Add compliance test for nullability annotations

src/main/java/net/dv8tion/jda/annotations/UnknownNullability.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2015 Austin Keener, Michael Ritter, Florian Spieß, and the JDA contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dv8tion.jda.annotations;
+
+import java.lang.annotation.*;
+
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.METHOD})
+public @interface UnknownNullability
+{
+}

src/main/java/net/dv8tion/jda/api/JDA.java

@@ -186,11 +186,13 @@ public int getShardTotal()
          *
          * @return A String representing the information used to build this shard.
          */
+        @Nonnull
         public String getShardString()
         {
             return "[" + shardId + " / " + shardTotal + "]";
         }
 
+        @Nonnull
         @Override
         public String toString()
         {

src/main/java/net/dv8tion/jda/api/OnlineStatus.java

@@ -15,6 +15,8 @@
  */
 package net.dv8tion.jda.api;
 
+import javax.annotation.Nonnull;
+
 /**
  * Represents the online presence of a {@link net.dv8tion.jda.api.entities.Member Member}.
  */
@@ -63,6 +65,7 @@ public enum OnlineStatus
      *
      * @see    <a href="https://discord.com/developers/docs/topics/gateway#presence-update">PRESENCE_UPDATE</a>
      */
+    @Nonnull
     public String getKey()
     {
         return key;
@@ -77,7 +80,8 @@ public String getKey()
      *
      * @return The matching {@link net.dv8tion.jda.api.OnlineStatus OnlineStatus}. If there is no match, returns {@link net.dv8tion.jda.api.OnlineStatus#UNKNOWN UNKNOWN}.
      */
-    public static OnlineStatus fromKey(String key)
+    @Nonnull
+    public static OnlineStatus fromKey(@Nonnull String key)
     {
         for (OnlineStatus onlineStatus : values())
         {

src/main/java/net/dv8tion/jda/api/audit/ActionType.java

@@ -22,6 +22,8 @@
 import net.dv8tion.jda.api.entities.channel.middleman.GuildChannel;
 import net.dv8tion.jda.api.entities.emoji.RichCustomEmoji;
 
+import javax.annotation.Nonnull;
+
 /**
  * ActionTypes for {@link net.dv8tion.jda.api.audit.AuditLogEntry AuditLogEntry} instances
  * <br>Found via {@link net.dv8tion.jda.api.audit.AuditLogEntry#getType() AuditLogEntry.getType()}
@@ -684,11 +686,13 @@ public int getKey()
      *
      * @return {@link net.dv8tion.jda.api.audit.TargetType TargetType}
      */
+    @Nonnull
     public TargetType getTargetType()
     {
         return target;
     }
 
+    @Nonnull
     public static ActionType from(int key)
     {
         for (ActionType type : values())

src/main/java/net/dv8tion/jda/api/audit/AuditLogKey.java

@@ -33,6 +33,8 @@
 import net.dv8tion.jda.api.entities.sticker.GuildSticker;
 import net.dv8tion.jda.internal.utils.EntityString;
 
+import javax.annotation.Nonnull;
+
 /**
  * Enum of possible/expected keys that can be provided
  * to {@link AuditLogEntry#getChangeByKey(AuditLogKey) AuditLogEntry.getChangeByKey(AuditLogEntry.AuditLogKey}.
@@ -686,11 +688,13 @@ public enum AuditLogKey
         this.key = key;
     }
 
+    @Nonnull
     public String getKey()
     {
         return key;
     }
 
+    @Nonnull
     @Override
     public String toString()
     {

src/main/java/net/dv8tion/jda/api/audit/AuditLogOption.java

@@ -18,6 +18,8 @@
 
 import net.dv8tion.jda.internal.utils.EntityString;
 
+import javax.annotation.Nonnull;
+
 /**
  * Enum constants for possible options
  * <br>Providing detailed description of possible occasions and expected types.
@@ -139,6 +141,7 @@ public enum AuditLogOption
      *
      * @return Key for this option
      */
+    @Nonnull
     public String getKey()
     {
         return key;

src/main/java/net/dv8tion/jda/api/entities/ClientType.java

@@ -47,6 +47,7 @@ public enum ClientType
      *
      * @return The raw key
      */
+    @Nonnull
     public String getKey()
     {
         return key;

src/main/java/net/dv8tion/jda/api/entities/Entitlement.java

@@ -79,6 +79,7 @@ default String getApplicationId()
      *
      * @return The id of the user that purchased the {@link Entitlement Entitlement}
      */
+    @Nonnull
     default String getUserId()
     {
         return Long.toUnsignedString(getUserIdLong());

src/main/java/net/dv8tion/jda/api/entities/RichPresence.java

@@ -84,6 +84,7 @@ public interface RichPresence extends Activity
      * @see    ActivityFlag
      * @see    ActivityFlag#getFlags(int)
      */
+    @Nonnull
     EnumSet<ActivityFlag> getFlagSet();
 
     /**

src/main/java/net/dv8tion/jda/api/entities/channel/middleman/MessageChannel.java

@@ -1136,6 +1136,7 @@ default PollVotersPaginationAction retrievePollVotersById(long messageId, long a
      *
      * @return A {@link net.dv8tion.jda.api.entities.MessageHistory MessageHistory} related to this channel.
      */
+    @Nonnull
     default MessageHistory getHistory()
     {
         return new MessageHistory(this);

src/main/java/net/dv8tion/jda/api/entities/messages/MessagePoll.java

@@ -262,6 +262,7 @@ public int getKey()
          *
          * @return The layout type or {@link #UNKNOWN}
          */
+        @Nonnull
         public static LayoutType fromKey(int key)
         {
             for (LayoutType type : values())

src/main/java/net/dv8tion/jda/api/entities/templates/TemplateChannel.java

@@ -89,6 +89,7 @@ public long getIdLong()
      * @throws java.lang.UnsupportedOperationException
      *         The date of creation cannot be calculated.
      */
+    @Nonnull
     @Override
     public OffsetDateTime getTimeCreated()
     {
@@ -341,6 +342,7 @@ public long getIdLong()
          * @throws java.lang.UnsupportedOperationException
          *         The date of creation cannot be calculated.
          */
+        @Nonnull
         @Override
         public OffsetDateTime getTimeCreated()
         {

src/main/java/net/dv8tion/jda/api/entities/templates/TemplateRole.java

@@ -66,6 +66,7 @@ public long getIdLong()
      * @throws java.lang.UnsupportedOperationException
      *         The date of creation cannot be calculated.
      */
+    @Nonnull
     @Override
     public OffsetDateTime getTimeCreated()
     {

src/main/java/net/dv8tion/jda/api/events/guild/member/GuildMemberRoleRemoveEvent.java

@@ -54,6 +54,7 @@ public GuildMemberRoleRemoveEvent(@Nonnull JDA api, long responseNumber, @Nonnul
      *
      * @return The removed roles
      */
+    @Nonnull
     public List<Role> getRoles()
     {
         return removedRoles;

src/main/java/net/dv8tion/jda/api/exceptions/ErrorResponseException.java

@@ -95,6 +95,7 @@ public boolean isServerError()
      *
      * @return Never-null meaning of this error.
      */
+    @Nonnull
     public String getMeaning()
     {
         return meaning;
@@ -118,6 +119,7 @@ public int getErrorCode()
      *
      * @return {@link net.dv8tion.jda.api.requests.ErrorResponse ErrorResponse}
      */
+    @Nonnull
     public ErrorResponse getErrorResponse()
     {
         return errorResponse;
@@ -128,6 +130,7 @@ public ErrorResponse getErrorResponse()
      *
      * @return {@link net.dv8tion.jda.api.requests.Response Response}
      */
+    @Nonnull
     public Response getResponse()
     {
         return response;
@@ -145,12 +148,14 @@ public List<SchemaError> getSchemaErrors()
         return schemaErrors;
     }
 
-    public static ErrorResponseException create(String message, ErrorResponseException cause)
+    @Nonnull
+    public static ErrorResponseException create(@Nonnull String message, @Nonnull ErrorResponseException cause)
     {
         return new ErrorResponseException(message, cause);
     }
 
-    public static ErrorResponseException create(ErrorResponse errorResponse, Response response)
+    @Nonnull
+    public static ErrorResponseException create(@Nonnull ErrorResponse errorResponse, @Nonnull Response response)
     {
         String meaning = errorResponse.getMeaning();
         int code = errorResponse.getCode();

src/main/java/net/dv8tion/jda/api/exceptions/RateLimitedException.java

@@ -19,6 +19,8 @@
 import net.dv8tion.jda.api.requests.Route;
 import net.dv8tion.jda.internal.utils.Helpers;
 
+import javax.annotation.Nonnull;
+
 /**
  * Indicates that we received a {@code 429: Too Many Requests} response
  */
@@ -45,6 +47,7 @@ public RateLimitedException(String route, long retryAfter)
      *
      * @return The corresponding route
      */
+    @Nonnull
     public String getRateLimitedRoute()
     {
         return rateLimitedRoute;

src/main/java/net/dv8tion/jda/api/interactions/commands/Command.java

@@ -426,6 +426,7 @@ public String getName()
          *
          * @return The Choice instance, for chaining
          */
+        @Nonnull
         public Choice setName(@Nonnull String name)
         {
             checkName(name);

src/main/java/net/dv8tion/jda/api/interactions/commands/CommandInteractionPayload.java

@@ -16,6 +16,7 @@
 
 package net.dv8tion.jda.api.interactions.commands;
 
+import net.dv8tion.jda.annotations.UnknownNullability;
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.entities.Guild;
 import net.dv8tion.jda.api.entities.Member;
@@ -24,6 +25,7 @@
 import net.dv8tion.jda.api.interactions.Interaction;
 import net.dv8tion.jda.api.interactions.commands.build.CommandData;
 import net.dv8tion.jda.internal.utils.Checks;
+import org.jetbrains.annotations.Contract;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -410,6 +412,7 @@ default <T> T getOption(@Nonnull String name, @Nonnull Function<? super OptionMa
      * @see    #getOption(String, Function)
      * @see    #getOption(String, Supplier, Function)
      */
+    @Contract("_,null,_->null")
     default <T> T getOption(@Nonnull String name,
                             @Nullable T fallback,
                             @Nonnull Function<? super OptionMapping, ? extends T> resolver)
@@ -459,6 +462,7 @@ default <T> T getOption(@Nonnull String name,
      * @see    #getOption(String, Function)
      * @see    #getOption(String, Object, Function)
      */
+    @UnknownNullability
     default <T> T getOption(@Nonnull String name,
                             @Nullable Supplier<? extends T> fallback,
                             @Nonnull Function<? super OptionMapping, ? extends T> resolver)

src/main/java/net/dv8tion/jda/api/requests/RestAction.java

@@ -16,6 +16,7 @@
 
 package net.dv8tion.jda.api.requests;
 
+import net.dv8tion.jda.annotations.UnknownNullability;
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.exceptions.ContextException;
 import net.dv8tion.jda.api.exceptions.RateLimitedException;
@@ -630,6 +631,7 @@ default void queue(@Nullable Consumer<? super T> success)
      * @return The response value
      */
     @Blocking
+    @UnknownNullability
     default T complete()
     {
         try
@@ -664,6 +666,7 @@ default T complete()
      * @return The response value
      */
     @Blocking
+    @UnknownNullability
     T complete(boolean shouldQueue) throws RateLimitedException;
 
     /**
@@ -1361,6 +1364,7 @@ default DelayedCompletableFuture<T> submitAfter(long delay, @Nonnull TimeUnit un
      * @return The response value
      */
     @Blocking
+    @UnknownNullability
     default T completeAfter(long delay, @Nonnull TimeUnit unit)
     {
         Checks.notNull(unit, "TimeUnit");

src/main/java/net/dv8tion/jda/api/requests/SequentialRestRateLimiter.java

@@ -450,6 +450,7 @@ else if (isStopped)
             });
         }
 
+        @Nonnull
         public Queue<Work> getRequests()
         {
             return requests;

src/main/java/net/dv8tion/jda/api/requests/restaction/pagination/PaginationAction.java

@@ -678,6 +678,7 @@ default CompletableFuture<?> forEachRemainingAsync(@Nonnull final Procedure<? su
     @Blocking
     void forEachRemaining(@Nonnull final Procedure<? super T> action);
 
+    @Nonnull
     @Override
     @Blocking
     default Spliterator<T> spliterator()
@@ -790,7 +791,9 @@ public boolean hasNext()
             return false;
         }
 
+        @Nonnull
         @Override
+        @SuppressWarnings("DataFlowIssue")
         public E next()
         {
             if (!hasNext())

src/main/java/net/dv8tion/jda/api/sharding/DefaultShardManager.java

@@ -252,6 +252,7 @@ public int getShardsTotal()
     }
 
     @Override
+    @Nullable
     public Guild getGuildById(long id)
     {
         int shardId = MiscUtil.getShardForGuild(id, getShardsTotal());

src/main/java/net/dv8tion/jda/api/utils/Compression.java

@@ -16,6 +16,8 @@
 
 package net.dv8tion.jda.api.utils;
 
+import javax.annotation.Nonnull;
+
 /**
  * Compression algorithms that can be used with JDA.
  *
@@ -41,6 +43,7 @@ public enum Compression
      *
      * @return The query key
      */
+    @Nonnull
     public String getKey()
     {
         return key;

src/main/java/net/dv8tion/jda/api/utils/IOFunction.java

@@ -16,6 +16,8 @@
 
 package net.dv8tion.jda.api.utils;
 
+import net.dv8tion.jda.annotations.UnknownNullability;
+
 import java.io.IOException;
 
 /**
@@ -27,5 +29,6 @@
 @FunctionalInterface
 public interface IOFunction<T, R>
 {
+    @UnknownNullability
     R apply(T t) throws IOException;
 }