A long time ago, in a galaxy far far away...

tests/test_workflow_modules.py

@@ -6,6 +6,10 @@ from pathlib import Path
 import pytest
 
 from imagepipeline.core.params import validate_params
+from imagepipeline.modules.color_to_alpha import (
+    ColorToAlphaModule,
+    build_color_to_alpha_args,
+)
 from imagepipeline.modules.composite import CompositeModule
 from imagepipeline.modules.crop_square import CropSquareModule
 from imagepipeline.modules.darktable_style import DarktableStyleModule
@@ -14,6 +18,10 @@ from imagepipeline.modules.imagemagick_fill import (
     build_fill_arguments,
 )
 from imagepipeline.modules.imagemagick_grayscale import ImageMagickGrayscale
+from imagepipeline.modules.imagemagick_resize import (
+    ImageMagickResizeModule,
+    build_resize_arguments,
+)
 from imagepipeline.modules.gmic_grayscale import GmicGrayscale
 from imagepipeline.modules.registry import get_module, list_modules
 from imagepipeline.modules.rembg import RembgModule
@@ -31,6 +39,8 @@ class TestModuleRegistration:
             "darktable_style",
             "imagemagick_grayscale",
             "imagemagick_fill",
+            "color_to_alpha",
+            "imagemagick_resize",
             "crop_square",
         ):
             assert name in names
@@ -42,6 +52,85 @@ class TestModuleRegistration:
         assert get_module("darktable_style") is DarktableStyleModule
         assert get_module("crop_square") is CropSquareModule
         assert get_module("imagemagick_fill") is ImageMagickFillModule
+        assert get_module("color_to_alpha") is ColorToAlphaModule
+
+
+class TestImageMagickResize:
+    def test_build_resize_arguments(self) -> None:
+        assert build_resize_arguments(max_edge=2000) == [
+            "-auto-orient",
+            "-resize",
+            "2000x2000>",
+        ]
+
+    def test_rejects_non_positive_max_edge(self) -> None:
+        with pytest.raises(ValueError, match="positive"):
+            build_resize_arguments(max_edge=0)
+
+    def test_default_max_edge(self) -> None:
+        params = ImageMagickResizeModule.validate_module_params({})
+        assert params["max_edge"] == 2000
+
+
+class TestColorToAlpha:
+    def test_build_args_exact(self) -> None:
+        assert build_color_to_alpha_args(color="#00ff00", fuzz=0.0) == [
+            "-alpha",
+            "on",
+            "-transparent",
+            "#00ff00",
+        ]
+
+    def test_build_args_with_fuzz(self) -> None:
+        assert build_color_to_alpha_args(color="ffffff", fuzz=2.5) == [
+            "-alpha",
+            "on",
+            "-fuzz",
+            "2.5%",
+            "-transparent",
+            "#ffffff",
+        ]
+
+    def test_requires_color(self) -> None:
+        with pytest.raises(ValueError, match="required"):
+            ColorToAlphaModule.validate_module_params({})
+
+    @pytest.mark.skipif(not has_magick, reason="ImageMagick not installed")
+    def test_makes_matching_color_transparent(self, tmp_path: Path) -> None:
+        from imagepipeline.core.context import ModuleContext
+        from imagepipeline.utils.subprocess import run_command
+
+        src = tmp_path / "green.png"
+        output_dir = tmp_path / "out"
+        output_dir.mkdir()
+        magick = shutil.which("magick") or shutil.which("convert")
+        run_command([magick, "-size", "8x8", "xc:#00ff00", str(src)])
+
+        ctx = ModuleContext(
+            input_paths=[src],
+            matched_groups=[],
+            output_dir=output_dir,
+            params=ColorToAlphaModule.validate_module_params({"color": "#00ff00"}),
+            pipeline_output_root=tmp_path,
+            step_id="color_to_alpha_01",
+            logger=None,
+        )
+        ColorToAlphaModule().run(ctx)
+
+        dst = output_dir / "green.png"
+        assert dst.is_file()
+        result = run_command(
+            [
+                magick,
+                str(dst),
+                "-alpha",
+                "extract",
+                "-format",
+                "%[fx:mean]",
+                "info:",
+            ]
+        )
+        assert float(result.stdout.strip()) == 0.0
 
 
 class TestImageMagickFill: