Add comprehensive test coverage for BoundingBox, PointInImage, SNTColor, LinAlgUtils, StrahlerAnalyzer, and PathStatistics

src/test/java/sc/fiji/snt/analysis/PathStatisticsTest.java

@@ -0,0 +1,190 @@
+/*-
+ * #%L
+ * Fiji distribution of ImageJ for the life sciences.
+ * %%
+ * Copyright (C) 2010 - 2026 Fiji developers.
+ * %%
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public
+ * License along with this program.  If not, see
+ * <http://www.gnu.org/licenses/gpl-3.0.html>.
+ * #L%
+ */
+
+package sc.fiji.snt.analysis;
+
+import static org.junit.Assert.*;
+import static org.junit.Assume.assumeNotNull;
+
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import sc.fiji.snt.Path;
+import sc.fiji.snt.SNTService;
+import sc.fiji.snt.Tree;
+import sc.fiji.snt.util.PointInImage;
+
+/**
+ * Tests for {@link PathStatistics}.
+ */
+public class PathStatisticsTest {
+
+	private static final double DELTA = 1e-6;
+	private Tree tree;
+	private Path primaryPath;
+
+	@Before
+	public void setUp() {
+		tree = new SNTService().demoTree("fractal");
+		assumeNotNull(tree);
+		// Get the primary (root) path
+		final TreeStatistics tStats = new TreeStatistics(tree);
+		final List<Path> primaries = tStats.getPrimaryPaths();
+		assumeNotNull(primaries);
+		assertFalse(primaries.isEmpty());
+		primaryPath = primaries.get(0);
+	}
+
+	@Test
+	public void testConstructor_singlePath() {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		assertNotNull(stats);
+		assertEquals(1, stats.getNBranches());
+	}
+
+	@Test
+	public void testConstructor_pathCollection() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		assertNotNull(stats);
+		assertEquals(tree.size(), stats.getNBranches());
+	}
+
+	@Test
+	public void testGetBranches_count() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		assertEquals(tree.size(), stats.getBranches().size());
+	}
+
+	@Test
+	public void testGetNBranches() {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		assertEquals(1, stats.getNBranches());
+	}
+
+	@Test
+	public void testGetMetric_pathId_singlePath() throws UnknownMetricException {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		final Number id = stats.getMetric("Path ID");
+		assertNotNull(id);
+		assertEquals(primaryPath.getID(), id.intValue());
+	}
+
+	@Test
+	public void testGetMetric_pathId_multiPath() throws UnknownMetricException {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final Number id = stats.getMetric("Path ID");
+		assertTrue("Multi-path should return NaN for Path ID", Double.isNaN(id.doubleValue()));
+	}
+
+	@Test
+	public void testGetMetric_byPath_length() throws UnknownMetricException {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		final Number length = stats.getMetric(PathStatistics.PATH_LENGTH, primaryPath);
+		assertNotNull(length);
+		assertEquals(primaryPath.getLength(), length.doubleValue(), DELTA);
+	}
+
+	@Test
+	public void testGetMetric_byPath_nNodes() throws UnknownMetricException {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		final Number nNodes = stats.getMetric(PathStatistics.N_PATH_NODES, primaryPath);
+		assertNotNull(nNodes);
+		assertEquals(primaryPath.size(), nNodes.intValue());
+	}
+
+	@Test
+	public void testGetMetric_byPath_nChildren() throws UnknownMetricException {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		final Number nChildren = stats.getMetric(PathStatistics.N_CHILDREN, primaryPath);
+		assertNotNull(nChildren);
+		assertEquals(primaryPath.getChildren().size(), nChildren.intValue());
+	}
+
+	@Test
+	public void testGetPrimaryBranches_containsPrimary() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final List<Path> primaries = stats.getPrimaryBranches();
+		assertNotNull(primaries);
+		assertTrue(primaries.contains(primaryPath));
+	}
+
+	@Test
+	public void testGetTerminalBranches_nonEmpty() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final List<Path> terminals = stats.getTerminalBranches();
+		assertNotNull(terminals);
+		// In PathStatistics, terminal branches are those with children
+		for (final Path p : terminals) {
+			assertFalse("Terminal branch should have children", p.getChildren().isEmpty());
+		}
+	}
+
+	@Test
+	public void testGetInnerBranches_samePrimary() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		assertEquals(stats.getPrimaryBranches(), stats.getInnerBranches());
+	}
+
+	@Test
+	public void testGetPrimaryLength() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final double primaryLen = stats.getPrimaryLength();
+		assertTrue("Primary length should be >= 0", primaryLen >= 0);
+	}
+
+	@Test
+	public void testGetTerminalLength() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final double terminalLen = stats.getTerminalLength();
+		assertTrue("Terminal length should be >= 0", terminalLen >= 0);
+	}
+
+	@Test
+	public void testGetInnerLength_equalsGetPrimaryLength() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		assertEquals(stats.getPrimaryLength(), stats.getInnerLength(), DELTA);
+	}
+
+	@Test
+	public void testGetCableLength_multiPath() {
+		final PathStatistics stats = new PathStatistics(tree.list(), "test");
+		final double totalLength = tree.list().stream().mapToDouble(Path::getLength).sum();
+		assertEquals("Cable length should equal sum of path lengths", totalLength, stats.getCableLength(), DELTA);
+	}
+
+	@Test
+	public void testSinglePathCableLength_matchesPathLength() {
+		final PathStatistics stats = new PathStatistics(primaryPath);
+		assertEquals(primaryPath.getLength(), stats.getCableLength(), DELTA);
+	}
+
+	@Test
+	public void testManualPathWithKnownLength() {
+		final Path p = new Path(1.0, 1.0, 1.0, "um");
+		p.addNode(new PointInImage(0, 0, 0));
+		p.addNode(new PointInImage(3, 4, 0));
+		final PathStatistics stats = new PathStatistics(p);
+		assertEquals(5.0, stats.getCableLength(), DELTA);
+	}
+}