From fb297f793713cbec7293195d80021abecc50f89a Mon Sep 17 00:00:00 2001
From: Ryan Malloy <ryan@supported.systems>
Date: Wed, 11 Feb 2026 03:38:37 -0700
Subject: [PATCH] Add pytest suite (216 tests) and fix UI/notification parser
 bugs

Test infrastructure with conftest fixtures mocking run_shell_args/run_adb
for device-free testing across all 8 mixins.

Fixed: UI parser regex couldn't match hyphenated XML attributes
(content-desc, resource-id). Notification parser captured trailing
parenthesis in package names.
---
 pyproject.toml             |   3 +
 src/mixins/settings.py     |   2 +-
 src/mixins/ui.py           |   2 +-
 tests/__init__.py          |   0
 tests/conftest.py          | 124 ++++++++++++
 tests/test_apps.py         | 233 ++++++++++++++++++++++
 tests/test_base.py         | 234 ++++++++++++++++++++++
 tests/test_config.py       |  78 ++++++++
 tests/test_connectivity.py | 122 ++++++++++++
 tests/test_devices.py      | 181 +++++++++++++++++
 tests/test_files.py        | 120 ++++++++++++
 tests/test_input.py        | 236 ++++++++++++++++++++++
 tests/test_models.py       |  56 ++++++
 tests/test_screenshot.py   | 132 +++++++++++++
 tests/test_server.py       |  36 ++++
 tests/test_settings.py     | 391 +++++++++++++++++++++++++++++++++++++
 tests/test_ui.py           | 141 +++++++++++++
 17 files changed, 2089 insertions(+), 2 deletions(-)
 create mode 100644 tests/__init__.py
 create mode 100644 tests/conftest.py
 create mode 100644 tests/test_apps.py
 create mode 100644 tests/test_base.py
 create mode 100644 tests/test_config.py
 create mode 100644 tests/test_connectivity.py
 create mode 100644 tests/test_devices.py
 create mode 100644 tests/test_files.py
 create mode 100644 tests/test_input.py
 create mode 100644 tests/test_models.py
 create mode 100644 tests/test_screenshot.py
 create mode 100644 tests/test_server.py
 create mode 100644 tests/test_settings.py
 create mode 100644 tests/test_ui.py

diff --git a/pyproject.toml b/pyproject.toml
index ed90c23..336d9d7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,6 +52,9 @@ line-length = 88
 [tool.ruff.lint]
 select = ["E", "F", "I", "UP", "B", "SIM"]
 
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+
 [tool.mypy]
 python_version = "3.11"
 strict = true
diff --git a/src/mixins/settings.py b/src/mixins/settings.py
index 9c8a265..848a94b 100644
--- a/src/mixins/settings.py
+++ b/src/mixins/settings.py
@@ -513,7 +513,7 @@ class SettingsMixin(ADBBaseMixin):
                         break
                 current = {}
                 # Extract package from NotificationRecord line
-                pkg_match = re.search(r"pkg=(\S+)", stripped)
+                pkg_match = re.search(r"pkg=([\w.]+)", stripped)
                 if pkg_match:
                     current["package"] = pkg_match.group(1)
 
diff --git a/src/mixins/ui.py b/src/mixins/ui.py
index 1e0f248..8f32dea 100644
--- a/src/mixins/ui.py
+++ b/src/mixins/ui.py
@@ -102,7 +102,7 @@ class UIMixin(ADBBaseMixin):
 
         # Regex to find node elements with their attributes
         node_pattern = re.compile(r"<node\s+([^>]+?)(?:/>|>)", re.DOTALL)
-        attr_pattern = re.compile(r'(\w+)="([^"]*)"')
+        attr_pattern = re.compile(r'([\w-]+)="([^"]*)"')
 
         for match in node_pattern.finditer(xml_content):
             attrs_str = match.group(1)
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..a5c7780
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,124 @@
+"""Shared test fixtures for mcadb tests."""
+
+from dataclasses import dataclass, field
+from typing import Any
+from unittest.mock import AsyncMock
+
+import pytest
+
+from src.models import CommandResult
+from src.server import ADBServer
+
+# --- Helpers ---
+
+
+def ok(stdout: str = "", stderr: str = "") -> CommandResult:
+    """Create a successful CommandResult."""
+    return CommandResult(success=True, stdout=stdout, stderr=stderr, returncode=0)
+
+
+def fail(stderr: str = "error", stdout: str = "") -> CommandResult:
+    """Create a failed CommandResult."""
+    return CommandResult(success=False, stdout=stdout, stderr=stderr, returncode=1)
+
+
+# --- Mock Context ---
+
+
+@dataclass
+class ElicitResult:
+    """Minimal stand-in for FastMCP's ElicitationResult."""
+
+    action: str = "accept"
+    content: str = ""
+
+
+@dataclass
+class MockContext:
+    """Mock MCP Context that records calls for assertion."""
+
+    messages: list[tuple[str, str]] = field(default_factory=list)
+    _elicit_response: ElicitResult = field(default_factory=ElicitResult)
+
+    async def info(self, msg: str) -> None:
+        self.messages.append(("info", msg))
+
+    async def warning(self, msg: str) -> None:
+        self.messages.append(("warning", msg))
+
+    async def error(self, msg: str) -> None:
+        self.messages.append(("error", msg))
+
+    async def elicit(self, msg: str, options: list[str] | None = None) -> ElicitResult:
+        self.messages.append(("elicit", msg))
+        return self._elicit_response
+
+    def set_elicit(self, action: str = "accept", content: str = "") -> None:
+        """Configure the next elicit response."""
+        self._elicit_response = ElicitResult(action=action, content=content)
+
+
+# --- Fixtures ---
+
+
+def _reset_config(monkeypatch: pytest.MonkeyPatch, config_dir: Any) -> None:
+    """Reset the Config singleton and point it at a temp directory.
+
+    CONFIG_DIR and CONFIG_FILE are module-level variables computed at
+    import time, so setting the env var isn't enough — we must patch
+    the variables directly.
+    """
+    from pathlib import Path
+
+    config_path = Path(config_dir)
+    monkeypatch.setattr("src.config.Config._instance", None)
+    monkeypatch.setattr("src.config.CONFIG_DIR", config_path)
+    monkeypatch.setattr("src.config.CONFIG_FILE", config_path / "config.json")
+
+
+@pytest.fixture
+def server() -> ADBServer:
+    """Create an ADBServer with mocked ADB execution.
+
+    Both run_adb and run_shell_args are replaced with AsyncMock,
+    so no real subprocess calls are made. Configure return values
+    per-test with server.run_adb.return_value = ok("...").
+    """
+    s = ADBServer()
+    s.run_adb = AsyncMock(return_value=ok())  # type: ignore[method-assign]
+    s.run_shell_args = AsyncMock(return_value=ok())  # type: ignore[method-assign]
+    s.run_shell = AsyncMock(return_value=ok())  # type: ignore[method-assign]
+    s.get_device_property = AsyncMock(return_value=None)  # type: ignore[method-assign]
+    return s
+
+
+@pytest.fixture
+def ctx() -> MockContext:
+    """Create a mock MCP Context."""
+    return MockContext()
+
+
+@pytest.fixture
+def _dev_mode(monkeypatch: pytest.MonkeyPatch, tmp_path: Any) -> None:
+    """Enable developer mode for the test."""
+    _reset_config(monkeypatch, tmp_path / "dev-config")
+    from src.config import get_config
+
+    config = get_config()
+    config._settings["developer_mode"] = True
+
+
+@pytest.fixture
+def _no_dev_mode(monkeypatch: pytest.MonkeyPatch, tmp_path: Any) -> None:
+    """Disable developer mode for the test."""
+    _reset_config(monkeypatch, tmp_path / "nodev-config")
+    from src.config import get_config
+
+    config = get_config()
+    config._settings["developer_mode"] = False
+
+
+@pytest.fixture(autouse=True)
+def _isolate_config(monkeypatch: pytest.MonkeyPatch, tmp_path: Any) -> None:
+    """Isolate config to a temp directory so tests don't touch real config."""
+    _reset_config(monkeypatch, tmp_path / "config")
diff --git a/tests/test_apps.py b/tests/test_apps.py
new file mode 100644
index 0000000..652ee9c
--- /dev/null
+++ b/tests/test_apps.py
@@ -0,0 +1,233 @@
+"""Tests for apps mixin (launch, close, current, install, intents)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestAppLaunch:
+    async def test_launch(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.app_launch("com.android.chrome")
+        assert result["success"] is True
+        assert result["package"] == "com.android.chrome"
+        args = server.run_shell_args.call_args[0][0]
+        assert "monkey" in args
+        assert "com.android.chrome" in args
+
+    async def test_failure(self, server):
+        server.run_shell_args.return_value = fail("not found")
+        result = await server.app_launch("com.missing.app")
+        assert result["success"] is False
+
+
+class TestAppOpenUrl:
+    async def test_open(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.app_open_url("https://example.com")
+        assert result["success"] is True
+        assert result["url"] == "https://example.com"
+        args = server.run_shell_args.call_args[0][0]
+        assert "am" in args
+        assert "android.intent.action.VIEW" in args
+
+
+class TestAppClose:
+    async def test_close(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.app_close("com.example.app")
+        assert result["success"] is True
+        assert result["package"] == "com.example.app"
+        args = server.run_shell_args.call_args[0][0]
+        assert "am" in args
+        assert "force-stop" in args
+
+
+class TestAppCurrent:
+    async def test_parse_focused(self, server):
+        focused = (
+            "  mCurrentFocus=Window{abc com.android.chrome"
+            "/org.chromium.chrome.browser.ChromeTabbedActivity}"
+        )
+        server.run_shell_args.return_value = ok(stdout=focused)
+        result = await server.app_current()
+        assert result["success"] is True
+        assert result["package"] == "com.android.chrome"
+
+    async def test_focused_app_format(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout="  mFocusedApp=ActivityRecord{abc com.example/.MainActivity t123}"
+        )
+        result = await server.app_current()
+        assert result["success"] is True
+        assert result["package"] == "com.example"
+
+    async def test_no_focus(self, server):
+        server.run_shell_args.return_value = ok(stdout="no focus info")
+        result = await server.app_current()
+        assert result["success"] is True
+        assert result["package"] is None
+
+
+class TestAppListPackages:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_list(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout="package:com.android.chrome\npackage:com.example.app\n"
+        )
+        result = await server.app_list_packages()
+        assert result["success"] is True
+        assert result["count"] == 2
+        assert "com.android.chrome" in result["packages"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_filter(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout="package:com.android.chrome\npackage:com.example.app\n"
+        )
+        result = await server.app_list_packages(filter_text="chrome")
+        assert result["count"] == 1
+        assert "com.android.chrome" in result["packages"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_third_party(self, server):
+        server.run_shell_args.return_value = ok(stdout="package:com.user.app\n")
+        await server.app_list_packages(third_party_only=True)
+        args = server.run_shell_args.call_args[0][0]
+        assert "-3" in args
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.app_list_packages()
+        assert result["success"] is False
+
+
+class TestAppInstall:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_install(self, server):
+        server.run_adb.return_value = ok(stdout="Success")
+        result = await server.app_install("/tmp/app.apk")
+        assert result["success"] is True
+        args = server.run_adb.call_args[0][0]
+        assert "install" in args
+        assert "-r" in args
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.app_install("/tmp/app.apk")
+        assert result["success"] is False
+
+
+class TestAppUninstall:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_uninstall(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, uninstall")
+        server.run_adb.return_value = ok()
+        result = await server.app_uninstall(ctx, "com.example.app")
+        assert result["success"] is True
+        assert result["package"] == "com.example.app"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_keep_data(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, uninstall")
+        server.run_adb.return_value = ok()
+        result = await server.app_uninstall(ctx, "com.example.app", keep_data=True)
+        assert result["kept_data"] is True
+        args = server.run_adb.call_args[0][0]
+        assert "-k" in args
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.app_uninstall(ctx, "com.example.app")
+        assert result["success"] is False
+        assert result.get("cancelled") is True
+
+
+class TestAppClearData:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_clear(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, clear all data")
+        server.run_shell_args.return_value = ok()
+        result = await server.app_clear_data(ctx, "com.example.app")
+        assert result["success"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.app_clear_data(ctx, "com.example.app")
+        assert result.get("cancelled") is True
+
+
+class TestActivityStart:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_basic(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.activity_start("com.example/.MainActivity")
+        assert result["success"] is True
+        assert result["component"] == "com.example/.MainActivity"
+        args = server.run_shell_args.call_args[0][0]
+        assert "am" in args
+        assert "start" in args
+        assert "-n" in args
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_with_action_and_data(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.activity_start(
+            "com.example/.DeepLink",
+            action="android.intent.action.VIEW",
+            data_uri="myapp://product/123",
+        )
+        args = server.run_shell_args.call_args[0][0]
+        assert "-a" in args
+        assert "-d" in args
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_with_extras(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.activity_start(
+            "com.example/.Act",
+            extras={"key": "value", "flag": "true", "count": "42"},
+        )
+        args = server.run_shell_args.call_args[0][0]
+        assert "--es" in args  # string extra
+        assert "--ez" in args  # boolean extra
+        assert "--ei" in args  # integer extra
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_with_flags(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.activity_start(
+            "com.example/.Act",
+            flags=["FLAG_ACTIVITY_NEW_TASK"],
+        )
+        args = server.run_shell_args.call_args[0][0]
+        assert "-f" in args
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.activity_start("com.example/.Act")
+        assert result["success"] is False
+
+
+class TestBroadcastSend:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_basic(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.broadcast_send("com.example.ACTION")
+        assert result["success"] is True
+        assert result["broadcast_action"] == "com.example.ACTION"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_with_package(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.broadcast_send("ACTION", package="com.target")
+        args = server.run_shell_args.call_args[0][0]
+        assert "-p" in args
+        assert "com.target" in args
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.broadcast_send("ACTION")
+        assert result["success"] is False
diff --git a/tests/test_base.py b/tests/test_base.py
new file mode 100644
index 0000000..401f545
--- /dev/null
+++ b/tests/test_base.py
@@ -0,0 +1,234 @@
+"""Tests for base ADB execution mixin."""
+
+import shlex
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from src.mixins.base import ADBBaseMixin
+from src.models import CommandResult
+
+
+class TestRunAdb:
+    @pytest.fixture
+    def base(self):
+        return ADBBaseMixin()
+
+    async def test_basic_command(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"output\n", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            result = await base.run_adb(["devices"])
+
+        mock_exec.assert_called_once_with(
+            "adb",
+            "devices",
+            stdout=-1,
+            stderr=-1,
+        )
+        assert result.success is True
+        assert result.stdout == "output"
+
+    async def test_device_targeting(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_adb(["shell", "ls"], device_id="ABC123")
+
+        # Should insert -s ABC123 before the command
+        mock_exec.assert_called_once_with(
+            "adb",
+            "-s",
+            "ABC123",
+            "shell",
+            "ls",
+            stdout=-1,
+            stderr=-1,
+        )
+
+    async def test_current_device_fallback(self, base):
+        base.set_current_device("DEF456")
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_adb(["devices"])
+
+        args = mock_exec.call_args[0]
+        assert "-s" in args
+        assert "DEF456" in args
+
+    async def test_device_id_overrides_current(self, base):
+        base.set_current_device("OLD")
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_adb(["shell", "ls"], device_id="NEW")
+
+        args = mock_exec.call_args[0]
+        assert "NEW" in args
+        assert "OLD" not in args
+
+    async def test_failure(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"", b"not found")
+        mock_proc.returncode = 1
+
+        with patch("asyncio.create_subprocess_exec", return_value=mock_proc):
+            result = await base.run_adb(["shell", "missing"])
+
+        assert result.success is False
+        assert result.stderr == "not found"
+        assert result.returncode == 1
+
+    async def test_timeout(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.side_effect = TimeoutError()
+        mock_proc.kill = MagicMock()
+
+        with patch("asyncio.create_subprocess_exec", return_value=mock_proc):
+            result = await base.run_adb(["shell", "hang"], timeout=1)
+
+        assert result.success is False
+        assert "timed out" in result.stderr
+        assert result.returncode == -1
+
+    async def test_exception(self, base):
+        with patch(
+            "asyncio.create_subprocess_exec",
+            side_effect=FileNotFoundError("adb not found"),
+        ):
+            result = await base.run_adb(["devices"])
+
+        assert result.success is False
+        assert "adb not found" in result.stderr
+
+
+class TestRunShellArgs:
+    @pytest.fixture
+    def base(self):
+        return ADBBaseMixin()
+
+    async def test_quotes_arguments(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_shell_args(["input", "text", "hello world"])
+
+        args = mock_exec.call_args[0]
+        # "shell" should be in the args
+        assert "shell" in args
+        # Arguments should be shlex-quoted
+        quoted_hello = shlex.quote("hello world")
+        assert quoted_hello in args
+
+    async def test_injection_safety(self, base):
+        """Verify dangerous characters get quoted."""
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_shell_args(["echo", "; rm -rf /"])
+
+        args = mock_exec.call_args[0]
+        # The dangerous string should be quoted, not bare
+        assert "; rm -rf /" not in args
+        quoted = shlex.quote("; rm -rf /")
+        assert quoted in args
+
+
+class TestRunShell:
+    @pytest.fixture
+    def base(self):
+        return ADBBaseMixin()
+
+    async def test_splits_command(self, base):
+        mock_proc = AsyncMock()
+        mock_proc.communicate.return_value = (b"ok", b"")
+        mock_proc.returncode = 0
+
+        patcher = patch(
+            "asyncio.create_subprocess_exec",
+            return_value=mock_proc,
+        )
+        with patcher as mock_exec:
+            await base.run_shell("ls -la /sdcard")
+
+        args = mock_exec.call_args[0]
+        assert "shell" in args
+        assert "ls" in args
+        assert "-la" in args
+        assert "/sdcard" in args
+
+
+class TestGetDeviceProperty:
+    @pytest.fixture
+    def base(self):
+        b = ADBBaseMixin()
+        b.run_shell_args = AsyncMock()  # type: ignore[method-assign]
+        return b
+
+    async def test_returns_value(self, base):
+        base.run_shell_args.return_value = CommandResult(
+            success=True, stdout="Pixel 6", stderr="", returncode=0
+        )
+        result = await base.get_device_property("ro.product.model")
+        assert result == "Pixel 6"
+
+    async def test_returns_none_on_empty(self, base):
+        base.run_shell_args.return_value = CommandResult(
+            success=True, stdout="", stderr="", returncode=0
+        )
+        result = await base.get_device_property("ro.missing")
+        assert result is None
+
+    async def test_returns_none_on_failure(self, base):
+        base.run_shell_args.return_value = CommandResult(
+            success=False, stdout="", stderr="err", returncode=1
+        )
+        result = await base.get_device_property("ro.missing")
+        assert result is None
+
+
+class TestDeviceState:
+    def test_set_get_device(self):
+        base = ADBBaseMixin()
+        assert base.get_current_device() is None
+        base.set_current_device("ABC")
+        assert base.get_current_device() == "ABC"
+        base.set_current_device(None)
+        assert base.get_current_device() is None
diff --git a/tests/test_config.py b/tests/test_config.py
new file mode 100644
index 0000000..ceaf154
--- /dev/null
+++ b/tests/test_config.py
@@ -0,0 +1,78 @@
+"""Tests for configuration management."""
+
+import json
+from pathlib import Path
+
+from src.config import get_config, is_developer_mode
+
+
+def _fresh_config(monkeypatch, config_dir):
+    """Reset singleton and point Config at a specific directory."""
+    config_path = Path(config_dir)
+    monkeypatch.setattr("src.config.Config._instance", None)
+    monkeypatch.setattr("src.config.CONFIG_DIR", config_path)
+    monkeypatch.setattr("src.config.CONFIG_FILE", config_path / "config.json")
+
+
+class TestConfig:
+    def test_defaults(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        assert config.developer_mode is False
+        assert config.auto_select_single_device is True
+        assert config.default_screenshot_dir is None
+
+    def test_developer_mode_toggle(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        assert config.developer_mode is False
+        config.developer_mode = True
+        assert config.developer_mode is True
+
+    def test_persistence(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        config.developer_mode = True
+
+        config_file = tmp_path / "config.json"
+        assert config_file.exists()
+        data = json.loads(config_file.read_text())
+        assert data["developer_mode"] is True
+
+    def test_screenshot_dir(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        config.default_screenshot_dir = "/tmp/shots"
+        assert config.default_screenshot_dir == "/tmp/shots"
+
+    def test_get_set(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        config.set("custom_key", "custom_value")
+        assert config.get("custom_key") == "custom_value"
+
+    def test_to_dict(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        config = get_config()
+        d = config.to_dict()
+        assert "developer_mode" in d
+        assert "auto_select_single_device" in d
+
+    def test_load_corrupt_file(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        (tmp_path / "config.json").write_text("{invalid json")
+        # Need a fresh singleton to trigger _load with corrupt file
+        monkeypatch.setattr("src.config.Config._instance", None)
+        config = get_config()
+        assert config.developer_mode is False
+
+
+class TestIsDeveloperMode:
+    def test_off_by_default(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        assert is_developer_mode() is False
+
+    def test_on_when_enabled(self, tmp_path, monkeypatch):
+        _fresh_config(monkeypatch, tmp_path)
+        get_config().developer_mode = True
+        assert is_developer_mode() is True
diff --git a/tests/test_connectivity.py b/tests/test_connectivity.py
new file mode 100644
index 0000000..607f840
--- /dev/null
+++ b/tests/test_connectivity.py
@@ -0,0 +1,122 @@
+"""Tests for connectivity mixin (connect, disconnect, tcpip, pair, properties)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestAdbConnect:
+    async def test_success(self, server):
+        server.run_adb.return_value = ok(stdout="connected to 10.0.0.1:5555")
+        result = await server.adb_connect("10.0.0.1")
+        assert result["success"] is True
+        assert result["address"] == "10.0.0.1:5555"
+        server.run_adb.assert_called_once_with(["connect", "10.0.0.1:5555"])
+
+    async def test_custom_port(self, server):
+        server.run_adb.return_value = ok(stdout="connected to 10.0.0.1:5556")
+        result = await server.adb_connect("10.0.0.1", port=5556)
+        assert result["address"] == "10.0.0.1:5556"
+
+    async def test_already_connected(self, server):
+        server.run_adb.return_value = ok(stdout="already connected to 10.0.0.1:5555")
+        result = await server.adb_connect("10.0.0.1")
+        assert result["success"] is True
+        assert result["already_connected"] is True
+
+    async def test_failure(self, server):
+        server.run_adb.return_value = ok(stdout="failed to connect")
+        result = await server.adb_connect("10.0.0.1")
+        assert result["success"] is False
+
+
+class TestAdbDisconnect:
+    async def test_success(self, server):
+        server.run_adb.return_value = ok(stdout="disconnected 10.0.0.1:5555")
+        result = await server.adb_disconnect("10.0.0.1")
+        assert result["success"] is True
+        assert result["address"] == "10.0.0.1:5555"
+
+    async def test_failure(self, server):
+        server.run_adb.return_value = ok(stdout="error: no such device")
+        result = await server.adb_disconnect("10.0.0.1")
+        assert result["success"] is False
+
+
+class TestAdbTcpip:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_success(self, server, ctx):
+        server.run_shell_args.return_value = ok(
+            stdout="10: wlan0    inet 192.168.1.100/24"
+        )
+        server.run_adb.return_value = ok(stdout="restarting in TCP mode port: 5555")
+        result = await server.adb_tcpip(ctx)
+        assert result["success"] is True
+        assert result["device_ip"] == "192.168.1.100"
+        assert result["connect_address"] == "192.168.1.100:5555"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_rejects_network_device(self, server, ctx):
+        server.set_current_device("10.20.0.25:5555")
+        result = await server.adb_tcpip(ctx)
+        assert result["success"] is False
+        assert "already a network device" in result["error"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_no_wifi_ip(self, server, ctx):
+        server.run_shell_args.return_value = ok(stdout="wlan0: no ip")
+        result = await server.adb_tcpip(ctx)
+        assert result["success"] is False
+        assert "WiFi" in result["error"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_custom_port(self, server, ctx):
+        server.run_shell_args.return_value = ok(
+            stdout="10: wlan0    inet 192.168.1.50/24"
+        )
+        server.run_adb.return_value = ok()
+        result = await server.adb_tcpip(ctx, port=5556)
+        assert result["port"] == 5556
+        assert result["connect_address"] == "192.168.1.50:5556"
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.adb_tcpip(ctx)
+        assert result["success"] is False
+        assert "developer mode" in result["error"].lower()
+
+
+class TestAdbPair:
+    async def test_success(self, server):
+        server.run_adb.return_value = ok(stdout="Successfully paired to 10.0.0.1:37000")
+        result = await server.adb_pair("10.0.0.1", 37000, "123456")
+        assert result["success"] is True
+        server.run_adb.assert_called_once_with(["pair", "10.0.0.1:37000", "123456"])
+
+    async def test_failure(self, server):
+        server.run_adb.return_value = fail("Failed: wrong code")
+        result = await server.adb_pair("10.0.0.1", 37000, "000000")
+        assert result["success"] is False
+
+
+class TestDeviceProperties:
+    async def test_returns_properties(self, server):
+        props = {
+            "ro.product.model": "Pixel 6",
+            "ro.product.manufacturer": "Google",
+            "ro.build.version.release": "14",
+            "ro.build.version.sdk": "34",
+            "ro.board.platform": "gs101",
+        }
+        server.get_device_property.side_effect = lambda p, d=None: props.get(p)
+        result = await server.device_properties()
+        assert result["success"] is True
+        assert result["identity"]["model"] == "Pixel 6"
+        assert result["software"]["android_version"] == "14"
+        assert result["hardware"]["chipset"] == "gs101"
+
+    async def test_no_properties(self, server):
+        server.get_device_property.return_value = None
+        result = await server.device_properties()
+        assert result["success"] is False
+        assert "No properties" in result["error"]
diff --git a/tests/test_devices.py b/tests/test_devices.py
new file mode 100644
index 0000000..0e45999
--- /dev/null
+++ b/tests/test_devices.py
@@ -0,0 +1,181 @@
+"""Tests for devices mixin (list, use, current, info, reboot, logcat)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestDevicesList:
+    async def test_parse_devices(self, server):
+        server.run_adb.return_value = ok(
+            stdout=(
+                "List of devices attached\n"
+                "ABC123\tdevice\tmodel:Pixel_6 product:oriole\n"
+                "10.20.0.25:5555\tdevice\tmodel:K2401 product:K2401\n"
+            )
+        )
+        devices = await server.devices_list()
+        assert len(devices) == 2
+        assert devices[0].device_id == "ABC123"
+        assert devices[0].model == "Pixel_6"
+        assert devices[1].device_id == "10.20.0.25:5555"
+
+    async def test_empty(self, server):
+        server.run_adb.return_value = ok(stdout="List of devices attached\n")
+        devices = await server.devices_list()
+        assert len(devices) == 0
+
+    async def test_failure(self, server):
+        server.run_adb.return_value = fail("adb not found")
+        devices = await server.devices_list()
+        assert len(devices) == 0
+
+
+class TestDevicesUse:
+    async def test_select_device(self, server):
+        server.run_adb.return_value = ok(
+            stdout="List of devices attached\nABC123\tdevice\n"
+        )
+        result = await server.devices_use("ABC123")
+        assert result["success"] is True
+        assert server.get_current_device() == "ABC123"
+
+    async def test_not_found(self, server):
+        server.run_adb.return_value = ok(
+            stdout="List of devices attached\nOTHER\tdevice\n"
+        )
+        result = await server.devices_use("MISSING")
+        assert result["success"] is False
+        assert "not found" in result["error"]
+
+    async def test_offline_device(self, server):
+        server.run_adb.return_value = ok(
+            stdout="List of devices attached\nABC123\toffline\n"
+        )
+        result = await server.devices_use("ABC123")
+        assert result["success"] is False
+        assert "offline" in result["error"]
+
+
+class TestDevicesCurrent:
+    async def test_no_device_set(self, server):
+        server.run_adb.return_value = ok(stdout="List of devices attached\n")
+        result = await server.devices_current()
+        assert result["device"] is None
+
+    async def test_auto_detect_single(self, server):
+        server.run_adb.return_value = ok(
+            stdout="List of devices attached\nABC123\tdevice\n"
+        )
+        result = await server.devices_current()
+        assert result.get("available") is not None
+
+    async def test_device_set(self, server):
+        # Pre-populate cache and set device
+        server.run_adb.return_value = ok(
+            stdout="List of devices attached\nABC123\tdevice\tmodel:Pixel\n"
+        )
+        await server.devices_list()
+        server.set_current_device("ABC123")
+        result = await server.devices_current()
+        assert result["device"]["device_id"] == "ABC123"
+
+
+class TestDeviceInfo:
+    async def test_full_info(self, server):
+        battery = (
+            "Current Battery Service state:\n  level: 85\n  status: 2\n  plugged: 2"
+        )
+        df_out = (
+            "Filesystem  1K-blocks  Used Available\n"
+            "/data       64000000  32000000  32000000"
+        )
+        server.run_shell_args.side_effect = [
+            ok(stdout=battery),
+            ok(stdout="10: wlan0    inet 192.168.1.100/24"),
+            ok(stdout="mWifiInfo SSID: MyNetwork, BSSID: ..."),
+            ok(stdout=df_out),
+        ]
+        server.get_device_property.side_effect = lambda p, d=None: {
+            "ro.build.version.release": "14",
+            "ro.build.version.sdk": "34",
+            "ro.product.model": "Pixel 6",
+            "ro.product.manufacturer": "Google",
+            "ro.product.device": "oriole",
+        }.get(p)
+
+        result = await server.device_info()
+        assert result["success"] is True
+        assert result["battery"]["level"] == 85
+        assert result["ip_address"] == "192.168.1.100"
+        assert result["wifi_ssid"] == "MyNetwork"
+        assert result["model"] == "Pixel 6"
+
+    async def test_device_offline(self, server):
+        server.run_shell_args.return_value = fail("device offline")
+        result = await server.device_info()
+        assert result["success"] is False
+
+
+class TestDeviceReboot:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_reboot(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, reboot now")
+        server.run_adb.return_value = ok()
+        result = await server.device_reboot(ctx)
+        assert result["success"] is True
+        assert result["mode"] == "normal"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_reboot_recovery(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, reboot now")
+        server.run_adb.return_value = ok()
+        result = await server.device_reboot(ctx, mode="recovery")
+        assert result["mode"] == "recovery"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.device_reboot(ctx)
+        assert result["success"] is False
+        assert result.get("cancelled") is True
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.device_reboot(ctx)
+        assert result["success"] is False
+
+
+class TestLogcat:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_capture(self, server):
+        logline = "01-01 00:00:00.000 I/TAG: message"
+        server.run_shell_args.return_value = ok(stdout=logline)
+        result = await server.logcat_capture()
+        assert result["success"] is True
+        assert result["output"].startswith("01-01")
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_with_filter(self, server):
+        server.run_shell_args.return_value = ok(stdout="filtered output")
+        result = await server.logcat_capture(filter_spec="MyApp:D *:S")
+        assert result["filter"] == "MyApp:D *:S"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_clear_first(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout="fresh logs")]
+        result = await server.logcat_capture(clear_first=True)
+        assert result["success"] is True
+        assert server.run_shell_args.call_count == 2
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.logcat_capture()
+        assert result["success"] is False
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_logcat_clear(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.logcat_clear()
+        assert result["success"] is True
+        assert result["action"] == "logcat_clear"
diff --git a/tests/test_files.py b/tests/test_files.py
new file mode 100644
index 0000000..c9d4524
--- /dev/null
+++ b/tests/test_files.py
@@ -0,0 +1,120 @@
+"""Tests for files mixin (push, pull, list, delete, exists)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestFilePush:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_push(self, server, ctx, tmp_path):
+        local_file = tmp_path / "test.txt"
+        local_file.write_text("content")
+        server.run_adb.return_value = ok(stdout="1 file pushed")
+        result = await server.file_push(ctx, str(local_file), "/sdcard/test.txt")
+        assert result["success"] is True
+        assert result["device_path"] == "/sdcard/test.txt"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_local_not_found(self, server, ctx):
+        result = await server.file_push(ctx, "/nonexistent/file.txt", "/sdcard/")
+        assert result["success"] is False
+        assert "not found" in result["error"]
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.file_push(ctx, "/tmp/f", "/sdcard/f")
+        assert result["success"] is False
+
+
+class TestFilePull:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_pull(self, server, ctx, tmp_path):
+        server.run_adb.return_value = ok(stdout="1 file pulled")
+        result = await server.file_pull(
+            ctx, "/sdcard/test.txt", str(tmp_path / "out.txt")
+        )
+        assert result["success"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_default_local_path(self, server, ctx):
+        server.run_adb.return_value = ok()
+        result = await server.file_pull(ctx, "/sdcard/data.db")
+        assert "data.db" in result["local_path"]
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.file_pull(ctx, "/sdcard/f")
+        assert result["success"] is False
+
+
+class TestFileList:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_parse_ls(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout=(
+                "total 16\n"
+                "drwxr-xr-x 2 root root 4096 2024-01-15 10:30 Documents\n"
+                "-rw-r--r-- 1 root root 1234 2024-01-15 10:31 test.txt\n"
+            )
+        )
+        result = await server.file_list("/sdcard/")
+        assert result["success"] is True
+        assert result["count"] == 2
+        assert result["files"][0]["name"] == "Documents"
+        assert result["files"][0]["is_directory"] is True
+        assert result["files"][1]["name"] == "test.txt"
+        assert result["files"][1]["is_directory"] is False
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_failure(self, server):
+        server.run_shell_args.return_value = fail("No such file")
+        result = await server.file_list("/nonexistent/")
+        assert result["success"] is False
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.file_list()
+        assert result["success"] is False
+
+
+class TestFileDelete:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_delete(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, delete")
+        server.run_shell_args.return_value = ok()
+        result = await server.file_delete(ctx, "/sdcard/old.txt")
+        assert result["success"] is True
+        assert result["path"] == "/sdcard/old.txt"
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.file_delete(ctx, "/sdcard/keep.txt")
+        assert result["success"] is False
+        assert result.get("cancelled") is True
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.file_delete(ctx, "/sdcard/f")
+        assert result["success"] is False
+
+
+class TestFileExists:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_exists(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.file_exists("/sdcard/file.txt")
+        assert result["success"] is True
+        assert result["exists"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_not_exists(self, server):
+        server.run_shell_args.return_value = fail()
+        result = await server.file_exists("/sdcard/missing.txt")
+        assert result["exists"] is False
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.file_exists("/sdcard/f")
+        assert result["success"] is False
diff --git a/tests/test_input.py b/tests/test_input.py
new file mode 100644
index 0000000..79eafc6
--- /dev/null
+++ b/tests/test_input.py
@@ -0,0 +1,236 @@
+"""Tests for input mixin (tap, swipe, keys, text, clipboard)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestInputTap:
+    async def test_tap(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_tap(100, 200)
+        assert result["success"] is True
+        assert result["coordinates"] == {"x": 100, "y": 200}
+        server.run_shell_args.assert_called_once_with(
+            ["input", "tap", "100", "200"], None
+        )
+
+    async def test_tap_with_device(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.input_tap(10, 20, device_id="ABC")
+        server.run_shell_args.assert_called_once_with(
+            ["input", "tap", "10", "20"], "ABC"
+        )
+
+    async def test_tap_failure(self, server):
+        server.run_shell_args.return_value = fail("no device")
+        result = await server.input_tap(0, 0)
+        assert result["success"] is False
+        assert result["error"] == "no device"
+
+
+class TestInputSwipe:
+    async def test_swipe(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_swipe(0, 100, 0, 500, duration_ms=500)
+        assert result["success"] is True
+        assert result["from"] == {"x": 0, "y": 100}
+        assert result["to"] == {"x": 0, "y": 500}
+        assert result["duration_ms"] == 500
+
+    async def test_swipe_default_duration(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_swipe(0, 0, 100, 100)
+        assert result["duration_ms"] == 300
+
+
+class TestInputScroll:
+    async def test_scroll_down(self, server):
+        # First call: wm size, second call: the swipe
+        server.run_shell_args.side_effect = [
+            ok("Physical size: 1080x1920"),
+            ok(),
+        ]
+        result = await server.input_scroll_down()
+        assert result["success"] is True
+        assert result["action"] == "scroll_down"
+
+        # Verify swipe args: center x, 65% down to 25% down
+        swipe_call = server.run_shell_args.call_args_list[1]
+        args = swipe_call[0][0]
+        assert args[0] == "input"
+        assert args[1] == "swipe"
+        assert args[2] == "540"  # 1080 // 2
+        assert args[3] == "1248"  # int(1920 * 0.65)
+        assert args[5] == "480"  # int(1920 * 0.25)
+
+    async def test_scroll_up(self, server):
+        server.run_shell_args.side_effect = [
+            ok("Physical size: 1080x1920"),
+            ok(),
+        ]
+        result = await server.input_scroll_up()
+        assert result["success"] is True
+        assert result["action"] == "scroll_up"
+
+    async def test_scroll_fallback_dimensions(self, server):
+        # wm size fails, should fall back to 1080x1920
+        server.run_shell_args.side_effect = [
+            fail("error"),
+            ok(),
+        ]
+        result = await server.input_scroll_down()
+        assert result["success"] is True
+
+
+class TestInputKeys:
+    async def test_back(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_back()
+        assert result["action"] == "back"
+        server.run_shell_args.assert_called_once_with(
+            ["input", "keyevent", "KEYCODE_BACK"], None
+        )
+
+    async def test_home(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_home()
+        assert result["action"] == "home"
+
+    async def test_recent_apps(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_recent_apps()
+        assert result["action"] == "recent_apps"
+
+
+class TestInputKey:
+    async def test_full_keycode(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_key("KEYCODE_ENTER")
+        assert result["key_code"] == "KEYCODE_ENTER"
+
+    async def test_auto_prefix(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_key("ENTER")
+        assert result["key_code"] == "KEYCODE_ENTER"
+
+    async def test_strips_dangerous_chars(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_key("KEYCODE_ENTER; rm -rf /")
+        # Shell metacharacters stripped
+        assert ";" not in result["key_code"]
+        assert " " not in result["key_code"]
+        assert "-" not in result["key_code"]
+        assert "/" not in result["key_code"]
+
+    async def test_lowercase_normalized(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_key("enter")
+        assert result["key_code"] == "KEYCODE_ENTER"
+
+
+class TestInputText:
+    async def test_simple_text(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_text("hello")
+        assert result["success"] is True
+        assert result["text"] == "hello"
+        server.run_shell_args.assert_called_once_with(["input", "text", "hello"], None)
+
+    async def test_spaces_escaped(self, server):
+        server.run_shell_args.return_value = ok()
+        await server.input_text("hello world")
+        server.run_shell_args.assert_called_once_with(
+            ["input", "text", "hello%sworld"], None
+        )
+
+    async def test_rejects_special_chars(self, server):
+        for char in "'\"\\`$(){}[]|&;<>!~#%^*?":
+            result = await server.input_text(f"text{char}here")
+            assert result["success"] is False
+            assert "clipboard_set" in result["error"]
+
+    async def test_rejects_semicolon_injection(self, server):
+        result = await server.input_text("hello; rm -rf /")
+        assert result["success"] is False
+
+
+class TestClipboardSet:
+    async def test_cmd_clipboard(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.clipboard_set("test text")
+        assert result["success"] is True
+        assert result["action"] == "clipboard_set"
+
+    async def test_cmd_clipboard_not_implemented_falls_back(self, server):
+        # First call: cmd clipboard returns "no shell command"
+        # Second call: am broadcast succeeds with result=-1
+        server.run_shell_args.side_effect = [
+            ok(stderr="No shell command implementation."),
+            ok(stdout="Broadcast completed: result=-1"),
+        ]
+        result = await server.clipboard_set("test")
+        assert result["success"] is True
+        assert server.run_shell_args.call_count == 2
+
+    async def test_no_receiver_reports_failure(self, server):
+        server.run_shell_args.side_effect = [
+            ok(stderr="No shell command implementation."),
+            ok(stdout="Broadcast completed: result=0"),  # No receiver
+        ]
+        result = await server.clipboard_set("test")
+        assert result["success"] is False
+        assert "no broadcast receiver" in result["error"].lower()
+
+    async def test_paste(self, server):
+        # First call: cmd clipboard set, second call: paste keyevent
+        server.run_shell_args.side_effect = [ok(), ok()]
+        result = await server.clipboard_set("text", paste=True)
+        assert result["success"] is True
+        assert result["pasted"] is True
+        # Verify KEYCODE_PASTE was sent
+        paste_call = server.run_shell_args.call_args_list[1]
+        assert "KEYCODE_PASTE" in paste_call[0][0]
+
+    async def test_text_preview_truncated(self, server):
+        server.run_shell_args.return_value = ok()
+        long_text = "x" * 200
+        result = await server.clipboard_set(long_text)
+        assert len(result["text"]) < 200
+        assert result["text"].endswith("...")
+
+
+class TestInputLongPress:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_long_press(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.input_long_press(100, 200, duration_ms=2000)
+        assert result["success"] is True
+        assert result["action"] == "long_press"
+        assert result["duration_ms"] == 2000
+        # Long press = swipe from same point to same point
+        args = server.run_shell_args.call_args[0][0]
+        assert args[2] == args[4]  # x1 == x2
+        assert args[3] == args[5]  # y1 == y2
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.input_long_press(0, 0)
+        assert result["success"] is False
+        assert "developer mode" in result["error"].lower()
+
+
+class TestShellCommand:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_executes(self, server):
+        server.run_shell.return_value = ok(stdout="output")
+        result = await server.shell_command("ls /sdcard")
+        assert result["success"] is True
+        assert result["stdout"] == "output"
+        assert result["command"] == "ls /sdcard"
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.shell_command("ls")
+        assert result["success"] is False
+        assert "developer mode" in result["error"].lower()
diff --git a/tests/test_models.py b/tests/test_models.py
new file mode 100644
index 0000000..7cd8c6b
--- /dev/null
+++ b/tests/test_models.py
@@ -0,0 +1,56 @@
+"""Tests for Pydantic models."""
+
+from src.models import CommandResult, DeviceInfo, ScreenshotResult
+
+
+class TestCommandResult:
+    def test_success(self):
+        r = CommandResult(success=True, stdout="ok", stderr="", returncode=0)
+        assert r.success is True
+        assert r.returncode == 0
+
+    def test_failure(self):
+        r = CommandResult(success=False, stdout="", stderr="err", returncode=1)
+        assert r.success is False
+        assert r.stderr == "err"
+
+    def test_defaults(self):
+        r = CommandResult(success=True, returncode=0)
+        assert r.stdout == ""
+        assert r.stderr == ""
+
+    def test_model_copy(self):
+        r = CommandResult(success=True, stdout="ok", stderr="", returncode=0)
+        r2 = r.model_copy(update={"success": False, "stderr": "changed"})
+        assert r2.success is False
+        assert r2.stderr == "changed"
+        assert r.success is True  # original unchanged
+
+
+class TestDeviceInfo:
+    def test_basic(self):
+        d = DeviceInfo(device_id="ABC123", status="device")
+        assert d.device_id == "ABC123"
+        assert d.model is None
+
+    def test_full(self):
+        d = DeviceInfo(
+            device_id="ABC123",
+            status="device",
+            model="Pixel_6",
+            product="oriole",
+        )
+        assert d.model == "Pixel_6"
+        dump = d.model_dump()
+        assert dump["product"] == "oriole"
+
+
+class TestScreenshotResult:
+    def test_success(self):
+        r = ScreenshotResult(success=True, local_path="/tmp/shot.png")
+        assert r.local_path == "/tmp/shot.png"
+
+    def test_failure(self):
+        r = ScreenshotResult(success=False, error="No device")
+        assert r.error == "No device"
+        assert r.local_path is None
diff --git a/tests/test_screenshot.py b/tests/test_screenshot.py
new file mode 100644
index 0000000..880a9fa
--- /dev/null
+++ b/tests/test_screenshot.py
@@ -0,0 +1,132 @@
+"""Tests for screenshot mixin (capture, screen size, density, record)."""
+
+import pytest
+
+from tests.conftest import fail, ok
+
+
+class TestScreenshot:
+    async def test_capture(self, server, ctx, tmp_path, monkeypatch):
+        from src.config import get_config
+
+        get_config().default_screenshot_dir = str(tmp_path)
+        server.run_shell_args.return_value = ok()
+        server.run_adb.return_value = ok()
+        result = await server.screenshot(ctx, filename="test.png")
+        assert result.success is True
+        assert result.local_path is not None
+        assert "test.png" in result.local_path
+
+    async def test_capture_failure(self, server, ctx):
+        server.run_shell_args.return_value = fail("no screen")
+        result = await server.screenshot(ctx)
+        assert result.success is False
+        assert result.error is not None
+
+    async def test_pull_failure(self, server, ctx):
+        server.run_shell_args.return_value = ok()
+        server.run_adb.return_value = fail("pull failed")
+        result = await server.screenshot(ctx)
+        assert result.success is False
+
+
+class TestScreenSize:
+    async def test_physical(self, server):
+        server.run_shell_args.return_value = ok(stdout="Physical size: 1080x1920")
+        result = await server.screen_size()
+        assert result["success"] is True
+        assert result["width"] == 1080
+        assert result["height"] == 1920
+
+    async def test_override(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout="Physical size: 1080x1920\nOverride size: 720x1280"
+        )
+        result = await server.screen_size()
+        assert result["success"] is True
+        # Should parse the first match
+        assert result["width"] == 1080
+
+    async def test_failure(self, server):
+        server.run_shell_args.return_value = fail("error")
+        result = await server.screen_size()
+        assert result["success"] is False
+
+
+class TestScreenDensity:
+    async def test_density(self, server):
+        server.run_shell_args.return_value = ok(stdout="Physical density: 420")
+        result = await server.screen_density()
+        assert result["success"] is True
+        assert result["dpi"] == 420
+
+    async def test_failure(self, server):
+        server.run_shell_args.return_value = fail("error")
+        result = await server.screen_density()
+        assert result["success"] is False
+
+
+class TestScreenOnOff:
+    async def test_screen_on(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.screen_on()
+        assert result["success"] is True
+        assert result["action"] == "screen_on"
+
+    async def test_screen_off(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.screen_off()
+        assert result["action"] == "screen_off"
+
+
+class TestScreenRecord:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_record(self, server, ctx, tmp_path):
+        from src.config import get_config
+
+        get_config().default_screenshot_dir = str(tmp_path)
+        server.run_shell_args.side_effect = [ok(), ok()]  # record + rm
+        server.run_adb.return_value = ok()  # pull
+        result = await server.screen_record(
+            ctx,
+            filename="test.mp4",
+            duration_seconds=5,
+        )
+        assert result["success"] is True
+        assert result["duration_seconds"] == 5
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_duration_capped(self, server, ctx, tmp_path):
+        from src.config import get_config
+
+        get_config().default_screenshot_dir = str(tmp_path)
+        server.run_shell_args.side_effect = [ok(), ok()]
+        server.run_adb.return_value = ok()
+        result = await server.screen_record(ctx, duration_seconds=999)
+        assert result["duration_seconds"] == 180  # Capped at 180
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.screen_record(ctx)
+        assert result["success"] is False
+
+
+class TestScreenSetSize:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_set(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.screen_set_size(720, 1280)
+        assert result["success"] is True
+        assert result["width"] == 720
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_reset(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.screen_reset_size()
+        assert result["success"] is True
+        assert result["action"] == "reset_size"
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.screen_set_size(720, 1280)
+        assert result["success"] is False
diff --git a/tests/test_server.py b/tests/test_server.py
new file mode 100644
index 0000000..dfd633b
--- /dev/null
+++ b/tests/test_server.py
@@ -0,0 +1,36 @@
+"""Tests for server-level tools (config, help resource)."""
+
+
+class TestConfigStatus:
+    async def test_status(self, server):
+        result = await server.config_status()
+        assert "developer_mode" in result
+        assert "auto_select_single_device" in result
+        assert "current_device" in result
+
+    async def test_reflects_current_device(self, server):
+        server.set_current_device("ABC123")
+        result = await server.config_status()
+        assert result["current_device"] == "ABC123"
+
+
+class TestConfigSetDeveloperMode:
+    async def test_enable(self, server):
+        result = await server.config_set_developer_mode(True)
+        assert result["success"] is True
+        assert result["developer_mode"] is True
+
+    async def test_disable(self, server):
+        result = await server.config_set_developer_mode(False)
+        assert result["developer_mode"] is False
+
+
+class TestConfigSetScreenshotDir:
+    async def test_set(self, server):
+        result = await server.config_set_screenshot_dir("/tmp/shots")
+        assert result["success"] is True
+        assert result["screenshot_dir"] == "/tmp/shots"
+
+    async def test_clear(self, server):
+        result = await server.config_set_screenshot_dir(None)
+        assert result["screenshot_dir"] is None
diff --git a/tests/test_settings.py b/tests/test_settings.py
new file mode 100644
index 0000000..37b1f10
--- /dev/null
+++ b/tests/test_settings.py
@@ -0,0 +1,391 @@
+"""Tests for settings mixin (settings, toggles, notifications, clipboard, media)."""
+
+import pytest
+
+from src.mixins.settings import _MEDIA_KEYCODES, SettingsMixin
+from tests.conftest import fail, ok
+
+
+class TestSettingsGet:
+    async def test_valid(self, server):
+        server.run_shell_args.return_value = ok(stdout="1")
+        result = await server.settings_get("global", "wifi_on")
+        assert result["success"] is True
+        assert result["value"] == "1"
+        assert result["exists"] is True
+
+    async def test_null_value(self, server):
+        server.run_shell_args.return_value = ok(stdout="null")
+        result = await server.settings_get("global", "missing_key")
+        assert result["success"] is True
+        assert result["value"] is None
+        assert result["exists"] is False
+
+    async def test_invalid_namespace(self, server):
+        result = await server.settings_get("invalid", "key")
+        assert result["success"] is False
+        assert "Invalid namespace" in result["error"]
+
+    async def test_invalid_key(self, server):
+        result = await server.settings_get("global", "bad key!")
+        assert result["success"] is False
+        assert "Invalid key" in result["error"]
+
+    async def test_all_namespaces_valid(self, server):
+        server.run_shell_args.return_value = ok(stdout="value")
+        for ns in ("system", "global", "secure"):
+            result = await server.settings_get(ns, "test_key")
+            assert result["success"] is True
+
+    async def test_key_with_dots(self, server):
+        server.run_shell_args.return_value = ok(stdout="value")
+        result = await server.settings_get("global", "wifi.scan_always_enabled")
+        assert result["success"] is True
+
+
+class TestSettingsPut:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_write_and_verify(self, server, ctx):
+        server.run_shell_args.side_effect = [ok(), ok(stdout="128")]
+        result = await server.settings_put(ctx, "system", "screen_brightness", "128")
+        assert result["success"] is True
+        assert result["readback"] == "128"
+        assert result["verified"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_invalid_namespace(self, server, ctx):
+        result = await server.settings_put(ctx, "bad", "key", "val")
+        assert result["success"] is False
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_invalid_key(self, server, ctx):
+        result = await server.settings_put(ctx, "global", "k;ey", "val")
+        assert result["success"] is False
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_secure_namespace_elicits(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, write setting")
+        server.run_shell_args.side_effect = [ok(), ok(stdout="val")]
+        result = await server.settings_put(ctx, "secure", "key", "val")
+        assert result["success"] is True
+        # Verify elicitation happened
+        assert any("secure" in msg for _, msg in ctx.messages)
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_secure_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.settings_put(ctx, "secure", "key", "val")
+        assert result["success"] is False
+        assert result.get("cancelled") is True
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.settings_put(ctx, "system", "k", "v")
+        assert result["success"] is False
+
+
+class TestWifiToggle:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_enable(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout="1")]
+        result = await server.wifi_toggle(True)
+        assert result["success"] is True
+        assert result["action"] == "enable"
+        assert result["verified"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_disable(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout="0")]
+        result = await server.wifi_toggle(False)
+        assert result["action"] == "disable"
+        assert result["verified"] is True
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.wifi_toggle(True)
+        assert result["success"] is False
+
+
+class TestBluetoothToggle:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_enable(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.bluetooth_toggle(True)
+        assert result["success"] is True
+        assert result["action"] == "enable"
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.bluetooth_toggle(False)
+        assert result["success"] is False
+
+
+class TestAirplaneModeToggle:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_enable_usb_device(self, server, ctx):
+        ctx.set_elicit("accept", "Yes, enable airplane mode")
+        server.run_shell_args.side_effect = [ok(), ok()]
+        result = await server.airplane_mode_toggle(ctx, True)
+        assert result["success"] is True
+        assert result["airplane_mode"] is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_enable_network_device_warns(self, server, ctx):
+        server.set_current_device("10.20.0.25:5555")
+        ctx.set_elicit("accept", "Yes, enable airplane mode")
+        server.run_shell_args.side_effect = [ok(), ok()]
+        result = await server.airplane_mode_toggle(ctx, True)
+        assert result["success"] is True
+        # Should have warned about network disconnection
+        warns = [msg for level, msg in ctx.messages if "sever" in msg.lower()]
+        assert len(warns) > 0
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_cancelled(self, server, ctx):
+        ctx.set_elicit("accept", "Cancel")
+        result = await server.airplane_mode_toggle(ctx, True)
+        assert result["success"] is False
+        assert result.get("cancelled") is True
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_disable_no_elicitation(self, server, ctx):
+        server.run_shell_args.side_effect = [ok(), ok()]
+        result = await server.airplane_mode_toggle(ctx, False)
+        assert result["success"] is True
+        # No elicitation for disable
+        elicits = [m for level, m in ctx.messages if level == "elicit"]
+        assert len(elicits) == 0
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server, ctx):
+        result = await server.airplane_mode_toggle(ctx, True)
+        assert result["success"] is False
+
+
+class TestScreenBrightness:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_set(self, server):
+        server.run_shell_args.side_effect = [ok(), ok()]
+        result = await server.screen_brightness(128)
+        assert result["success"] is True
+        assert result["brightness"] == 128
+        assert result["auto_brightness"] is False
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_out_of_range(self, server):
+        result = await server.screen_brightness(300)
+        assert result["success"] is False
+        assert "0-255" in result["error"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_negative(self, server):
+        result = await server.screen_brightness(-1)
+        assert result["success"] is False
+
+    @pytest.mark.usefixtures("_no_dev_mode")
+    async def test_requires_dev_mode(self, server):
+        result = await server.screen_brightness(128)
+        assert result["success"] is False
+
+
+class TestScreenTimeout:
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_set(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.screen_timeout(30)
+        assert result["success"] is True
+        assert result["timeout_seconds"] == 30
+        assert result["timeout_ms"] == 30000
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_too_large(self, server):
+        result = await server.screen_timeout(9999)
+        assert result["success"] is False
+        assert "1-1800" in result["error"]
+
+    @pytest.mark.usefixtures("_dev_mode")
+    async def test_zero(self, server):
+        result = await server.screen_timeout(0)
+        assert result["success"] is False
+
+
+class TestNotificationList:
+    async def test_parse_notifications(self, server):
+        dumpsys_output = """
+  NotificationRecord(0x1234 pkg=com.example.app)
+    extras {
+      android.title=Test Title
+      android.text=Test message body
+    }
+    postTime=1700000000000
+  NotificationRecord(0x5678 pkg=com.other.app)
+    extras {
+      android.title=Second
+      android.text=Another notification
+    }
+    postTime=1700000001000
+"""
+        server.run_shell_args.return_value = ok(stdout=dumpsys_output)
+        result = await server.notification_list()
+        assert result["success"] is True
+        assert result["count"] == 2
+        assert result["notifications"][0]["package"] == "com.example.app"
+        assert result["notifications"][0]["title"] == "Test Title"
+        assert result["notifications"][0]["text"] == "Test message body"
+
+    async def test_limit(self, server):
+        # Build output with many notifications
+        lines = []
+        for i in range(10):
+            lines.append(f"  NotificationRecord(0x{i:04x} pkg=com.app{i})")
+            lines.append(f"    android.title=Title {i}")
+        server.run_shell_args.return_value = ok(stdout="\n".join(lines))
+        result = await server.notification_list(limit=3)
+        assert result["count"] <= 3
+
+    async def test_empty(self, server):
+        server.run_shell_args.return_value = ok(stdout="")
+        result = await server.notification_list()
+        assert result["success"] is True
+        assert result["count"] == 0
+
+
+class TestClipboardGet:
+    async def test_parses_parcel(self, server):
+        # Build parcel programmatically with correct encoding
+        server.run_shell_args.return_value = ok(stdout=_build_parcel("hello world"))
+        result = await server.clipboard_get()
+        assert result["success"] is True
+        assert result["text"] == "hello world"
+
+    async def test_empty_clipboard(self, server):
+        server.run_shell_args.return_value = ok(
+            stdout="Result: Parcel(00000000 00000000 '........')"
+        )
+        result = await server.clipboard_get()
+        # No text/plain marker = not parseable
+        assert result["success"] is False
+
+    async def test_failure(self, server):
+        server.run_shell_args.return_value = fail("error")
+        result = await server.clipboard_get()
+        assert result["success"] is False
+
+
+def _build_parcel(text: str) -> str:
+    """Build a fake service call parcel output containing clipboard text.
+
+    Mimics the format of `service call clipboard 4` output with a
+    ClipData Parcel containing text/plain MIME type and UTF-8 text.
+    """
+    import struct
+
+    parts = []
+    # Status word (0 = success)
+    parts.append(struct.pack("<I", 0))
+    # Non-null marker
+    parts.append(struct.pack("<I", 1))
+    # ClipDescription: label length = 0 (no label)
+    parts.append(struct.pack("<I", 0))
+    # MIME type count = 1
+    parts.append(struct.pack("<I", 1))
+    # MIME type "text/plain" in UTF-16LE with length prefix
+    mime = "text/plain"
+    mime_utf16 = mime.encode("utf-16-le")
+    parts.append(struct.pack("<I", len(mime)))
+    parts.append(mime_utf16)
+    # Pad to 4-byte boundary
+    pad = (4 - len(mime_utf16) % 4) % 4
+    parts.append(b"\x00" * pad)
+    # Extras (none), timestamps, flags
+    parts.append(struct.pack("<I", 0xFFFFFFFF))  # no extras
+    parts.append(struct.pack("<I", 0xFFFFFFFF))  # no extras
+    parts.append(struct.pack("<I", 0))  # flags
+    # Item count = 1
+    parts.append(struct.pack("<I", 1))
+    # CharSequence type marker
+    parts.append(struct.pack("<I", 0))
+    # Text as length-prefixed UTF-8
+    text_bytes = text.encode("utf-8")
+    parts.append(struct.pack("<I", len(text_bytes)))
+    parts.append(text_bytes)
+    pad = (4 - len(text_bytes) % 4) % 4
+    parts.append(b"\x00" * pad)
+
+    data = b"".join(parts)
+
+    # Format as hex words like real parcel output
+    hex_lines = []
+    for i in range(0, len(data), 16):
+        chunk = data[i : i + 16]
+        words = []
+        for j in range(0, len(chunk), 4):
+            word = chunk[j : j + 4].ljust(4, b"\x00")
+            words.append(int.from_bytes(word, "little"))
+        hex_str = " ".join(f"{w:08x}" for w in words)
+        hex_lines.append(f"  0x{i:08x}: {hex_str} '...'")
+
+    return "Result: Parcel(\n" + "\n".join(hex_lines) + "\n)"
+
+
+class TestParseClipboardParcel:
+    """Direct tests for the static parcel parser."""
+
+    def test_valid_parcel(self):
+        raw = _build_parcel("test data here")
+        result = SettingsMixin._parse_clipboard_parcel(raw)
+        assert result == "test data here"
+
+    def test_nonzero_status(self):
+        raw = "Result: Parcel(00000001 '....')"
+        result = SettingsMixin._parse_clipboard_parcel(raw)
+        assert result is None
+
+    def test_no_hex_words(self):
+        result = SettingsMixin._parse_clipboard_parcel("no hex here")
+        assert result is None
+
+    def test_no_mime_marker(self):
+        raw = "Result: Parcel(00000000 00000001 '........')"
+        result = SettingsMixin._parse_clipboard_parcel(raw)
+        assert result is None
+
+    def test_long_text(self):
+        long_text = "The quick brown fox jumps over the lazy dog. " * 10
+        raw = _build_parcel(long_text)
+        result = SettingsMixin._parse_clipboard_parcel(raw)
+        assert result == long_text
+
+
+class TestMediaControl:
+    async def test_play(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.media_control("play")
+        assert result["success"] is True
+        assert result["action"] == "play"
+        assert result["keycode"] == "KEYCODE_MEDIA_PLAY"
+
+    async def test_all_actions(self, server):
+        server.run_shell_args.return_value = ok()
+        for action, keycode in _MEDIA_KEYCODES.items():
+            result = await server.media_control(action)
+            assert result["success"] is True
+            assert result["keycode"] == keycode
+
+    async def test_case_insensitive(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.media_control("PLAY")
+        assert result["success"] is True
+        assert result["action"] == "play"
+
+    async def test_unknown_action(self, server):
+        result = await server.media_control("rewind")
+        assert result["success"] is False
+        assert "Unknown action" in result["error"]
+        assert "play" in result["error"]  # Lists available actions
+
+    async def test_whitespace_stripped(self, server):
+        server.run_shell_args.return_value = ok()
+        result = await server.media_control("  pause  ")
+        assert result["success"] is True
+        assert result["action"] == "pause"
diff --git a/tests/test_ui.py b/tests/test_ui.py
new file mode 100644
index 0000000..17102e1
--- /dev/null
+++ b/tests/test_ui.py
@@ -0,0 +1,141 @@
+"""Tests for UI inspection mixin (dump, find, wait, tap_text)."""
+
+from tests.conftest import fail, ok
+
+SAMPLE_UI_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<hierarchy>
+  <node text="Settings" class="android.widget.TextView"
+        resource-id="com.android.settings:id/title"
+        bounds="[0,100][200,150]" clickable="true" focusable="true"
+        content-desc="" />
+  <node text="" class="android.widget.ImageView"
+        resource-id="com.android.settings:id/icon"
+        bounds="[0,50][48,98]" clickable="false" focusable="false"
+        content-desc="Settings icon" />
+  <node text="Wi-Fi" class="android.widget.TextView"
+        resource-id="com.android.settings:id/title"
+        bounds="[200,100][400,150]" clickable="true" focusable="false"
+        content-desc="" />
+</hierarchy>
+"""
+
+
+class TestUiDump:
+    async def test_dump(self, server, ctx):
+        server.run_shell_args.side_effect = [
+            ok(),  # uiautomator dump
+            ok(stdout=SAMPLE_UI_XML),  # cat
+            ok(),  # rm cleanup
+        ]
+        result = await server.ui_dump(ctx)
+        assert result["success"] is True
+        assert result["element_count"] >= 2  # Settings + Wi-Fi at minimum
+        assert "xml" in result
+
+    async def test_dump_failure(self, server, ctx):
+        server.run_shell_args.return_value = fail("error")
+        result = await server.ui_dump(ctx)
+        assert result["success"] is False
+
+
+class TestParseUiElements:
+    def test_parse_clickable(self, server):
+        elements = server._parse_ui_elements(SAMPLE_UI_XML)
+        texts = [e["text"] for e in elements]
+        assert "Settings" in texts
+        assert "Wi-Fi" in texts
+
+    def test_center_coordinates(self, server):
+        elements = server._parse_ui_elements(SAMPLE_UI_XML)
+        settings = [e for e in elements if e["text"] == "Settings"][0]
+        assert settings["center"] == {"x": 100, "y": 125}
+
+    def test_content_desc_included(self, server):
+        elements = server._parse_ui_elements(SAMPLE_UI_XML)
+        icon = [e for e in elements if e["content_desc"] == "Settings icon"]
+        assert len(icon) == 1
+
+    def test_empty_xml(self, server):
+        elements = server._parse_ui_elements("")
+        assert elements == []
+
+
+class TestUiFindElement:
+    async def test_find_by_text(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout=SAMPLE_UI_XML), ok()]
+        result = await server.ui_find_element(text="Settings")
+        assert result["success"] is True
+        assert result["count"] == 1
+        assert result["matches"][0]["text"] == "Settings"
+
+    async def test_find_by_resource_id(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout=SAMPLE_UI_XML), ok()]
+        result = await server.ui_find_element(resource_id="title")
+        # Settings and Wi-Fi both have "title" in their resource-id
+        assert result["count"] >= 2
+
+    async def test_not_found(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout=SAMPLE_UI_XML), ok()]
+        result = await server.ui_find_element(text="Missing")
+        assert result["success"] is True
+        assert result["count"] == 0
+
+
+class TestWaitForText:
+    async def test_found_immediately(self, server):
+        server.run_shell_args.side_effect = [ok(), ok(stdout=SAMPLE_UI_XML), ok()]
+        result = await server.wait_for_text("Settings", timeout_seconds=1)
+        assert result["success"] is True
+        assert result["found"] is True
+        assert result["attempts"] == 1
+
+    async def test_timeout(self, server):
+        server.run_shell_args.side_effect = [
+            ok(),
+            ok(stdout="<hierarchy></hierarchy>"),
+            ok(),
+        ] * 10
+        result = await server.wait_for_text(
+            "Missing", timeout_seconds=0.1, poll_interval=0.05
+        )
+        assert result["success"] is False
+        assert result["found"] is False
+
+
+class TestWaitForTextGone:
+    async def test_already_gone(self, server):
+        server.run_shell_args.side_effect = [
+            ok(),
+            ok(stdout="<hierarchy></hierarchy>"),
+            ok(),
+        ]
+        result = await server.wait_for_text_gone("Missing", timeout_seconds=1)
+        assert result["success"] is True
+        assert result["gone"] is True
+
+
+class TestTapText:
+    async def test_tap_found(self, server):
+        # find_element calls ui_dump which has 3 calls, then tap has 1
+        server.run_shell_args.side_effect = [
+            ok(),
+            ok(stdout=SAMPLE_UI_XML),
+            ok(),  # ui_dump for find
+            ok(),  # tap
+        ]
+        result = await server.tap_text("Settings")
+        assert result["success"] is True
+        assert result["coordinates"] == {"x": 100, "y": 125}
+
+    async def test_not_found(self, server):
+        server.run_shell_args.side_effect = [
+            ok(),
+            ok(stdout=SAMPLE_UI_XML),
+            ok(),  # first search by text
+            ok(),
+            ok(stdout=SAMPLE_UI_XML),
+            ok(),  # fallback search by content_desc
+        ]
+        result = await server.tap_text("NonExistent")
+        assert result["success"] is False
+        assert "No element found" in result["error"]