Fix error prone warns

extras/src/test/java/com/google/gson/typeadapters/UtcDateTypeAdapterTest.java

@@ -29,6 +29,7 @@
 import java.util.TimeZone;
 import org.junit.Test;
 
+@SuppressWarnings("JavaUtilDate")
 public final class UtcDateTypeAdapterTest {
   private final Gson gson = new GsonBuilder()
     .registerTypeAdapter(Date.class, new UtcDateTypeAdapter())

gson/pom.xml

@@ -59,6 +59,7 @@
       <groupId>com.google.errorprone</groupId>
       <artifactId>error_prone_annotations</artifactId>
       <version>2.18.0</version>
+      <optional>true</optional>
     </dependency>
   </dependencies>
 

gson/src/main/java/com/google/gson/stream/JsonReader.java

@@ -1590,7 +1590,7 @@ public String getPath() {
    * @throws NumberFormatException if any unicode escape sequences are
    *     malformed.
    */
-  @SuppressWarnings({"fallthrough", "NarrowingCompoundAssignment"})
+  @SuppressWarnings("fallthrough")
   private char readEscapeCharacter() throws IOException {
     if (pos == limit && !fillBuffer(1)) {
       throw syntaxError("Unterminated escape sequence");
@@ -1603,7 +1603,7 @@ private char readEscapeCharacter() throws IOException {
         throw syntaxError("Unterminated escape sequence");
       }
       // Equivalent to Integer.parseInt(stringPool.get(buffer, pos, 4), 16);
-      char result = 0;
+      int result = 0;
       for (int i = pos, end = i + 4; i < end; i++) {
         char c = buffer[i];
         result <<= 4;
@@ -1618,7 +1618,7 @@ private char readEscapeCharacter() throws IOException {
         }
       }
       pos += 4;
-      return result;
+      return (char) result;
 
     case 't':
       return '\t';

gson/src/main/java/module-info.java

@@ -25,7 +25,7 @@
   exports com.google.gson.stream;
 
   // Dependency on Error Prone Annotations
-  requires com.google.errorprone.annotations;
+  requires static com.google.errorprone.annotations;
 
   // Optional dependency on java.sql
   requires static java.sql;

gson/src/test/java/com/google/gson/CommentsTest.java

@@ -23,6 +23,8 @@
 import org.junit.Test;
 
 /**
+ * Tests that by default Gson accepts several forms of comments.
+ *
  * @author Jesse Wilson
  */
 public final class CommentsTest {

gson/src/test/java/com/google/gson/InnerClassExclusionStrategyTest.java

@@ -56,6 +56,7 @@ public void testIncludeStaticNestedClassField() throws Exception {
     assertThat(excluder.excludeField(f, true)).isFalse();
   }
 
+  @SuppressWarnings("ClassCanBeStatic")
   class InnerClass {
   }
 

gson/src/test/java/com/google/gson/JsonArrayTest.java

@@ -26,6 +26,8 @@
 import org.junit.Test;
 
 /**
+ * Tests handling of JSON arrays.
+ *
  * @author Jesse Wilson
  */
 public final class JsonArrayTest {

gson/src/test/java/com/google/gson/JsonNullTest.java

@@ -22,6 +22,8 @@
 import org.junit.Test;
 
 /**
+ * Tests handling of JSON nulls.
+ *
  * @author Jesse Wilson
  */
 public final class JsonNullTest {

gson/src/test/java/com/google/gson/ObjectTypeAdapterTest.java

@@ -111,7 +111,7 @@ public void testDeserializeDeeplyNestedObjects() throws IOException {
     assertThat(actualTimes).isEqualTo(times);
   }
 
-  @SuppressWarnings("unused")
+  @SuppressWarnings({"unused", "ClassCanBeStatic"})
   private class RuntimeType {
     Object a = 5;
     Object b = Arrays.asList(1, 2, null);

gson/src/test/java/com/google/gson/OverrideCoreTypeAdaptersTest.java

@@ -25,6 +25,8 @@
 import org.junit.Test;
 
 /**
+ * Tests handling of Core Type Adapters
+ *
  * @author Jesse Wilson
  */
 public class OverrideCoreTypeAdaptersTest {

gson/src/test/java/com/google/gson/ParameterizedTypeFixtures.java

@@ -36,7 +36,7 @@
  */
 public class ParameterizedTypeFixtures {
 
-  public static class MyParameterizedType<T> {
+  public static final class MyParameterizedType<T> {
     public final T value;
     public MyParameterizedType(T value) {
       this.value = value;
@@ -103,7 +103,7 @@ public static class MyParameterizedTypeInstanceCreator<T>
      * This is usually fine in tests since there we deserialize just once, but quite
      * dangerous in practice.
      *
-     * @param instanceOfT
+     * @param instanceOfT Instance of Type
      */
     public MyParameterizedTypeInstanceCreator(T instanceOfT) {
       this.instanceOfT = instanceOfT;

gson/src/test/java/com/google/gson/functional/CollectionTest.java

@@ -93,6 +93,7 @@ public void testTopLevelListOfIntegerCollectionsDeserialization() {
   }
 
   @Test
+  @SuppressWarnings("JdkObsolete")
   public void testLinkedListSerialization() {
     List<String> list = new LinkedList<>();
     list.add("a1");
@@ -113,6 +114,7 @@ public void testLinkedListDeserialization() {
   }
 
   @Test
+  @SuppressWarnings("JdkObsolete")
   public void testQueueSerialization() {
     Queue<String> queue = new LinkedList<>();
     queue.add("a1");
@@ -266,11 +268,11 @@ public void testObjectCollectionSerialization() {
   }
 
   @Test
-  public void testRawCollectionDeserializationNotAlllowed() {
+  public void testRawCollectionDeserializationNotAllowed() {
     String json = "[0,1,2,3,4,5,6,7,8,9]";
     Collection<?> integers = gson.fromJson(json, Collection.class);
     // JsonReader converts numbers to double by default so we need a floating point comparison
-    assertThat(integers).isEqualTo(Arrays.asList(0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0));
+    assertThat(integers).containsExactly(0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0).inOrder();
 
     json = "[\"Hello\", \"World\"]";
     Collection<?> strings = gson.fromJson(json, Collection.class);
@@ -416,9 +418,9 @@ public void testSetDeserialization() {
     }
   }
 
-  private class BigClass { private Map<String, ? extends List<SmallClass>> inBig; }
+  private static class BigClass { private Map<String, ? extends List<SmallClass>> inBig; }
 
-  private class SmallClass { private String inSmall; }
+  private static class SmallClass { private String inSmall; }
 
   @Test
   public void testIssue1107() {

gson/src/test/java/com/google/gson/functional/CustomDeserializerTest.java

@@ -18,6 +18,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.errorprone.annotations.Immutable;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonDeserializationContext;
@@ -130,6 +131,7 @@ private static class MyBase {
     static final String TYPE_ACCESS = "__type__";
   }
 
+  @SuppressWarnings("ImmutableEnumChecker")
   private enum SubTypes {
     SUB_TYPE1(SubType1.class),
     SUB_TYPE2(SubType2.class);

gson/src/test/java/com/google/gson/functional/CustomTypeAdaptersTest.java

@@ -17,6 +17,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.common.base.Splitter;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.InstanceCreator;
@@ -35,6 +36,7 @@
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import org.junit.Before;
@@ -291,9 +293,9 @@ private static final class StringHolder {
     String part2;
 
     public StringHolder(String string) {
-      String[] parts = string.split(":");
-      part1 = parts[0];
-      part2 = parts[1];
+      List<String> parts = Splitter.on(':').splitToList(string);
+      part1 = parts.get(0);
+      part2 = parts.get(1);
     }
     public StringHolder(String part1, String part2) {
       this.part1 = part1;
@@ -425,7 +427,7 @@ public void testEnsureCustomDeserializerNotInvokedForNullValues() {
 
   // Test created from Issue 352
   @Test
-  @SuppressWarnings("JavaUtilDate")
+  @SuppressWarnings({"JavaUtilDate", "UndefinedEquals"})
   public void testRegisterHierarchyAdapterForDate() {
     Gson gson = new GsonBuilder()
         .registerTypeHierarchyAdapter(Date.class, new DateTypeAdapter())

gson/src/test/java/com/google/gson/functional/DefaultTypeAdaptersTest.java

@@ -701,6 +701,7 @@ public void testStringBuilderDeserialization() {
   }
 
   @Test
+  @SuppressWarnings("JdkObsolete")
   public void testStringBufferSerialization() {
     StringBuffer sb = new StringBuffer("abc");
     String json = gson.toJson(sb);

gson/src/test/java/com/google/gson/functional/EnumTest.java

@@ -121,7 +121,7 @@ public String getExpectedJson() {
    */
   @Test
   public void testEnumSubclass() {
-    assertThat(Roshambo.ROCK.getClass()).isAssignableTo(Roshambo.class);
+    assertThat(Roshambo.ROCK.getDeclaringClass()).isAssignableTo(Roshambo.class);
     assertThat(gson.toJson(Roshambo.ROCK)).isEqualTo("\"ROCK\"");
     assertThat(gson.toJson(EnumSet.allOf(Roshambo.class))).isEqualTo("[\"ROCK\",\"PAPER\",\"SCISSORS\"]");
     assertThat(gson.fromJson("\"ROCK\"", Roshambo.class)).isEqualTo(Roshambo.ROCK);
@@ -135,7 +135,7 @@ public void testEnumSubclassWithRegisteredTypeAdapter() {
     gson = new GsonBuilder()
         .registerTypeHierarchyAdapter(Roshambo.class, new MyEnumTypeAdapter())
         .create();
-    assertThat(Roshambo.ROCK.getClass()).isAssignableTo(Roshambo.class);
+    assertThat(Roshambo.ROCK.getDeclaringClass()).isAssignableTo(Roshambo.class);
     assertThat(gson.toJson(Roshambo.ROCK)).isEqualTo("\"123ROCK\"");
     assertThat(gson.toJson(EnumSet.allOf(Roshambo.class))).isEqualTo("[\"123ROCK\",\"123PAPER\",\"123SCISSORS\"]");
     assertThat(gson.fromJson("\"123ROCK\"", Roshambo.class)).isEqualTo(Roshambo.ROCK);
@@ -207,6 +207,7 @@ private enum Roshambo {
       }
     };
 
+    @SuppressWarnings("unused")
     abstract Roshambo defeats();
   }
 
@@ -239,8 +240,8 @@ public void testEnumClassWithFields() {
 
   private enum Color {
     RED("red", 1), BLUE("blue", 2), GREEN("green", 3);
-    String value;
-    int index;
+    final String value;
+    final int index;
     private Color(String value, int index) {
       this.value = value;
       this.index = index;

gson/src/test/java/com/google/gson/functional/EscapingTest.java

@@ -70,7 +70,7 @@ public void testEscapingObjectFields() {
     assertThat(jsonRepresentation).contains("\\\"");
 
     BagOfPrimitives expectedObject = gson.fromJson(jsonRepresentation, BagOfPrimitives.class);
-    assertThat(expectedObject.getExpectedJson()).isEqualTo(objWithPrimitives.getExpectedJson());
+    assertThat(objWithPrimitives.getExpectedJson()).isEqualTo(expectedObject.getExpectedJson());
   }
 
   @Test

gson/src/test/java/com/google/gson/functional/FieldExclusionTest.java

@@ -75,6 +75,8 @@ public void testDefaultNestedStaticClassIncluded() {
   }
 
   private static class Outer {
+
+    @SuppressWarnings("ClassCanBeStatic")
     private class Inner extends NestedClass {
       public Inner(String value) {
         super(value);

gson/src/test/java/com/google/gson/functional/GsonVersionDiagnosticsTest.java

@@ -59,6 +59,7 @@ public void testVersionPattern() {
   }
 
   @Test
+  @SuppressWarnings("AssertionFailureIgnored")
   public void testAssertionErrorInSerializationPrintsVersion() {
     try {
       gson.toJson(new TestType());
@@ -69,6 +70,7 @@ public void testAssertionErrorInSerializationPrintsVersion() {
   }
 
   @Test
+  @SuppressWarnings("AssertionFailureIgnored")
   public void testAssertionErrorInDeserializationPrintsVersion() {
     try {
       gson.fromJson("{'a':'abc'}", TestType.class);

gson/src/test/java/com/google/gson/functional/InheritanceTest.java

@@ -162,6 +162,7 @@ public void appendFields(StringBuilder sb) {
   }
 
   @Test
+  @SuppressWarnings("JdkObsolete")
   public void testSubInterfacesOfCollectionSerialization() {
     List<Integer> list = new LinkedList<>();
     list.add(0);

gson/src/test/java/com/google/gson/functional/Java17RecordTest.java

@@ -136,6 +136,7 @@ record LocalRecord(String s) {
 
   /** Tests behavior when the canonical constructor throws an exception */
   @Test
+  @SuppressWarnings("StaticAssignmentOfThrowable")
   public void testThrowingConstructor() {
     record LocalRecord(String s) {
       static final RuntimeException thrownException = new RuntimeException("Custom exception");
@@ -172,6 +173,7 @@ public String s() {
 
   /** Tests behavior when a record accessor method throws an exception */
   @Test
+  @SuppressWarnings("StaticAssignmentOfThrowable")
   public void testThrowingAccessor() {
     record LocalRecord(String s) {
       static final RuntimeException thrownException = new RuntimeException("Custom exception");

gson/src/test/java/com/google/gson/functional/JsonAdapterAnnotationOnClassesTest.java

@@ -19,6 +19,7 @@
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.fail;
 
+import com.google.common.base.Splitter;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonDeserializationContext;
@@ -36,6 +37,7 @@
 import com.google.gson.stream.JsonWriter;
 import java.io.IOException;
 import java.lang.reflect.Type;
+import java.util.List;
 import java.util.Locale;
 import org.junit.Test;
 
@@ -226,9 +228,9 @@ private static class UserJsonAdapter extends TypeAdapter<User> {
       // implement read: split name into firstName and lastName
       in.beginObject();
       in.nextName();
-      String[] nameParts = in.nextString().split(" ");
+      List<String> nameParts = Splitter.on(" ").splitToList(in.nextString());
       in.endObject();
-      return new User(nameParts[0], nameParts[1]);
+      return new User(nameParts.get(0), nameParts.get(1));
     }
   }
 

gson/src/test/java/com/google/gson/functional/ObjectTest.java

@@ -161,7 +161,7 @@ public void testClassWithNoFieldsDeserialization() {
   private static class Subclass extends Superclass1 {
   }
   private static class Superclass1 extends Superclass2 {
-    @SuppressWarnings("unused")
+    @SuppressWarnings({"unused", "HidingField"})
     String s;
   }
   private static class Superclass2 {
@@ -414,6 +414,8 @@ public void testInnerClassDeserialization() {
   private static class Parent {
     @SuppressWarnings("unused")
     int value1 = 1;
+
+    @SuppressWarnings("ClassCanBeStatic")
     private class Child {
       int value2 = 2;
     }
@@ -655,6 +657,7 @@ public void testThrowingDefaultConstructor() {
     }
   }
 
+  @SuppressWarnings("StaticAssignmentOfThrowable")
   static class ClassWithThrowingConstructor {
     static final RuntimeException thrownException = new RuntimeException("Custom exception");
 

gson/src/test/java/com/google/gson/functional/ParameterizedTypesTest.java

@@ -400,7 +400,7 @@ public String toString(T obj) {
     }
   }
 
-  private static class MultiParameters<A, B, C, D, E> {
+  private static final class MultiParameters<A, B, C, D, E> {
     A a;
     B b;
     C c;