graphql-java · Copilot · Jan 24, 2026 · Jan 24, 2026 · Jan 24, 2026 · Jan 25, 2026
diff --git a/.claude/commands/jspecify-annotate.md b/.claude/commands/jspecify-annotate.md
diff --git a/src/main/java/graphql/language/Comment.java b/src/main/java/graphql/language/Comment.java
@@ -1,18 +1,21 @@
 package graphql.language;
 
 import graphql.PublicApi;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.io.Serializable;
 
 /**
  * A single-line comment. These are comments that start with a {@code #} in source documents.
  */
 @PublicApi
+@NullMarked
 public class Comment implements Serializable {
     public final String content;
-    public final SourceLocation sourceLocation;
+    public final @Nullable SourceLocation sourceLocation;
 
-    public Comment(String content, SourceLocation sourceLocation) {
+    public Comment(String content, @Nullable SourceLocation sourceLocation) {
         this.content = content;
         this.sourceLocation = sourceLocation;
     }
@@ -21,7 +24,7 @@ public String getContent() {
         return content;
     }
 
-    public SourceLocation getSourceLocation() {
+    public @Nullable SourceLocation getSourceLocation() {
         return sourceLocation;
     }
 }
diff --git a/src/main/java/graphql/language/Definition.java b/src/main/java/graphql/language/Definition.java
@@ -2,8 +2,10 @@
 
 
 import graphql.PublicApi;
+import org.jspecify.annotations.NullMarked;
 
 @PublicApi
+@NullMarked
 public interface Definition<T extends Definition> extends Node<T> {
 
 }
diff --git a/src/main/java/graphql/language/IgnoredChar.java b/src/main/java/graphql/language/IgnoredChar.java
@@ -1,6 +1,8 @@
 package graphql.language;
 
 import graphql.PublicApi;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.io.Serializable;
 import java.util.Objects;
@@ -12,6 +14,7 @@
  * This costs more memory but for certain use cases (like editors) this maybe be useful
  */
 @PublicApi
+@NullMarked
 public class IgnoredChar implements Serializable {
 
     public enum IgnoredCharKind {
@@ -51,7 +54,7 @@ public String toString() {
     }
 
     @Override
-    public boolean equals(Object o) {
+    public boolean equals(@Nullable Object o) {
         if (this == o) {
             return true;
         }

diff --git a/src/main/java/graphql/language/IgnoredChars.java b/src/main/java/graphql/language/IgnoredChars.java
@@ -3,6 +3,7 @@
 import com.google.common.collect.ImmutableList;
 import graphql.PublicApi;
 import graphql.collect.ImmutableKit;
+import org.jspecify.annotations.NullMarked;
 
 import java.io.Serializable;
 import java.util.List;
@@ -14,6 +15,7 @@
  * This costs more memory but for certain use cases (like editors) this maybe be useful
  */
 @PublicApi
+@NullMarked
 public class IgnoredChars implements Serializable {
 
     private final ImmutableList<IgnoredChar> left;

diff --git a/src/main/java/graphql/language/ImplementingTypeDefinition.java b/src/main/java/graphql/language/ImplementingTypeDefinition.java
@@ -2,6 +2,7 @@
 
 
 import graphql.PublicApi;
+import org.jspecify.annotations.NullMarked;
 
 import java.util.List;
 
@@ -11,6 +12,7 @@
  * @param <T> for two
  */
 @PublicApi
+@NullMarked
 public interface ImplementingTypeDefinition<T extends TypeDefinition> extends TypeDefinition<T> {
 
     List<Type> getImplements();

diff --git a/src/main/java/graphql/language/InlineFragment.java b/src/main/java/graphql/language/InlineFragment.java
@@ -7,6 +7,9 @@
 import graphql.collect.ImmutableKit;
 import graphql.util.TraversalControl;
 import graphql.util.TraverserContext;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
@@ -20,8 +23,9 @@
 import static graphql.language.NodeChildrenContainer.newNodeChildrenContainer;
 
 @PublicApi
+@NullMarked
 public class InlineFragment extends AbstractNode<InlineFragment> implements Selection<InlineFragment>, SelectionSetContainer<InlineFragment>, DirectivesContainer<InlineFragment> {
-    private final TypeName typeCondition;
+    private final @Nullable TypeName typeCondition;
     private final NodeUtil.DirectivesHolder directives;
     private final SelectionSet selectionSet;
 
@@ -30,10 +34,10 @@ public class InlineFragment extends AbstractNode<InlineFragment> implements Sele
     public static final String CHILD_SELECTION_SET = "selectionSet";
 
     @Internal
-    protected InlineFragment(TypeName typeCondition,
+    protected InlineFragment(@Nullable TypeName typeCondition,
                              List<Directive> directives,
                              SelectionSet selectionSet,
-                             SourceLocation sourceLocation,
+                             @Nullable SourceLocation sourceLocation,
                              List<Comment> comments,
                              IgnoredChars ignoredChars,
                              Map<String, String> additionalData) {
@@ -48,8 +52,8 @@ protected InlineFragment(TypeName typeCondition,
      *
      * @param typeCondition the type condition of the inline fragment
      */
-    public InlineFragment(TypeName typeCondition) {
-        this(typeCondition, emptyList(), null, null, emptyList(), IgnoredChars.EMPTY, emptyMap());
+    public InlineFragment(@Nullable TypeName typeCondition) {
+        this(typeCondition, emptyList(), SelectionSet.newSelectionSet().build(), null, emptyList(), IgnoredChars.EMPTY, emptyMap());
     }
 
     /**
@@ -58,11 +62,11 @@ public InlineFragment(TypeName typeCondition) {
      * @param typeCondition the type condition of the inline fragment
      * @param selectionSet  of the inline fragment
      */
-    public InlineFragment(TypeName typeCondition, SelectionSet selectionSet) {
+    public InlineFragment(@Nullable TypeName typeCondition, SelectionSet selectionSet) {
         this(typeCondition, emptyList(), selectionSet, null, emptyList(), IgnoredChars.EMPTY, emptyMap());
     }
 
-    public TypeName getTypeCondition() {
+    public @Nullable TypeName getTypeCondition() {
         return typeCondition;
     }
 
@@ -121,7 +125,7 @@ public InlineFragment withNewChildren(NodeChildrenContainer newChildren) {
     }
 
     @Override
-    public boolean isEqualTo(Node o) {
+    public boolean isEqualTo(@Nullable Node o) {
         if (this == o) {
             return true;
         }
@@ -132,8 +136,8 @@ public boolean isEqualTo(Node o) {
     public InlineFragment deepCopy() {
         return new InlineFragment(
                 deepCopy(typeCondition),
-                deepCopy(directives.getDirectives()),
-                deepCopy(selectionSet),
+                assertNotNull(deepCopy(directives.getDirectives()), "directives cannot be null"),
+                assertNotNull(deepCopy(selectionSet), "selectionSet cannot be null"),
                 getSourceLocation(),
                 getComments(),
                 getIgnoredChars(),
@@ -164,6 +168,7 @@ public InlineFragment transform(Consumer<Builder> builderConsumer) {
         return builder.build();
     }
 
+    @NullUnmarked
     public static final class Builder implements NodeDirectivesBuilder {
         private SourceLocation sourceLocation;
         private ImmutableList<Comment> comments = emptyList();

diff --git a/src/main/java/graphql/language/InputObjectTypeDefinition.java b/src/main/java/graphql/language/InputObjectTypeDefinition.java
@@ -7,6 +7,9 @@
 import graphql.util.FpKit;
 import graphql.util.TraversalControl;
 import graphql.util.TraverserContext;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -19,6 +22,7 @@
 import static graphql.language.NodeChildrenContainer.newNodeChildrenContainer;
 
 @PublicApi
+@NullMarked
 public class InputObjectTypeDefinition extends AbstractDescribedNode<InputObjectTypeDefinition> implements TypeDefinition<InputObjectTypeDefinition>, DirectivesContainer<InputObjectTypeDefinition>, NamedNode<InputObjectTypeDefinition> {
 
     private final String name;
@@ -32,8 +36,8 @@ public class InputObjectTypeDefinition extends AbstractDescribedNode<InputObject
     protected InputObjectTypeDefinition(String name,
                                         List<Directive> directives,
                                         List<InputValueDefinition> inputValueDefinitions,
-                                        Description description,
-                                        SourceLocation sourceLocation,
+                                        @Nullable Description description,
+                                        @Nullable SourceLocation sourceLocation,
                                         List<Comment> comments,
                                         IgnoredChars ignoredChars,
                                         Map<String, String> additionalData) {
@@ -94,7 +98,7 @@ public InputObjectTypeDefinition withNewChildren(NodeChildrenContainer newChildr
     }
 
     @Override
-    public boolean isEqualTo(Node o) {
+    public boolean isEqualTo(@Nullable Node o) {
         if (this == o) {
             return true;
         }
@@ -110,8 +114,8 @@ public boolean isEqualTo(Node o) {
     @Override
     public InputObjectTypeDefinition deepCopy() {
         return new InputObjectTypeDefinition(name,
-                deepCopy(directives.getDirectives()),
-                deepCopy(inputValueDefinitions),
+                assertNotNull(deepCopy(directives.getDirectives()), "directives cannot be null"),
+                assertNotNull(deepCopy(inputValueDefinitions), "inputValueDefinitions cannot be null"),
                 description,
                 getSourceLocation(),
                 getComments(),
@@ -144,6 +148,7 @@ public InputObjectTypeDefinition transform(Consumer<Builder> builderConsumer) {
         return builder.build();
     }
 
+    @NullUnmarked
     public static final class Builder implements NodeDirectivesBuilder {
         private SourceLocation sourceLocation;
         private ImmutableList<Comment> comments = emptyList();

diff --git a/src/main/java/graphql/language/InputObjectTypeExtensionDefinition.java b/src/main/java/graphql/language/InputObjectTypeExtensionDefinition.java
@@ -4,6 +4,9 @@
 import graphql.Internal;
 import graphql.PublicApi;
 import graphql.collect.ImmutableKit;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.NullUnmarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -14,14 +17,15 @@
 import static graphql.collect.ImmutableKit.emptyList;
 
 @PublicApi
+@NullMarked
 public class InputObjectTypeExtensionDefinition extends InputObjectTypeDefinition implements SDLExtensionDefinition {
 
     @Internal
     protected InputObjectTypeExtensionDefinition(String name,
                                                  List<Directive> directives,
                                                  List<InputValueDefinition> inputValueDefinitions,
-                                                 Description description,
-                                                 SourceLocation sourceLocation,
+                                                 @Nullable Description description,
+                                                 @Nullable SourceLocation sourceLocation,
                                                  List<Comment> comments,
                                                  IgnoredChars ignoredChars,
                                                  Map<String, String> additionalData) {
@@ -31,8 +35,8 @@ protected InputObjectTypeExtensionDefinition(String name,
     @Override
     public InputObjectTypeExtensionDefinition deepCopy() {
         return new InputObjectTypeExtensionDefinition(getName(),
-                deepCopy(getDirectives()),
-                deepCopy(getInputValueDefinitions()),
+                assertNotNull(deepCopy(getDirectives()), "directives cannot be null"),
+                assertNotNull(deepCopy(getInputValueDefinitions()), "inputValueDefinitions cannot be null"),
                 getDescription(),
                 getSourceLocation(),
                 getComments(),
@@ -67,6 +71,7 @@ public InputObjectTypeExtensionDefinition transformExtension(Consumer<Builder> b
         return builder.build();
     }
 
+    @NullUnmarked
     public static final class Builder implements NodeDirectivesBuilder {
         private SourceLocation sourceLocation;
         private ImmutableList<Comment> comments = emptyList();