[parser] report better errors for multiple ForBindings in ForIn/Of loops

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index a086c3ec617142db00252cb462ba2a06506ac4e3..1f880c53ce4b285264679e073a8141bd8c9c27ad 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -4628,6 +4628,159 @@ TEST(ConstParsingInForInError) {
 }
 
 
+TEST(InitializedDeclarationsInStrictForInError) {
+  const char* context_data[][2] = {{"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i = 1 in {}) {}",
+      "for (var i = void 0 in [1, 2, 3]) {}",
+      "for (let i = 1 in {}) {}",
+      "for (let i = void 0 in [1, 2, 3]) {}",
+      "for (const i = 1 in {}) {}",
+      "for (const i = void 0 in [1, 2, 3]) {}",
+      NULL};
+  RunParserSyncTest(context_data, data, kError);
+}
+
+
+TEST(InitializedDeclarationsInStrictForOfError) {
+  const char* context_data[][2] = {{"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i = 1 of {}) {}",
+      "for (var i = void 0 of [1, 2, 3]) {}",
+      "for (let i = 1 of {}) {}",
+      "for (let i = void 0 of [1, 2, 3]) {}",
+      "for (const i = 1 of {}) {}",
+      "for (const i = void 0 of [1, 2, 3]) {}",
+      NULL};
+  RunParserSyncTest(context_data, data, kError);
+}
+
+
+TEST(InitializedDeclarationsInSloppyForInError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i = 1 in {}) {}",
+      "for (var i = void 0 in [1, 2, 3]) {}",
+      NULL};
+  // TODO(caitp): This should be an error in sloppy mode.
+  RunParserSyncTest(context_data, data, kSuccess);
+}
+
+
+TEST(InitializedDeclarationsInSloppyForOfError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i = 1 of {}) {}",
+      "for (var i = void 0 of [1, 2, 3]) {}",
+      NULL};
+  RunParserSyncTest(context_data, data, kError);
+}
+
+
+TEST(ForInMultipleDeclarationsError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i, j in {}) {}",
+      "for (var i, j in [1, 2, 3]) {}",
+      "for (var i, j = 1 in {}) {}",
+      "for (var i, j = void 0 in [1, 2, 3]) {}",
+
+      "for (let i, j in {}) {}",
+      "for (let i, j in [1, 2, 3]) {}",
+      "for (let i, j = 1 in {}) {}",
+      "for (let i, j = void 0 in [1, 2, 3]) {}",
+
+      "for (const i, j in {}) {}",
+      "for (const i, j in [1, 2, 3]) {}",
+      "for (const i, j = 1 in {}) {}",
+      "for (const i, j = void 0 in [1, 2, 3]) {}",
+      NULL};
+  static const ParserFlag always_flags[] = {kAllowHarmonySloppy};
+  RunParserSyncTest(context_data, data, kError, nullptr, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
+TEST(ForOfMultipleDeclarationsError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var i, j of {}) {}",
+      "for (var i, j of [1, 2, 3]) {}",
+      "for (var i, j = 1 of {}) {}",
+      "for (var i, j = void 0 of [1, 2, 3]) {}",
+
+      "for (let i, j of {}) {}",
+      "for (let i, j of [1, 2, 3]) {}",
+      "for (let i, j = 1 of {}) {}",
+      "for (let i, j = void 0 of [1, 2, 3]) {}",
+
+      "for (const i, j of {}) {}",
+      "for (const i, j of [1, 2, 3]) {}",
+      "for (const i, j = 1 of {}) {}",
+      "for (const i, j = void 0 of [1, 2, 3]) {}",
+      NULL};
+  static const ParserFlag always_flags[] = {kAllowHarmonySloppy};
+  RunParserSyncTest(context_data, data, kError, nullptr, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
+TEST(ForInNoDeclarationsError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var in {}) {}",
+      "for (const in {}) {}",
+      NULL};
+  static const ParserFlag always_flags[] = {kAllowHarmonySloppy};
+  RunParserSyncTest(context_data, data, kError, nullptr, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
+TEST(ForOfNoDeclarationsError) {
+  const char* context_data[][2] = {{"", ""},
+                                   {"function foo(){", "}"},
+                                   {"'use strict';", ""},
+                                   {"function foo(){ 'use strict';", "}"},
+                                   {NULL, NULL}};
+
+  const char* data[] = {
+      "for (var of [1, 2, 3]) {}",
+      "for (const of [1, 2, 3]) {}",
+      NULL};
+  static const ParserFlag always_flags[] = {kAllowHarmonySloppy};
+  RunParserSyncTest(context_data, data, kError, nullptr, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
 TEST(InvalidUnicodeEscapes) {
   const char* context_data[][2] = {{"", ""},
                                    {"'use strict';", ""},