Update plugin versions and support Java 21 build

Update spotbugs and add necessary exclusions
  Fix one small thing in Context that was making it upset
Update other plugins
Make spotless work -- currently only runs on Java 11

.github/workflows/gradle.yml

@@ -15,7 +15,7 @@ jobs:
       # Some tests require more CPU, and all can use multiple CPUs
       max-parallel: 1
       matrix:
-        java: [ '11', '17' ]
+        java: [ '11', '17', '21' ]
     name: Rhino Java ${{ matrix.java }}
     steps:
     - name: Checkout

buildSrc/build.gradle

@@ -8,5 +8,5 @@ repositories {
 
 dependencies {
     implementation 'com.diffplug.spotless:spotless-plugin-gradle:6.25.0'
-    implementation 'com.github.spotbugs.snom:spotbugs-gradle-plugin:5.0.14'
+    implementation 'com.github.spotbugs.snom:spotbugs-gradle-plugin:6.0.15'
 }

buildSrc/src/main/groovy/rhino.java-conventions.gradle

@@ -28,8 +28,14 @@ test {
 }
 
 spotless {
-    java {
-        // Newer versions of GoogleJavaFormat seem to require JDK 15+
-        googleJavaFormat('1.10.0').aosp()
+    // There is no version of googleJavaFormat that works for Java 11 and 17,
+    // and different versions format differently. For now, only run spotless on Java 11.
+    // This will have to be changed when Java 11 support is removed.
+    if (JavaVersion.current() == JavaVersion.VERSION_11) {
+        java {
+            googleJavaFormat('1.10.0').aosp()
+        }
+    } else {
+        System.out.println("Not running Spotless: Java language version is " + JavaVersion.current())
     }
 }

buildSrc/src/main/groovy/rhino.library-conventions.gradle

@@ -3,6 +3,9 @@ plugins {
     id 'com.github.spotbugs'
 }
 
+import com.github.spotbugs.snom.Confidence
+import com.github.spotbugs.snom.Effort
+
 version = project.version
 
 tasks.named('compileJava') {
@@ -21,8 +24,8 @@ tasks.withType(Jar).configureEach {
 }
 
 spotbugs {
-    effort = "less"
-    reportLevel = "medium"
+    effort = Effort.valueOf('LESS')
+    reportLevel = Confidence.valueOf('MEDIUM')
     excludeFilter = file("${projectDir}/../spotbugs-exclude.xml")
 }
 

examples/src/main/java/File.java

@@ -53,6 +53,7 @@ public class File extends ScriptableObject {
 
     /** */
     private static final long serialVersionUID = 2549960399774237828L;
+
     /**
      * The zero-parameter constructor.
      *

rhino-runtime/src/main/java/org/mozilla/javascript/ClassCache.java

@@ -35,6 +35,7 @@ public class ClassCache implements Serializable {
     static class CacheKey {
         final Class<?> cls;
         final Object sec;
+
         /** Constructor. */
         public CacheKey(Class<?> cls, Object securityContext) {
             this.cls = cls;

rhino-runtime/src/main/java/org/mozilla/javascript/CompilerEnvirons.java

@@ -41,7 +41,7 @@ public void initFromContext(Context cx) {
         activationNames = cx.activationNames;
 
         // Observer code generation in compiled code :
-        generateObserverCount = cx.generateObserverCount;
+        generateObserverCount = cx.isGenerateObserverCount();
     }
 
     public final ErrorReporter getErrorReporter() {

rhino-runtime/src/main/java/org/mozilla/javascript/Context.java

@@ -2278,6 +2278,11 @@ public void setGenerateObserverCount(boolean generateObserverCount) {
         this.generateObserverCount = generateObserverCount;
     }
 
+    /** Determine if observer counts should be generated. */
+    public boolean isGenerateObserverCount() {
+        return this.generateObserverCount;
+    }
+
     /**
      * Allow application to monitor counter of executed script instructions in Context subclasses.
      * Run-time calls this when instruction counting is enabled and the counter reaches limit set by
@@ -2711,7 +2716,7 @@ public static boolean isCurrentContextStrict() {
     Scriptable scratchScriptable;
 
     // Generate an observer count on compiled code
-    public boolean generateObserverCount = false;
+    boolean generateObserverCount = false;
 
     boolean isTopLevelStrict;
 }

rhino-runtime/src/main/java/org/mozilla/javascript/LambdaConstructor.java

@@ -24,8 +24,10 @@ public class LambdaConstructor extends LambdaFunction {
 
     /** If this flag is set, the constructor may be invoked as an ordinary function */
     public static final int CONSTRUCTOR_FUNCTION = 1;
+
     /** If this flag is set, the constructor may be invoked using "new" */
     public static final int CONSTRUCTOR_NEW = 1 << 1;
+
     /** By default, the constructor may be invoked either way */
     public static final int CONSTRUCTOR_DEFAULT = CONSTRUCTOR_FUNCTION | CONSTRUCTOR_NEW;
 

rhino-runtime/src/main/java/org/mozilla/javascript/NativeJavaMethod.java

@@ -447,6 +447,7 @@ static int findFunction(Context cx, MemberBox[] methodsOrCtors, Object[] args) {
 
     private static final int PREFERENCE_FIRST_ARG = 1;
     private static final int PREFERENCE_SECOND_ARG = 2;
+
     /** No clear "easy" conversion */
     private static final int PREFERENCE_AMBIGUOUS = 3;
 

rhino-runtime/src/main/java/org/mozilla/javascript/ScriptRuntime.java

@@ -76,6 +76,7 @@ static class NoSuchMethodShim implements Callable {
             this.noSuchMethodMethod = noSuchMethodMethod;
             this.methodName = methodName;
         }
+
         /**
          * Perform the call.
          *
@@ -94,6 +95,7 @@ public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] ar
             return noSuchMethodMethod.call(cx, scope, thisObj, nestedArgs);
         }
     }
+
     /*
      * There's such a huge space (and some time) waste for the Foo.class
      * syntax: the compiler sticks in a test of a static field in the
@@ -2536,6 +2538,7 @@ public static boolean loadFromIterable(
         }
         return true;
     }
+
     /**
      * Prepare for calling name(...): return function corresponding to name and make current top
      * scope available as ScriptRuntime.lastStoredScriptable() for consumption as thisObj. The

rhino-runtime/src/main/java/org/mozilla/javascript/ScriptableObject.java

@@ -98,6 +98,7 @@ public abstract class ScriptableObject
     public static final int UNINITIALIZED_CONST = 0x08;
 
     public static final int CONST = PERMANENT | READONLY | UNINITIALIZED_CONST;
+
     /** The prototype of this object. */
     private Scriptable prototypeObject;
 

rhino-runtime/src/main/java/org/mozilla/javascript/ast/AstNode.java

@@ -134,6 +134,7 @@ public abstract class AstNode extends Node implements Comparable<AstNode> {
 
     public static class PositionComparator implements Comparator<AstNode>, Serializable {
         private static final long serialVersionUID = 1L;
+
         /**
          * Sorts nodes by (relative) start position. The start positions are relative to their
          * parent, so this comparator is only meaningful for comparing siblings.

rhino-runtime/src/main/java/org/mozilla/javascript/debug/DebugFrame.java

@@ -27,6 +27,7 @@ public interface DebugFrame {
      * @param args the array of arguments
      */
     public void onEnter(Context cx, Scriptable activation, Scriptable thisObj, Object[] args);
+
     /**
      * Called when executed code reaches new line in the source.
      *

rhino-runtime/src/main/java/org/mozilla/javascript/typedarrays/NativeArrayBufferView.java

@@ -26,8 +26,10 @@ public abstract class NativeArrayBufferView extends IdScriptableObject {
 
     /** Many view objects can share the same backing array */
     protected final NativeArrayBuffer arrayBuffer;
+
     /** The offset, in bytes, from the start of the backing array */
     protected final int offset;
+
     /** The length, in bytes, of the portion of the backing array that we use */
     protected final int byteLength;
 

rhino-tools/src/main/java/org/mozilla/javascript/tools/debugger/treetable/JTreeTable.java

@@ -64,6 +64,7 @@
 public class JTreeTable extends JTable {
     /** */
     private static final long serialVersionUID = -2103973006456695515L;
+
     /** A subclass of JTree. */
     protected TreeTableCellRenderer tree;
 
@@ -143,6 +144,7 @@ public JTree getTree() {
     /** A TreeCellRenderer that displays a JTree. */
     public class TreeTableCellRenderer extends JTree implements TableCellRenderer {
         private static final long serialVersionUID = -193867880014600717L;
+
         /** Last table/tree row asked to renderer. */
         protected int visibleRow;
 

rhino-tools/src/main/java/org/mozilla/javascript/tools/jsc/Main.java

@@ -193,6 +193,7 @@ public String[] processOptions(String args[]) {
         p(ToolErrorReporter.getMessage("msg.no.file"));
         return null;
     }
+
     /** Print a usage message. */
     private static void badUsage(String s) {
         System.err.println(

rhino-xml/src/main/java/org/mozilla/javascript/xmlimpl/Namespace.java

@@ -132,6 +132,7 @@ protected int findInstanceIdInfo(String s) {
         }
         return instanceIdInfo(attr, super.getMaxInstanceId() + id);
     }
+
     // #/string_id_map#
 
     @Override
@@ -192,6 +193,7 @@ protected int findPrototypeId(String s) {
         // #/generated#
         return id;
     }
+
     // #/string_id_map#
 
     @Override

rhino-xml/src/main/java/org/mozilla/javascript/xmlimpl/QName.java

@@ -162,6 +162,7 @@ protected int findInstanceIdInfo(String s) {
         }
         return instanceIdInfo(attr, super.getMaxInstanceId() + id);
     }
+
     // #/string_id_map#
 
     @Override
@@ -221,6 +222,7 @@ protected int findPrototypeId(String s) {
         // #/generated#
         return id;
     }
+
     // #/string_id_map#
 
     @Override

rhino-xml/src/main/java/org/mozilla/javascript/xmlimpl/XMLCtor.java

@@ -19,6 +19,7 @@ class XMLCtor extends IdFunctionObject {
     private static final Object XMLCTOR_TAG = "XMLCtor";
 
     private XmlProcessor options;
+
     //    private XMLLibImpl lib;
 
     XMLCtor(XML xml, Object tag, int id, int arity) {
@@ -225,6 +226,7 @@ protected int findPrototypeId(String s) {
         // #/generated#
         return id;
     }
+
     // #/string_id_map#
 
     @Override

rhino-xml/src/main/java/org/mozilla/javascript/xmlimpl/XMLObjectImpl.java

@@ -239,6 +239,7 @@ public boolean has(String name, Scriptable start) {
         Context cx = Context.getCurrentContext();
         return hasXMLProperty(lib.toXMLNameFromString(cx, name));
     }
+
     /** Implementation of ECMAScript [[Get]] */
     @Override
     public final Object get(Context cx, Object id) {
@@ -261,6 +262,7 @@ public Object get(String name, Scriptable start) {
         Context cx = Context.getCurrentContext();
         return getXMLProperty(lib.toXMLNameFromString(cx, name));
     }
+
     /** Implementation of ECMAScript [[Put]] */
     @Override
     public final void put(Context cx, Object id, Object value) {
@@ -280,6 +282,7 @@ public void put(String name, Scriptable start, Object value) {
         Context cx = Context.getCurrentContext();
         putXMLProperty(lib.toXMLNameFromString(cx, name), value);
     }
+
     /** Implementation of ECMAScript [[Delete]]. */
     @Override
     public final boolean delete(Context cx, Object id) {
@@ -650,6 +653,7 @@ protected int findPrototypeId(String s) {
         // #/generated#
         return id;
     }
+
     // #/string_id_map#
 
     @Override

spotbugs-exclude.xml

@@ -92,6 +92,19 @@
     <Class name="org.mozilla.javascript.optimizer.OptRuntime$GeneratorState"/>
     <Bug pattern="URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD"/>
   </Match>
+  <Match>
+    <!-- Don't want to break decades of other code -->
+    <Class name="org.mozilla.javascript.ContextFactory"/>
+    <Bug pattern="SING_SINGLETON_HAS_NONPRIVATE_CONSTRUCTOR"/>
+  </Match>
+  <Match>
+    <!-- Lots of constructors in Rhino throw exceptions. -->
+    <Bug pattern="CT_CONSTRUCTOR_THROW"/>
+  </Match>
+  <Match>
+    <!-- Our serialization calls lots and lots of methods -->
+    <Bug pattern="MC_OVERRIDABLE_METHOD_CALL_IN_READ_OBJECT"/>
+  </Match>
 
   <!-- Things below are things that we aspire to fix! -->
   <Match>

tests/src/test/java/org/mozilla/javascript/tests/SecurityControllerTest.java

@@ -32,6 +32,7 @@ public class SecurityControllerTest {
 
     /** Sets up the security manager and loads the "grant-all-java.policy". */
     static void setupSecurityManager() {}
+
     /** Setup the security */
     @BeforeClass
     public static void setup() throws Exception {