Improve coverage for section 9 (#726)

* Assert creation of 'arguments' object

Ensure that the 'arguments' object is created in cases where it is not
required by the body but is required by the parameters.

* Add tests for cases that disable "arguments" map

* Add tests for NewTarget override of bound function

* Add test for properties of exotic String objects

test/built-ins/Function/prototype/bind/instance-construct-newtarget-boundtarget-bound.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-bound-function-exotic-objects-construct-argumentslist-newtarget
+es6id: 9.4.1.2
+description: >
+  The NewTarget value is changed to the target function when the bound function
+  object is constructed using Reflect.construct and the "bound target" is
+  specified as the NewTarget value (and the bound target is itself a bound
+  function)
+info: |
+  [...]
+  5. If SameValue(F, newTarget) is true, let newTarget be target.
+  6. Return ? Construct(target, args, newTarget). 
+features: [Reflect, new.target]
+---*/
+
+var newTarget;
+function A() {
+  newTarget = new.target;
+}
+var B = A.bind();
+var C = B.bind();
+
+var c = Reflect.construct(C, [], B);
+
+assert.sameValue(newTarget, A);
+assert.sameValue(Object.getPrototypeOf(c), A.prototype);

test/built-ins/Function/prototype/bind/instance-construct-newtarget-boundtarget.js

@@ -0,0 +1,27 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-bound-function-exotic-objects-construct-argumentslist-newtarget
+es6id: 9.4.1.2
+description: >
+  The NewTarget value is changed to the target function when the bound function
+  object is constructed using Reflect.construct and the "bound target" is
+  specified as the NewTarget value
+info: |
+  [...]
+  5. If SameValue(F, newTarget) is true, let newTarget be target.
+  6. Return ? Construct(target, args, newTarget). 
+features: [Reflect, new.target]
+---*/
+
+var newTarget;
+function A() {
+  newTarget = new.target;
+}
+var B = A.bind();
+var C = B.bind();
+
+var c = Reflect.construct(C, [], A);
+
+assert.sameValue(newTarget, A);
+assert.sameValue(Object.getPrototypeOf(c), A.prototype);

test/built-ins/Function/prototype/bind/instance-construct-newtarget-self-new.js

@@ -0,0 +1,26 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-bound-function-exotic-objects-construct-argumentslist-newtarget
+es6id: 9.4.1.2
+description: >
+  The NewTarget value is changed to the target function when the bound function
+  object is constructed using the `new` operator
+info: |
+  [...]
+  5. If SameValue(F, newTarget) is true, let newTarget be target.
+  6. Return ? Construct(target, args, newTarget). 
+features: [new.target]
+---*/
+
+var newTarget;
+function A() {
+  newTarget = new.target;
+}
+var B = A.bind();
+var C = B.bind();
+
+var c = new C();
+
+assert.sameValue(newTarget, A);
+assert.sameValue(Object.getPrototypeOf(c), A.prototype);

test/built-ins/Function/prototype/bind/instance-construct-newtarget-self-reflect.js

@@ -0,0 +1,27 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-bound-function-exotic-objects-construct-argumentslist-newtarget
+es6id: 9.4.1.2
+description: >
+  The NewTarget value is changed to the target function when the bound function
+  object is constructed using Reflect.construct and the bound function is
+  specified as the NewTarget value
+info: |
+  [...]
+  5. If SameValue(F, newTarget) is true, let newTarget be target.
+  6. Return ? Construct(target, args, newTarget). 
+features: [Reflect, new.target]
+---*/
+
+var newTarget;
+function A() {
+  newTarget = new.target;
+}
+var B = A.bind();
+var C = B.bind();
+
+var c = Reflect.construct(C, [], C);
+
+assert.sameValue(newTarget, A);
+assert.sameValue(Object.getPrototypeOf(c), A.prototype);

test/built-ins/String/numeric-properties.js

@@ -0,0 +1,32 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-string-exotic-objects-getownproperty-p
+es6id: 9.4.3.1
+description: >
+  Property descriptor for numeric "own" properties of an exotic String object
+info: |
+  [...]
+  12. Let resultStr be a String value of length 1, containing one code unit
+      from str, specifically the code unit at index index.
+  13. Return a PropertyDescriptor{[[Value]]: resultStr, [[Writable]]: false,
+      [[Enumerable]]: true, [[Configurable]]: false}. 
+includes: [propertyHelper.js]
+---*/
+
+var str = new String('abc');
+
+assert.sameValue(str[0], 'a');
+verifyEnumerable(str, '0');
+verifyNotWritable(str, '0');
+verifyNotConfigurable(str, '0');
+
+assert.sameValue(str[1], 'b');
+verifyEnumerable(str, '1');
+verifyNotWritable(str, '1');
+verifyNotConfigurable(str, '1');
+
+assert.sameValue(str[2], 'c');
+verifyEnumerable(str, '2');
+verifyNotWritable(str, '2');
+verifyNotConfigurable(str, '2');

test/language/arguments-object/unmapped/via-params-dflt.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments are "unmapped" when paramater list is non-simple due to "default"
+  parameter
+info: |
+  [...]
+  9. Let simpleParameterList be IsSimpleParameterList of formals.
+  [...]
+  22. If argumentsObjectNeeded is true, then
+      a. If strict is true or if simpleParameterList is false, then
+         i. Let ao be CreateUnmappedArgumentsObject(argumentsList).
+      [...]
+---*/
+
+var value;
+
+function dflt(a, b = 0) {
+  arguments[0] = 2;
+  value = a;
+}
+
+dflt(1);
+
+assert.sameValue(value, 1);

test/language/arguments-object/unmapped/via-params-dstr.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments are "unmapped" when paramater list is non-simple due to
+  destructuring pattern
+info: |
+  [...]
+  9. Let simpleParameterList be IsSimpleParameterList of formals.
+  [...]
+  22. If argumentsObjectNeeded is true, then
+      a. If strict is true or if simpleParameterList is false, then
+         i. Let ao be CreateUnmappedArgumentsObject(argumentsList).
+      [...]
+---*/
+
+var value;
+
+function dstr(a, [b]) {
+  arguments[0] = 2;
+  value = a;
+}
+
+dstr(1, []);
+
+assert.sameValue(value, 1);

test/language/arguments-object/unmapped/via-params-rest.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments are "unmapped" when paramater list is non-simple due to "rest"
+  parameter
+info: |
+  [...]
+  9. Let simpleParameterList be IsSimpleParameterList of formals.
+  [...]
+  22. If argumentsObjectNeeded is true, then
+      a. If strict is true or if simpleParameterList is false, then
+         i. Let ao be CreateUnmappedArgumentsObject(argumentsList).
+      [...]
+---*/
+
+var value;
+
+function rest(a, ...b) {
+  arguments[0] = 2;
+  value = a;
+}
+
+rest(1);
+
+assert.sameValue(value, 1);

test/language/expressions/function/arguments-with-arguments-fn.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a lexically-scoped
+  binding named "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+var f = function(x = args = arguments) {
+  function arguments() {}
+};
+
+f();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/expressions/function/arguments-with-arguments-lex.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a function named
+  "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+var f = function (x = args = arguments) {
+  let arguments;
+};
+
+f();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/expressions/generators/arguments-with-arguments-fn.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a lexically-scoped
+  binding named "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+var g = function* (x = args = arguments) {
+  function arguments() {}
+};
+
+g().next();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/expressions/generators/arguments-with-arguments-lex.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a function named
+  "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+var g  = function* (x = args = arguments) {
+  let arguments;
+};
+
+g().next();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/statements/function/arguments-with-arguments-fn.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a lexically-scoped
+  binding named "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+function f(x = args = arguments) {
+  function arguments() {}
+}
+
+f();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/statements/function/arguments-with-arguments-lex.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a function named
+  "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+function f(x = args = arguments) {
+  let arguments;
+}
+
+f();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/statements/generators/arguments-with-arguments-fn.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a lexically-scoped
+  binding named "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+function* g(x = args = arguments) {
+  function arguments() {}
+}
+
+g().next();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);

test/language/statements/generators/arguments-with-arguments-lex.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-functiondeclarationinstantiation
+es6id: 9.2.12
+description: >
+  Arguments object is created even when the body contains a function named
+  "arguments"
+info: |
+  [...]
+  19. Else if "arguments" is an element of parameterNames, then
+      a. Let argumentsObjectNeeded be false.
+  20. Else if hasParameterExpressions is false, then
+      a. If "arguments" is an element of functionNames or if "arguments" is an
+         element of lexicalNames, then
+         i. Let argumentsObjectNeeded be false.
+  [...]
+flags: [noStrict]
+---*/
+
+var args;
+
+function* g(x = args = arguments) {
+  let arguments;
+}
+
+g().next();
+
+assert.sameValue(typeof args, 'object');
+assert.sameValue(args.length, 0);