refactor: remove optional patchright backend

Patchright scored identically to plain Playwright on reCAPTCHA v3 (the
binary handles stealth at C++ level) while breaking proxy auth and
add_init_script (#27). Removed the backend param, CLOAKBROWSER_BACKEND
env var, the patchright extra, and the two backend-specific tests.
Stock Playwright is now the only backend.

tests/conftest.py

@@ -1,11 +0,0 @@
-"""Shared test fixtures."""
-
-import os
-
-import pytest
-
-
-@pytest.fixture(autouse=True)
-def _clean_backend_env(monkeypatch):
-    """Ensure CLOAKBROWSER_BACKEND doesn't leak into tests from the host environment."""
-    monkeypatch.delenv("CLOAKBROWSER_BACKEND", raising=False)

tests/test_backend.py

@@ -1,45 +0,0 @@
-"""Unit tests for backend resolution (_resolve_backend)."""
-
-import os
-from unittest.mock import patch
-
-import pytest
-
-from cloakbrowser.browser import _resolve_backend
-
-
-def test_resolve_backend_default():
-    """No param, no env var → 'playwright'."""
-    with patch.dict(os.environ, {}, clear=True):
-        assert _resolve_backend(None) == "playwright"
-
-
-def test_resolve_backend_explicit_playwright():
-    assert _resolve_backend("playwright") == "playwright"
-
-
-def test_resolve_backend_explicit_patchright():
-    assert _resolve_backend("patchright") == "patchright"
-
-
-def test_resolve_backend_env_var():
-    """CLOAKBROWSER_BACKEND env var used when no param."""
-    with patch.dict(os.environ, {"CLOAKBROWSER_BACKEND": "patchright"}):
-        assert _resolve_backend(None) == "patchright"
-
-
-def test_resolve_backend_param_beats_env():
-    """Explicit param overrides env var."""
-    with patch.dict(os.environ, {"CLOAKBROWSER_BACKEND": "patchright"}):
-        assert _resolve_backend("playwright") == "playwright"
-
-
-def test_resolve_backend_invalid_raises():
-    with pytest.raises(ValueError, match="Unknown backend 'bogus'"):
-        _resolve_backend("bogus")
-
-
-def test_resolve_backend_invalid_env_raises():
-    with patch.dict(os.environ, {"CLOAKBROWSER_BACKEND": "bogus"}):
-        with pytest.raises(ValueError, match="Unknown backend 'bogus'"):
-            _resolve_backend(None)

tests/test_extension_loading.py

@@ -5,8 +5,8 @@ from cloakbrowser import launch
 
 
 @patch("cloakbrowser.browser.ensure_binary")
-@patch("cloakbrowser.browser._import_sync_playwright")
-def test_extension_loading(mock_playwright_import, mock_ensure_binary):
+@patch("playwright.sync_api.sync_playwright")
+def test_extension_loading(mock_sync_playwright, mock_ensure_binary):
     mock_ensure_binary.return_value = "/fake/chrome"
 
     mock_browser = MagicMock()
@@ -14,10 +14,7 @@ def test_extension_loading(mock_playwright_import, mock_ensure_binary):
     mock_pw = MagicMock()
     mock_pw.chromium.launch.return_value = mock_browser
 
-    mock_pw_manager = MagicMock()
-    mock_pw_manager.return_value.start.return_value = mock_pw
-
-    mock_playwright_import.return_value = mock_pw_manager
+    mock_sync_playwright.return_value.start.return_value = mock_pw
 
     launch(extension_paths=["./ext"])
 

tests/test_launch.py

@@ -1,10 +1,33 @@
 """Basic launch tests for cloakbrowser."""
 
 import pytest
-from cloakbrowser import launch, launch_async, binary_info
+from cloakbrowser import (
+    launch,
+    launch_async,
+    launch_context,
+    launch_persistent_context,
+    binary_info,
+)
 from cloakbrowser.config import get_chromium_version
 
 
+@pytest.mark.parametrize("env", [None, "patchright"])
+def test_removed_backend_kwarg_raises(env, monkeypatch):
+    """The removed `backend` parameter raises a clear TypeError before any
+    launch side effects, regardless of the (also removed) CLOAKBROWSER_BACKEND
+    env var. Guards the patchright removal."""
+    if env is None:
+        monkeypatch.delenv("CLOAKBROWSER_BACKEND", raising=False)
+    else:
+        monkeypatch.setenv("CLOAKBROWSER_BACKEND", env)
+    with pytest.raises(TypeError, match="backend"):
+        launch(backend="patchright")
+    with pytest.raises(TypeError, match="backend"):
+        launch_context(backend="patchright")
+    with pytest.raises(TypeError, match="backend"):
+        launch_persistent_context("/tmp/cloakbrowser-test-profile", backend="patchright")
+
+
 def test_binary_info():
     """binary_info() returns expected structure."""
     info = binary_info()

tests/test_stealth.py

@@ -259,9 +259,8 @@ class TestIssueRegressions:
     def test_add_init_script_with_proxy(self, browser):
         """Issue #27: add_init_script + proxy must not cause ERR_TUNNEL_CONNECTION_FAILED.
 
-        Patchright bug: add_init_script breaks proxy auth. This test guards
-        against regression if/when the upstream fix lands. Uses context-level
-        proxy to avoid launching a separate browser (event loop conflict).
+        Uses context-level proxy to avoid launching a separate browser
+        (event loop conflict).
         """
         proxy = os.environ.get("CLOAKBROWSER_TEST_PROXY")
         if not proxy:
@@ -276,11 +275,6 @@ class TestIssueRegressions:
             val = page.evaluate("window.__cloaktest")
             assert val == 99, f"init_script value wrong: {val}"
             assert "origin" in body, f"Page didn't load through proxy: {body[:100]}"
-        except Exception as e:
-            err = str(e)
-            if "ERR_TUNNEL_CONNECTION_FAILED" in err:
-                pytest.xfail("Known patchright bug: add_init_script + proxy auth (issue #27)")
-            raise
         finally:
             page.close()
             ctx.close()