[Fix] internal ToString operation should throw on Symbols

In particular, this happened with `String.raw`, however, in every engine with Symbols but without `String.raw`, `String(Symbol())` also incorrectly throws, so this isn’t actually a bug
paulmillr · Oct 12, 2020 · b293878 · b293878
1 parent b81dcfa
commit b293878
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/es6-shim.js b/es6-shim.js
@@ -356,7 +356,7 @@
     },
 
     ToNumber: function (value) {
-      if (_toString(value) === '[object Symbol]') {
+      if (hasSymbols && _toString(value) === '[object Symbol]') {
         throw new TypeError('Cannot convert a Symbol value to a number');
       }
       return +value;
@@ -527,6 +527,9 @@
     },
 
     ToString: function ToString(string) {
+      if (hasSymbols && _toString(string) === '[object Symbol]') {
+        throw new TypeError('Cannot convert a Symbol value to a number');
+      }
       return $String(string);
     }
   };

diff --git a/test/string.js b/test/string.js
@@ -616,6 +616,15 @@ var runStringTests = function (it) {
         var str = 'The total is 10 ($ with tax)';
         expect(String.raw(template, 10)).to.equal(str);
       });
+
+      ifSymbolsDescribe('Symbol substitutions', function () {
+        it('throws', function () {
+          var template = {
+            raw: { 0: 'The total is ', 1: ' ($', 2: ' with tax)', length: 3 }
+          };
+          var str = 'The total is 10 ($ with tax)';
+          expect(function () { String.raw(template, Symbol()); }).to['throw'](TypeError);
+        });
       });
     });