Fix enum concatenation especially in the media search endpoint

Author: rubengees

library/src/main/java/me/proxer/library/api/list/MediaSearchEndpoint.java

@@ -9,6 +9,7 @@
 import me.proxer.library.util.ProxerUtils;
 
 import javax.annotation.Nullable;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
 
@@ -88,21 +89,21 @@ public final class MediaSearchEndpoint implements PagingLimitEndpoint<List<Media
      */
     @Nullable
     @Setter
-    private Set<Genre> genres;
+    private EnumSet<Genre> genres;
 
     /**
      * Sets the excluded genres.
      */
     @Nullable
     @Setter
-    private Set<Genre> excludedGenres;
+    private EnumSet<Genre> excludedGenres;
 
     /**
      * Sets the required fsk ratings.
      */
     @Nullable
     @Setter
-    private Set<FskConstraint> fskConstraints;
+    private EnumSet<FskConstraint> fskConstraints;
 
     /**
      * {@inheritDoc}
@@ -156,9 +157,9 @@ public MediaSearchEndpoint excludedTags(@Nullable final Set<String> excludedIds)
 
     @Override
     public ProxerCall<List<MediaListEntry>> build() {
-        String joinedGenres = genres == null ? null : ProxerUtils.join(DELIMITER, genres);
-        String joinedExcludedGenres = excludedGenres == null ? null : ProxerUtils.join(DELIMITER, excludedGenres);
-        String joinedFskConstraints = fskConstraints == null ? null : ProxerUtils.join(DELIMITER, fskConstraints);
+        String joinedGenres = genres == null ? null : ProxerUtils.joinEnums(DELIMITER, genres);
+        String joinedExcludedGenres = excludedGenres == null ? null : ProxerUtils.joinEnums(DELIMITER, excludedGenres);
+        String joinedFskConstraints = fskConstraints == null ? null : ProxerUtils.joinEnums(DELIMITER, fskConstraints);
 
         return internalApi.mediaSearch(name, language, type, joinedGenres, joinedExcludedGenres, joinedFskConstraints,
                 sort, length, lengthBound, tags, excludedTags, tagRateFilter, tagSpoilerFilter, page, limit);

library/src/main/java/me/proxer/library/util/ProxerUtils.java

@@ -5,6 +5,8 @@
 
 import javax.annotation.Nullable;
 import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.EnumSet;
 import java.util.Iterator;
 
 /**
@@ -67,4 +69,21 @@ public String join(final String delimiter, final Iterable<?> iterable) {
 
         return builder.toString();
     }
+
+    /**
+     * Joins an Iterator of enums with a given delimiter to a {@link String} and returns the result.
+     * <p>
+     * For String conversion, the {@link #getApiEnumName(Enum)} method is used, so this method will only work with enums
+     * from this library.
+     */
+    @SuppressWarnings("checkstyle:designforextension") // Lombok makes it static.
+    public String joinEnums(final String delimiter, final EnumSet<?> enums) {
+        final ArrayList<String> convertedEnums = new ArrayList<>();
+
+        for (final Enum<?> value : enums) {
+            convertedEnums.add(ProxerUtils.getApiEnumName(value));
+        }
+
+        return join(delimiter, convertedEnums);
+    }
 }

library/src/test/java/me/proxer/library/api/list/MediaSearchEndpointTest.java

@@ -56,7 +56,7 @@ public void testPath() throws ProxerException, IOException, InterruptedException
                 .execute();
 
         assertThat(server.takeRequest().getPath()).isEqualTo("/api/v1/list/entrysearch?name=test&language=en&"
-                + "type=all-manga&genre=ACTION%2BADULT&nogenre=DRAMA%2BFANTASY&fsk=FEAR&sort=clicks&length=300&"
+                + "type=all-manga&genre=Action%2BAdult&nogenre=Drama%2BFantasy&fsk=fear&sort=clicks&length=300&"
                 + "length-limit=down&tags=3%2B7&notags=5%2B20&tagratefilter=rate_1&"
                 + "tagspoilerfilter=spoiler_1&p=3&limit=10");
     }

library/src/test/java/me/proxer/library/util/ProxerUtilsTest.java

@@ -7,6 +7,7 @@
 
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.EnumSet;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -45,6 +46,17 @@ public void testJoinEmpty() {
         assertThat(ProxerUtils.join(";", Collections.emptyList())).isEmpty();
     }
 
+    @Test
+    public void testJoinEnums() {
+        assertThat(ProxerUtils.joinEnums(";", EnumSet.of(Genre.ADVENTURE, Genre.ACTION, Genre.DRAMA)))
+                .isEqualTo("Abenteuer;Action;Drama");
+    }
+
+    @Test
+    public void testJoinEnumsEmpty() {
+        assertThat(ProxerUtils.joinEnums(";", EnumSet.noneOf(Genre.class))).isEmpty();
+    }
+
     @Test
     public void testIsUtilityClass() {
         PrivateConstructorChecker