Index: trunk/test/unit/org/openstreetmap/josm/data/validation/tests/SharpAnglesTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/data/validation/tests/SharpAnglesTest.java	(revision 15405)
+++ trunk/test/unit/org/openstreetmap/josm/data/validation/tests/SharpAnglesTest.java	(revision 15405)
@@ -0,0 +1,132 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.validation.tests;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.Node;
+import org.openstreetmap.josm.data.osm.Way;
+
+/**
+ * JUnit Test of the Sharp Angles validation test.
+ */
+
+public class SharpAnglesTest {
+    private SharpAngles angles;
+
+    /**
+     * Setup test.
+     * @throws Exception if an error occurs
+     */
+    @Before
+    public void setUp() throws Exception {
+        JOSMFixture.createUnitTestFixture().init();
+        angles = new SharpAngles();
+        angles.initialize();
+    }
+
+    /**
+     * Check a closed loop with no sharp angles
+     */
+    @Test
+    public void closedLoopNoSharpAngles() {
+        Way way = TestUtils.newWay("highway=residential",
+                new Node(new LatLon(0, 0)), new Node(new LatLon(0.1, 0.1)),
+                new Node(new LatLon(0.1, -0.2)), new Node(new LatLon(-0.1, -0.1)));
+        way.addNode(way.firstNode());
+        angles.visit(way);
+        Assert.assertEquals(0, angles.getErrors().size());
+    }
+
+    /**
+     * Check a closed loop with a sharp angle
+     */
+    @Test
+    public void closedLoopSharpAngles() {
+        Way way = TestUtils.newWay("highway=residential",
+                new Node(new LatLon(0, 0)), new Node(new LatLon(0.1, 0.1)),
+                new Node(new LatLon(0.1, -0.2)));
+        way.addNode(way.firstNode());
+        angles.setMaxLength(Double.MAX_VALUE);
+        angles.visit(way);
+        Assert.assertEquals(1, angles.getErrors().size());
+    }
+
+    /**
+     * Check a way for multiple sharp angles
+     */
+    @Test
+    public void testMultipleSharpAngles() {
+        Way way = TestUtils.newWay("highway=residential",
+                new Node(new LatLon(0.005069377713748322, -0.0014832642674429382)),
+                new Node(new LatLon(0.005021097951663415, 0.0008636686205880686)),
+                new Node(new LatLon(0.005085470967776624, -0.00013411313295197088)),
+                new Node(new LatLon(0.005031826787678042, 0.0020116540789620915)));
+        angles.setMaxLength(Double.MAX_VALUE);
+        angles.visit(way);
+        Assert.assertEquals(2, angles.getErrors().size());
+    }
+
+    /**
+     * Check for no sharp angles
+     */
+    @Test
+    public void testNoSharpAngles() {
+        Way way = TestUtils.newWay("highway=residential",
+                new Node(new LatLon(0, 0)), new Node(new LatLon(0.1, 0.1)),
+                new Node(new LatLon(0.2, 0.3)), new Node(new LatLon(0.3, 0.1)));
+        angles.visit(way);
+        Assert.assertEquals(0, angles.getErrors().size());
+    }
+
+    /**
+     * Ensure that we aren't accidentally using the same node twice.
+     * This was found during initial testing. See way 10041221 (on 20190914)
+     */
+    @Test
+    public void testCheckBadAnglesFromSameNodeTwice() {
+        Way way = TestUtils.newWay("highway=service oneway=yes",
+                new Node(new LatLon(52.8903308, 8.4302322)),
+                new Node(new LatLon(52.8902468, 8.4302138)),
+                new Node(new LatLon(52.8902191, 8.4302282)),
+                new Node(new LatLon(52.8901155, 8.4304753)),
+                new Node(new LatLon(52.8900669, 8.430763)),
+                new Node(new LatLon(52.8901138, 8.4308262)),
+                new Node(new LatLon(52.8902482, 8.4307568)));
+        way.addNode(way.firstNode());
+        angles.visit(way);
+        Assert.assertEquals(0, angles.getErrors().size());
+    }
+
+    /**
+     * Check that special cases are ignored
+     */
+    @Test
+    public void testIgnoredCases() {
+        Way way = TestUtils.newWay("highway=residential",
+                new Node(new LatLon(0, 0)), new Node(new LatLon(0.1, 0.1)),
+                new Node(new LatLon(0, 0.01)));
+        angles.setMaxLength(Double.MAX_VALUE);
+        angles.visit(way);
+        Assert.assertEquals(1, angles.getErrors().size());
+        angles.getErrors().clear();
+
+        way.put("highway", "rest_area");
+        angles.visit(way);
+        Assert.assertEquals(0, angles.getErrors().size());
+
+        way.put("highway", "residential");
+        angles.visit(way);
+        Assert.assertEquals(1, angles.getErrors().size());
+        angles.getErrors().clear();
+        way.put("area", "yes");
+        angles.visit(way);
+        Assert.assertEquals(0, angles.getErrors().size());
+        way.put("area", "no");
+        angles.visit(way);
+        Assert.assertEquals(1, angles.getErrors().size());
+    }
+}