removing code that restricts duplicate key names and associated tests

lib/coffee-script/nodes.js

@@ -1172,37 +1172,14 @@
     Obj.prototype.children = ['properties'];
 
     Obj.prototype.compileNode = function(o) {
-      var i, idt, indent, join, lastNoncom, node, normalise, normalisedPropName, obj, prop, propName, propNames, props, _i, _j, _len, _len1, _ref2;
+      var i, idt, indent, join, lastNoncom, node, obj, prop, props, _i, _len;
       props = this.properties;
-      propNames = [];
-      normalise = function(v) {
-        if (IDENTIFIER.test(v)) {
-          return v;
-        } else {
-          return "" + Function("return " + v)();
-        }
-      };
-      _ref2 = this.properties;
-      for (_i = 0, _len = _ref2.length; _i < _len; _i++) {
-        prop = _ref2[_i];
-        if (prop.isComplex()) {
-          prop = prop.variable;
-        }
-        if (prop != null) {
-          propName = prop.unwrapAll().value.toString();
-          normalisedPropName = normalise(propName);
-          if (__indexOf.call(propNames, normalisedPropName) >= 0) {
-            throw SyntaxError("multiple object literal properties named \"" + propName + "\"");
-          }
-          propNames.push(normalisedPropName);
-        }
-      }
       if (!props.length) {
         return (this.front ? '({})' : '{}');
       }
       if (this.generated) {
-        for (_j = 0, _len1 = props.length; _j < _len1; _j++) {
+        for (_i = 0, _len = props.length; _i < _len; _i++) {
-          node = props[_j];
+          node = props[_i];
           if (node instanceof Value) {
             throw new Error('cannot have an implicit value in an implicit object');
           }
@@ -1211,9 +1188,9 @@
       idt = o.indent += TAB;
       lastNoncom = this.lastNonComment(this.properties);
       props = (function() {
-        var _k, _len2, _results;
+        var _j, _len1, _results;
         _results = [];
-        for (i = _k = 0, _len2 = props.length; _k < _len2; i = ++_k) {
+        for (i = _j = 0, _len1 = props.length; _j < _len1; i = ++_j) {
           prop = props[i];
           join = i === props.length - 1 ? '' : prop === lastNoncom || prop instanceof Comment ? '\n' : ',\n';
           indent = prop instanceof Comment ? '' : idt;

src/nodes.coffee

@@ -801,16 +801,6 @@ exports.Obj = class Obj extends Base
 
   compileNode: (o) ->
     props = @properties
-    propNames = []
-    normalise = (v) -> if IDENTIFIER.test v then v else "" + do Function "return #{v}"
-    for prop in @properties
-      prop = prop.variable if prop.isComplex()
-      if prop?
-        propName = prop.unwrapAll().value.toString()
-        normalisedPropName = normalise propName
-        if normalisedPropName in propNames
-          throw SyntaxError "multiple object literal properties named \"#{propName}\""
-        propNames.push normalisedPropName
     return (if @front then '({})' else '{}') unless props.length
     if @generated
       for node in props when node instanceof Value

test/strict.coffee

@@ -55,41 +55,8 @@ test "octal escape sequences prohibited", ->
   strictOk  "`'\\1'`"
   eq "\\" + "1", `"\\1"`
 
-
-test "duplicate property definitions in object literals are prohibited", ->
-  strict 'o = {x:1, x:1}'
-  strict 'x = 1; o = {x, x: 2}'
-
-test "#2333: more duplicate property prohibitions", ->
-  usingKeys = (a, b) -> "{#{a}:0, #{b}:0}"
-  strict '{a, "a":0}'
-  strict usingKeys "a", '"a"'
-  strict usingKeys "'a'", "a"
-  strict usingKeys "'a'", '"a"'
-  strict usingKeys "'a'", "'a'"
-  strict usingKeys "0", "0x0"
-  strict usingKeys "0", "'\\x30'"
-  strict usingKeys ".1", "0.1"
-  strict usingKeys ".1", "1e-1"
-  strict usingKeys "100", "1e2"
-  strict usingKeys "'\\0'", "'\\x00'"
-  strict usingKeys "'\\t'", "'\\x09'"
-  strict usingKeys "'\\\\x00'", "'\\\\\\x7800'"
-  strict usingKeys "'c'", "'\\c'"
-  strict usingKeys "'\\\\'", "'\\x5c'"
-  strict usingKeys "'\\\n0'", "0"
-  strict usingKeys "'\\\n0'", "'\\x00'"
-  strict usingKeys "'\\'a'", "\"'a\""
-  strict usingKeys "'\\\\a'", "'\\\\a'"
-  strictOk usingKeys "a", "b"
-  strictOk usingKeys "'\"a\"'", "'a'"
-  strictOk usingKeys "'\"a\"'", '"\'a\'"'
-  strictOk usingKeys "0", '"0x0"'
-  strictOk usingKeys "0", '"\\\\x30"'
-
 test "duplicate formal parameters are prohibited", ->
   nonce = {}
-
   # a Param can be an Identifier, ThisProperty( @-param ), Array, or Object
   # a Param can also be a splat (...) or an assignment (param=value)
   # the following function expressions should throw errors