test: added some tests for geohashToEnvelope Esri#213

src/test/java/com/esri/core/geometry/TestGeohash.java

@@ -0,0 +1,75 @@
+package com.esri.core.geometry;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class TestGeohash {
+
+    /**
+     * Check if the center of the new envelope is well placed
+     */
+    @Test
+    public void testGeohashToEnvelopeWellCentered(){
+        double delta = 0.00000001;
+
+        String geohash1 = "ghgh";
+
+        double lat1 = 72.50976563;
+        double lon1 =  -40.60546875;
+        Envelope2D env1 = Geohash.geohashToEnvelope(geohash1);
+        double centerX1 = (env1.xmax + env1.xmin)*0.5;
+        double centerY1 = (env1.ymax + env1.ymin)*0.5;
+
+        assertEquals(lon1, centerX1, delta);
+        assertEquals(lat1, centerY1, delta);
+
+        String geohash2 = "p";
+
+        double lat2 = -67.50000000; 
+        double lon2 =  157.50000000;
+        Envelope2D env2 = Geohash.geohashToEnvelope(geohash2);
+        double centerX2 = (env2.xmax + env2.xmin)*0.5;
+        double centerY2 = (env2.ymax + env2.ymin)*0.5;
+
+        assertEquals(lon2, centerX2, delta);
+        assertEquals(lat2, centerY2, delta);
+    }
+
+    /**
+     * Check if the dimension of the new envelope is correct for low precision
+     */
+    @Test
+    public void testGeohashToEnvelopeGoodDimensions(){
+        double delta = 0.00000001;
+
+        double latDiff = 180/4;
+        double lonDiff = 360/8;
+
+        String geohash = "h";
+
+        Envelope2D env = Geohash.geohashToEnvelope(geohash);
+
+        assertEquals(lonDiff, env.xmax-env.xmin, delta);
+        assertEquals(latDiff, env.ymax-env.ymin, delta);
+    }
+
+    /**
+     * Check if the dimension of the new envelope is correct for higher precision
+     */
+    @Test
+    public void testGeohashToEnvelopeGoodDimensions2(){
+        double delta = 0.00000001;
+
+        double latDiff = 180.0/32768;
+        double lonDiff = 360.0/32768;
+
+        String geohash = "hggggg";
+
+        Envelope2D env = Geohash.geohashToEnvelope(geohash);
+
+        assertEquals(lonDiff, env.xmax-env.xmin, delta);
+        assertEquals(latDiff, env.ymax-env.ymin, delta);
+    }
+
+}