Toggle legends on visualization via CLI or settings file (#43)

* Adding --hide-legends switch

* Make CLI provided --hide-legends override configured "hide_legends" settting

* Better cli test coverage

* Test that a hide_legends_override works

* CLI tested with actual testfile

README.md

@@ -94,6 +94,7 @@ options:
                         Specify the output path for the generated
                         graph image.
   --open-image          Open the generated image after visualization.
+  --hide-legends        Do not show legends in the visualization. (Default: False)
 ```
 
 ## Sample output

docs/sample_settingsfile.json

@@ -0,0 +1,8 @@
+{
+  "node_size": 40,
+  "edge_color": "blue",
+  "with_labels": true,
+  "font_size": 12,
+  "alpha": 0.6,
+  "hide_legends": false
+}

src/graphedexcel/cli.py

@@ -63,6 +63,15 @@ def parse_arguments():
         "--open-image",
         action="store_true",
         help="Open the generated image after visualization.",
+        default=False,
+    )
+
+    parser.add_argument(
+        "--hide-legends",
+        "-hl",
+        action="store_true",
+        help="Do not show legends in the visualization.",
+        default=None,
     )
 
     return parser.parse_args()
@@ -76,6 +85,8 @@ def main():
     # Check if the file exists
     if not os.path.exists(path_to_excel):
         logger.error(f"File not found: {path_to_excel}")
+        print(f"File not found: {path_to_excel}", file=sys.stderr)
+
         sys.exit(1)
 
     # Build the dependency graph and gather statistics
@@ -108,10 +119,12 @@ def main():
         filename = f"{base_name}_dependency_graph.png"
 
     # Visualize the dependency graph
-    visualize_dependency_graph(dependency_graph, filename, config_path, layout)
+    visualize_dependency_graph(
+        dependency_graph, filename, config_path, layout, args.hide_legends
+    )
 
     logger.info(f"Dependency graph image saved to {filename}.")
-
+    print(f"Dependency graph image saved to {filename}.")
     # Open the image file if requested
     if args.open_image:
         try:

src/graphedexcel/graph_visualizer.py

@@ -20,6 +20,7 @@
     "with_labels": False,  # whether to show the node labels
     "font_size": 10,  # the size of the node labels
     "cmap": "tab20b",  # the color map to use for coloring nodes
+    "hide_legends": False,  # whether to show the legend
 }
 
 # Sized-based settings for small, medium, and large graphs
@@ -146,6 +147,7 @@ def visualize_dependency_graph(
     output_path: str = None,
     config_path: str = None,
     layout: str = "spring",
+    hide_legends_override: bool = None,
 ):
     """
     Render the dependency graph using matplotlib and networkx.
@@ -158,6 +160,10 @@ def visualize_dependency_graph(
         f"Using the following settings for the graph visualization: {graph_settings}"
     )
 
+    hide_legends = graph_settings.pop("hide_legends")
+    if hide_legends_override is not None:
+        hide_legends = hide_legends_override
+
     fig_size = calculate_fig_size(len(graph.nodes))
     logger.info(f"Calculated figure size: {fig_size}")
 
@@ -195,7 +201,8 @@ def visualize_dependency_graph(
         **graph_settings,
     )
 
-    plt.legend(handles=legend_patches, title="Sheets", loc="upper left")
+    if not hide_legends:
+        plt.legend(handles=legend_patches, title="Sheets", loc="upper left")
 
     plt.savefig(output_path, bbox_inches="tight")
     plt.close()  # Close the figure to free memory

tests/test_cli.py

@@ -1,3 +1,6 @@
+import os
+import tempfile
+from openpyxl import Workbook
 import pytest
 import sys
 
@@ -6,6 +9,61 @@
 from unittest.mock import patch, MagicMock
 
 
+@pytest.fixture
+def create_excel_file(tmp_path):
+    def _create_excel_file(data):
+        file_path = tmp_path / "test.xlsx"
+        wb = Workbook()
+        for sheet_name, sheet_data in data.items():
+            ws = wb.create_sheet(title=sheet_name)
+            for row in sheet_data:
+                ws.append(row)
+        wb.save(file_path)
+        return file_path
+
+    return _create_excel_file
+
+
+# test cli.main
+def test_main():
+    # assert that main with no arguments raises SystemExit error
+    test_args = ["graphedexcel"]
+    with patch("sys.argv", test_args):
+        with pytest.raises(SystemExit):
+            main()
+
+
+def test_main_with_nonexistent_file(capsys):
+    test_args = ["graphedexcel", "nonexistent_file.xlsx"]
+    with patch("sys.argv", test_args):
+        with pytest.raises(SystemExit) as exc_info:
+            main()
+        assert exc_info.value.code != 0
+    captured = capsys.readouterr()
+    assert "File not found:" in captured.err
+
+
+def test_main_with_test_xlsx_file(capsys):
+    """Test main with a test excel file to exercise the cli module"""
+    with tempfile.NamedTemporaryFile(delete=False, suffix=".xlsx") as tmp_file:
+        test_file_path = tmp_file.name
+        try:
+            wb = Workbook()
+            ws = wb.active
+            ws["A1"] = "Test Data"
+
+            wb.save(test_file_path)
+            wb.close()
+            test_args = ["graphedexcel", test_file_path]
+            with patch("sys.argv", test_args):
+                main()
+        finally:
+            print("here")
+            wb.close()
+    captured = capsys.readouterr()
+    assert "Dependency graph image saved" in captured.out
+
+
 def test_parse_arguments_required(monkeypatch):
     """
     Test that the required positional argument is parsed correctly.
@@ -20,12 +78,19 @@ def test_parse_arguments_optional_flags():
     """
     Test that optional flags are parsed correctly.
     """
-    test_args = ["graphedexcel", "test.xlsx", "--as-directed-graph", "--no-visualize"]
+    test_args = [
+        "graphedexcel",
+        "test.xlsx",
+        "--as-directed-graph",
+        "--no-visualize",
+        "--hide-legends",
+    ]
     with patch("sys.argv", test_args):
         args = parse_arguments()
         assert args.path_to_excel == "test.xlsx"
         assert args.as_directed_graph is True
         assert args.no_visualize is True
+        assert args.hide_legends is True
 
 
 def test_parse_arguments_optional_arguments():
@@ -65,6 +130,7 @@ def test_parse_arguments_default_values():
         assert args.as_directed_graph is False
         assert args.no_visualize is False
         assert args.open_image is False
+        assert args.hide_legends is None
 
 
 def test_parse_arguments_invalid():

tests/test_graph_visualizer.py

@@ -109,6 +109,13 @@ def test_all_layouts():
         visualize_dependency_graph(G, layout=layout, output_path=layout + "_layout.png")
 
 
+def test_provided_hide_legends_override():
+    G = create_two_node_graph()
+    visualize_dependency_graph(
+        G, hide_legends_override=True, output_path="hide_legends.png"
+    )
+
+
 def test_unknown_layout_will_fallback():
     G = create_two_node_graph()
     visualize_dependency_graph(G, layout="nosuchlayout", output_path="nosuchlayout.png")