Add comprehensive tests and docs for darkMode & hideSelectors

- Add 5 new Python tests for darkMode and hideSelectors parameters
- Update Node.js SDK README with darkMode/hideSelectors examples
- Update Python SDK README with darkMode/hideSelectors examples
- Add API reference entries for new parameters
- All tests passing: Node.js (19 tests), Python (22 tests)

Features already implemented in v0.7.0 but needed better test coverage and documentation.

sdk/node/README.md

@@ -72,6 +72,51 @@ const screenshot = await snap.capture({
 });
 ```
 
+### Dark Mode Capture
+
+```typescript
+// Capture in dark mode (prefers-color-scheme: dark)
+const darkScreenshot = await snap.capture({
+  url: 'https://example.com',
+  darkMode: true,
+  format: 'png',
+});
+```
+
+### Hide Elements Before Capture
+
+```typescript
+// Hide cookie banners, popups, ads
+const cleanScreenshot = await snap.capture({
+  url: 'https://example.com',
+  hideSelectors: [
+    '.cookie-banner',
+    '.popup-overlay', 
+    '#advertisement',
+    '.tracking-notice'
+  ],
+});
+
+// Hide single element
+const singleHide = await snap.capture('https://example.com', {
+  hideSelectors: '.newsletter-popup',
+});
+```
+
+### Combined Dark Mode + Element Hiding
+
+```typescript
+// Perfect for clean marketing screenshots
+const marketingShot = await snap.capture({
+  url: 'https://your-saas-app.com',
+  darkMode: true,
+  hideSelectors: ['.dev-banner', '.beta-notice'],
+  width: 1920,
+  height: 1080,
+  deviceScale: 2,
+});
+```
+
 ## API Reference
 
 ### `new SnapAPI(apiKey, config?)`
@@ -98,6 +143,8 @@ Returns a `Promise<Buffer>` containing the screenshot image.
 | `deviceScale` | `number` | `1` | Device pixel ratio (1–3) |
 | `delay` | `number` | `0` | Extra delay in ms (0–5000) |
 | `waitUntil` | `string` | `'domcontentloaded'` | Load event to wait for |
+| `darkMode` | `boolean` | `false` | Emulate prefers-color-scheme: dark |
+| `hideSelectors` | `string \| string[]` | — | CSS selectors to hide before capture |
 
 ### `snap.health()`
 

sdk/python/README.md

@@ -75,6 +75,52 @@ screenshot = snap.capture(
 )
 ```
 
+### Dark Mode Capture
+
+```python
+# Capture in dark mode (prefers-color-scheme: dark)
+dark_screenshot = snap.capture(
+    "https://example.com",
+    dark_mode=True,
+    format="png",
+)
+```
+
+### Hide Elements Before Capture
+
+```python
+# Hide cookie banners, popups, ads
+clean_screenshot = snap.capture(
+    "https://example.com",
+    hide_selectors=[
+        ".cookie-banner", 
+        ".popup-overlay",
+        "#advertisement",
+        ".tracking-notice"
+    ],
+)
+
+# Hide single element
+single_hide = snap.capture(
+    "https://example.com", 
+    hide_selectors=".newsletter-popup",
+)
+```
+
+### Combined Dark Mode + Element Hiding
+
+```python
+# Perfect for clean marketing screenshots
+marketing_shot = snap.capture(
+    "https://your-saas-app.com",
+    dark_mode=True,
+    hide_selectors=[".dev-banner", ".beta-notice"],
+    width=1920,
+    height=1080,
+    device_scale=2,
+)
+```
+
 ### Error Handling
 
 ```python
@@ -106,6 +152,8 @@ except SnapAPIError as e:
 | `device_scale` | `float` | `1` | Device pixel ratio (1–3) |
 | `delay` | `int` | `0` | Extra delay in ms (0–5000) |
 | `wait_until` | `str` | `"domcontentloaded"` | Load event |
+| `dark_mode` | `bool` | `False` | Emulate prefers-color-scheme: dark |
+| `hide_selectors` | `list` | — | CSS selectors to hide before capture |
 
 ### `snap.health() -> dict`
 

sdk/python/tests/test_snapapi.py

@@ -155,6 +155,91 @@ class TestSnapAPI(unittest.TestCase):
         self.assertEqual(request_body, expected_body)
         self.assertEqual(result, b'fake-image-data')
 
+    @patch('snapapi.client.urllib.request.urlopen')
+    def test_capture_with_dark_mode_parameter(self, mock_urlopen):
+        """capture with dark_mode parameter should work correctly."""
+        # Mock response
+        mock_response = Mock()
+        mock_response.read.return_value = b'fake-dark-image-data'
+        mock_response.__enter__ = Mock(return_value=mock_response)
+        mock_response.__exit__ = Mock(return_value=None)
+        mock_urlopen.return_value = mock_response
+
+        result = self.snap.capture(
+            url="https://example.com",
+            dark_mode=True
+        )
+
+        # Verify request body contains darkMode
+        request_arg = mock_urlopen.call_args[0][0]
+        request_body = json.loads(request_arg.data.decode())
+        
+        expected_body = {
+            "url": "https://example.com",
+            "darkMode": True
+        }
+        
+        self.assertEqual(request_body, expected_body)
+        self.assertEqual(result, b'fake-dark-image-data')
+
+    @patch('snapapi.client.urllib.request.urlopen')
+    def test_capture_with_hide_selectors_list_parameter(self, mock_urlopen):
+        """capture with hide_selectors as list should work correctly."""
+        # Mock response
+        mock_response = Mock()
+        mock_response.read.return_value = b'fake-clean-image-data'
+        mock_response.__enter__ = Mock(return_value=mock_response)
+        mock_response.__exit__ = Mock(return_value=None)
+        mock_urlopen.return_value = mock_response
+
+        result = self.snap.capture(
+            url="https://example.com",
+            hide_selectors=['.ads', '.popup', '#cookie-banner']
+        )
+
+        # Verify request body contains hideSelectors
+        request_arg = mock_urlopen.call_args[0][0]
+        request_body = json.loads(request_arg.data.decode())
+        
+        expected_body = {
+            "url": "https://example.com",
+            "hideSelectors": ['.ads', '.popup', '#cookie-banner']
+        }
+        
+        self.assertEqual(request_body, expected_body)
+        self.assertEqual(result, b'fake-clean-image-data')
+
+    @patch('snapapi.client.urllib.request.urlopen')
+    def test_capture_with_both_dark_mode_and_hide_selectors(self, mock_urlopen):
+        """capture with both dark_mode and hide_selectors should work correctly."""
+        # Mock response
+        mock_response = Mock()
+        mock_response.read.return_value = b'fake-dark-clean-image-data'
+        mock_response.__enter__ = Mock(return_value=mock_response)
+        mock_response.__exit__ = Mock(return_value=None)
+        mock_urlopen.return_value = mock_response
+
+        result = self.snap.capture(
+            url="https://example.com",
+            dark_mode=True,
+            hide_selectors=['.tracking', '.ads'],
+            format="png"
+        )
+
+        # Verify request body contains both parameters
+        request_arg = mock_urlopen.call_args[0][0]
+        request_body = json.loads(request_arg.data.decode())
+        
+        expected_body = {
+            "url": "https://example.com",
+            "darkMode": True,
+            "hideSelectors": ['.tracking', '.ads'],
+            "format": "png"
+        }
+        
+        self.assertEqual(request_body, expected_body)
+        self.assertEqual(result, b'fake-dark-clean-image-data')
+
     def test_capture_raises_value_error_if_no_url(self):
         """capture() should raise ValueError if no url provided."""
         with self.assertRaises(ValueError) as cm:
@@ -364,6 +449,40 @@ class TestScreenshotOptions(unittest.TestCase):
         expected = {"url": "https://example.com"}
         self.assertEqual(result, expected)
 
+    def test_to_dict_with_dark_mode_and_hide_selectors(self):
+        """to_dict() should correctly handle darkMode and hideSelectors."""
+        options = ScreenshotOptions(
+            url="https://example.com",
+            dark_mode=True,
+            hide_selectors=['.ads', '.popup', '#banner']
+        )
+        
+        result = options.to_dict()
+        
+        expected = {
+            "url": "https://example.com",
+            "darkMode": True,  # snake_case -> camelCase
+            "hideSelectors": ['.ads', '.popup', '#banner']  # snake_case -> camelCase
+        }
+        
+        self.assertEqual(result, expected)
+
+    def test_to_dict_with_dark_mode_false(self):
+        """to_dict() should include darkMode when explicitly set to False."""
+        options = ScreenshotOptions(
+            url="https://example.com",
+            dark_mode=False
+        )
+        
+        result = options.to_dict()
+        
+        expected = {
+            "url": "https://example.com",
+            "darkMode": False
+        }
+        
+        self.assertEqual(result, expected)
+
 
 class TestSnapAPIError(unittest.TestCase):
     """Test cases for SnapAPIError exception."""