added tests for vis styles

tests/test_vis_styles.py

@@ -0,0 +1,96 @@
+import pytest
+from networkcommons.visual._styles import get_styles, set_style_attributes, merge_styles
+
+
+class MockItem:
+    """
+    A simple mock class to simulate graph items (nodes or edges) for testing.
+    """
+
+    def __init__(self):
+        self.attr = {}
+
+
+def test_get_styles():
+    styles = get_styles()
+
+    # Check if the returned styles are as expected
+    assert isinstance(styles, dict), "Styles should be a dictionary."
+    assert 'default' in styles, "'default' should be a key in styles."
+    assert 'sign_consistent' in styles, "'sign_consistent' should be a key in styles."
+
+    # Check structure of a 'nodes' style
+    assert 'nodes' in styles['default'], "'nodes' should be a key in 'default' style."
+    assert 'sources' in styles['default']['nodes'], "'sources' should be a key in 'default.nodes' style."
+    assert 'color' in styles['default']['nodes']['sources'], "'color' should be a key in 'default.nodes.sources'."
+    assert styles['default']['nodes']['sources']['color'] == '#1f78b4', "Unexpected color for 'default.nodes.sources'."
+
+    # Check structure of an 'edges' style
+    assert 'edges' in styles['default'], "'edges' should be a key in 'default' style."
+    assert 'positive' in styles['default']['edges'], "'positive' should be a key in 'default.edges'."
+    assert styles['default']['edges']['positive'][
+               'color'] == '#33a02c', "Unexpected color for 'default.edges.positive'."
+
+
+def test_set_style_attributes():
+    item = MockItem()
+    base_style = {'color': 'blue', 'shape': 'circle'}
+    condition_style = {'color': 'red'}
+
+    # Apply base and condition styles to the item
+    result = set_style_attributes(item, base_style, condition_style)
+
+    # Check if the attributes were set correctly
+    assert result.attr['color'] == 'red', "Condition style should override base style for 'color'."
+    assert result.attr['shape'] == 'circle', "Base style 'shape' should be applied."
+
+    # Test when condition_style is None
+    item2 = MockItem()
+    result2 = set_style_attributes(item2, base_style)
+
+    assert result2.attr['color'] == 'blue', "Base style 'color' should be applied when no condition style."
+    assert result2.attr['shape'] == 'circle', "Base style 'shape' should be applied when no condition style."
+
+
+def test_merge_styles():
+    default_style = {
+        'nodes': {
+            'color': 'blue',
+            'shape': 'circle'
+        },
+        'edges': {
+            'color': 'gray',
+            'penwidth': 2
+        }
+    }
+
+    custom_style = {
+        'nodes': {
+            'color': 'red'
+        },
+        'edges': {
+            'penwidth': 3
+        }
+    }
+
+    merged = merge_styles(default_style, custom_style)
+
+    # Check if the merged style correctly reflects the custom style
+    assert merged['nodes']['color'] == 'red', "Custom style should override default 'color' for 'nodes'."
+    assert merged['nodes']['shape'] == 'circle', "'shape' should remain from default style."
+    assert merged['edges']['color'] == 'gray', "'color' for 'edges' should remain from default style."
+    assert merged['edges']['penwidth'] == 3, "Custom style should override 'penwidth' for 'edges'."
+
+    # Test missing keys handling (logging is ignored in this test)
+    custom_style_missing = {
+        'nodes': {
+            # Missing 'shape'
+            'color': 'red'
+        }
+    }
+
+    merged_missing = merge_styles(default_style, custom_style_missing)
+
+    assert merged_missing['nodes'][
+               'shape'] == 'circle', "'shape' should remain from default style when missing in custom."
+    assert merged_missing['nodes']['color'] == 'red', "Custom 'color' should still override the default."