✅ Add unit tests for xcassets image processing

.github/workflows/kivy_ios.yml

@@ -19,6 +19,29 @@ jobs:
         pip install tox>=2.0
         tox -e pep8
 
+  # Unit tests for the Python side of kivy-ios (e.g. tools/external/xcassets.py).
+  # Runs on Ubuntu on purpose: it's cheap/fast and the absence of macOS binaries
+  # like `sips` forces tests to be hermetic (proper mocking). macOS integration
+  # coverage stays in the build_python3_kivy* jobs below.
+  unit_tests:
+    name: Unit tests (Ubuntu)
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout kivy-ios
+      uses: actions/checkout@v5
+    - name: Set up Python 3.x
+      uses: actions/setup-python@v6
+      with:
+        python-version: '3.x'
+    - name: Install kivy-ios and test dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e .
+        pip install pytest
+    - name: Run pytest
+      run: |
+        pytest tests/tools -v
+
   build_python3_kivy:
     runs-on: ${{ matrix.runs_on }}
     strategy:

tests/tools/external/test_xcassets.py

@@ -0,0 +1,171 @@
+"""Unit tests for kivy_ios.tools.external.xcassets.
+
+These cover the Python-side pieces that can be exercised without macOS's
+`sips` binary: the Pillow-based `_buildimage` (used by launch images) and
+the argument list built by `_generate` for the sips invocation.
+"""
+from os.path import join
+from unittest.mock import patch
+
+from PIL import Image
+
+from kivy_ios.tools.external import xcassets
+
+
+def _save_palette_png(path):
+    """Write a tiny palette-mode ("P") PNG — triggers the original crash."""
+    im = Image.new("P", (20, 20), color=5)
+    palette = []
+    for i in range(256):
+        palette.extend((i, i, i))
+    im.putpalette(palette)
+    im.save(path)
+
+
+def _save_rgb_png(path, size=(20, 20), color=(10, 20, 30)):
+    Image.new("RGB", size, color).save(path)
+
+
+class TestBuildImage:
+    def test_palette_mode_does_not_crash(self, tmp_path):
+        """Palette-mode PNGs must not raise, regression for PR #994.
+
+        Before the `.convert("RGBA")` fix, `im.getpixel((0, 0))` returns an
+        int for "P" mode and `bgcolor[:3]` raises TypeError.
+        """
+        src = tmp_path / "in.png"
+        dst = tmp_path / "out.png"
+        _save_palette_png(str(src))
+
+        xcassets._buildimage(str(src), str(dst), [100, 100])
+
+        assert dst.exists()
+        with Image.open(dst) as out:
+            assert out.size == (100, 100)
+            assert out.mode == "RGB"
+
+    def test_rgb_centers_and_pads(self, tmp_path):
+        """RGB source smaller than target is centered on a bg-color canvas."""
+        src = tmp_path / "in.png"
+        dst = tmp_path / "out.png"
+        _save_rgb_png(str(src), size=(10, 10), color=(10, 20, 30))
+
+        xcassets._buildimage(str(src), str(dst), [30, 30])
+
+        with Image.open(dst) as out:
+            assert out.size == (30, 30)
+            assert out.getpixel((0, 0)) == (10, 20, 30)
+            assert out.getpixel((15, 15)) == (10, 20, 30)
+
+    def test_resizes_oversized_source(self, tmp_path):
+        """Source larger than target is scaled down preserving aspect ratio."""
+        src = tmp_path / "in.png"
+        dst = tmp_path / "out.png"
+        _save_rgb_png(str(src), size=(200, 100))
+
+        xcassets._buildimage(str(src), str(dst), [50, 50])
+
+        with Image.open(dst) as out:
+            assert out.size == (50, 50)
+
+    def test_accepts_list_size(self, tmp_path):
+        """`size` arrives as a list from _generate — Image.new wants a tuple.
+
+        Regression for the `tuple(size)` hunk in PR #994.
+        """
+        src = tmp_path / "in.png"
+        dst = tmp_path / "out.png"
+        _save_rgb_png(str(src))
+
+        xcassets._buildimage(str(src), str(dst), [40, 40])
+        assert dst.exists()
+
+
+class TestGenerateIcon:
+    def test_forces_exact_dimensions(self, tmp_path):
+        """Icon generation must call sips with `-z H W`, not `-Z max`.
+
+        Apple rejects non-square icons. The old `-Z` only bounded the
+        largest side and kept aspect ratio, producing rectangular output
+        for rectangular sources. PR #994 switches to `-z c c` to force an
+        exact square.
+        """
+        image_xcassets = tmp_path
+        (image_xcassets / "AppIcon.appiconset").mkdir()
+
+        options = (("120", None, "Icon120.png"),)
+        src_image = tmp_path / "src.png"
+        _save_rgb_png(str(src_image))
+
+        with patch.object(xcassets.sh, "sips", create=True) as mock_sips:
+            xcassets._generate(
+                "AppIcon.appiconset",
+                str(image_xcassets),
+                str(src_image),
+                options,
+                icon=True,
+            )
+
+        mock_sips.assert_called_once()
+        args = mock_sips.call_args.args
+
+        assert "-z" in args, f"expected -z flag, got: {args}"
+        assert "-Z" not in args, f"legacy -Z flag still present: {args}"
+
+        z_index = args.index("-z")
+        assert args[z_index + 1] == "120"
+        assert args[z_index + 2] == "120"
+
+        assert "--out" in args
+        out_index = args.index("--out")
+        assert args[out_index + 1] == join(
+            str(image_xcassets), "AppIcon.appiconset", "Icon120.png"
+        )
+
+    def test_uses_in_fn_when_provided(self, tmp_path):
+        """When `in_fn` is set, sips reads from the already-generated larger
+        icon in the appiconset dir rather than the user-provided source."""
+        image_xcassets = tmp_path
+        (image_xcassets / "AppIcon.appiconset").mkdir()
+
+        options = (("60", "Icon120.png", "Icon60.png"),)
+        src_image = tmp_path / "src.png"
+        _save_rgb_png(str(src_image))
+
+        with patch.object(xcassets.sh, "sips", create=True) as mock_sips:
+            xcassets._generate(
+                "AppIcon.appiconset",
+                str(image_xcassets),
+                str(src_image),
+                options,
+                icon=True,
+            )
+
+        args = mock_sips.call_args.args
+        assert args[0] == join(
+            str(image_xcassets), "AppIcon.appiconset", "Icon120.png"
+        )
+
+
+class TestGenerateLaunchImage:
+    def test_calls_buildimage(self, tmp_path):
+        """Non-icon path skips sips and routes through Pillow-based _buildimage."""
+        image_xcassets = tmp_path
+        (image_xcassets / "LaunchImage.launchimage").mkdir()
+
+        options = (("40 30", None, "Default40x30.png"),)
+        src_image = tmp_path / "src.png"
+        _save_rgb_png(str(src_image), size=(10, 10))
+
+        xcassets._generate(
+            "LaunchImage.launchimage",
+            str(image_xcassets),
+            str(src_image),
+            options,
+            icon=False,
+        )
+
+        out = image_xcassets / "LaunchImage.launchimage" / "Default40x30.png"
+        assert out.exists()
+        with Image.open(out) as im:
+            assert im.size == (40, 30)