Change default version to VERSION_ECMASCRIPT

This changes the version set when a Context object is created to
VERSION_ECMASCRIPT by default. This version is equivalent to 
VERSION_ES6, which many people have been using in newer apps.

rhino-engine/src/main/java/org/mozilla/javascript/engine/RhinoScriptEngine.java

@@ -68,7 +68,7 @@ public class RhinoScriptEngine extends AbstractScriptEngine implements Compilabl
      */
     public static final String INTERPRETED_MODE = "org.mozilla.javascript.interpreted_mode";
 
-    static final int DEFAULT_LANGUAGE_VERSION = Context.VERSION_ES6;
+    static final int DEFAULT_LANGUAGE_VERSION = Context.VERSION_ECMASCRIPT;
     private static final boolean DEFAULT_DEBUG = true;
     private static final String DEFAULT_FILENAME = "eval";
 
@@ -349,7 +349,7 @@ protected boolean hasFeature(Context cx, int featureIndex) {
 
         @Override
         protected void onContextCreated(Context cx) {
-            cx.setLanguageVersion(Context.VERSION_ES6);
+            cx.setLanguageVersion(Context.VERSION_ECMASCRIPT);
             cx.setGeneratingDebug(DEFAULT_DEBUG);
         }
     }

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

@@ -169,7 +169,7 @@ public static void main(String[] args) {
 
         main.attachTo(org.mozilla.javascript.tools.shell.Main.shellContextFactory);
         try (Context cx = Context.enter()) {
-            cx.setLanguageVersion(Context.VERSION_ES6);
+            cx.setLanguageVersion(Context.VERSION_ECMASCRIPT);
 
             Global global = org.mozilla.javascript.tools.shell.Main.getGlobal();
             global.init(cx);

rhino-tools/src/main/java/org/mozilla/javascript/tools/shell/ShellContextFactory.java

@@ -13,7 +13,7 @@
 public class ShellContextFactory extends ContextFactory {
     private boolean strictMode;
     private boolean warningAsError;
-    private int languageVersion = Context.VERSION_ES6;
+    private int languageVersion = Context.VERSION_ECMASCRIPT;
     private boolean interpretedMode;
     private boolean generatingDebug;
     private boolean allowReservedKeywords = true;

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

@@ -12,7 +12,7 @@
 public class CompilerEnvirons {
     public CompilerEnvirons() {
         errorReporter = DefaultErrorReporter.instance;
-        languageVersion = Context.VERSION_DEFAULT;
+        languageVersion = Context.VERSION_ECMASCRIPT;
         generateDebugInfo = true;
         reservedKeywordAsIdentifier = true;
         allowMemberExprAsFunctionName = false;

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

@@ -66,10 +66,11 @@ public class Context implements Closeable {
      * The unknown version.
      *
      * <p>Be aware, this version will not support many of the newer language features and will not
-     * change in the future.
+     * change in the future. In practice, for historical reasons, this is an odd version that
+     * doesn't necessarily match any particular version of JavaScript and should not be used.
      *
-     * <p>Please use one of the other constants like VERSION_ES6 to get support for recent language
-     * features.
+     * <p>Please use one of the other constants like {@link #VERSION_ECMASCRIPT} to get support for
+     * recent language features.
      */
     public static final int VERSION_UNKNOWN = -1;
 
@@ -103,9 +104,23 @@ public class Context implements Closeable {
     /** JavaScript 1.8 */
     public static final int VERSION_1_8 = 180;
 
-    /** ECMAScript 6. */
+    /**
+     * Old constant for ECMAScript 6 and after. This has been replaced with the more clearly-named
+     * {@link #VERSION_ECMASCRIPT}. Both constants have the same value, and this is retained for
+     * compatibility.
+     */
     public static final int VERSION_ES6 = 200;
 
+    /**
+     * ECMAScript 6 and after. Since around version 1.7, this has been used to denote most new
+     * language features. This has the same value as {@link #VERSION_ES6}.
+     *
+     * <p>As of version 1.8, the Rhino community has no plans to continue adding new language
+     * versions, but instead plans to track the ECMAScript specification as it evolves and add new
+     * features in new versions of Rhino.
+     */
+    public static final int VERSION_ECMASCRIPT = VERSION_ES6;
+
     /**
      * Controls behaviour of <code>Date.prototype.getYear()</code>. If <code>
      * hasFeature(FEATURE_NON_ECMA_GET_YEAR)</code> returns true, Date.prototype.getYear subtructs
@@ -363,7 +378,11 @@ public class Context implements Closeable {
 
     /**
      * Creates a new Context. The context will be associated with the {@link
-     * ContextFactory#getGlobal() global context factory}.
+     * ContextFactory#getGlobal() global context factory}. By default, the new context will run in
+     * compiled mode and use the {@link #VERSION_ECMASCRIPT} language version, which supports
+     * features as defined in the most recent ECMAScript standard. This default behavior can be
+     * changed by overriding the ContextFactory class and installing the new implementation as the
+     * global ContextFactory.
      *
      * <p>Note that the Context must be associated with a thread before it can be used to execute a
      * script.
@@ -380,7 +399,10 @@ public Context() {
 
     /**
      * Creates a new context. Provided as a preferred super constructor for subclasses in place of
-     * the deprecated default public constructor.
+     * the deprecated default public constructor. By default, the new context will run in compiled
+     * mode and use the {@link #VERSION_ECMASCRIPT} language version, which supports features as
+     * defined in the most recent ECMAScript standard. This default behavior can be changed by
+     * overriding the ContextFactory class
      *
      * @param factory the context factory associated with this context (most likely, the one that
      *     created the context). Can not be null. The context features are inherited from the
@@ -392,7 +414,7 @@ protected Context(ContextFactory factory) {
             throw new IllegalArgumentException("factory == null");
         }
         this.factory = factory;
-        version = VERSION_DEFAULT;
+        version = VERSION_ECMASCRIPT;
         interpretedMode = codegenClass == null;
         maximumInterpreterStackDepth = Integer.MAX_VALUE;
     }
@@ -659,7 +681,16 @@ public final int getLanguageVersion() {
      * Set the language version.
      *
      * <p>Setting the language version will affect functions and scripts compiled subsequently. See
-     * the overview documentation for version-specific behavior.
+     * the overview documentation for version-specific behavior. The default version is {@link
+     * #VERSION_ECMASCRIPT}, which represents the newest ECMAScript features implemented by Rhino,
+     * and this is the version that should be used unless a project needs backwards compatibility
+     * with older Rhino scripts that may depend on behaviors from the earlier history of JavaScript.
+     *
+     * <p>As of version 1.8, the Rhino community has no plans to continue to add new language
+     * versions, but instead plans to track the ECMAScript standard and add new features as the
+     * language evolves in new versions of Rhino, like other JavaScript engines. Projects that use
+     * Rhino are encouraged to migrate to the {@link #VERSION_ECMASCRIPT} version and stop relying
+     * on older behaviors of Rhino that are no longer compatible with ECMAScript.
      *
      * @param version the version as specified by VERSION_1_0, VERSION_1_1, etc.
      */

rhino/src/test/java/org/mozilla/javascript/EqualObjectGraphsTest.java

@@ -81,6 +81,7 @@ public void sameValueDifferentTopology() {
     @Test
     public void heterogenousScriptables() {
         try (Context cx = Context.enter()) {
+            cx.setLanguageVersion(Context.VERSION_DEFAULT);
             ScriptableObject top = cx.initStandardObjects();
             ScriptRuntime.doTopCall(
                     (Callable)

rhino/src/test/java/org/mozilla/javascript/tests/Bug783797Test.java

@@ -25,6 +25,7 @@ private interface Action {
 
     private static ContextAction<Void> action(final String fn, final Action a) {
         return cx -> {
+            cx.setLanguageVersion(Context.VERSION_DEFAULT);
             ScriptableObject scope1 = cx.initStandardObjects();
             ScriptableObject scope2 = cx.initStandardObjects();
             scope1.put("scope2", scope1, scope2);

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

@@ -31,6 +31,7 @@ public void test1() throws Exception {
 
     private NativeContinuation createContinuation() throws Exception {
         try (Context cx = Context.enter()) {
+            cx.setLanguageVersion(Context.VERSION_DEFAULT);
             cx.setOptimizationLevel(-1); // interpreter for continuations
             ScriptableObject global = cx.initStandardObjects();
             final AtomicReference<NativeContinuation> captured = new AtomicReference<>();

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

@@ -89,6 +89,7 @@ public static Collection<Object[]> singleDoctest() throws IOException {
     public void runDoctest() throws Exception {
         ContextFactory factory = ContextFactory.getGlobal();
         try (Context cx = factory.enterContext()) {
+            cx.setLanguageVersion(Context.VERSION_DEFAULT);
             cx.setInterpretedMode(interpretedMode);
             Global global = new Global(cx);
             // global.runDoctest throws an exception on any failure

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

@@ -16,21 +16,33 @@ public static Object eval(String source) {
         return eval(source, null);
     }
 
+    public static Object eval(Context cx, String source) {
+        return eval(cx, source, null);
+    }
+
     public static Object eval(String source, String id, Scriptable object) {
         return eval(source, Collections.singletonMap(id, object));
     }
 
+    public static Object eval(Context cx, String source, String id, Scriptable object) {
+        return eval(cx, source, Collections.singletonMap(id, object));
+    }
+
     public static Object eval(String source, Map<String, Scriptable> bindings) {
         try (Context cx = ContextFactory.getGlobal().enterContext()) {
-            Scriptable scope = cx.initStandardObjects();
-            if (bindings != null) {
-                for (Map.Entry<String, Scriptable> entry : bindings.entrySet()) {
-                    final Scriptable object = entry.getValue();
-                    object.setParentScope(scope);
-                    scope.put(entry.getKey(), scope, object);
-                }
+            return eval(cx, source, bindings);
+        }
+    }
+
+    public static Object eval(Context cx, String source, Map<String, Scriptable> bindings) {
+        Scriptable scope = cx.initStandardObjects();
+        if (bindings != null) {
+            for (Map.Entry<String, Scriptable> entry : bindings.entrySet()) {
+                final Scriptable object = entry.getValue();
+                object.setParentScope(scope);
+                scope.put(entry.getKey(), scope, object);
             }
-            return cx.evaluateString(scope, source, "source", 1, null);
         }
+        return cx.evaluateString(scope, source, "source", 1, null);
     }
 }

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

@@ -566,6 +566,7 @@ private static void assertPrintMsg(String source, String expectedMsg) {
         DummyConsolePrinter printer = new DummyConsolePrinter();
 
         try (Context cx = Context.enter()) {
+            cx.setLanguageVersion(Context.VERSION_DEFAULT);
             Scriptable scope = cx.initStandardObjects();
             NativeConsole.init(scope, false, printer);
             cx.evaluateString(scope, source, "source", 1, null);

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

@@ -3,6 +3,7 @@
 import static org.junit.Assert.assertThrows;
 
 import org.junit.Test;
+import org.mozilla.javascript.Context;
 import org.mozilla.javascript.EvaluatorException;
 import org.mozilla.javascript.Scriptable;
 
@@ -11,6 +12,7 @@ public class NullishCoalescingOpTest {
     public void testNullishCoalescingOperatorRequiresES6() {
         Utils.runWithAllOptimizationLevels(
                 cx -> {
+                    cx.setLanguageVersion(Context.VERSION_DEFAULT);
                     Scriptable scope = cx.initStandardObjects();
                     assertThrows(
                             EvaluatorException.class,
@@ -77,6 +79,7 @@ public void testNullishCoalescingDoesNotLeakVariables() {
     public void testNullishAssignmentRequiresES6() {
         Utils.runWithAllOptimizationLevels(
                 cx -> {
+                    cx.setLanguageVersion(Context.VERSION_DEFAULT);
                     Scriptable scope = cx.initStandardObjects();
                     assertThrows(
                             EvaluatorException.class,

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

@@ -3,6 +3,7 @@
 import static org.junit.Assert.assertThrows;
 
 import org.junit.Test;
+import org.mozilla.javascript.Context;
 import org.mozilla.javascript.EvaluatorException;
 import org.mozilla.javascript.Scriptable;
 import org.mozilla.javascript.Undefined;
@@ -12,6 +13,7 @@ public class OptionalChainingOperatorTest {
     public void requiresES6() {
         Utils.runWithAllOptimizationLevels(
                 cx -> {
+                    cx.setLanguageVersion(Context.VERSION_DEFAULT);
                     Scriptable scope = cx.initStandardObjects();
                     assertThrows(
                             EvaluatorException.class,

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

@@ -66,6 +66,7 @@ public class ParserTest {
     @Before
     public void setUp() throws Exception {
         environment = new CompilerEnvirons();
+        environment.setLanguageVersion(Context.VERSION_DEFAULT);
     }
 
     @Test

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

@@ -40,6 +40,7 @@ public void setUp() throws Exception {
         }
 
         ctx = Context.enter();
+        ctx.setLanguageVersion(Context.VERSION_DEFAULT);
         scope1 = ctx.newObject(sharedScope);
         scope1.setPrototype(sharedScope);
         scope1.setParentScope(null);
@@ -79,7 +80,7 @@ public void importClassWithImporter() throws Exception {
         assertEquals(java.sql.Date.class, o);
 
         o = evaluateString(scope1, "Date"); // JavaScript "Statement" function
-        assertEquals(IdFunctionObject.class, o.getClass());
+        assertTrue(o instanceof IdFunctionObject);
 
         o = evaluateString(scope2, "typeof imp1"); // scope 2 has
         // no imp1
@@ -104,7 +105,7 @@ public void importPackageWithImporter() throws Exception {
         assertEquals(java.sql.Date.class, o);
 
         o = evaluateString(scope1, "Date"); // JavaScript "Statement" function
-        assertEquals(IdFunctionObject.class, o.getClass());
+        assertTrue(o instanceof IdFunctionObject);
 
         o = evaluateString(scope2, "typeof imp1 == 'undefined'"); // scope 2 has
         // no imp1

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

@@ -40,7 +40,6 @@ public Object call(
 
     @After
     public void tearDown() throws Exception {
-        cx.setLanguageVersion(Context.VERSION_DEFAULT);
         Context.exit();
     }
 
@@ -106,6 +105,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForApplyJS() {
         NativeArray arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(undefined)];");
 
         assertNotEquals(arr.get(0), arr.get(1));
@@ -117,6 +117,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForApplyJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(null)];");
         assertNotEquals(arr.get(0), arr.get(1));
         assertNotEquals(arr.get(0), arr.get(2));
@@ -126,6 +127,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForApplyJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(undefined)];");
 
         assertNotEquals(arr.get(0), arr.get(1));
@@ -137,6 +139,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForApplyJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(null)];");
         assertNotEquals(arr.get(0), arr.get(1));
         assertNotEquals(arr.get(0), arr.get(2));
@@ -149,6 +152,7 @@ public void whenVersionLtEq17ThenPassGlobalThisObjForApplyJS() {
         NativeArray arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(undefined)];");
 
         assertEquals(arr.get(0), arr.get(1));
@@ -158,6 +162,7 @@ public void whenVersionLtEq17ThenPassGlobalThisObjForApplyJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.apply(), F2.apply(null)];");
 
         assertEquals(arr.get(0), arr.get(1));
@@ -171,6 +176,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForCallJS() {
         NativeArray arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(undefined)];");
 
         assertNotEquals(arr.get(0), arr.get(1));
@@ -182,6 +188,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForCallJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(null)];");
         assertNotEquals(arr.get(0), arr.get(1));
         assertNotEquals(arr.get(0), arr.get(2));
@@ -191,6 +198,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForCallJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(undefined)];");
 
         assertNotEquals(arr.get(0), arr.get(1));
@@ -202,6 +210,7 @@ public void whenVersionGt17ThenPassNullAsThisObjForCallJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(null)];");
         assertNotEquals(arr.get(0), arr.get(1));
         assertNotEquals(arr.get(0), arr.get(2));
@@ -214,6 +223,7 @@ public void whenVersionLtEq17ThenPassGlobalThisObjForCallJS() {
         NativeArray arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(undefined)];");
 
         assertEquals(arr.get(0), arr.get(1));
@@ -223,6 +233,7 @@ public void whenVersionLtEq17ThenPassGlobalThisObjForCallJS() {
         arr =
                 (NativeArray)
                         Evaluator.eval(
+                                cx,
                                 "function F2() {return this;};[this, F2.call(), F2.call(null)];");
 
         assertEquals(arr.get(0), arr.get(1));