Made tests pass for plants not in zone

src/main/java/ch/zhaw/gartenverwaltung/io/JsonPlantDatabase.java

@@ -1,6 +1,5 @@
 package ch.zhaw.gartenverwaltung.io;
 
-import ch.zhaw.gartenverwaltung.types.GrowthPhase;
 import ch.zhaw.gartenverwaltung.types.HardinessZone;
 import ch.zhaw.gartenverwaltung.types.Plant;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -32,6 +31,7 @@ public class JsonPlantDatabase implements PlantDatabase {
      * Creating constant objects required to deserialize the {@link MonthDay} classes
      */
     private final static JavaTimeModule timeModule = new JavaTimeModule();
+
     static {
         DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("MM-dd");
         MonthDayDeserializer dateDeserializer = new MonthDayDeserializer(dateFormat);
@@ -82,21 +82,16 @@ public class JsonPlantDatabase implements PlantDatabase {
             List<Plant> result;
             result = mapper.readerForListOf(Plant.class).readValue(dataSource);
 
-            for (Plant plant : result) {
-                // for discussion because of failing tests:
-                // for(GrowthPhase growthPhase: plant.lifecycle()) {
-                //    if(growthPhase.zone()==zone) {
-                //      keep in result, remove if no match
-                //    }
-                // }
-                plant.inZone(currentZone);
-            }
-
-            // Turn list into a HashMap with structure id => Plant
             plantMap = result.stream()
+                    // Remove plants not in the current zone
+                    .filter(plant -> {
+                        plant.inZone(currentZone);
+                        return !plant.lifecycle().isEmpty();
+                    })
+                    // Create Hashmap from results
                     .collect(HashMap::new,
                             (res, plant) -> res.put(plant.id(), plant),
-                            (existing, replacement) -> { });
+                            (existing, replacement) -> {});
         }
     }
 }