[destructuring] Implement parameter pattern matching.

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 675b48797952dbaf3e0afd23b933c61651ea1998..f60e2d10f874bbce243b4e38885ed1fea5840354 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -6389,7 +6389,6 @@ TEST(DestructuringPositiveTests) {
                                    {"function f(", ") {}"},
                                    {"function f(argument1, ", ") {}"},
                                    {"var f = (", ") => {};"},
-                                   {"var f = ", " => {};"},
                                    {"var f = (argument1,", ") => {};"},
                                    {NULL, NULL}};
 
@@ -6417,6 +6416,7 @@ TEST(DestructuringPositiveTests) {
     "{42 : x = 42}",
     "{42e-2 : x}",
     "{42e-2 : x = 42}",
+    "{x : y, x : z}",
     "{'hi' : x}",
     "{'hi' : x = 42}",
     "{var: x}",
@@ -6605,6 +6605,85 @@ TEST(DestructuringDisallowPatternsInForVarIn) {
 }
 
 
+TEST(DestructuringDuplicateParams) {

[wingo, 2015/06/22 10:28:33]

Need tests that patterns are not allowed in rest parameters

function(...{}) {}
function(...{x}) {}
function(...[x]) {}
(...{}) => {}
(...{x}) => {}
(...[x]) => {}

[Dmitry Lomov (no reviews), 2015/06/22 11:11:42]

Done (also fixed)

+  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}) {}",
+    "function f([x,x]) {}",
+    "function f(x, [y,{z:x}]) {}",
+    "function f([x,{y:x}]) {}",
+    // non-simple parameter list causes duplicates to be errors in sloppy mode.
+    "function f(x, x, {a}) {}",

[wingo, 2015/06/22 10:28:33]

Arrow function tests would be nice here:

  ({x, x}) => {}
  (x, {y, y}) => {}
  (x, {x, y}) => {}
  ({x}, ...x) => {}

  ([x, x]) => {}
  (x, [y, y]) => {}
  (x, [x, y]) => {}
  ([x], ...x) => {}

[Dmitry Lomov (no reviews), 2015/06/22 11:11:42]

For arrow functions duplicate parameter detection does not work in preparser (it
is too expensive to use duplicate finder).
The test are in destructuring.js

+    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}) {}",
+    nullptr};
+  // clang-format on
+  RunParserSyncTest(context_data, error_data, kError, NULL, 0, always_flags,
+                    arraysize(always_flags));
+}
+
+
+TEST(DestructuringDisallowPatternsInSingleParamArrows) {
+  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';", "}"},
+                                   {"", ""},
+                                   {"function outer() { ", "}"},
+                                   {nullptr, nullptr}};
+
+  // clang-format off
+  const char* error_data[] = {
+    "var f = {x} => {};",
+    "var f = {x,y} => {};",
+    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;