Updated #256: avoids 200 when fields are empty

src/main/java/com/restcountries/controller/ControllerHelper.java

@@ -4,6 +4,11 @@ import com.restcountries.domain.ResponseEntity;
 import io.micronaut.http.HttpResponse;
 import jakarta.ws.rs.core.Response;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
 import static com.restcountries.utils.Constants.CACHE_CONTROL_VALUE;
 import static io.micronaut.http.HttpHeaders.CACHE_CONTROL;
 
@@ -80,4 +85,21 @@ public class ControllerHelper {
             )
     );
   }
+
+  protected static boolean hasValidFields(Optional<String> fields) {
+    if (fields.isEmpty()) {
+      return true;
+    }
+    var totalFields = Arrays
+            .stream(fields.get().split(","))
+            .toList()
+            .stream()
+            .map(String::trim)
+            .collect(Collectors.toCollection(ArrayList::new));
+    boolean isEmptyOrHasBlank = totalFields.isEmpty() || totalFields.stream().anyMatch(String::isEmpty);
+    if (isEmptyOrHasBlank || totalFields.size() > 10) {
+      return true;
+    }
+    return false;
+  }
 }

src/main/java/com/restcountries/controller/CountryControllerV2.java

@@ -20,6 +20,9 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
+
+import static com.restcountries.controller.ControllerHelper.hasValidFields;
 
 @Hidden
 @Controller("/v2/")
@@ -27,11 +30,7 @@ public class CountryControllerV2 {
 
   @Get(uri = "all", produces = MediaType.APPLICATION_JSON)
   public Object getAllCountries(@QueryValue("fields") Optional<String> fields) {
-    if (fields.isEmpty()) {
-      return ControllerHelper.badAllRequest();
-    }
-    var totalFields = fields.get().split(",").length;
-    if (totalFields > 10) {
+    if (hasValidFields(fields)) {
       return ControllerHelper.badAllRequest();
     }
     List<Country> countries = CountryServiceV2.getInstance().getAll();

src/main/java/com/restcountries/controller/CountryControllerV3.java

@@ -10,7 +10,12 @@ import io.micronaut.http.annotation.QueryValue;
 import io.swagger.v3.oas.annotations.Hidden;
 
 import javax.ws.rs.QueryParam;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Optional;
+import java.util.stream.Collectors;
+
+import static com.restcountries.controller.ControllerHelper.hasValidFields;
 
 @Hidden
 @Controller("/v3/")
@@ -18,11 +23,7 @@ public class CountryControllerV3 extends ControllerV3Helper {
 
   @Get(uri = "all", produces = MediaType.APPLICATION_JSON)
   public HttpResponse<Object> getAllCountries(@QueryValue("fields") Optional<String> fields) {
-    if (fields.isEmpty()) {
-      return ControllerHelper.badAllRequest();
-    }
-    var totalFields = fields.get().split(",").length;
-    if (totalFields > 10) {
+    if (hasValidFields(fields)) {
       return ControllerHelper.badAllRequest();
     }
     var countries = CountryServiceV3.getInstance().getAll();

src/main/java/com/restcountries/controller/CountryControllerV31.java

@@ -11,7 +11,12 @@ import io.swagger.v3.oas.annotations.media.Schema;
 
 import javax.ws.rs.QueryParam;
 import javax.ws.rs.core.Response;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Optional;
+import java.util.stream.Collectors;
+
+import static com.restcountries.controller.ControllerHelper.hasValidFields;
 
 @Controller("/v3.1/")
 public class CountryControllerV31 extends ControllerV3Helper {
@@ -19,11 +24,7 @@ public class CountryControllerV31 extends ControllerV3Helper {
     @Get(uri = "all", produces = MediaType.APPLICATION_JSON)
     @Schema(name = "RestCountries")
     public Object getAllCountries(@QueryValue("fields") Optional<String> fields) {
-        if (fields.isEmpty()) {
-            return ControllerHelper.badAllRequest();
-        }
-        var totalFields = fields.get().split(",").length;
-        if (totalFields > 10) {
+        if (hasValidFields(fields)) {
             return ControllerHelper.badAllRequest();
         }
         var countries = CountryServiceV31.getInstance().getAll();