Ask for the type of crossing for crossing=island (fixes #1637)

app/src/main/java/de/westnordost/streetcomplete/quests/crossing_type/AddCrossingType.kt

@@ -7,7 +7,7 @@ import de.westnordost.streetcomplete.data.osm.download.OverpassMapDataAndGeometr
 
 class AddCrossingType(o: OverpassMapDataAndGeometryDao) : SimpleOverpassQuestType<String>(o) {
 
-    override val tagFilters = "nodes with highway = crossing and !crossing"
+    override val tagFilters = "nodes with highway = crossing and (!crossing or crossing = island)"
     override val commitMessage = "Add crossing type"
     override val icon = R.drawable.ic_quest_pedestrian_crossing
 
@@ -16,6 +16,11 @@ class AddCrossingType(o: OverpassMapDataAndGeometryDao) : SimpleOverpassQuestTyp
     override fun createForm() = AddCrossingTypeForm()
 
     override fun applyAnswerTo(answer: String, changes: StringMapChangesBuilder) {
-        changes.add("crossing", answer)
+        if(changes.getPreviousValue("crossing") == "island") {
+            changes.modify("crossing", answer)
+            changes.addOrModify("crossing:island", "yes")
+        } else {
+            changes.add("crossing", answer)
+        }
     }
 }

app/src/test/java/de/westnordost/streetcomplete/quests/AddCrossingTypeTest.kt

@@ -0,0 +1,37 @@
+package de.westnordost.streetcomplete.quests
+
+import de.westnordost.streetcomplete.data.osm.changes.StringMapEntryAdd
+import de.westnordost.streetcomplete.data.osm.changes.StringMapEntryModify
+import de.westnordost.streetcomplete.mock
+import de.westnordost.streetcomplete.quests.crossing_type.AddCrossingType
+import org.junit.Test
+
+class AddCrossingTypeTest {
+
+    private val questType = AddCrossingType(mock())
+
+    @Test fun `apply normal answer`() {
+        questType.verifyAnswer(
+            "bla",
+            StringMapEntryAdd("crossing", "bla")
+        )
+    }
+
+    @Test fun `apply answer for crossing = island`() {
+        questType.verifyAnswer(
+            mapOf("crossing" to "island"),
+            "blub",
+            StringMapEntryModify("crossing", "island", "blub"),
+            StringMapEntryAdd("crossing:island", "yes")
+        )
+    }
+
+    @Test fun `apply answer for crossing = island and crossing_island set`() {
+        questType.verifyAnswer(
+            mapOf("crossing" to "island", "crossing:island" to "something"),
+            "blub",
+            StringMapEntryModify("crossing", "island", "blub"),
+            StringMapEntryModify("crossing:island", "something", "yes")
+        )
+    }
+}