Merge pull request databrickslabs#254 from databrickslabs/fix/duplica…

…ted_indexes

Fixed duplicated indexes

src/main/scala/com/databricks/labs/mosaic/core/Mosaic.scala

@@ -37,7 +37,7 @@ object Mosaic {
             }
 
         val coreIndices = indexSystem.polyfill(carvedGeometry, resolution, Some(geometryAPI))
-        val borderIndices = indexSystem.polyfill(borderGeometry, resolution, Some(geometryAPI))
+        val borderIndices = indexSystem.polyfill(borderGeometry, resolution, Some(geometryAPI)).diff(coreIndices)
 
         val coreChips = indexSystem.getCoreChips(coreIndices, keepCoreGeom, geometryAPI)
         val borderChips = indexSystem.getBorderChips(geometry, borderIndices, keepCoreGeom, geometryAPI)

src/test/scala/com/databricks/labs/mosaic/core/TestMosaic.scala

@@ -0,0 +1,17 @@
+package com.databricks.labs.mosaic.core
+
+import com.databricks.labs.mosaic.core.geometry.api.GeometryAPI.ESRI
+import com.databricks.labs.mosaic.core.index.H3IndexSystem
+import org.scalatest.funsuite.AnyFunSuite
+
+class TestMosaic extends AnyFunSuite {
+
+  test("mosaicFill should not return duplicates with H3") {
+    // This tests the fix for issue #243 https://github.com/databrickslabs/mosaic/issues/243
+    val geom = ESRI.geometry("POLYGON ((4.42 51.78, 4.38 51.78, 4.39 51.83, 4.40 51.83, 4.41 51.8303, 4.417 51.8295, 4.42 51.83, 4.44 51.81, 4.42 51.78))", "WKT")
+    val result = Mosaic.mosaicFill(geom, 7, true, H3IndexSystem, ESRI)
+
+    assert(result.length == 10)
+    assert(result.map(x => x.index).distinct.length == 10)
+  }
+}