chore: Updating JSpecify coverage

boms/test-utils/src/main/java/io/a2a/bom/test/DynamicBomVerifier.java

@@ -8,6 +8,7 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Base class for dynamically discovering and verifying all classes in a BOM can be loaded.
@@ -180,7 +181,7 @@ private boolean isForbidden(String relativePath) {
         return forbiddenPaths.stream().anyMatch(relativePath::startsWith);
     }
 
-    private static String extractClassName(Path javaFile) throws IOException {
+    private static @Nullable String extractClassName(Path javaFile) throws IOException {
         // Extract simple class name from filename
         String fileName = javaFile.getFileName().toString();
         if (!fileName.endsWith(".java")) {
@@ -198,11 +199,9 @@ private static String extractClassName(Path javaFile) throws IOException {
                     .findFirst()
                     .orElse(null);
         }
-
         if (packageName != null) {
             return packageName + "." + simpleClassName;
         }
-
         return null;
     }
 }

boms/test-utils/src/main/java/io/a2a/bom/test/package-info.java

@@ -0,0 +1,5 @@
+@NullMarked
+package io.a2a.bom.test;
+
+import org.jspecify.annotations.NullMarked;
+

common/src/main/java/io/a2a/common/package-info.java

@@ -0,0 +1,5 @@
+@NullMarked
+package io.a2a.common;
+
+import org.jspecify.annotations.NullMarked;
+

common/src/main/java/io/a2a/util/package-info.java

@@ -0,0 +1,5 @@
+@NullMarked
+package io.a2a.util;
+
+import org.jspecify.annotations.NullMarked;
+

pom.xml

@@ -69,6 +69,7 @@
         <error-prone.version>2.45.0</error-prone.version>
         <nullaway.version>0.12.14</nullaway.version>
         <error-prone.flag>-XDaddTypeAnnotationsToSymbol=true</error-prone.flag>
+        <nullaway.args>-Xplugin:ErrorProne -XepDisableAllChecks -Xep:NullAway:ERROR -Xep:RequireExplicitNullMarking:WARN -XepOpt:NullAway:ExhaustiveOverride=true -XepOpt:NullAway:OnlyNullMarked=true -XepOpt:NullAway:JSpecifyMode=true -XepExcludedPaths:.*/src/test/.* -XepDisableWarningsInGeneratedCode</nullaway.args>
 
         <!-- Redirect test output to file -->
         <maven.test.redirectTestOutputToFile>true</maven.test.redirectTestOutputToFile>
@@ -342,7 +343,7 @@
                             <arg>--should-stop=ifError=FLOW</arg>
                             <arg>-parameters</arg>
                             <arg>${error-prone.flag}</arg>
-                            <arg>-Xplugin:ErrorProne -XepDisableAllChecks -Xep:NullAway:ERROR -XepOpt:NullAway:OnlyNullMarked=true -XepOpt:NullAway:JSpecifyMode=true -XepExcludedPaths:.*/src/test/.* -XepDisableWarningsInGeneratedCode</arg>
+                            <arg>${nullaway.args}</arg>
                         </compilerArgs>
                         <annotationProcessorPaths>
                             <path>
@@ -554,6 +555,7 @@
                 <error-prone.version>2.42.0</error-prone.version>
                 <nullaway.version>0.12.10</nullaway.version>
                 <error-prone.flag></error-prone.flag>
+                <nullaway.args>-Xplugin:ErrorProne -XepDisableAllChecks -Xep:NullAway:ERROR -XepOpt:NullAway:OnlyNullMarked=true -XepOpt:NullAway:JSpecifyMode=true -XepExcludedPaths:.*/src/test/.* -XepDisableWarningsInGeneratedCode</nullaway.args>
                 <quarkus.jvm.args></quarkus.jvm.args>
             </properties>
         </profile>

reference/rest/src/main/java/io/a2a/server/rest/quarkus/A2AServerRoutes.java

@@ -369,12 +369,11 @@ public boolean isAuthenticated() {
                     }
 
                     @Override
-                    public @Nullable
-                    String getUsername() {
-                        if (rc.user() != null) {
+                    public String getUsername() {
+                        if (rc.user() != null && rc.user().subject() != null) {
                             return rc.user().subject();
                         }
-                        return null;
+                        return "";
                     }
                 };
             }

server-common/src/main/java/io/a2a/server/agentexecution/RequestContext.java

@@ -6,6 +6,8 @@
 import java.util.UUID;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
+
 import io.a2a.server.ServerCallContext;
 import io.a2a.spec.InvalidParamsError;
 import io.a2a.spec.Message;
@@ -17,20 +19,20 @@
 
 public class RequestContext {
 
-    private MessageSendParams params;
-    private String taskId;
-    private String contextId;
-    private Task task;
+    private @Nullable MessageSendParams params;
+    private @Nullable String taskId;
+    private @Nullable String contextId;
+    private @Nullable Task task;
     private List<Task> relatedTasks;
-    private final ServerCallContext callContext;
+    private final @Nullable ServerCallContext callContext;
 
     public RequestContext(
-            MessageSendParams params,
-            String taskId,
-            String contextId,
-            Task task,
-            List<Task> relatedTasks,
-            ServerCallContext callContext) throws InvalidParamsError {
+            @Nullable MessageSendParams params,
+            @Nullable String taskId,
+            @Nullable String contextId,
+            @Nullable Task task,
+            @Nullable List<Task> relatedTasks,
+            @Nullable ServerCallContext callContext) throws InvalidParamsError {
         this.params = params;
         this.taskId = taskId;
         this.contextId = contextId;
@@ -53,35 +55,35 @@ public RequestContext(
         }
     }
 
-    public MessageSendParams getParams() {
+    public @Nullable MessageSendParams getParams() {
         return params;
     }
 
-    public String getTaskId() {
+    public @Nullable String getTaskId() {
         return taskId;
     }
 
-    public String getContextId() {
+    public @Nullable String getContextId() {
         return contextId;
     }
 
-    public Task getTask() {
+    public @Nullable Task getTask() {
         return task;
     }
 
     public List<Task> getRelatedTasks() {
         return Collections.unmodifiableList(relatedTasks);
     }
 
-    public Message getMessage() {
+    public @Nullable Message getMessage() {
         return params != null ? params.message() : null;
     }
 
-    public MessageSendConfiguration getConfiguration() {
+    public @Nullable MessageSendConfiguration getConfiguration() {
         return params != null ? params.configuration() : null;
     }
 
-    public ServerCallContext getCallContext() {
+    public @Nullable ServerCallContext getCallContext() {
         return callContext;
     }
 
@@ -137,64 +139,64 @@ private List<String> getTextParts(List<Part<?>> parts) {
     }
 
     public static class Builder {
-        private MessageSendParams params;
-        private String taskId;
-        private String contextId;
-        private Task task;
-        private List<Task> relatedTasks;
-        private ServerCallContext serverCallContext;
-
-        public Builder setParams(MessageSendParams params) {
+        private @Nullable MessageSendParams params;
+        private @Nullable String taskId;
+        private @Nullable String contextId;
+        private @Nullable Task task;
+        private @Nullable List<Task> relatedTasks;
+        private @Nullable ServerCallContext serverCallContext;
+
+        public Builder setParams(@Nullable MessageSendParams params) {
             this.params = params;
             return this;
         }
 
-        public Builder setTaskId(String taskId) {
+        public Builder setTaskId(@Nullable String taskId) {
             this.taskId = taskId;
             return this;
         }
 
-        public Builder setContextId(String contextId) {
+        public Builder setContextId(@Nullable String contextId) {
             this.contextId = contextId;
             return this;
         }
 
-        public Builder setTask(Task task) {
+        public Builder setTask(@Nullable Task task) {
             this.task = task;
             return this;
         }
 
-        public Builder setRelatedTasks(List<Task> relatedTasks) {
+        public Builder setRelatedTasks(@Nullable List<Task> relatedTasks) {
             this.relatedTasks = relatedTasks;
             return this;
         }
 
-        public Builder setServerCallContext(ServerCallContext serverCallContext) {
+        public Builder setServerCallContext(@Nullable ServerCallContext serverCallContext) {
             this.serverCallContext = serverCallContext;
             return this;
         }
 
-        public MessageSendParams getParams() {
+        public @Nullable MessageSendParams getParams() {
             return params;
         }
 
-        public String getTaskId() {
+        public @Nullable String getTaskId() {
             return taskId;
         }
 
-        public String getContextId() {
+        public @Nullable String getContextId() {
             return contextId;
         }
 
-        public Task getTask() {
+        public @Nullable Task getTask() {
             return task;
         }
 
-        public List<Task> getRelatedTasks() {
+        public @Nullable List<Task> getRelatedTasks() {
             return relatedTasks;
         }
 
-        public ServerCallContext getServerCallContext() {
+        public @Nullable ServerCallContext getServerCallContext() {
             return serverCallContext;
         }
 

server-common/src/main/java/io/a2a/server/agentexecution/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.a2a.server.agentexecution;
+
+import org.jspecify.annotations.NullMarked;

server-common/src/main/java/io/a2a/server/auth/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.a2a.server.auth;
+
+import org.jspecify.annotations.NullMarked;

server-common/src/main/java/io/a2a/server/config/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.a2a.server.config;
+
+import org.jspecify.annotations.NullMarked;

server-common/src/main/java/io/a2a/server/events/EnhancedRunnable.java

@@ -3,11 +3,13 @@
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 
+import org.jspecify.annotations.Nullable;
+
 public abstract class EnhancedRunnable implements Runnable {
-    private volatile Throwable error;
+    private volatile @Nullable Throwable error;
     private final List<DoneCallback> doneCallbacks = new CopyOnWriteArrayList<>();
 
-    public Throwable getError() {
+    public @Nullable Throwable getError() {
         return error;
     }
 

server-common/src/main/java/io/a2a/server/events/EventConsumer.java

@@ -2,6 +2,8 @@
 
 import java.util.concurrent.Flow;
 
+import org.jspecify.annotations.Nullable;
+
 import io.a2a.spec.A2AServerException;
 import io.a2a.spec.Event;
 import io.a2a.spec.Message;
@@ -16,7 +18,7 @@
 public class EventConsumer {
     private static final Logger LOGGER = LoggerFactory.getLogger(EventConsumer.class);
     private final EventQueue queue;
-    private Throwable error;
+    private volatile @Nullable Throwable error;
 
     private static final String ERROR_MSG = "Agent did not return any response";
     private static final int NO_WAIT = -1;

server-common/src/main/java/io/a2a/server/events/EventQueue.java

@@ -9,6 +9,8 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import org.jspecify.annotations.Nullable;
+
 import io.a2a.server.tasks.TaskStateProvider;
 import io.a2a.spec.Event;
 import org.slf4j.Logger;
@@ -49,10 +51,10 @@ static EventQueueBuilder builder() {
 
     public static class EventQueueBuilder {
         private int queueSize = DEFAULT_QUEUE_SIZE;
-        private EventEnqueueHook hook;
-        private String taskId;
+        private @Nullable EventEnqueueHook hook;
+        private @Nullable String taskId;
         private List<Runnable> onCloseCallbacks = new java.util.ArrayList<>();
-        private TaskStateProvider taskStateProvider;
+        private @Nullable TaskStateProvider taskStateProvider;
 
         public EventQueueBuilder queueSize(int queueSize) {
             this.queueSize = queueSize;
@@ -132,7 +134,7 @@ public void enqueueItem(EventQueueItem item) {
      * @return the EventQueueItem, or null if timeout occurs
      * @throws EventQueueClosedException if the queue is closed and empty
      */
-    public EventQueueItem dequeueEventItem(int waitMilliSeconds) throws EventQueueClosedException {
+    public @Nullable EventQueueItem dequeueEventItem(int waitMilliSeconds) throws EventQueueClosedException {
         if (closed && queue.isEmpty()) {
             LOGGER.debug("Queue is closed, and empty. Sending termination message. {}", this);
             throw new EventQueueClosedException();
@@ -218,10 +220,10 @@ static class MainQueue extends EventQueue {
         private final List<ChildQueue> children = new CopyOnWriteArrayList<>();
         private final CountDownLatch pollingStartedLatch = new CountDownLatch(1);
         private final AtomicBoolean pollingStarted = new AtomicBoolean(false);
-        private final EventEnqueueHook enqueueHook;
-        private final String taskId;
+        private final @Nullable EventEnqueueHook enqueueHook;
+        private final @Nullable String taskId;
         private final List<Runnable> onCloseCallbacks;
-        private final TaskStateProvider taskStateProvider;
+        private final @Nullable TaskStateProvider taskStateProvider;
 
         MainQueue() {
             super();
@@ -255,7 +257,7 @@ static class MainQueue extends EventQueue {
             this.taskStateProvider = null;
         }
 
-        MainQueue(int queueSize, EventEnqueueHook hook, String taskId, List<Runnable> onCloseCallbacks, TaskStateProvider taskStateProvider) {
+        MainQueue(int queueSize, @Nullable EventEnqueueHook hook, @Nullable String taskId, List<Runnable> onCloseCallbacks, @Nullable TaskStateProvider taskStateProvider) {
             super(queueSize);
             this.enqueueHook = hook;
             this.taskId = taskId;

server-common/src/main/java/io/a2a/server/events/InMemoryQueueManager.java

@@ -6,6 +6,8 @@
 import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.inject.Inject;
 
+import org.jspecify.annotations.Nullable;
+
 import io.a2a.server.tasks.TaskStateProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -39,12 +41,12 @@ public void add(String taskId, EventQueue queue) {
     }
 
     @Override
-    public EventQueue get(String taskId) {
+    public @Nullable EventQueue get(String taskId) {
         return queues.get(taskId);
     }
 
     @Override
-    public EventQueue tap(String taskId) {
+    public @Nullable EventQueue tap(String taskId) {
         EventQueue queue = queues.get(taskId);
         return queue == null ? null : queue.tap();
     }
@@ -92,6 +94,9 @@ public EventQueue createOrTap(String taskId) {
         }
 
         EventQueue main = existing == null ? newQueue : existing;
+        if (main == null) {
+            throw new IllegalStateException("Failed to create or retrieve queue for task " + taskId);
+        }
         EventQueue result = main.tap();  // Always return ChildQueue
 
         if (existing == null) {