36 authored Nov 20, 2021 by finswimmer Committed by GitHub Nov 20, 2021
19 changed files
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -424,5 +424,5 @@ def do_lock(command_tester_factory: "CommandTesterFactory", poetry: "Poetry") ->
 @pytest.fixture
-def project_root():
+def project_root() -> Path:
    return Path(__file__).parent.parent
--- a/tests/console/commands/test_lock.py
+++ b/tests/console/commands/test_lock.py
@@ -22,7 +22,7 @@ if TYPE_CHECKING:
 @pytest.fixture
 def source_dir(tmp_path: Path) -> Path:
-    yield Path(tmp_path.as_posix())
+    return Path(tmp_path.as_posix())
 @pytest.fixture

--- a/tests/inspection/test_info.py
+++ b/tests/inspection/test_info.py
 from pathlib import Path
 from subprocess import CalledProcessError
+from typing import TYPE_CHECKING
 from typing import Set
 import pytest
@@ -11,6 +12,9 @@ from poetry.utils.env import EnvCommandError
 from poetry.utils.env import VirtualEnv
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
 FIXTURE_DIR_BASE = Path(__file__).parent.parent / "fixtures"
 FIXTURE_DIR_INSPECTIONS = FIXTURE_DIR_BASE / "inspection"
@@ -32,7 +36,7 @@ def demo_wheel() -> Path:
 @pytest.fixture
 def source_dir(tmp_path: Path) -> Path:
-    yield Path(tmp_path.as_posix())
+    return Path(tmp_path.as_posix())
 @pytest.fixture
@@ -46,7 +50,7 @@ def demo_setup(source_dir: Path) -> Path:
            'install_requires=["package"])'
        )
    )
-    yield source_dir
+    return source_dir
 @pytest.fixture
@@ -65,7 +69,7 @@ def demo_setup_cfg(source_dir: Path) -> Path:
            )
        )
    )
-    yield source_dir
+    return source_dir
 @pytest.fixture
@@ -79,7 +83,7 @@ def demo_setup_complex(source_dir: Path) -> Path:
            'install_requires=[i for i in ["package"]])'
        )
    )
-    yield source_dir
+    return source_dir
 @pytest.fixture
@@ -88,7 +92,7 @@ def demo_setup_complex_pep517_legacy(demo_setup_complex: Path) -> Path:
    pyproject_toml.write_text(
        decode("[build-system]\n" 'requires = ["setuptools", "wheel"]')
    )
-    yield demo_setup_complex
+    return demo_setup_complex
 def demo_check_info(info: PackageInfo, requires_dist: Set[str] = None) -> None:
@@ -104,17 +108,17 @@ def demo_check_info(info: PackageInfo, requires_dist: Set[str] = None) -> None:
    assert set(info.requires_dist) == requires_dist
-def test_info_from_sdist(demo_sdist):
+def test_info_from_sdist(demo_sdist: Path):
    info = PackageInfo.from_sdist(demo_sdist)
    demo_check_info(info)
-def test_info_from_wheel(demo_wheel):
+def test_info_from_wheel(demo_wheel: Path):
    info = PackageInfo.from_wheel(demo_wheel)
    demo_check_info(info)
-def test_info_from_bdist(demo_wheel):
+def test_info_from_bdist(demo_wheel: Path):
    info = PackageInfo.from_bdist(demo_wheel)
    demo_check_info(info)
@@ -133,12 +137,12 @@ def test_info_from_requires_txt():
    demo_check_info(info)
-def test_info_from_setup_py(demo_setup):
+def test_info_from_setup_py(demo_setup: Path):
    info = PackageInfo.from_setup_files(demo_setup)
    demo_check_info(info, requires_dist={"package"})
-def test_info_from_setup_cfg(demo_setup_cfg):
+def test_info_from_setup_cfg(demo_setup_cfg: Path):
    info = PackageInfo.from_setup_files(demo_setup_cfg)
    demo_check_info(info, requires_dist={"package"})
@@ -153,26 +157,28 @@ def test_info_no_setup_pkg_info_no_deps():
    assert info.requires_dist is None
-def test_info_setup_simple(mocker, demo_setup):
+def test_info_setup_simple(mocker: "MockerFixture", demo_setup: Path):
    spy = mocker.spy(VirtualEnv, "run")
    info = PackageInfo.from_directory(demo_setup)
    assert spy.call_count == 0
    demo_check_info(info, requires_dist={"package"})
-def test_info_setup_cfg(mocker, demo_setup_cfg):
+def test_info_setup_cfg(mocker: "MockerFixture", demo_setup_cfg: Path):
    spy = mocker.spy(VirtualEnv, "run")
    info = PackageInfo.from_directory(demo_setup_cfg)
    assert spy.call_count == 0
    demo_check_info(info, requires_dist={"package"})
-def test_info_setup_complex(demo_setup_complex):
+def test_info_setup_complex(demo_setup_complex: Path):
    info = PackageInfo.from_directory(demo_setup_complex)
    demo_check_info(info, requires_dist={"package"})
-def test_info_setup_complex_pep517_error(mocker, demo_setup_complex):
+def test_info_setup_complex_pep517_error(
+    mocker: "MockerFixture", demo_setup_complex: Path
+):
    mocker.patch(
        "poetry.utils.env.VirtualEnv.run",
        autospec=True,
@@ -183,12 +189,14 @@ def test_info_setup_complex_pep517_error(mocker, demo_setup_complex):
        PackageInfo.from_directory(demo_setup_complex)
-def test_info_setup_complex_pep517_legacy(demo_setup_complex_pep517_legacy):
+def test_info_setup_complex_pep517_legacy(demo_setup_complex_pep517_legacy: Path):
    info = PackageInfo.from_directory(demo_setup_complex_pep517_legacy)
    demo_check_info(info, requires_dist={"package"})
-def test_info_setup_complex_disable_build(mocker, demo_setup_complex):
+def test_info_setup_complex_disable_build(
+    mocker: "MockerFixture", demo_setup_complex: Path
+):
    spy = mocker.spy(VirtualEnv, "run")
    info = PackageInfo.from_directory(demo_setup_complex, disable_build=True)
    assert spy.call_count == 0
@@ -199,7 +207,7 @@ def test_info_setup_complex_disable_build(mocker, demo_setup_complex):
 @pytest.mark.parametrize("missing", ["version", "name", "install_requires"])
 def test_info_setup_missing_mandatory_should_trigger_pep517(
-    mocker, source_dir, missing
+    mocker: "MockerFixture", source_dir: Path, missing: str
 ):
    setup = "from setuptools import setup; "
    setup += "setup("

--- a/tests/installation/test_chef.py
+++ b/tests/installation/test_chef.py
 from pathlib import Path
+from typing import TYPE_CHECKING
 from packaging.tags import Tag
@@ -7,7 +8,13 @@ from poetry.installation.chef import Chef
 from poetry.utils.env import MockEnv
-def test_get_cached_archive_for_link(config, mocker):
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+    from tests.conftest import Config
+def test_get_cached_archive_for_link(config: "Config", mocker: "MockerFixture"):
    chef = Chef(
        config,
        MockEnv(
@@ -38,7 +45,7 @@ def test_get_cached_archive_for_link(config, mocker):
    assert Link("file:///foo/demo-0.1.0-cp38-cp38-macosx_10_15_x86_64.whl") == archive
-def test_get_cached_archives_for_link(config, mocker):
+def test_get_cached_archives_for_link(config: "Config", mocker: "MockerFixture"):
    chef = Chef(
        config,
        MockEnv(
@@ -63,7 +70,7 @@ def test_get_cached_archives_for_link(config, mocker):
    }
-def test_get_cache_directory_for_link(config, config_cache_dir):
+def test_get_cache_directory_for_link(config: "Config", config_cache_dir: Path):
    chef = Chef(
        config,
        MockEnv(

--- a/tests/installation/test_chooser.py
+++ b/tests/installation/test_chooser.py
 import re
 from pathlib import Path
+from typing import TYPE_CHECKING
+from typing import Any
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Type
+from typing import Union
 import pytest
@@ -14,6 +21,12 @@ from poetry.repositories.pypi_repository import PyPiRepository
 from poetry.utils.env import MockEnv
+if TYPE_CHECKING:
+    import httpretty
+    from httpretty.core import HTTPrettyRequest
 JSON_FIXTURES = (
    Path(__file__).parent.parent / "repositories" / "fixtures" / "pypi.org" / "json"
 )
@@ -22,7 +35,7 @@ LEGACY_FIXTURES = Path(__file__).parent.parent / "repositories" / "fixtures" / "
 @pytest.fixture()
-def env():
+def env() -> MockEnv:
    return MockEnv(
        supported_tags=[
            Tag("cp37", "cp37", "macosx_10_15_x86_64"),
@@ -32,8 +45,10 @@ def env():
 @pytest.fixture()
-def mock_pypi(http):
+def mock_pypi(http: Type["httpretty.httpretty"]) -> None:
-    def callback(request, uri, headers):
+    def callback(
+        request: "HTTPrettyRequest", uri: str, headers: Dict[str, Any]
+    ) -> Optional[List[Union[int, Dict[str, Any], str]]]:
        parts = uri.rsplit("/")
        name = parts[-3]
@@ -57,8 +72,10 @@ def mock_pypi(http):
 @pytest.fixture()
-def mock_legacy(http):
+def mock_legacy(http: Type["httpretty.httpretty"]) -> None:
-    def callback(request, uri, headers):
+    def callback(
+        request: "HTTPrettyRequest", uri: str, headers: Dict[str, Any]
+    ) -> List[Union[int, Dict[str, Any], str]]:
        parts = uri.rsplit("/")
        name = parts[-2]
@@ -75,7 +92,7 @@ def mock_legacy(http):
 @pytest.fixture()
-def pool():
+def pool() -> Pool:
    pool = Pool()
    pool.add_repository(PyPiRepository(disable_cache=True))
@@ -88,7 +105,7 @@ def pool():
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_chooses_universal_wheel_link_if_available(
-    env, mock_pypi, mock_legacy, source_type, pool
+    env: MockEnv, mock_pypi: None, mock_legacy: None, source_type: str, pool: Pool
 ):
    chooser = Chooser(pool, env)
@@ -109,7 +126,7 @@ def test_chooser_chooses_universal_wheel_link_if_available(
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_chooses_specific_python_universal_wheel_link_if_available(
-    env, mock_pypi, mock_legacy, source_type, pool
+    env: MockEnv, mock_pypi: None, mock_legacy: None, source_type: str, pool: Pool
 ):
    chooser = Chooser(pool, env)
@@ -130,7 +147,7 @@ def test_chooser_chooses_specific_python_universal_wheel_link_if_available(
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_chooses_system_specific_wheel_link_if_available(
-    mock_pypi, mock_legacy, source_type, pool
+    mock_pypi: None, mock_legacy: None, source_type: str, pool: Pool
 ):
    env = MockEnv(
        supported_tags=[Tag("cp37", "cp37m", "win32"), Tag("py3", "none", "any")]
@@ -154,11 +171,11 @@ def test_chooser_chooses_system_specific_wheel_link_if_available(
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_chooses_sdist_if_no_compatible_wheel_link_is_available(
-    env,
+    env: MockEnv,
-    mock_pypi,
+    mock_pypi: None,
-    mock_legacy,
+    mock_legacy: None,
-    source_type,
+    source_type: str,
-    pool,
+    pool: Pool,
 ):
    chooser = Chooser(pool, env)
@@ -179,11 +196,11 @@ def test_chooser_chooses_sdist_if_no_compatible_wheel_link_is_available(
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_chooses_distributions_that_match_the_package_hashes(
-    env,
+    env: MockEnv,
-    mock_pypi,
+    mock_pypi: None,
-    mock_legacy,
+    mock_legacy: None,
-    source_type,
+    source_type: str,
-    pool,
+    pool: Pool,
 ):
    chooser = Chooser(pool, env)
@@ -212,11 +229,11 @@ def test_chooser_chooses_distributions_that_match_the_package_hashes(
 @pytest.mark.parametrize("source_type", ["", "legacy"])
 def test_chooser_throws_an_error_if_package_hashes_do_not_match(
-    env,
+    env: MockEnv,
-    mock_pypi,
+    mock_pypi: None,
-    mock_legacy,
+    mock_legacy: None,
-    source_type,
+    source_type: None,
-    pool,
+    pool: Pool,
 ):
    chooser = Chooser(pool, env)

--- a/tests/installation/test_executor.py
+++ b/tests/installation/test_executor.py
@@ -3,6 +3,14 @@ import re
 import shutil
 from pathlib import Path
+from typing import TYPE_CHECKING
+from typing import Any
+from typing import Callable
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Type
+from typing import Union
 import pytest
@@ -22,8 +30,17 @@ from poetry.utils.env import MockEnv
 from tests.repositories.test_pypi_repository import MockRepository
+if TYPE_CHECKING:
+    import httpretty
+    from httpretty.core import HTTPrettyRequest
+    from pytest_mock import MockerFixture
+    from poetry.utils.env import VirtualEnv
 @pytest.fixture
-def env(tmp_dir):
+def env(tmp_dir: str) -> MockEnv:
    path = Path(tmp_dir) / ".venv"
    path.mkdir(parents=True)
@@ -31,7 +48,7 @@ def env(tmp_dir):
 @pytest.fixture()
-def io():
+def io() -> BufferedIO:
    io = BufferedIO()
    io.output.formatter.set_style("c1_dark", Style("cyan", options=["dark"]))
    io.output.formatter.set_style("c2_dark", Style("default", options=["bold", "dark"]))
@@ -42,7 +59,7 @@ def io():
 @pytest.fixture()
-def io_decorated():
+def io_decorated() -> BufferedIO:
    io = BufferedIO(decorated=True)
    io.output.formatter.set_style("c1", Style("cyan"))
    io.output.formatter.set_style("success", Style("green"))
@@ -51,14 +68,14 @@ def io_decorated():
 @pytest.fixture()
-def io_not_decorated():
+def io_not_decorated() -> BufferedIO:
    io = BufferedIO(decorated=False)
    return io
 @pytest.fixture()
-def pool():
+def pool() -> Pool:
    pool = Pool()
    pool.add_repository(MockRepository())
@@ -66,8 +83,10 @@ def pool():
 @pytest.fixture()
-def mock_file_downloads(http):
+def mock_file_downloads(http: Type["httpretty.httpretty"]) -> None:
-    def callback(request, uri, headers):
+    def callback(
+        request: "HTTPrettyRequest", uri: str, headers: Dict[str, Any]
+    ) -> List[Union[int, Dict[str, Any], str]]:
        fixture = Path(__file__).parent.parent.joinpath(
            "fixtures/distributions/demo-0.1.0-py2.py3-none-any.whl"
        )
@@ -83,7 +102,13 @@ def mock_file_downloads(http):
 def test_execute_executes_a_batch_of_operations(
-    mocker, config, pool, io, tmp_dir, mock_file_downloads, env
+    mocker: "MockerFixture",
+    config: Config,
+    pool: Pool,
+    io: BufferedIO,
+    tmp_dir: str,
+    mock_file_downloads: None,
+    env: MockEnv,
 ):
    pip_editable_install = mocker.patch(
        "poetry.installation.executor.pip_editable_install", unsafe=not PY36
@@ -159,7 +184,7 @@ Package operations: 4 installs, 1 update, 1 removal
 def test_execute_shows_skipped_operations_if_verbose(
-    config, pool, io, config_cache_dir, env
+    config: Config, pool: Pool, io: BufferedIO, config_cache_dir: Path, env: MockEnv
 ):
    config = Config()
    config.merge({"cache-dir": config_cache_dir.as_posix()})
@@ -180,7 +205,9 @@ Package operations: 0 installs, 0 updates, 0 removals, 1 skipped
    assert 0 == len(env.executed)
-def test_execute_should_show_errors(config, mocker, io, env):
+def test_execute_should_show_errors(
+    config: Config, pool: Pool, mocker: "MockerFixture", io: BufferedIO, env: MockEnv
+):
    executor = Executor(env, pool, config, io)
    executor.verbose()
@@ -202,7 +229,13 @@ Package operations: 1 install, 0 updates, 0 removals
 def test_execute_works_with_ansi_output(
-    mocker, config, pool, io_decorated, tmp_dir, mock_file_downloads, env
+    mocker: "MockerFixture",
+    config: Config,
+    pool: Pool,
+    io_decorated: BufferedIO,
+    tmp_dir: str,
+    mock_file_downloads: None,
+    env: MockEnv,
 ):
    config = Config()
    config.merge({"cache-dir": tmp_dir})
@@ -236,7 +269,13 @@ def test_execute_works_with_ansi_output(
 def test_execute_works_with_no_ansi_output(
-    mocker, config, pool, io_not_decorated, tmp_dir, mock_file_downloads, env
+    mocker: "MockerFixture",
+    config: Config,
+    pool: Pool,
+    io_not_decorated: BufferedIO,
+    tmp_dir: str,
+    mock_file_downloads: None,
+    env: MockEnv,
 ):
    config = Config()
    config.merge({"cache-dir": tmp_dir})
@@ -266,7 +305,7 @@ Package operations: 1 install, 0 updates, 0 removals
 def test_execute_should_show_operation_as_cancelled_on_subprocess_keyboard_interrupt(
-    config, mocker, io, env
+    config: Config, pool: Pool, mocker: "MockerFixture", io: BufferedIO, env: MockEnv
 ):
    executor = Executor(env, pool, config, io)
    executor.verbose()
@@ -286,13 +325,15 @@ Package operations: 1 install, 0 updates, 0 removals
    assert expected == io.fetch_output()
-def test_execute_should_gracefully_handle_io_error(config, mocker, io, env):
+def test_execute_should_gracefully_handle_io_error(
+    config: Config, pool: Pool, mocker: "MockerFixture", io: BufferedIO, env: MockEnv
+):
    executor = Executor(env, pool, config, io)
    executor.verbose()
    original_write_line = executor._io.write_line
-    def write_line(string, **kwargs):
+    def write_line(string: str, **kwargs: Any) -> None:
        # Simulate UnicodeEncodeError
        string.encode("ascii")
        original_write_line(string, **kwargs)
@@ -312,7 +353,13 @@ Package operations: 1 install, 0 updates, 0 removals
 def test_executor_should_delete_incomplete_downloads(
-    config, io, tmp_dir, mocker, pool, mock_file_downloads, env
+    config: Config,
+    io: BufferedIO,
+    tmp_dir: str,
+    mocker: "MockerFixture",
+    pool: Pool,
+    mock_file_downloads: None,
+    env: MockEnv,
 ):
    fixture = Path(__file__).parent.parent.joinpath(
        "fixtures/distributions/demo-0.1.0-py2.py3-none-any.whl"
@@ -343,7 +390,9 @@ def test_executor_should_delete_incomplete_downloads(
    assert not destination_fixture.exists()
-def verify_installed_distribution(venv, package, url_reference=None):
+def verify_installed_distribution(
+    venv: "VirtualEnv", package: Package, url_reference: Optional[Dict[str, Any]] = None
+):
    distributions = list(venv.site_packages.distributions(name=package.name))
    assert len(distributions) == 1
@@ -368,7 +417,7 @@ def verify_installed_distribution(venv, package, url_reference=None):
 def test_executor_should_write_pep610_url_references_for_files(
-    tmp_venv, pool, config, io
+    tmp_venv: "VirtualEnv", pool: Pool, config: Config, io: BufferedIO
 ):
    url = (
        Path(__file__)
@@ -387,7 +436,7 @@ def test_executor_should_write_pep610_url_references_for_files(
 def test_executor_should_write_pep610_url_references_for_directories(
-    tmp_venv, pool, config, io
+    tmp_venv: "VirtualEnv", pool: Pool, config: Config, io: BufferedIO
 ):
    url = Path(__file__).parent.parent.joinpath("fixtures/simple_project").resolve()
    package = Package(
@@ -402,7 +451,7 @@ def test_executor_should_write_pep610_url_references_for_directories(
 def test_executor_should_write_pep610_url_references_for_editable_directories(
-    tmp_venv, pool, config, io
+    tmp_venv: "VirtualEnv", pool: Pool, config: Config, io: BufferedIO
 ):
    url = Path(__file__).parent.parent.joinpath("fixtures/simple_project").resolve()
    package = Package(
@@ -421,7 +470,11 @@ def test_executor_should_write_pep610_url_references_for_editable_directories(
 def test_executor_should_write_pep610_url_references_for_urls(
-    tmp_venv, pool, config, io, mock_file_downloads
+    tmp_venv: "VirtualEnv",
+    pool: Pool,
+    config: Config,
+    io: BufferedIO,
+    mock_file_downloads: None,
 ):
    package = Package(
        "demo",
@@ -438,7 +491,11 @@ def test_executor_should_write_pep610_url_references_for_urls(
 def test_executor_should_write_pep610_url_references_for_git(
-    tmp_venv, pool, config, io, mock_file_downloads
+    tmp_venv: "VirtualEnv",
+    pool: Pool,
+    config: Config,
+    io: BufferedIO,
+    mock_file_downloads: None,
 ):
    package = Package(
        "demo",
@@ -466,7 +523,12 @@ def test_executor_should_write_pep610_url_references_for_git(
 def test_executor_should_use_cached_link_and_hash(
-    tmp_venv, pool, config, io, mocker, fixture_dir
+    tmp_venv: "VirtualEnv",
+    pool: Pool,
+    config: Config,
+    io: BufferedIO,
+    mocker: "MockerFixture",
+    fixture_dir: Callable[[str], Path],
 ):
    # Produce a file:/// URI that is a valid link
    link_cached = Link(

--- a/tests/installation/test_installer.py
+++ b/tests/installation/test_installer.py
--- a/tests/installation/test_installer_old.py
+++ b/tests/installation/test_installer_old.py
--- a/tests/installation/test_pip_installer.py
+++ b/tests/installation/test_pip_installer.py
@@ -2,6 +2,7 @@ import re
 import shutil
 from pathlib import Path
+from typing import TYPE_CHECKING
 import pytest
@@ -14,8 +15,14 @@ from poetry.repositories.pool import Pool
 from poetry.utils.env import NullEnv
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+    from poetry.utils.env import VirtualEnv
 @pytest.fixture
-def package_git():
+def package_git() -> Package:
    package = Package(
        "demo",
        "1.0.0",
@@ -28,16 +35,16 @@ def package_git():
 @pytest.fixture
-def pool():
+def pool() -> Pool:
    return Pool()
 @pytest.fixture
-def installer(pool):
+def installer(pool: Pool) -> PipInstaller:
    return PipInstaller(NullEnv(), NullIO(), pool)
-def test_requirement(installer):
+def test_requirement(installer: PipInstaller):
    package = Package("ipython", "7.5.0")
    package.files = [
        {"file": "foo-0.1.0.tar.gz", "hash": "md5:dbdc53e3918f28fa335a173432402a00"},
@@ -74,7 +81,7 @@ def test_requirement_source_type_url():
    assert expected == result
-def test_requirement_git_develop_false(installer, package_git):
+def test_requirement_git_develop_false(installer: PipInstaller, package_git: Package):
    package_git.develop = False
    result = installer.requirement(package_git)
    expected = "git+git@github.com:demo/demo.git@master#egg=demo"
@@ -82,7 +89,7 @@ def test_requirement_git_develop_false(installer, package_git):
    assert expected == result
-def test_install_with_non_pypi_default_repository(pool, installer):
+def test_install_with_non_pypi_default_repository(pool: Pool, installer: PipInstaller):
    default = LegacyRepository("default", "https://default.com")
    another = LegacyRepository("another", "https://another.com")
@@ -170,7 +177,7 @@ def test_install_with_client_cert():
    assert cmd[cert_index + 1] == str(Path(client_path))
-def test_requirement_git_develop_true(installer, package_git):
+def test_requirement_git_develop_true(installer: PipInstaller, package_git: Package):
    package_git.develop = True
    result = installer.requirement(package_git)
    expected = ["-e", "git+git@github.com:demo/demo.git@master#egg=demo"]
@@ -178,7 +185,9 @@ def test_requirement_git_develop_true(installer, package_git):
    assert expected == result
-def test_uninstall_git_package_nspkg_pth_cleanup(mocker, tmp_venv, pool):
+def test_uninstall_git_package_nspkg_pth_cleanup(
+    mocker: "MockerFixture", tmp_venv: "VirtualEnv", pool: Pool
+):
    # this test scenario requires a real installation using the pip installer
    installer = PipInstaller(tmp_venv, NullIO(), pool)
@@ -194,7 +203,7 @@ def test_uninstall_git_package_nspkg_pth_cleanup(mocker, tmp_venv, pool):
    # in order to reproduce the scenario where the git source is removed prior to proper
    # clean up of nspkg.pth file, we need to make sure the fixture is copied and not
    # symlinked into the git src directory
-    def copy_only(source, dest):
+    def copy_only(source: Path, dest: Path) -> None:
        if dest.exists():
            dest.unlink()

--- a/tests/masonry/builders/test_editable_builder.py
+++ b/tests/masonry/builders/test_editable_builder.py
@@ -2,6 +2,7 @@ import os
 import shutil
 from pathlib import Path
+from typing import TYPE_CHECKING
 import pytest
@@ -14,8 +15,14 @@ from poetry.utils.env import MockEnv
 from poetry.utils.env import VirtualEnv
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+    from poetry.poetry import Poetry
 @pytest.fixture()
-def simple_poetry():
+def simple_poetry() -> "Poetry":
    poetry = Factory().create_poetry(
        Path(__file__).parent.parent.parent / "fixtures" / "simple_project"
    )
@@ -24,7 +31,7 @@ def simple_poetry():
 @pytest.fixture()
-def project_with_include():
+def project_with_include() -> "Poetry":
    poetry = Factory().create_poetry(
        Path(__file__).parent.parent.parent / "fixtures" / "with-include"
    )
@@ -33,7 +40,7 @@ def project_with_include():
 @pytest.fixture()
-def extended_poetry():
+def extended_poetry() -> "Poetry":
    poetry = Factory().create_poetry(
        Path(__file__).parent.parent.parent / "fixtures" / "extended_project"
    )
@@ -42,7 +49,7 @@ def extended_poetry():
 @pytest.fixture()
-def extended_without_setup_poetry():
+def extended_without_setup_poetry() -> "Poetry":
    poetry = Factory().create_poetry(
        Path(__file__).parent.parent.parent
        / "fixtures"
@@ -53,12 +60,12 @@ def extended_without_setup_poetry():
 @pytest.fixture()
-def env_manager(simple_poetry):
+def env_manager(simple_poetry: "Poetry") -> EnvManager:
    return EnvManager(simple_poetry)
 @pytest.fixture
-def tmp_venv(tmp_dir, env_manager):
+def tmp_venv(tmp_dir: str, env_manager: EnvManager) -> VirtualEnv:
    venv_path = Path(tmp_dir) / "venv"
    env_manager.build_venv(str(venv_path))
@@ -69,7 +76,9 @@ def tmp_venv(tmp_dir, env_manager):
    shutil.rmtree(str(venv.path))
-def test_builder_installs_proper_files_for_standard_packages(simple_poetry, tmp_venv):
+def test_builder_installs_proper_files_for_standard_packages(
+    simple_poetry: "Poetry", tmp_venv: VirtualEnv
+):
    builder = EditableBuilder(simple_poetry, tmp_venv, NullIO())
    builder.build()
@@ -184,7 +193,7 @@ if __name__ == '__main__':
 def test_builder_falls_back_on_setup_and_pip_for_packages_with_build_scripts(
-    mocker, extended_poetry, tmp_dir
+    mocker: "MockerFixture", extended_poetry: "Poetry", tmp_dir: str
 ):
    pip_editable_install = mocker.patch(
        "poetry.masonry.builders.editable.pip_editable_install"
@@ -200,7 +209,7 @@ def test_builder_falls_back_on_setup_and_pip_for_packages_with_build_scripts(
 def test_builder_installs_proper_files_when_packages_configured(
-    project_with_include, tmp_venv
+    project_with_include: "Poetry", tmp_venv: VirtualEnv
 ):
    builder = EditableBuilder(project_with_include, tmp_venv, NullIO())
    builder.build()
@@ -224,7 +233,9 @@ def test_builder_installs_proper_files_when_packages_configured(
    assert len(paths) == len(expected)
-def test_builder_should_execute_build_scripts(extended_without_setup_poetry, tmp_dir):
+def test_builder_should_execute_build_scripts(
+    extended_without_setup_poetry: "Poetry", tmp_dir: str
+):
    env = MockEnv(path=Path(tmp_dir) / "foo")
    builder = EditableBuilder(extended_without_setup_poetry, env, NullIO())

--- a/tests/mixology/helpers.py
+++ b/tests/mixology/helpers.py
+from typing import TYPE_CHECKING
+from typing import Dict
+from typing import List
+from typing import Optional
 from poetry.core.packages.package import Package
 from poetry.factory import Factory
 from poetry.mixology.failure import SolveFailure
@@ -5,7 +10,19 @@ from poetry.mixology.version_solver import VersionSolver
 from poetry.packages import DependencyPackage
-def add_to_repo(repository, name, version, deps=None, python=None):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def add_to_repo(
+    repository: "Repository",
+    name: str,
+    version: str,
+    deps: Optional[Dict[str, str]] = None,
+    python: Optional[str] = None,
+) -> None:
    package = Package(name, version)
    if python:
        package.python_versions = python
@@ -18,8 +35,14 @@ def add_to_repo(repository, name, version, deps=None, python=None):
 def check_solver_result(
-    root, provider, result=None, error=None, tries=None, locked=None, use_latest=None
+    root: "ProjectPackage",
-):
+    provider: "Provider",
+    result: Optional[Dict[str, str]] = None,
+    error: Optional[str] = None,
+    tries: Optional[int] = None,
+    locked: Optional[Dict[str, Package]] = None,
+    use_latest: Optional[List[str]] = None,
+) -> None:
    if locked is not None:
        locked = {k: DependencyPackage(l.to_dependency(), l) for k, l in locked.items()}

--- a/tests/mixology/version_solver/conftest.py
+++ b/tests/mixology/version_solver/conftest.py
+from typing import TYPE_CHECKING
 import pytest
 from cleo.io.null_io import NullIO
@@ -8,19 +10,23 @@ from poetry.repositories import Pool
 from poetry.repositories import Repository
+if TYPE_CHECKING:
+    from tests.helpers import TestRepository
 class Provider(BaseProvider):
-    def set_package_python_versions(self, python_versions):
+    def set_package_python_versions(self, python_versions: str) -> None:
        self._package.python_versions = python_versions
        self._python_constraint = self._package.python_constraint
 @pytest.fixture
-def repo():
+def repo() -> Repository:
    return Repository()
 @pytest.fixture
-def pool(repo):
+def pool(repo: "TestRepository") -> Pool:
    pool = Pool()
    pool.add_repository(repo)
@@ -28,10 +34,10 @@ def pool(repo):
 @pytest.fixture
-def root():
+def root() -> ProjectPackage:
    return ProjectPackage("myapp", "0.0.0")
 @pytest.fixture
-def provider(pool, root):
+def provider(pool: Pool, root: ProjectPackage) -> Provider:
    return Provider(root, pool, NullIO())
--- a/tests/mixology/version_solver/test_backtracking.py
+++ b/tests/mixology/version_solver/test_backtracking.py
+from typing import TYPE_CHECKING
 from poetry.factory import Factory
 from tests.mixology.helpers import add_to_repo
 from tests.mixology.helpers import check_solver_result
-def test_circular_dependency_on_older_version(root, provider, repo):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def test_circular_dependency_on_older_version(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", ">=1.0.0"))
    add_to_repo(repo, "a", "1.0.0")
@@ -13,7 +23,9 @@ def test_circular_dependency_on_older_version(root, provider, repo):
    check_solver_result(root, provider, {"a": "1.0.0"}, tries=2)
-def test_diamond_dependency_graph(root, provider, repo):
+def test_diamond_dependency_graph(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", "*"))
    root.add_dependency(Factory.create_dependency("b", "*"))
@@ -30,7 +42,9 @@ def test_diamond_dependency_graph(root, provider, repo):
    check_solver_result(root, provider, {"a": "1.0.0", "b": "2.0.0", "c": "3.0.0"})
-def test_backjumps_after_partial_satisfier(root, provider, repo):
+def test_backjumps_after_partial_satisfier(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    # c 2.0.0 is incompatible with y 2.0.0 because it requires x 1.0.0, but that
    # requirement only exists because of both a and b. The solver should be able
    # to deduce c 2.0.0's incompatibility and select c 1.0.0 instead.
@@ -53,7 +67,9 @@ def test_backjumps_after_partial_satisfier(root, provider, repo):
    check_solver_result(root, provider, {"c": "1.0.0", "y": "2.0.0"}, tries=2)
-def test_rolls_back_leaf_versions_first(root, provider, repo):
+def test_rolls_back_leaf_versions_first(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    # The latest versions of a and b disagree on c. An older version of either
    # will resolve the problem. This test validates that b, which is farther
    # in the dependency graph from myapp is downgraded first.
@@ -69,7 +85,9 @@ def test_rolls_back_leaf_versions_first(root, provider, repo):
    check_solver_result(root, provider, {"a": "2.0.0", "b": "1.0.0", "c": "2.0.0"})
-def test_simple_transitive(root, provider, repo):
+def test_simple_transitive(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    # Only one version of baz, so foo and bar will have to downgrade
    # until they reach it
    root.add_dependency(Factory.create_dependency("foo", "*"))
@@ -89,7 +107,9 @@ def test_simple_transitive(root, provider, repo):
    )
-def test_backjump_to_nearer_unsatisfied_package(root, provider, repo):
+def test_backjump_to_nearer_unsatisfied_package(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    # This ensures it doesn't exhaustively search all versions of b when it's
    # a-2.0.0 whose dependency on c-2.0.0-nonexistent led to the problem. We
    # make sure b has more versions than a so that the solver tries a first
@@ -109,7 +129,9 @@ def test_backjump_to_nearer_unsatisfied_package(root, provider, repo):
    )
-def test_traverse_into_package_with_fewer_versions_first(root, provider, repo):
+def test_traverse_into_package_with_fewer_versions_first(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    # Dependencies are ordered so that packages with fewer versions are tried
    # first. Here, there are two valid solutions (either a or b must be
    # downgraded once). The chosen one depends on which dep is traversed first.
@@ -133,7 +155,9 @@ def test_traverse_into_package_with_fewer_versions_first(root, provider, repo):
    check_solver_result(root, provider, {"a": "4.0.0", "b": "4.0.0", "c": "2.0.0"})
-def test_backjump_past_failed_package_on_disjoint_constraint(root, provider, repo):
+def test_backjump_past_failed_package_on_disjoint_constraint(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", "*"))
    root.add_dependency(Factory.create_dependency("foo", ">2.0.0"))

--- a/tests/mixology/version_solver/test_basic_graph.py
+++ b/tests/mixology/version_solver/test_basic_graph.py
+from typing import TYPE_CHECKING
 from poetry.factory import Factory
 from tests.mixology.helpers import add_to_repo
 from tests.mixology.helpers import check_solver_result
-def test_simple_dependencies(root, provider, repo):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def test_simple_dependencies(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", "1.0.0"))
    root.add_dependency(Factory.create_dependency("b", "1.0.0"))
@@ -28,7 +38,9 @@ def test_simple_dependencies(root, provider, repo):
    )
-def test_shared_dependencies_with_overlapping_constraints(root, provider, repo):
+def test_shared_dependencies_with_overlapping_constraints(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", "1.0.0"))
    root.add_dependency(Factory.create_dependency("b", "1.0.0"))
@@ -44,7 +56,7 @@ def test_shared_dependencies_with_overlapping_constraints(root, provider, repo):
 def test_shared_dependency_where_dependent_version_affects_other_dependencies(
-    root, provider, repo
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
 ):
    root.add_dependency(Factory.create_dependency("foo", "<=1.0.2"))
    root.add_dependency(Factory.create_dependency("bar", "1.0.0"))
@@ -63,7 +75,9 @@ def test_shared_dependency_where_dependent_version_affects_other_dependencies(
    )
-def test_circular_dependency(root, provider, repo):
+def test_circular_dependency(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "1.0.0"))
    add_to_repo(repo, "foo", "1.0.0", deps={"bar": "1.0.0"})

--- a/tests/mixology/version_solver/test_python_constraint.py
+++ b/tests/mixology/version_solver/test_python_constraint.py
+from typing import TYPE_CHECKING
 from poetry.factory import Factory
 from tests.mixology.helpers import add_to_repo
 from tests.mixology.helpers import check_solver_result
-def test_dependency_does_not_match_root_python_constraint(root, provider, repo):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def test_dependency_does_not_match_root_python_constraint(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    provider.set_package_python_versions("^3.6")
    root.add_dependency(Factory.create_dependency("foo", "*"))

--- a/tests/mixology/version_solver/test_unsolvable.py
+++ b/tests/mixology/version_solver/test_unsolvable.py
+from typing import TYPE_CHECKING
 from poetry.factory import Factory
 from tests.mixology.helpers import add_to_repo
 from tests.mixology.helpers import check_solver_result
-def test_no_version_matching_constraint(root, provider, repo):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def test_no_version_matching_constraint(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "^1.0"))
    add_to_repo(repo, "foo", "2.0.0")
@@ -19,7 +29,9 @@ def test_no_version_matching_constraint(root, provider, repo):
    )
-def test_no_version_that_matches_combined_constraints(root, provider, repo):
+def test_no_version_that_matches_combined_constraints(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "1.0.0"))
    root.add_dependency(Factory.create_dependency("bar", "1.0.0"))
@@ -37,7 +49,9 @@ So, because myapp depends on both foo (1.0.0) and bar (1.0.0), version solving f
    check_solver_result(root, provider, error=error)
-def test_disjoint_constraints(root, provider, repo):
+def test_disjoint_constraints(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "1.0.0"))
    root.add_dependency(Factory.create_dependency("bar", "1.0.0"))
@@ -55,7 +69,9 @@ So, because myapp depends on both foo (1.0.0) and bar (1.0.0), version solving f
    check_solver_result(root, provider, error=error)
-def test_disjoint_root_constraints(root, provider, repo):
+def test_disjoint_root_constraints(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "1.0.0"))
    root.add_dependency(Factory.create_dependency("foo", "2.0.0"))
@@ -68,7 +84,9 @@ Because myapp depends on both foo (1.0.0) and foo (2.0.0), version solving faile
    check_solver_result(root, provider, error=error)
-def test_no_valid_solution(root, provider, repo):
+def test_no_valid_solution(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("a", "*"))
    root.add_dependency(Factory.create_dependency("b", "*"))

--- a/tests/mixology/version_solver/test_with_lock.py
+++ b/tests/mixology/version_solver/test_with_lock.py
+from typing import TYPE_CHECKING
 from poetry.factory import Factory
 from tests.helpers import get_package
 from tests.mixology.helpers import add_to_repo
 from tests.mixology.helpers import check_solver_result
-def test_with_compatible_locked_dependencies(root, provider, repo):
+if TYPE_CHECKING:
+    from poetry.packages.project_package import ProjectPackage
+    from poetry.repositories import Repository
+    from tests.mixology.version_solver.conftest import Provider
+def test_with_compatible_locked_dependencies(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "*"))
    add_to_repo(repo, "foo", "1.0.0", deps={"bar": "1.0.0"})
@@ -22,7 +32,9 @@ def test_with_compatible_locked_dependencies(root, provider, repo):
    )
-def test_with_incompatible_locked_dependencies(root, provider, repo):
+def test_with_incompatible_locked_dependencies(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", ">1.0.1"))
    add_to_repo(repo, "foo", "1.0.0", deps={"bar": "1.0.0"})
@@ -40,7 +52,9 @@ def test_with_incompatible_locked_dependencies(root, provider, repo):
    )
-def test_with_unrelated_locked_dependencies(root, provider, repo):
+def test_with_unrelated_locked_dependencies(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "*"))
    add_to_repo(repo, "foo", "1.0.0", deps={"bar": "1.0.0"})
@@ -60,7 +74,7 @@ def test_with_unrelated_locked_dependencies(root, provider, repo):
 def test_unlocks_dependencies_if_necessary_to_ensure_that_a_new_dependency_is_statisfied(
-    root, provider, repo
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
 ):
    root.add_dependency(Factory.create_dependency("foo", "*"))
    root.add_dependency(Factory.create_dependency("newdep", "2.0.0"))
@@ -94,7 +108,9 @@ def test_unlocks_dependencies_if_necessary_to_ensure_that_a_new_dependency_is_st
    )
-def test_with_compatible_locked_dependencies_use_latest(root, provider, repo):
+def test_with_compatible_locked_dependencies_use_latest(
+    root: "ProjectPackage", provider: "Provider", repo: "Repository"
+):
    root.add_dependency(Factory.create_dependency("foo", "*"))
    root.add_dependency(Factory.create_dependency("baz", "*"))

--- a/tests/packages/test_locker.py
+++ b/tests/packages/test_locker.py
@@ -2,6 +2,7 @@ import logging
 import tempfile
 from pathlib import Path
+from typing import TYPE_CHECKING
 import pytest
 import tomlkit
@@ -15,8 +16,13 @@ from tests.helpers import get_dependency
 from tests.helpers import get_package
+if TYPE_CHECKING:
+    from _pytest.logging import LogCaptureFixture
+    from pytest_mock import MockerFixture
 @pytest.fixture
-def locker():
+def locker() -> Locker:
    with tempfile.NamedTemporaryFile() as f:
        f.close()
        locker = Locker(f.name, {})
@@ -25,11 +31,11 @@ def locker():
 @pytest.fixture
-def root():
+def root() -> ProjectPackage:
    return ProjectPackage("root", "1.2.3")
-def test_lock_file_data_is_ordered(locker, root):
+def test_lock_file_data_is_ordered(locker: Locker, root: ProjectPackage):
    package_a = get_package("A", "1.0.0")
    package_a.add_dependency(Factory.create_dependency("B", "^1.0"))
    package_a.files = [{"file": "foo", "hash": "456"}, {"file": "bar", "hash": "123"}]
@@ -99,7 +105,7 @@ git-package = []
    assert expected == content
-def test_locker_properly_loads_extras(locker):
+def test_locker_properly_loads_extras(locker: Locker):
    content = """\
 [[package]]
 name = "cachecontrol"
@@ -144,7 +150,7 @@ cachecontrol = []
    assert lockfile_dep.name == "lockfile"
-def test_locker_properly_loads_nested_extras(locker):
+def test_locker_properly_loads_nested_extras(locker: Locker):
    content = """\
 [[package]]
 name = "a"
@@ -224,7 +230,7 @@ content-hash = "123456789"
    assert len(packages) == 1
-def test_locker_properly_loads_extras_legacy(locker):
+def test_locker_properly_loads_extras_legacy(locker: Locker):
    content = """\
 [[package]]
 name = "a"
@@ -274,7 +280,7 @@ content-hash = "123456789"
    assert dependency_b.name == "b"
-def test_lock_packages_with_null_description(locker, root):
+def test_lock_packages_with_null_description(locker: Locker, root: ProjectPackage):
    package_a = get_package("A", "1.0.0")
    package_a.description = None
@@ -303,7 +309,7 @@ A = []
    assert expected == content
-def test_lock_file_should_not_have_mixed_types(locker, root):
+def test_lock_file_should_not_have_mixed_types(locker: Locker, root: ProjectPackage):
    package_a = get_package("A", "1.0.0")
    package_a.add_dependency(Factory.create_dependency("B", "^1.0.0"))
    package_a.add_dependency(
@@ -346,7 +352,7 @@ A = []
    assert expected == content
-def test_reading_lock_file_should_raise_an_error_on_invalid_data(locker):
+def test_reading_lock_file_should_raise_an_error_on_invalid_data(locker: Locker):
    content = """[[package]]
 name = "A"
 version = "1.0.0"
@@ -378,7 +384,9 @@ A = []
    assert "Unable to read the lock file" in str(e.value)
-def test_locking_legacy_repository_package_should_include_source_section(root, locker):
+def test_locking_legacy_repository_package_should_include_source_section(
+    root: ProjectPackage, locker: Locker
+):
    package_a = Package(
        "A",
        "1.0.0",
@@ -419,7 +427,7 @@ A = []
 def test_locker_should_emit_warnings_if_lock_version_is_newer_but_allowed(
-    locker, caplog
+    locker: Locker, caplog: "LogCaptureFixture"
 ):
    content = """\
 [metadata]
@@ -453,7 +461,7 @@ regenerate the lock file with the `poetry lock` command.\
 def test_locker_should_raise_an_error_if_lock_version_is_newer_and_not_allowed(
-    locker, caplog
+    locker: Locker, caplog: "LogCaptureFixture"
 ):
    content = """\
 [metadata]
@@ -471,7 +479,7 @@ content-hash = "c3d07fca33fba542ef2b2a4d75bf5b48d892d21a830e2ad9c952ba5123a52f77
        _ = locker.lock_data
-def test_extras_dependencies_are_ordered(locker, root):
+def test_extras_dependencies_are_ordered(locker: Locker, root: ProjectPackage):
    package_a = get_package("A", "1.0.0")
    package_a.add_dependency(
        Factory.create_dependency(
@@ -509,7 +517,7 @@ A = []
 def test_locker_should_neither_emit_warnings_nor_raise_error_for_lower_compatible_versions(
-    locker, caplog
+    locker: Locker, caplog: "LogCaptureFixture"
 ):
    current_version = Version.parse(Locker._VERSION)
    older_version = ".".join(
@@ -534,7 +542,9 @@ content-hash = "c3d07fca33fba542ef2b2a4d75bf5b48d892d21a830e2ad9c952ba5123a52f77
    assert 0 == len(caplog.records)
-def test_locker_dumps_dependency_information_correctly(locker, root):
+def test_locker_dumps_dependency_information_correctly(
+    locker: Locker, root: ProjectPackage
+):
    root_dir = Path(__file__).parent.parent.joinpath("fixtures")
    package_a = get_package("A", "1.0.0")
    package_a.add_dependency(
@@ -599,7 +609,9 @@ A = []
    assert expected == content
-def test_locked_repository_uses_root_dir_of_package(locker, mocker):
+def test_locked_repository_uses_root_dir_of_package(
+    locker: Locker, mocker: "MockerFixture"
+):
    content = """\
 [[package]]
 name = "lib-a"

--- a/tests/plugins/test_plugin_manager.py
+++ b/tests/plugins/test_plugin_manager.py
 from pathlib import Path
+from typing import TYPE_CHECKING
+from typing import List
 import pytest
@@ -11,31 +13,42 @@ from poetry.plugins import ApplicationPlugin
 from poetry.plugins import Plugin
 from poetry.plugins.plugin_manager import PluginManager
 from poetry.poetry import Poetry
+from tests.compat import Protocol
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+    from tests.conftest import Config
 CWD = Path(__file__).parent.parent / "fixtures" / "simple_project"
+class ManagerFactory(Protocol):
+    def __call__(self, type: str = "plugin") -> PluginManager:
+        ...
 class MyPlugin(Plugin):
-    def activate(self, poetry, io):
+    def activate(self, poetry: Poetry, io: BufferedIO) -> None:
        io.write_line("Updating version")
        poetry.package.set_version("9.9.9")
 class MyCommandPlugin(ApplicationPlugin):
    @property
-    def commands(self):
+    def commands(self) -> List[str]:
        return []
 class InvalidPlugin:
-    def activate(self, poetry, io):
+    def activate(self, poetry: Poetry, io: BufferedIO) -> None:
        io.write_line("Updating version")
        poetry.package.version = "9.9.9"
 @pytest.fixture()
-def poetry(tmp_dir, config):
+def poetry(tmp_dir: str, config: "Config") -> Poetry:
    poetry = Poetry(
        CWD / "pyproject.toml",
        {},
@@ -48,24 +61,29 @@ def poetry(tmp_dir, config):
 @pytest.fixture()
-def io():
+def io() -> BufferedIO:
    return BufferedIO()
 @pytest.fixture()
-def manager_factory(poetry, io):
+def manager_factory(poetry: Poetry, io: BufferedIO) -> ManagerFactory:
-    def _manager(type="plugin"):
+    def _manager(type: str = "plugin") -> PluginManager:
        return PluginManager(type)
    return _manager
 @pytest.fixture()
-def no_plugin_manager(poetry, io):
+def no_plugin_manager(poetry: Poetry, io: BufferedIO) -> PluginManager:
    return PluginManager("plugin", disable_plugins=True)
-def test_load_plugins_and_activate(manager_factory, poetry, io, mocker):
+def test_load_plugins_and_activate(
+    manager_factory: ManagerFactory,
+    poetry: Poetry,
+    io: BufferedIO,
+    mocker: "MockerFixture",
+):
    manager = manager_factory()
    mocker.patch(
@@ -82,7 +100,12 @@ def test_load_plugins_and_activate(manager_factory, poetry, io, mocker):
    assert "Updating version\n" == io.fetch_output()
-def test_load_plugins_with_invalid_plugin(manager_factory, poetry, io, mocker):
+def test_load_plugins_with_invalid_plugin(
+    manager_factory: ManagerFactory,
+    poetry: Poetry,
+    io: BufferedIO,
+    mocker: "MockerFixture",
+):
    manager = manager_factory()
    mocker.patch(
@@ -98,7 +121,12 @@ def test_load_plugins_with_invalid_plugin(manager_factory, poetry, io, mocker):
        manager.load_plugins()
-def test_load_plugins_with_plugins_disabled(no_plugin_manager, poetry, io, mocker):
+def test_load_plugins_with_plugins_disabled(
+    no_plugin_manager: PluginManager,
+    poetry: Poetry,
+    io: BufferedIO,
+    mocker: "MockerFixture",
+):
    mocker.patch(
        "entrypoints.get_group_all",
        return_value=[