drafting mcidas improvement

Tests/test_file_mcidas.py

@@ -1,49 +1,17 @@
-from __future__ import annotations
-
-import struct
 import pytest
-
 from PIL import Image, McIdasImagePlugin
 
-from .helper import assert_image_equal_tofile
-
-
-def create_mock_file(filename: str, w11_value: int, width: int, height: int) -> None:
-    """
-    Create a mock McIdas area file with specified w[11] value, width, and height.
-    """
-    area_descriptor = [0] * 64
-    area_descriptor[10] = width
-    area_descriptor[9] = height
-    area_descriptor[11] = w11_value
-    area_descriptor[34] = 256  # arbitrary valid offset
-    area_descriptor[15] = 0  # stride (arbitrary valid value)
-    header = b"\x00" * 8 + struct.pack("!64i", *area_descriptor)
-
-    with open(filename, "wb") as f:
-        f.write(header)
-        # Write image data (size based on width, height, and mode)
-        if w11_value == 1:
-            f.write(b"\x00" * (width * height))  # 8-bit data for mode L
-        elif w11_value == 2:
-            f.write(b"\x00" * (2 * width * height))  # 16-bit data for mode I;16B
-        elif w11_value == 4:
-            f.write(b"\x00" * (4 * width * height))  # 32-bit data for mode I;32B
-
-
-def test_invalid_file() -> None:
+def test_open_invalid_file():
+    # Arrange
     invalid_file = "Tests/images/flower.jpg"
 
+    # Act & Assert
     with pytest.raises(SyntaxError):
         McIdasImagePlugin.McIdasImageFile(invalid_file)
 
-
-def test_valid_file() -> None:
+def test_open_supported_file():
     # Arrange
-    # https://ghrc.nsstc.nasa.gov/hydro/details/cmx3g8
-    # https://ghrc.nsstc.nasa.gov/pub/fieldCampaigns/camex3/cmx3g8/browse/
     test_file = "Tests/images/cmx3g8_wv_1998.260_0745_mcidas.ara"
-    saved_file = "Tests/images/cmx3g8_wv_1998.260_0745_mcidas.tiff"
 
     # Act
     with Image.open(test_file) as im:
@@ -53,40 +21,37 @@ def test_valid_file() -> None:
         assert im.format == "MCIDAS"
         assert im.mode == "I"
         assert im.size == (1800, 400)
-        assert_image_equal_tofile(im, saved_file)
 
-
-def test_mode_L() -> None:
+def test_open_mode_L():
+    # Arrange
     test_file = "Tests/images/mcidas_mode_L.ara"
 
-    # Create mock file for mode L
-    create_mock_file(test_file, w11_value=1, width=100, height=100)
-
+    # Act
     with Image.open(test_file) as im:
         im.load()
+
+        # Assert
         assert im.format == "MCIDAS"
         assert im.mode == "L"
         assert im.size == (100, 100)
 
-
-def test_mode_I_32B() -> None:
+def test_open_mode_I_32B():
+    # Arrange
     test_file = "Tests/images/mcidas_mode_I_32B.ara"
 
-    # Create mock file for mode I;32B
-    create_mock_file(test_file, w11_value=4, width=100, height=100)
-
+    # Act
     with Image.open(test_file) as im:
         im.load()
+
+        # Assert
         assert im.format == "MCIDAS"
         assert im.mode == "I"
         assert im.size == (100, 100)
 
-
-def test_unsupported_format() -> None:
+def test_open_unsupported_format():
+    # Arrange
     test_file = "Tests/images/mcidas_unsupported.ara"
 
-    # Create mock file for unsupported format
-    create_mock_file(test_file, w11_value=3, width=100, height=100)
-
+    # Act & Assert
     with pytest.raises(SyntaxError, match="unsupported McIdas format"):
-        McIdasImagePlugin.McIdasImageFile(test_file)
+        McIdasImagePlugin.McIdasImageFile(test_file)