Add 100% cover to uvicorn/main.py (#1154)

- Mostly test main as a cli client
- Test main functions directly when it's impossible to do is as a cli client (i.e. app non string case)
- Add no cover to the module entrypoint main call

Related to: #102

tests/test_cli.py

@@ -1,15 +1,40 @@
 import importlib
+import platform
+import sys
+from pathlib import Path
 from unittest import mock
 
+import pytest
 from click.testing import CliRunner
 
+import uvicorn
+from uvicorn.config import Config
 from uvicorn.main import main as cli
+from uvicorn.server import Server
+from uvicorn.supervisors import ChangeReload, Multiprocess
 
 HEADERS = "Content-Security-Policy:default-src 'self'; script-src https://example.com"
 main = importlib.import_module("uvicorn.main")
 
 
-def test_cli_headers():
+def test_cli_print_version() -> None:
+    runner = CliRunner()
+
+    result = runner.invoke(cli, ["--version"])
+
+    assert result.exit_code == 0
+    assert (
+        "Running uvicorn %s with %s %s on %s"
+        % (
+            uvicorn.__version__,
+            platform.python_implementation(),
+            platform.python_version(),
+            platform.system(),
+        )
+    ) in result.output
+
+
+def test_cli_headers() -> None:
     runner = CliRunner()
 
     with mock.patch.object(main, "run") as mock_run:
@@ -26,5 +51,70 @@ def test_cli_headers():
     ]
 
 
+def test_cli_call_server_run() -> None:
+    runner = CliRunner()
+
+    with mock.patch.object(Server, "run") as mock_run:
+        result = runner.invoke(cli, ["tests.test_cli:App"])
+
+    assert result.exit_code == 0
+    mock_run.assert_called_once()
+
+
+def test_cli_call_change_reload_run() -> None:
+    runner = CliRunner()
+
+    with mock.patch.object(Config, "bind_socket") as mock_bind_socket:
+        with mock.patch.object(ChangeReload, "run") as mock_run:
+            result = runner.invoke(cli, ["tests.test_cli:App", "--reload"])
+
+    assert result.exit_code == 0
+    mock_bind_socket.assert_called_once()
+    mock_run.assert_called_once()
+
+
+def test_cli_call_multiprocess_run() -> None:
+    runner = CliRunner()
+
+    with mock.patch.object(Config, "bind_socket") as mock_bind_socket:
+        with mock.patch.object(Multiprocess, "run") as mock_run:
+            result = runner.invoke(cli, ["tests.test_cli:App", "--workers=2"])
+
+    assert result.exit_code == 0
+    mock_bind_socket.assert_called_once()
+    mock_run.assert_called_once()
+
+
+@pytest.mark.skipif(sys.platform == "win32", reason="require unix-like system")
+def test_cli_uds(tmp_path: Path) -> None:
+    runner = CliRunner()
+    uds_file = tmp_path / "uvicorn.sock"
+    uds_file.touch(exist_ok=True)
+
+    with mock.patch.object(Config, "bind_socket") as mock_bind_socket:
+        with mock.patch.object(Multiprocess, "run") as mock_run:
+            result = runner.invoke(
+                cli, ["tests.test_cli:App", "--workers=2", "--uds", str(uds_file)]
+            )
+
+    assert result.exit_code == 0
+    assert result.output == ""
+    mock_bind_socket.assert_called_once()
+    mock_run.assert_called_once()
+    assert not uds_file.exists()
+
+
+def test_cli_incomplete_app_parameter() -> None:
+    runner = CliRunner()
+
+    result = runner.invoke(cli, ["tests.test_cli"])
+
+    assert (
+        'Error loading ASGI app. Import string "tests.test_cli" '
+        'must be in format "<module>:<attribute>".'
+    ) in result.output
+    assert result.exit_code == 1
+
+
 class App:
     pass

tests/test_main.py

@@ -1,8 +1,11 @@
+from logging import WARNING
+
 import httpx
 import pytest
 
 from tests.utils import run_server
 from uvicorn.config import Config
+from uvicorn.main import run
 
 
 async def app(scope, receive, send):
@@ -59,3 +62,15 @@ async def test_run_reload():
         async with httpx.AsyncClient() as client:
             response = await client.get("http://127.0.0.1:8000")
     assert response.status_code == 204
+
+
+def test_run_invalid_app_config_combination(caplog: pytest.LogCaptureFixture) -> None:
+    with pytest.raises(SystemExit) as exit_exception:
+        run(app, reload=True)
+    assert exit_exception.value.code == 1
+    assert caplog.records[-1].name == "uvicorn.error"
+    assert caplog.records[-1].levelno == WARNING
+    assert caplog.records[-1].message == (
+        "You must pass the application as an import string to enable "
+        "'reload' or 'workers'."
+    )

uvicorn/main.py

@@ -450,4 +450,4 @@ def run(app: typing.Union[ASGIApplication, str], **kwargs: typing.Any) -> None:
 
 
 if __name__ == "__main__":
-    main()
+    main()  # pragma: no cover