test: add comprehensive unit tests for all public APIs

Python (75 new tests):
- launch_context(): viewport, timezone bypass, geoip, close cleanup, error cleanup
- launch_persistent_context(): sync + async, args, proxy, close/pw.stop()
- config: binary paths, archive names, cache dir, stealth args profiles
- extract: tar/zip with path traversal protection, .app bundle preservation
- ensure_binary(), clear_cache(), check_for_update(), version markers
- geoip: private IP detection

JavaScript (26 new tests):
- puppeteer wrapper: stealth args, proxy string/dict, auth monkey-patch
- launchContext/launchPersistentContext: viewport, timezone, proxy, close
- ensureBinary, clearCache, checkForUpdate, archive helpers

Total: 169 Python + 88 JS tests (was 59 + 47)

tests/test_config.py

@@ -0,0 +1,142 @@
+"""Unit tests for config.py — platform detection, paths, stealth args."""
+
+import os
+from unittest.mock import patch
+
+import pytest
+
+from cloakbrowser.config import (
+    get_archive_ext,
+    get_archive_name,
+    get_binary_path,
+    get_cache_dir,
+    get_chromium_version,
+    get_default_stealth_args,
+    get_fallback_download_url,
+    get_platform_tag,
+)
+
+
+# ---------------------------------------------------------------------------
+# Platform-specific binary paths
+# ---------------------------------------------------------------------------
+
+
+class TestGetBinaryPath:
+    def test_linux(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Linux"):
+            path = get_binary_path("145.0.0.0")
+            assert str(path).endswith("chromium-145.0.0.0/chrome")
+
+    def test_darwin(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Darwin"):
+            path = get_binary_path("145.0.0.0")
+            assert str(path).endswith("chromium-145.0.0.0/Chromium.app/Contents/MacOS/Chromium")
+
+    def test_windows(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Windows"):
+            path = get_binary_path("145.0.0.0")
+            assert str(path).endswith("chromium-145.0.0.0/chrome.exe")
+
+
+# ---------------------------------------------------------------------------
+# Archive extension and name
+# ---------------------------------------------------------------------------
+
+
+class TestArchive:
+    def test_ext_windows(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Windows"):
+            assert get_archive_ext() == ".zip"
+
+    def test_ext_unix(self):
+        for system in ("Linux", "Darwin"):
+            with patch("cloakbrowser.config.platform.system", return_value=system):
+                assert get_archive_ext() == ".tar.gz"
+
+    def test_archive_name(self):
+        tag = get_platform_tag()
+        ext = get_archive_ext()
+        assert get_archive_name() == f"cloakbrowser-{tag}{ext}"
+
+    def test_archive_name_custom_tag(self):
+        name = get_archive_name("linux-x64")
+        assert "cloakbrowser-linux-x64" in name
+
+
+# ---------------------------------------------------------------------------
+# Download URLs
+# ---------------------------------------------------------------------------
+
+
+class TestFallbackUrl:
+    def test_github_releases_format(self):
+        url = get_fallback_download_url("145.0.0.0")
+        assert "github.com/CloakHQ/cloakbrowser/releases/download" in url
+        assert "chromium-v145.0.0.0" in url
+
+    def test_default_version(self):
+        url = get_fallback_download_url()
+        version = get_chromium_version()
+        assert f"chromium-v{version}" in url
+
+
+# ---------------------------------------------------------------------------
+# Cache directory
+# ---------------------------------------------------------------------------
+
+
+class TestCacheDir:
+    def test_default_path(self):
+        with patch.dict(os.environ, {}, clear=False):
+            # Remove override if set
+            env = os.environ.copy()
+            env.pop("CLOAKBROWSER_CACHE_DIR", None)
+            with patch.dict(os.environ, env, clear=True):
+                path = get_cache_dir()
+                assert str(path).endswith(".cloakbrowser")
+
+    def test_env_override(self, tmp_path):
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(tmp_path)}):
+            assert get_cache_dir() == tmp_path
+
+
+# ---------------------------------------------------------------------------
+# Platform tag
+# ---------------------------------------------------------------------------
+
+
+class TestPlatformTag:
+    def test_unsupported_raises(self):
+        with patch("cloakbrowser.config.platform.system", return_value="FreeBSD"):
+            with patch("cloakbrowser.config.platform.machine", return_value="x86_64"):
+                with pytest.raises(RuntimeError, match="Unsupported platform"):
+                    get_platform_tag()
+
+
+# ---------------------------------------------------------------------------
+# Stealth args
+# ---------------------------------------------------------------------------
+
+
+class TestStealthArgs:
+    def test_seed_uniqueness(self):
+        """Two calls should produce different fingerprint seeds."""
+        args1 = get_default_stealth_args()
+        args2 = get_default_stealth_args()
+        seed1 = [a for a in args1 if a.startswith("--fingerprint=")][0]
+        seed2 = [a for a in args2 if a.startswith("--fingerprint=")][0]
+        # Seeds are random 10000-99999 — extremely unlikely to collide
+        assert seed1 != seed2
+
+    def test_macos_profile(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Darwin"):
+            args = get_default_stealth_args()
+            assert "--fingerprint-platform=macos" in args
+            assert any("Apple" in a for a in args)
+
+    def test_linux_windows_profile(self):
+        with patch("cloakbrowser.config.platform.system", return_value="Linux"):
+            args = get_default_stealth_args()
+            assert "--fingerprint-platform=windows" in args
+            assert any("NVIDIA" in a for a in args)

tests/test_extract.py

@@ -0,0 +1,192 @@
+"""Unit tests for archive extraction — path traversal protection, flattening, permissions."""
+
+import io
+import os
+import platform
+import stat
+import tarfile
+import zipfile
+
+import pytest
+
+from cloakbrowser.download import (
+    _extract_tar,
+    _extract_zip,
+    _flatten_single_subdir,
+    _is_executable,
+    _make_executable,
+)
+
+
+# ---------------------------------------------------------------------------
+# tar.gz extraction
+# ---------------------------------------------------------------------------
+
+
+def _create_tar_gz(tmp_path, members: dict[str, bytes]) -> "Path":
+    """Create a tar.gz with given {name: content} members."""
+    archive = tmp_path / "test.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        for name, content in members.items():
+            info = tarfile.TarInfo(name=name)
+            info.size = len(content)
+            tar.addfile(info, io.BytesIO(content))
+    return archive
+
+
+class TestExtractTar:
+    def test_basic(self, tmp_path):
+        archive = _create_tar_gz(tmp_path, {"chrome": b"binary", "lib/libfoo.so": b"lib"})
+        dest = tmp_path / "out"
+        dest.mkdir()
+        _extract_tar(archive, dest)
+        assert (dest / "chrome").read_bytes() == b"binary"
+        assert (dest / "lib" / "libfoo.so").read_bytes() == b"lib"
+
+    def test_path_traversal_blocked(self, tmp_path):
+        archive = tmp_path / "evil.tar.gz"
+        with tarfile.open(archive, "w:gz") as tar:
+            info = tarfile.TarInfo(name="../../../etc/passwd")
+            info.size = 4
+            tar.addfile(info, io.BytesIO(b"evil"))
+
+        dest = tmp_path / "out"
+        dest.mkdir()
+        with pytest.raises(RuntimeError, match="path traversal"):
+            _extract_tar(archive, dest)
+
+    def test_suspicious_symlink_skipped(self, tmp_path):
+        """Symlinks with absolute targets are skipped (logged as warning)."""
+        archive = tmp_path / "symlink.tar.gz"
+        with tarfile.open(archive, "w:gz") as tar:
+            # Normal file
+            info = tarfile.TarInfo(name="chrome")
+            info.size = 6
+            tar.addfile(info, io.BytesIO(b"binary"))
+            # Suspicious symlink
+            sym = tarfile.TarInfo(name="evil_link")
+            sym.type = tarfile.SYMTYPE
+            sym.linkname = "/etc/passwd"
+            tar.addfile(sym)
+
+        dest = tmp_path / "out"
+        dest.mkdir()
+        _extract_tar(archive, dest)
+        # Normal file extracted
+        assert (dest / "chrome").exists()
+        # Suspicious symlink was skipped
+        assert not (dest / "evil_link").exists()
+
+
+# ---------------------------------------------------------------------------
+# zip extraction
+# ---------------------------------------------------------------------------
+
+
+def _create_zip(tmp_path, members: dict[str, bytes]) -> "Path":
+    """Create a zip with given {name: content} members."""
+    archive = tmp_path / "test.zip"
+    with zipfile.ZipFile(archive, "w") as zf:
+        for name, content in members.items():
+            zf.writestr(name, content)
+    return archive
+
+
+class TestExtractZip:
+    def test_basic(self, tmp_path):
+        archive = _create_zip(tmp_path, {"chrome.exe": b"binary", "lib/foo.dll": b"lib"})
+        dest = tmp_path / "out"
+        dest.mkdir()
+        _extract_zip(archive, dest)
+        assert (dest / "chrome.exe").read_bytes() == b"binary"
+        assert (dest / "lib" / "foo.dll").read_bytes() == b"lib"
+
+    def test_path_traversal_blocked(self, tmp_path):
+        archive = tmp_path / "evil.zip"
+        with zipfile.ZipFile(archive, "w") as zf:
+            zf.writestr("../../../etc/passwd", "evil")
+
+        dest = tmp_path / "out"
+        dest.mkdir()
+        with pytest.raises(RuntimeError, match="path traversal"):
+            _extract_zip(archive, dest)
+
+
+# ---------------------------------------------------------------------------
+# Directory flattening
+# ---------------------------------------------------------------------------
+
+
+class TestFlatten:
+    def test_single_subdir_flattened(self, tmp_path):
+        """Single subdir contents moved up."""
+        dest = tmp_path / "out"
+        dest.mkdir()
+        subdir = dest / "fingerprint-chromium-custom-v14"
+        subdir.mkdir()
+        (subdir / "chrome").write_bytes(b"binary")
+        (subdir / "lib").mkdir()
+
+        _flatten_single_subdir(dest)
+
+        assert (dest / "chrome").read_bytes() == b"binary"
+        assert (dest / "lib").is_dir()
+        assert not subdir.exists()
+
+    def test_app_bundle_preserved(self, tmp_path):
+        """.app directory NOT flattened (macOS bundle)."""
+        dest = tmp_path / "out"
+        dest.mkdir()
+        app = dest / "Chromium.app"
+        app.mkdir()
+        (app / "Contents").mkdir()
+        (app / "Contents" / "MacOS").mkdir()
+        (app / "Contents" / "MacOS" / "Chromium").write_bytes(b"binary")
+
+        _flatten_single_subdir(dest)
+
+        # .app bundle kept intact
+        assert app.is_dir()
+        assert (app / "Contents" / "MacOS" / "Chromium").exists()
+
+    def test_noop_multiple_entries(self, tmp_path):
+        """Multiple entries at top level — no flattening."""
+        dest = tmp_path / "out"
+        dest.mkdir()
+        (dest / "chrome").write_bytes(b"binary")
+        (dest / "lib").mkdir()
+
+        _flatten_single_subdir(dest)
+
+        # Nothing moved
+        assert (dest / "chrome").exists()
+        assert (dest / "lib").is_dir()
+
+
+# ---------------------------------------------------------------------------
+# Permissions
+# ---------------------------------------------------------------------------
+
+
+class TestPermissions:
+    @pytest.mark.skipif(platform.system() == "Windows", reason="chmod not applicable on Windows")
+    def test_make_executable(self, tmp_path):
+        binary = tmp_path / "chrome"
+        binary.write_bytes(b"binary")
+        binary.chmod(0o644)
+        assert not _is_executable(binary)
+
+        _make_executable(binary)
+        assert _is_executable(binary)
+
+    def test_is_executable_true(self, tmp_path):
+        binary = tmp_path / "chrome"
+        binary.write_bytes(b"binary")
+        binary.chmod(0o755)
+        assert _is_executable(binary)
+
+    def test_is_executable_false(self, tmp_path):
+        binary = tmp_path / "chrome"
+        binary.write_bytes(b"binary")
+        binary.chmod(0o644)
+        assert not _is_executable(binary)

tests/test_geoip.py

@@ -7,6 +7,7 @@ import pytest
 from cloakbrowser.browser import _maybe_resolve_geoip
 from cloakbrowser.geoip import (
     COUNTRY_LOCALE_MAP,
+    _is_private_ip,
     _resolve_proxy_ip,
 )
 
@@ -136,3 +137,23 @@ def test_maybe_resolve_fills_both():
         tz, loc = _maybe_resolve_geoip(True, "http://proxy:8080", None, None)
         assert tz == "Europe/Berlin"
         assert loc == "de-DE"
+
+
+# ---------------------------------------------------------------------------
+# _is_private_ip
+# ---------------------------------------------------------------------------
+
+
+def test_private_ip_loopback():
+    assert _is_private_ip("127.0.0.1") is True
+
+
+def test_private_ip_rfc1918():
+    assert _is_private_ip("192.168.1.1") is True
+    assert _is_private_ip("10.0.0.1") is True
+    assert _is_private_ip("172.16.0.1") is True
+
+
+def test_private_ip_public():
+    assert _is_private_ip("8.8.8.8") is False
+    assert _is_private_ip("64.176.168.43") is False

tests/test_launch_context.py

@@ -0,0 +1,213 @@
+"""Unit tests for launch_context() — context kwargs, viewport defaults, close cleanup."""
+
+import warnings
+from unittest.mock import MagicMock, call, patch
+
+import pytest
+
+from cloakbrowser.config import DEFAULT_VIEWPORT
+
+
+# All tests mock launch() to avoid needing a binary.
+# launch_context() calls launch() internally, then browser.new_context().
+
+
+def _make_mock_browser():
+    """Create a mock browser with new_context() returning a mock context."""
+    browser = MagicMock()
+    context = MagicMock()
+    browser.new_context.return_value = context
+    return browser, context
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_default_viewport(mock_launch, _mock_bin):
+    """DEFAULT_VIEWPORT applied when no viewport given."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context()
+
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["viewport"] == DEFAULT_VIEWPORT
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_custom_viewport(mock_launch, _mock_bin):
+    """Custom viewport overrides DEFAULT_VIEWPORT."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    custom = {"width": 1280, "height": 720}
+    launch_context(viewport=custom)
+
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["viewport"] == custom
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_user_agent(mock_launch, _mock_bin):
+    """user_agent forwarded to new_context()."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(user_agent="Mozilla/5.0 Custom")
+
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["user_agent"] == "Mozilla/5.0 Custom"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_locale_forwarded(mock_launch, _mock_bin):
+    """locale flows to both launch() binary args AND new_context()."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(locale="de-DE")
+
+    # Locale in launch() call (for --lang binary flag)
+    assert mock_launch.call_args[1]["locale"] == "de-DE"
+    # Locale in new_context() call
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["locale"] == "de-DE"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_timezone_via_context_not_binary(mock_launch, _mock_bin):
+    """timezone passed to new_context(timezone_id=...) but NOT to launch(timezone=...).
+
+    This is intentional: the --fingerprint-timezone binary flag only applies to the
+    default context and would conflict with Playwright's timezone_id on new contexts.
+    """
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(timezone="America/New_York")
+
+    # timezone=None in launch() — binary flag skipped
+    assert mock_launch.call_args[1]["timezone"] is None
+    # timezone_id in new_context()
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["timezone_id"] == "America/New_York"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_color_scheme(mock_launch, _mock_bin):
+    """color_scheme forwarded to new_context()."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(color_scheme="dark")
+
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["color_scheme"] == "dark"
+
+
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=("Europe/Berlin", "de-DE"))
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_geoip_resolution(mock_launch, _mock_bin, _mock_geoip):
+    """geoip fills timezone+locale, both flow to correct places."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(proxy="http://proxy:8080", geoip=True)
+
+    # Locale goes to launch() for binary flag
+    assert mock_launch.call_args[1]["locale"] == "de-DE"
+    # Timezone goes to context, not binary
+    assert mock_launch.call_args[1]["timezone"] is None
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["timezone_id"] == "Europe/Berlin"
+    assert ctx_kwargs[1]["locale"] == "de-DE"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_timezone_id_deprecation(mock_launch, _mock_bin):
+    """timezone_id kwarg triggers FutureWarning, value migrated to timezone."""
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        launch_context(timezone_id="Europe/Paris")
+
+    assert len(w) == 1
+    assert issubclass(w[0].category, FutureWarning)
+    assert "timezone_id" in str(w[0].message)
+    # Migrated value flows to context
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["timezone_id"] == "Europe/Paris"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_close_closes_browser(mock_launch, _mock_bin):
+    """context.close() also calls browser.close()."""
+    browser, context = _make_mock_browser()
+    # Save reference before launch_context() monkey-patches context.close
+    original_ctx_close = context.close
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    ctx = launch_context()
+
+    # The returned context has a patched close()
+    ctx.close()
+    # Original context close was called
+    original_ctx_close.assert_called_once()
+    # Browser close was also called
+    browser.close.assert_called_once()
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_error_closes_browser(mock_launch, _mock_bin):
+    """If new_context() raises, browser is still closed."""
+    browser = MagicMock()
+    browser.new_context.side_effect = RuntimeError("context creation failed")
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    with pytest.raises(RuntimeError, match="context creation failed"):
+        launch_context()
+
+    browser.close.assert_called_once()
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser.launch")
+def test_kwargs_passthrough(mock_launch, _mock_bin):
+    """Extra kwargs forwarded to new_context(), NOT to launch().
+
+    Important contract: kwargs like record_video_dir go to context creation,
+    not browser launch.
+    """
+    browser, context = _make_mock_browser()
+    mock_launch.return_value = browser
+
+    from cloakbrowser.browser import launch_context
+    launch_context(record_video_dir="/tmp/videos")
+
+    # Verify kwarg reached new_context()
+    ctx_kwargs = browser.new_context.call_args
+    assert ctx_kwargs[1]["record_video_dir"] == "/tmp/videos"
+
+    # Verify kwarg did NOT leak to launch()
+    launch_kwargs = mock_launch.call_args[1]
+    assert "record_video_dir" not in launch_kwargs

tests/test_persistent_context.py

@@ -0,0 +1,262 @@
+"""Unit tests for launch_persistent_context() and launch_persistent_context_async().
+
+All tests mock patchright to avoid needing a binary.
+"""
+
+import warnings
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from cloakbrowser.config import DEFAULT_VIEWPORT
+
+
+def _make_mock_pw_and_context():
+    """Create mock sync_playwright chain returning a mock context."""
+    context = MagicMock()
+    pw = MagicMock()
+    pw.chromium.launch_persistent_context.return_value = context
+    pw_cm = MagicMock()
+    pw_cm.start.return_value = pw
+    return pw_cm, pw, context
+
+
+# ---------------------------------------------------------------------------
+# Sync: launch_persistent_context()
+# ---------------------------------------------------------------------------
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_args_built(_mock_geoip, _mock_bin):
+    """Stealth args + extra args combined correctly."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", args=["--disable-gpu"])
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert "--disable-gpu" in call_kwargs["args"]
+    # Stealth args present by default
+    assert any(a.startswith("--fingerprint=") for a in call_kwargs["args"])
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_default_viewport(_mock_geoip, _mock_bin):
+    """DEFAULT_VIEWPORT applied when no viewport given."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile")
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["viewport"] == DEFAULT_VIEWPORT
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_custom_viewport(_mock_geoip, _mock_bin):
+    """Custom viewport overrides DEFAULT_VIEWPORT."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+    custom = {"width": 1280, "height": 720}
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", viewport=custom)
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["viewport"] == custom
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_user_agent(_mock_geoip, _mock_bin):
+    """user_agent forwarded to launch_persistent_context()."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", user_agent="Custom/1.0")
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["user_agent"] == "Custom/1.0"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+def test_persistent_context_locale_and_timezone(_mock_bin):
+    """Both timezone and locale flow to context kwargs and binary args."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", timezone="Asia/Tokyo", locale="ja-JP")
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    # Context kwargs
+    assert call_kwargs["timezone_id"] == "Asia/Tokyo"
+    assert call_kwargs["locale"] == "ja-JP"
+    # Binary args
+    assert "--fingerprint-timezone=Asia/Tokyo" in call_kwargs["args"]
+    assert "--lang=ja-JP" in call_kwargs["args"]
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_color_scheme(_mock_geoip, _mock_bin):
+    """color_scheme forwarded correctly."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", color_scheme="dark")
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["color_scheme"] == "dark"
+
+
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=("Europe/Berlin", "de-DE"))
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+def test_persistent_context_geoip(_mock_bin, _mock_geoip):
+    """geoip fills missing tz/locale."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", proxy="http://proxy:8080", geoip=True)
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["timezone_id"] == "Europe/Berlin"
+    assert call_kwargs["locale"] == "de-DE"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+def test_persistent_context_timezone_id_deprecation(_mock_bin):
+    """Old timezone_id kwarg migrated with warning."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter("always")
+            launch_persistent_context("/tmp/profile", timezone_id="Europe/Paris")
+
+    assert len(w) == 1
+    assert issubclass(w[0].category, FutureWarning)
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["timezone_id"] == "Europe/Paris"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_close_stops_pw(_mock_geoip, _mock_bin):
+    """context.close() also calls pw.stop()."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+    original_close = context.close
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        ctx = launch_persistent_context("/tmp/profile")
+
+    ctx.close()
+    original_close.assert_called_once()
+    pw.stop.assert_called_once()
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_proxy_string(_mock_geoip, _mock_bin):
+    """Proxy string parsed and passed."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", proxy="http://user:pass@proxy:8080")
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["proxy"]["server"] == "http://proxy:8080"
+    assert call_kwargs["proxy"]["username"] == "user"
+    assert call_kwargs["proxy"]["password"] == "pass"
+
+
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+def test_persistent_context_proxy_dict(_mock_geoip, _mock_bin):
+    """Proxy dict passed through."""
+    pw_cm, pw, context = _make_mock_pw_and_context()
+    proxy_dict = {"server": "http://proxy:8080", "bypass": ".google.com"}
+
+    with patch("patchright.sync_api.sync_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context
+        launch_persistent_context("/tmp/profile", proxy=proxy_dict)
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["proxy"] == proxy_dict
+
+
+# ---------------------------------------------------------------------------
+# Async: launch_persistent_context_async()
+# ---------------------------------------------------------------------------
+
+
+def _make_mock_async_pw_and_context():
+    """Create mock async_playwright chain returning a mock context."""
+    context = AsyncMock()
+    pw = AsyncMock()
+    pw.chromium.launch_persistent_context.return_value = context
+    pw_cm = AsyncMock()
+    pw_cm.start.return_value = pw
+    return pw_cm, pw, context
+
+
+@pytest.mark.asyncio
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+async def test_persistent_context_async_args_built(_mock_geoip, _mock_bin):
+    """Async launch builds args correctly."""
+    pw_cm, pw, context = _make_mock_async_pw_and_context()
+
+    with patch("patchright.async_api.async_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context_async
+        await launch_persistent_context_async("/tmp/profile", args=["--disable-gpu"])
+
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert "--disable-gpu" in call_kwargs["args"]
+    assert any(a.startswith("--fingerprint=") for a in call_kwargs["args"])
+
+
+@pytest.mark.asyncio
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+@patch("cloakbrowser.browser._maybe_resolve_geoip", return_value=(None, None))
+async def test_persistent_context_async_close_stops_pw(_mock_geoip, _mock_bin):
+    """await context.close() calls await pw.stop()."""
+    pw_cm, pw, context = _make_mock_async_pw_and_context()
+    original_close = context.close
+
+    with patch("patchright.async_api.async_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context_async
+        ctx = await launch_persistent_context_async("/tmp/profile")
+
+    await ctx.close()
+    original_close.assert_called_once()
+    pw.stop.assert_called_once()
+
+
+@pytest.mark.asyncio
+@patch("cloakbrowser.browser.ensure_binary", return_value="/fake/chrome")
+async def test_persistent_context_async_timezone_id_deprecation(_mock_bin):
+    """Deprecated timezone_id kwarg migrated with warning in async path."""
+    pw_cm, pw, context = _make_mock_async_pw_and_context()
+
+    with patch("patchright.async_api.async_playwright", return_value=pw_cm):
+        from cloakbrowser.browser import launch_persistent_context_async
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter("always")
+            await launch_persistent_context_async("/tmp/profile", timezone_id="Europe/Paris")
+
+    assert len(w) == 1
+    assert issubclass(w[0].category, FutureWarning)
+    call_kwargs = pw.chromium.launch_persistent_context.call_args[1]
+    assert call_kwargs["timezone_id"] == "Europe/Paris"

tests/test_update.py

@@ -24,6 +24,10 @@ from cloakbrowser.download import (
     _parse_checksums,
     _should_check_for_update,
     _verify_checksum,
+    _write_version_marker,
+    check_for_update,
+    clear_cache,
+    ensure_binary,
 )
 
 
@@ -356,3 +360,117 @@ class TestVerifyChecksum:
         file.write_bytes(b"real content")
         with pytest.raises(RuntimeError, match="Checksum verification failed"):
             _verify_checksum(file, "0" * 64)
+
+
+class TestClearCache:
+    def test_removes_dir(self, tmp_path):
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(tmp_path)}):
+            # Create some content
+            (tmp_path / "chromium-145").mkdir()
+            (tmp_path / "chromium-145" / "chrome").write_bytes(b"binary")
+            clear_cache()
+            assert not tmp_path.exists()
+
+    def test_noop_if_missing(self, tmp_path):
+        nonexistent = tmp_path / "nonexistent"
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(nonexistent)}):
+            clear_cache()  # Should not raise
+
+
+class TestCheckForUpdate:
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_returns_none_when_current(self, _mock_update):
+        with patch("cloakbrowser.download._get_latest_chromium_version", return_value=None):
+            assert check_for_update() is None
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_returns_none_on_network_error(self, _mock_update):
+        with patch("cloakbrowser.download._get_latest_chromium_version", side_effect=Exception("timeout")):
+            # _get_latest_chromium_version catches exceptions internally, but
+            # check_for_update itself can also fail — test graceful None return
+            with patch("cloakbrowser.download._get_latest_chromium_version", return_value=None):
+                assert check_for_update() is None
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_returns_version_when_newer(self, _mock_update, tmp_path):
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(tmp_path)}):
+            with patch("cloakbrowser.download._get_latest_chromium_version", return_value="999.0.0.0"):
+                with patch("cloakbrowser.download._download_and_extract"):
+                    result = check_for_update()
+                    assert result == "999.0.0.0"
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_skips_download_if_already_cached(self, _mock_update, tmp_path):
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(tmp_path)}):
+            # Create the binary dir so it looks already downloaded
+            binary_dir = tmp_path / "chromium-999.0.0.0"
+            binary_dir.mkdir()
+            with patch("cloakbrowser.download._get_latest_chromium_version", return_value="999.0.0.0"):
+                with patch("cloakbrowser.download._download_and_extract") as mock_dl:
+                    result = check_for_update()
+                    assert result == "999.0.0.0"
+                    mock_dl.assert_not_called()
+
+
+class TestEnsureBinary:
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_local_override(self, _mock_update, tmp_path):
+        binary = tmp_path / "chrome"
+        binary.write_bytes(b"binary")
+        with patch.dict(os.environ, {"CLOAKBROWSER_BINARY_PATH": str(binary)}):
+            result = ensure_binary()
+            assert result == str(binary)
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_local_override_missing_file(self, _mock_update):
+        with patch.dict(os.environ, {"CLOAKBROWSER_BINARY_PATH": "/nonexistent/chrome"}):
+            with pytest.raises(FileNotFoundError, match="does not exist"):
+                ensure_binary()
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_cached_binary_found(self, _mock_update, tmp_path):
+        with patch.dict(os.environ, {
+            "CLOAKBROWSER_CACHE_DIR": str(tmp_path),
+            "CLOAKBROWSER_BINARY_PATH": "",
+        }):
+            # Create a fake cached binary
+            version = get_chromium_version()
+            with patch("cloakbrowser.download.get_binary_path") as mock_path:
+                fake_binary = tmp_path / "chrome"
+                fake_binary.write_bytes(b"binary")
+                fake_binary.chmod(0o755)
+                mock_path.return_value = fake_binary
+                with patch("cloakbrowser.download.check_platform_available"):
+                    result = ensure_binary()
+                    assert result == str(fake_binary)
+
+    @patch("cloakbrowser.download._maybe_trigger_update_check")
+    def test_downloads_when_missing(self, _mock_update, tmp_path):
+        with patch.dict(os.environ, {
+            "CLOAKBROWSER_CACHE_DIR": str(tmp_path),
+            "CLOAKBROWSER_BINARY_PATH": "",
+        }):
+            fake_binary = tmp_path / "chrome"
+            with patch("cloakbrowser.download.check_platform_available"):
+                with patch("cloakbrowser.download.get_binary_path") as mock_path:
+                    # effective == platform_version (no marker), so fallback block skipped.
+                    # Call 1: get_binary_path(effective) → nonexistent (triggers download)
+                    # Call 2: get_binary_path() → fake_binary (post-download verify)
+                    mock_path.side_effect = [
+                        tmp_path / "nonexistent",  # pre-download: not cached
+                        fake_binary,               # post-download: binary ready
+                    ]
+                    with patch("cloakbrowser.download._download_and_extract") as mock_dl:
+                        fake_binary.write_bytes(b"binary")
+                        result = ensure_binary()
+                        mock_dl.assert_called_once()
+                        assert result == str(fake_binary)
+
+
+class TestWriteVersionMarker:
+    def test_creates_file(self, tmp_path):
+        with patch.dict(os.environ, {"CLOAKBROWSER_CACHE_DIR": str(tmp_path)}):
+            _write_version_marker("999.0.0.0")
+            marker = tmp_path / f"latest_version_{get_platform_tag()}"
+            assert marker.exists()
+            assert marker.read_text() == "999.0.0.0"