Add unit tests for the ImgLib2 <-> NDArray converters

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: ctrueden

src/test/java/org/scijava/plugins/scripting/appose/python/ConvertersTest.java

@@ -0,0 +1,134 @@
+/*
+ * #%L
+ * Python scripting language plugin to be used via scyjava.
+ * %%
+ * Copyright (C) 2021 - 2025 SciJava developers.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+
+package org.scijava.plugins.scripting.appose.python;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+
+import net.imglib2.appose.ShmImg;
+import net.imglib2.img.Img;
+import net.imglib2.img.array.ArrayImgs;
+import net.imglib2.img.planar.PlanarImg;
+import net.imglib2.type.numeric.integer.UnsignedByteType;
+import net.imglib2.type.numeric.real.FloatType;
+import net.imglib2.util.Intervals;
+import net.imglib2.view.Views;
+
+import org.apposed.appose.NDArray;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.scijava.Context;
+import org.scijava.convert.ConvertService;
+
+/**
+ * Tests {@link RAIToNDArrayConverter} and {@link NDArrayToImgConverter}.
+ *
+ * @author Curtis Rueden
+ */
+public class ConvertersTest {
+
+	private Context context;
+	private ConvertService convertService;
+
+	@Before
+	public void setUp() {
+		context = new Context();
+		convertService = context.service(ConvertService.class);
+	}
+
+	@After
+	public void tearDown() {
+		context.dispose();
+	}
+
+	@Test
+	public void testRoundTrip() {
+		final byte[] data = { 1, 2, 3, 4, 5, 6 };
+		final Img<UnsignedByteType> img = ArrayImgs.unsignedBytes(data, 3, 2);
+		assertTrue(convertService.supports(img, NDArray.class));
+
+		try (final NDArray nd = convertService.convert(img, NDArray.class)) {
+			assertNotNull(nd);
+			assertEquals(NDArray.DType.UINT8, nd.dType());
+			assertArrayEquals(new int[] { 3, 2 },
+				nd.shape().toIntArray(NDArray.Shape.Order.F_ORDER));
+
+			assertTrue(convertService.supports(nd, Img.class));
+			final Img<?> result = convertService.convert(nd, Img.class);
+			assertTrue(result instanceof PlanarImg);
+			assertTrue(result.firstElement() instanceof UnsignedByteType);
+			assertArrayEquals(new long[] { 3, 2 }, Intervals.dimensionsAsLongArray(result));
+			@SuppressWarnings("unchecked")
+			final Img<UnsignedByteType> typed = (Img<UnsignedByteType>) result;
+			int i = 0;
+			for (final UnsignedByteType t : Views.flatIterable(typed)) {
+				assertEquals(data[i++], t.get());
+			}
+		}
+	}
+
+	@Test
+	public void testConvertedImgOutlivesNDArray() {
+		final NDArray nd = convertService.convert(ArrayImgs.floats(
+			new float[] { 1.5f, -2 }, 2), NDArray.class);
+		@SuppressWarnings("unchecked")
+		final Img<FloatType> result = convertService.convert(nd, Img.class);
+		nd.close();
+		// The result is a copy, so it must remain usable after closing.
+		assertEquals(1.5f, result.firstElement().get(), 0);
+	}
+
+	@Test
+	public void testShmImgIsNotCopied() {
+		final ShmImg<UnsignedByteType> img =
+			ShmImg.copyOf(ArrayImgs.unsignedBytes(4, 4));
+		try (final NDArray nd = img.ndArray()) {
+			assertSame(nd, convertService.convert(img, NDArray.class));
+		}
+	}
+
+	@Test
+	public void testNonImagesAreNotConverted() {
+		for (final Object o : new Object[] { "text", 5, 2.5, true,
+			new File("x.tif"), new int[] { 1, 2, 3 } })
+		{
+			assertFalse(o.getClass().getName(),
+				convertService.supports(o, NDArray.class));
+		}
+	}
+}