[destructuring] Implement parameter pattern matching.

test/cctest/test-parsing.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6371 matching lines @@
   i::FLAG_harmony_destructuring = true;
   i::FLAG_harmony_arrow_functions = true;
   i::FLAG_harmony_computed_property_names = true;
 
   const char* context_data[][2] = {{"'use strict'; let ", " = {};"},
                                    {"var ", " = {};"},
                                    {"'use strict'; const ", " = {};"},
                                    {"function f(", ") {}"},
                                    {"function f(argument1, ", ") {}"},
                                    {"var f = (", ") => {};"},
-                                   {"var f = ", " => {};"},
                                    {"var f = (argument1,", ") => {};"},
                                    {NULL, NULL}};
 
   // clang-format off
   const char* data[] = {
     "a",
     "{ x : y }",
     "{ x : y = 1 }",
     "[a]",
     "[a = 1]",
@@ skipping 195 matching lines @@
   // clang-format off
   const char* success_data[] = {
     "for (var x = {} in null);",
     NULL};
   // clang-format on
   RunParserSyncTest(context_data, success_data, kSuccess, NULL, 0, always_flags,
                     arraysize(always_flags));
 }
 
 
+TEST(DestructuringDuplicateParams) {
+  i::FLAG_harmony_destructuring = true;
+  i::FLAG_harmony_arrow_functions = true;
+  i::FLAG_harmony_computed_property_names = true;
+  static const ParserFlag always_flags[] = {
+      kAllowHarmonyObjectLiterals, kAllowHarmonyComputedPropertyNames,
+      kAllowHarmonyArrowFunctions, kAllowHarmonyDestructuring};
+  const char* context_data[][2] = {{"'use strict';", ""},
+                                   {"function outer() { 'use strict';", "}"},
+                                   {nullptr, nullptr}};
+
+
+  // clang-format off
+  const char* error_data[] = {
+    "function f(x,x){}",
+    "function f(x, {x : x}){}",
+    "function f(x, {x}){}",
+    "function f({x,x}) {}",
+    // non-simple parameter list causes duplicates to be errors in sloppy mode.
+    "function f(x, x, {a}) {}",
+    "var f = {x,y} => {};",

[rossberg, 2015/06/19 16:26:35]

{x,x} ? But isn't this a plain syntax error anyway?

[Dmitry Lomov (no reviews), 2015/06/22 10:14:10]

Moved to separate test.

+    nullptr};
+  // clang-format on
+  RunParserSyncTest(context_data, error_data, kError, NULL, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
+TEST(DestructuringDuplicateParamsSloppy) {
+  i::FLAG_harmony_destructuring = true;
+  i::FLAG_harmony_arrow_functions = true;
+  i::FLAG_harmony_computed_property_names = true;
+  static const ParserFlag always_flags[] = {
+      kAllowHarmonyObjectLiterals, kAllowHarmonyComputedPropertyNames,
+      kAllowHarmonyArrowFunctions, kAllowHarmonyDestructuring};
+  const char* context_data[][2] = {
+      {"", ""}, {"function outer() {", "}"}, {nullptr, nullptr}};
+
+
+  // clang-format off
+  const char* error_data[] = {
+    // non-simple parameter list causes duplicates to be errors in sloppy mode.
+    "function f(x, {x : x}){}",
+    "function f(x, {x}){}",
+    "function f({x,x}) {}",
+    "function f(x, x, {a}) {}",
+    "var f = {x} => {};",

[rossberg, 2015/06/19 16:26:35]

Same here, this test is unrelated to duplicates.

[Dmitry Lomov (no reviews), 2015/06/22 10:14:10]

Moved to separate test.

+    nullptr};
+  // clang-format on
+  RunParserSyncTest(context_data, error_data, kError, NULL, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
 TEST(SpreadArray) {
   i::FLAG_harmony_spread_arrays = true;
 
   const char* context_data[][2] = {
       {"'use strict';", ""}, {"", ""}, {NULL, NULL}};
 
   // clang-format off
   const char* data[] = {
     "[...a]",
     "[a, ...b]",
@@ skipping 80 matching lines @@
     kAllowHarmonyObjectLiterals,
     kAllowHarmonySloppy,
   };
   // clang-format on
 
   RunParserSyncTest(good_context_data, data, kSuccess, NULL, 0, always_flags,
                     arraysize(always_flags));
   RunParserSyncTest(bad_context_data, data, kError, NULL, 0, always_flags,
                     arraysize(always_flags));
 }