Implement delete trap for proxies.

test/mjsunit/harmony/proxies.js

 // Flags: --harmony-proxies
 
 // Copyright 2008 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
@@ skipping 271 matching lines @@
   defineProperty2: function(k, d) { key = k; desc = d; return true }
 })
 TestDefine(Proxy.create({
   get: function(pr, pk) {
     return function(k, d) { key = k; desc = d; return true }
   }
 }))
 
 
 
+// Property deletion (delete).
+
+var key
+function TestDelete(handler) {
+  var o = Proxy.create(handler)
+  assertEquals(true, delete o.a)
+  assertEquals("a", key)
+  assertEquals(true, delete o["b"])
+  assertEquals("b", key)
+
+  assertEquals(false, delete o.z1)
+  assertEquals("z1", key)
+  assertEquals(false, delete o["z2"])
+  assertEquals("z2", key);
+
+  (function() {
+    "use strict"
+    assertEquals(true, delete o.c)
+    assertEquals("c", key)
+    assertEquals(true, delete o["d"])
+    assertEquals("d", key)
+
+    assertThrows(function() { delete o.z3 }, TypeError)
+    assertEquals("z3", key)
+    assertThrows(function() { delete o["z4"] }, TypeError)
+    assertEquals("z4", key)
+  })()
+}
+
+TestDelete({
+  'delete': function(k) { key = k; return k < "z" }
+})
+TestDelete({
+  'delete': function(k) { return this.delete2(k) },
+  delete2: function(k) { key = k; return k < "z" }
+})
+TestDelete(Proxy.create({
+  get: function(pr, pk) {
+    return function(k) { key = k; return k < "z" }
+  }
+}))
+
+
+
 // Property descriptors (Object.getOwnPropertyDescriptor).
 
 function TestDescriptor(handler) {
   var o = Proxy.create(handler)
   var descs = [
     {configurable: true},
     {value: 34, enumerable: true, configurable: true},
     {value: 3, writable: false, mine: "eyes", configurable: true},
     {get value() { return 20 }, get configurable() { return true }},
     {get: function() { "get" }, set: function() { "set" }, configurable: true}
@@ skipping 176 matching lines @@
   get getOwnPropertyDescriptor() {
     return function(k) { return {enumerable: k >= "44"} }
   }
 })
 TestKeys([], {
   get getOwnPropertyNames() {
     return function() { return ["a", "b", "c"] }
   },
   getOwnPropertyDescriptor: function(k) { return {} }
 })