make arguments a function prototype property

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

@@ -69,6 +69,16 @@ static LambdaConstructor init(Context cx, Scriptable scope, boolean sealed) {
         if (cx.getLanguageVersion() >= Context.VERSION_ES6) {
             ctor.setStandardPropertyAttributes(READONLY | DONTENUM);
         }
+
+        if (!cx.isStrictMode() && cx.getLanguageVersion() >= Context.VERSION_ES6) {
+            ctor.definePrototypeProperty(
+                    cx,
+                    "arguments",
+                    BaseFunction::js_protoArgumentsGetter,
+                    BaseFunction::js_protoArgumentsSetter,
+                    DONTENUM | READONLY);
+        }
+
         ScriptableObject.defineProperty(scope, FUNCTION_CLASS, ctor, DONTENUM);
         if (sealed) {
             ctor.sealObject();
@@ -177,20 +187,21 @@ protected void createProperties() {
                 DONTENUM | READONLY,
                 BaseFunction::nameGetter,
                 BaseFunction::nameSetter);
-        if (includeNonStandardProps()) {
+
+        Context cx = Context.getCurrentContext();
+        if (cx == null || !cx.isStrictMode()) {
             ScriptableObject.defineBuiltInProperty(
                     this, "arity", PERMANENT | DONTENUM | READONLY, BaseFunction::arityGetter);
-            ScriptableObject.defineBuiltInProperty(
-                    this,
-                    "arguments",
-                    PERMANENT | DONTENUM,
-                    BaseFunction::argumentsGetter,
-                    BaseFunction::argumentsSetter);
-        }
-    }
 
-    protected boolean includeNonStandardProps() {
-        return !Context.isCurrentContextStrict();
+            if (cx == null || cx.getLanguageVersion() < Context.VERSION_ES6) {
+                ScriptableObject.defineBuiltInProperty(
+                        this,
+                        "arguments",
+                        PERMANENT | DONTENUM,
+                        BaseFunction::argumentsGetter,
+                        BaseFunction::argumentsSetter);
+            }
+        }
     }
 
     private static Object lengthGetter(BaseFunction function, Scriptable start) {
@@ -627,6 +638,14 @@ public int getLength() {
         return 0;
     }
 
+    private static Object js_protoArgumentsGetter(Scriptable thisObj) {
+        return LambdaConstructor.convertThisObject(thisObj, BaseFunction.class).getArguments();
+    }
+
+    private static void js_protoArgumentsSetter(Scriptable thisObj, Object value) {
+        LambdaConstructor.convertThisObject(thisObj, BaseFunction.class).setArguments(value);
+    }
+
     public String getFunctionName() {
         return "";
     }
@@ -713,7 +732,7 @@ protected synchronized Object setupDefaultPrototype(Scriptable scope) {
         return obj;
     }
 
-    private Object getArguments() {
+    Object getArguments() {
         // <Function name>.arguments is deprecated, so we use a slow
         // way of getting it that doesn't add to the invocation cost.
         // TODO: add warning, error based on version
@@ -731,13 +750,18 @@ private Object getArguments() {
         if (activation == null) {
             return null;
         }
+        if (activation.isStrict && cx.getLanguageVersion() >= Context.VERSION_ES6) {
+            ScriptRuntime.ThrowTypeError.throwNotAllowed();
+        }
         Object arguments = activation.get("arguments", activation);
         if (arguments instanceof Arguments && cx.getLanguageVersion() >= Context.VERSION_ES6) {
             return new Arguments.ReadonlyArguments((Arguments) arguments, cx);
         }
         return arguments;
     }
 
+    void setArguments(Object caller) {}
+
     private static Scriptable jsConstructor(
             Context cx, Scriptable scope, Object[] args, boolean isGeneratorFunction) {
         int arglen = args.length;

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

@@ -40,8 +40,21 @@ public BoundFunction(
         Function thrower = ScriptRuntime.typeErrorThrower(cx);
         var throwing = new DescriptorInfo(false, NOT_FOUND, false, thrower, thrower, NOT_FOUND);
 
-        this.defineOwnProperty(cx, "caller", throwing, false);
-        this.defineOwnProperty(cx, "arguments", throwing, false);
+        defineOwnProperty(cx, "caller", throwing, false);
+        if (cx.getLanguageVersion() < Context.VERSION_ES6) {
+            defineOwnProperty(cx, "arguments", throwing, false);
+        }
+    }
+
+    @Override
+    Object getArguments() {
+        ScriptRuntime.ThrowTypeError.throwNotAllowed();
+        return null;
+    }
+
+    @Override
+    void setArguments(Object caller) {
+        ScriptRuntime.ThrowTypeError.throwNotAllowed();
     }
 
     @Override

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

@@ -74,7 +74,7 @@ public static BaseFunction typeErrorThrower(Context cx) {
         return cx.typeErrorThrower;
     }
 
-    private static final class ThrowTypeError extends BaseFunction {
+    static final class ThrowTypeError extends BaseFunction {
         private static final long serialVersionUID = -5891740962154902286L;
 
         ThrowTypeError(Scriptable scope) {
@@ -101,6 +101,11 @@ private static Slot removeWithoutChecking(
 
         @Override
         public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
+            throwNotAllowed();
+            return null;
+        }
+
+        public static void throwNotAllowed() {
             throw typeErrorById("msg.op.not.allowed");
         }
     }

tests/src/test/java/org/mozilla/javascript/tests/es6/ArgumentsTest.java

@@ -238,7 +238,7 @@ public void argumentsShouldBeNullOutsideFunctionStrict() {
                         + "res";
 
         // Utils.assertWithAllModes_ES6("ex [object Arguments] ex ex", code);
-        Utils.assertWithAllModes_ES6("null [object Arguments] null null", code);
+        Utils.assertWithAllModes_ES6("null [object Arguments] ex null", code);
         Utils.assertWithAllModes_1_8("null [object Arguments] null null", code);
     }
 
@@ -255,7 +255,7 @@ public void argumentsOutsideFunction() {
                         + "res";
 
         // Utils.assertWithAllModes_ES6("undefined length,name,prototype", code);
-        Utils.assertWithAllModes_ES6("[object Object] arguments,arity,length,name,prototype", code);
+        Utils.assertWithAllModes_ES6("undefined arity,length,name,prototype", code);
         Utils.assertWithAllModes_1_8("[object Object] arguments,arity,length,name,prototype", code);
     }
 
@@ -340,8 +340,7 @@ public void passedCountDifferentFromDeclaredStrict() {
                         + "test('hi', 'there');\n"
                         + "res";
 
-        // Utils.assertWithAllModes_ES6("2 ex", code);
-        Utils.assertWithAllModes_ES6("2 null", code);
+        Utils.assertWithAllModes_ES6("2 ex", code);
         Utils.assertWithAllModes_1_8("2 null", code);
     }
 
@@ -636,7 +635,7 @@ public void argumentsEqualsFnArgumentsStrict() {
                         + "function test() {\n"
                         + "  try {\n"
                         + "    res += ' ' + (arguments == test.arguments);\n"
-                        + "  } catch(e) { res += 'ex'; }"
+                        + "  } catch(e) { res += ' ex'; }"
                         + "  try {\n"
                         + "    res += ' ' + (arguments === test.arguments);\n"
                         + "  } catch(e) { res += ' ex'; }"
@@ -645,8 +644,7 @@ public void argumentsEqualsFnArgumentsStrict() {
                         + "test('hello', 'world');\n"
                         + "res";
 
-        // Utils.assertWithAllModes_ES6("ex ex", code);
-        Utils.assertWithAllModes_ES6("null false false", code);
+        Utils.assertWithAllModes_ES6("null ex ex", code);
         Utils.assertWithAllModes_1_8("null false false", code);
     }
 

tests/src/test/java/org/mozilla/javascript/tests/es6/BoundFunctionTest.java

@@ -2,14 +2,14 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/*
- * Tests for the Object.getOwnPropertyDescriptor(obj, prop) method
- */
 package org.mozilla.javascript.tests.es6;
 
 import org.junit.Test;
 import org.mozilla.javascript.testutils.Utils;
 
+/*
+ * Tests for BoundFunction
+ */
 public class BoundFunctionTest {
 
     @Test
@@ -20,7 +20,7 @@ public void name() {
     }
 
     @Test
-    public void lenght() {
+    public void length() {
         Utils.assertWithAllModes_ES6(0, "function foo() {}; foo.bind({}).length;");
 
         Utils.assertWithAllModes_ES6(1, "function foo(a) {}; foo.bind({}).length;");
@@ -39,6 +39,30 @@ public void lenght() {
         Utils.assertWithAllModes_ES6(1, "function foo(a, b, c) {}; foo.bind({}, 'x', 'y').length;");
     }
 
+    @Test
+    public void arguments() {
+        String code =
+                "function foo() { return 'Hello!'; };\n"
+                        + "var boundFoo = foo.bind({});\n"
+                        + "'' + Object.getOwnPropertyDescriptor(boundFoo, 'arguments');";
+        Utils.assertWithAllModes_ES6("undefined", code);
+        Utils.assertWithAllModes_1_8("[object Object]", code);
+    }
+
+    @Test
+    public void argumentsAccess() {
+        String code =
+                "function foo() { return 'Hello!'; };\n"
+                        + "var boundFoo = foo.bind({});\n"
+                        + "let res = '';\n"
+                        + "try { boundFoo.arguments; res += 'no ex'; } catch (e) { res += e.message; };\n"
+                        + "try { boundFoo.arguments = 7; res += ' no ex'; } catch (e) { res += ' ' + e.message; };";
+        Utils.assertWithAllModes_ES6(
+                "This operation is not allowed. This operation is not allowed.", code);
+        Utils.assertWithAllModes_1_8(
+                "This operation is not allowed. This operation is not allowed.", code);
+    }
+
     @Test
     public void fooArgs0_boundArgs0_invokeArgs0() {
         Utils.assertWithAllModes_ES6("boundThis []", constructCode(0, 0, "(", 0, false));

tests/src/test/java/org/mozilla/javascript/tests/es6/FunctionArityTest.java

@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.javascript.tests.es6;
+
+import org.junit.jupiter.api.Test;
+import org.mozilla.javascript.testutils.Utils;
+
+class FunctionArityTest {
+
+    @Test
+    void simple() {
+        // todo Utils.assertWithAllModes_ES6("undefined", "function f(a,b) {}; '' + f.arity");
+        // todo Utils.assertWithAllModes_ES6("undefined", "function f() {}; '' + f.arity");
+        Utils.assertWithAllModes_ES6("2", "function f(a,b) {}; '' + f.arity");
+        Utils.assertWithAllModes_ES6("0", "function f() {}; '' + f.arity");
+
+        Utils.assertWithAllModes_1_8("2", "function f(a,b) {}; '' + f.arity");
+        Utils.assertWithAllModes_1_8("0", "function f() {}; '' + f.arity");
+    }
+
+    @Test
+    void arrow() {
+        // todo Utils.assertWithAllModes_ES6("undefined", "'' + ((a,b) => {}).arity");
+        // todo Utils.assertWithAllModes_ES6("undefined", "'' + (() => {}).arity");
+        Utils.assertWithAllModes_ES6("2", "'' + ((a,b) => {}).arity");
+        Utils.assertWithAllModes_ES6("0", "'' + (() => {}).arity");
+
+        Utils.assertWithAllModes_1_8("2", "'' + ((a,b) => {}).arity");
+        Utils.assertWithAllModes_1_8("0", "'' + (() => {}).arity");
+    }
+}

tests/src/test/java/org/mozilla/javascript/tests/es6/GeneratorFunctionTest.java

@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.javascript.tests.es6;
+
+import org.junit.Test;
+import org.mozilla.javascript.testutils.Utils;
+
+/*
+ * Tests for GeneratorFunction
+ */
+public class GeneratorFunctionTest {
+
+    @Test
+    public void arguments() {
+        String code =
+                "function* foo() { yield 'Hello!'; };\n"
+                        + "'' + Object.getOwnPropertyDescriptor(foo, 'arguments');";
+        Utils.assertWithAllModes_ES6("undefined", code);
+    }
+
+    @Test
+    public void argumentsAccess() {
+        String code =
+                "function* foo() { yield 'Hello!'; };\n"
+                        + "let res = '';\n"
+                        + "try { foo.arguments; res += 'no ex'; } catch (e) { res += e.message; };\n"
+                        + "try { foo.arguments = 7; res += ' no ex'; } catch (e) { res += ' ' + e.message; };";
+        // todo Utils.assertWithAllModes_ES6("This operation is not allowed. This operation is not
+        // allowed.", code);
+        Utils.assertWithAllModes_ES6("no ex no ex", code);
+    }
+}