Increase test coverage

Author: tech4bueno

tests/test_cli.py

@@ -0,0 +1,184 @@
+import argparse
+import os
+from unittest.mock import patch, MagicMock
+
+import pytest
+import pyvips
+
+from image_slicer.cli import main
+
+
+@pytest.fixture(scope="module")
+def test_image_path(tmpdir_factory):
+    """
+    Creates a temporary black PNG image for testing.
+    """
+    path = str(tmpdir_factory.mktemp("data").join("test_image.png"))
+    image = pyvips.Image.black(100, 85, bands=1)
+    image.write_to_file(path)
+    return path
+
+
+def test_main_with_grid_arguments(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with grid arguments.
+    """
+    output_dir = str(tmp_path / "output_cli_grid")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '--grid', '2', '3']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert len(files) == 6  # 2*3 = 6 tiles
+
+
+def test_main_with_number_of_tiles_argument(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with number of tiles argument.
+    """
+    output_dir = str(tmp_path / "output_cli_tiles")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '--number-of-tiles', '4']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert len(files) == 4
+
+
+def test_main_with_tile_size_arguments(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with tile size arguments.
+    """
+    output_dir = str(tmp_path / "output_cli_size")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '--tile-size', '50', '40']):
+        main()
+    
+    files = os.listdir(output_dir)
+    # 100/50 = 2 cols, 85/40 = 3 rows (rounded up) = 2*3 = 6 tiles
+    assert len(files) == 6
+
+
+def test_main_with_custom_format(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with custom naming format.
+    """
+    output_dir = str(tmp_path / "output_cli_format")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '--grid', '2', '2', 
+                           '--format', 'custom_{row}_{col}.jpg']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert 'custom_0_0.jpg' in files
+    assert 'custom_1_1.jpg' in files
+    assert len(files) == 4
+
+
+def test_main_with_short_arguments(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with short argument forms.
+    """
+    output_dir = str(tmp_path / "output_cli_short")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '-g', '3', '2']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert len(files) == 6  # 3*2 = 6 tiles
+
+
+def test_main_number_of_tiles_short_form(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with short form of number-of-tiles.
+    """
+    output_dir = str(tmp_path / "output_cli_n")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '-n', '9']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert len(files) == 9
+
+
+def test_main_tile_size_short_form(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with short form of tile-size.
+    """
+    output_dir = str(tmp_path / "output_cli_t")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '-t', '25', '30']):
+        main()
+    
+    files = os.listdir(output_dir)
+    # 100/25 = 4 cols, 85/30 = 3 rows (rounded up) = 4*3 = 12 tiles
+    assert len(files) == 12
+
+
+def test_main_custom_format_short_form(test_image_path, tmp_path):
+    """
+    Tests the CLI main function with short form of format.
+    """
+    output_dir = str(tmp_path / "output_cli_f")
+    
+    with patch('sys.argv', ['imslice', test_image_path, output_dir, '-g', '2', '2', 
+                           '-f', 'piece_{row}_{col}.png']):
+        main()
+    
+    files = os.listdir(output_dir)
+    assert 'piece_0_0.png' in files
+    assert 'piece_1_1.png' in files
+
+
+def test_main_missing_required_argument():
+    """
+    Tests that the CLI raises SystemExit when required mutually exclusive group is missing.
+    """
+    with patch('sys.argv', ['imslice', 'source.png', 'output_dir']):
+        with pytest.raises(SystemExit):
+            main()
+
+
+def test_main_conflicting_arguments():
+    """
+    Tests that the CLI raises SystemExit when mutually exclusive arguments are provided.
+    """
+    with patch('sys.argv', ['imslice', 'source.png', 'output_dir', 
+                           '--grid', '2', '2', '--number-of-tiles', '4']):
+        with pytest.raises(SystemExit):
+            main()
+
+
+def test_main_invalid_image_path(tmp_path):
+    """
+    Tests that the CLI handles invalid image paths gracefully.
+    """
+    output_dir = str(tmp_path / "output_cli_invalid")
+    
+    with patch('sys.argv', ['imslice', 'nonexistent.png', output_dir, '--grid', '2', '2']):
+        with pytest.raises(pyvips.Error):
+            main()
+
+
+def test_main_module_execution(test_image_path, tmp_path):
+    """
+    Tests the __main__ execution path of the CLI module.
+    """
+    import subprocess
+    import sys
+    
+    output_dir = str(tmp_path / "output_main_module")
+    
+    # Execute the CLI module directly via Python
+    result = subprocess.run([
+        sys.executable, '-m', 'image_slicer.cli',
+        test_image_path, output_dir, '--grid', '2', '2'
+    ], cwd='/Users/sam/image_slicer', env={'PYTHONPATH': 'src'}, 
+       capture_output=True, text=True)
+    
+    # Check that it executed successfully
+    assert result.returncode == 0
+    
+    # Check that files were created
+    files = os.listdir(output_dir)
+    assert len(files) == 4  # 2*2 = 4 tiles

tests/test_slicer.py

@@ -103,6 +103,12 @@ def test_get_grid_from_tiles_logic():
     """
     Tests the internal logic for calculating grid dimensions from tile count.
     """
+    # Test small numbers (edge cases)
+    assert _get_grid_from_tiles(1) == (1, 1)
+    assert _get_grid_from_tiles(2) == (1, 2)
+    assert _get_grid_from_tiles(3) == (1, 3)
+    
+    # Test larger numbers
     assert _get_grid_from_tiles(4) == (2, 2)
     assert _get_grid_from_tiles(6) == (2, 3)
     assert _get_grid_from_tiles(8) == (2, 4)
@@ -220,3 +226,25 @@ def test_naming_format(test_image_path, tmp_path):
     assert "slice_row0_col0.jpg" in files
     assert "slice_row1_col1.jpg" in files
     assert len(files) == 4
+
+
+def test_calculate_tile_dimensions_error_case(test_image_path):
+    """
+    Tests the error case in _calculate_tile_dimensions when insufficient parameters are provided.
+    """
+    slicer = ImageSlicer(test_image_path)
+    
+    # This should raise an error since neither tile_width/height nor cols/rows nor number_of_tiles are provided
+    with pytest.raises(ValueError, match="You must specify either"):
+        slicer._calculate_tile_dimensions()
+
+
+def test_generate_tiles_without_criteria_raises_error(test_image_path):
+    """
+    Tests that calling generate_tiles without any slicing criteria raises an error.
+    """
+    slicer = ImageSlicer(test_image_path)
+    
+    # This should match the error on line 195
+    with pytest.raises(ValueError, match="Slicing criteria not provided"):
+        list(slicer.generate_tiles())