Fix #167: non-enumerable globals are now also prefixed with var

Author: rensbaardman

lib/getImportGlobalsSrc.js

@@ -9,7 +9,6 @@
  */
 function getImportGlobalsSrc(ignore) {
     var key,
-        value,
         src = "",
         globalObj = typeof global === "undefined"? window: global;
 
@@ -20,12 +19,21 @@ function getImportGlobalsSrc(ignore) {
     // shadow the module-internal variables
     // @see https://github.com/jhnns/rewire-webpack/pull/6
     ignore.push("module", "exports", "require");
+    // strict mode doesn't allow to (re)define 'undefined', 'eval' & 'arguments'
+    ignore.push("undefined", "eval", "arguments");
+    // 'GLOBAL' and 'root' are deprecated in Node
+    // (assigning them causes a DeprecationWarning)
+    ignore.push("GLOBAL", "root");
+    // 'NaN' and 'Infinity' are immutable
+    // (doesn't throw an error if you set 'var NaN = ...', but doesn't work either)
+    ignore.push("NaN", "Infinity");
 
-    for (key in globalObj) { /* jshint forin: false */
+    const globals = Object.getOwnPropertyNames(globalObj);
+
+    for (key of globals) {
         if (ignore.indexOf(key) !== -1) {
             continue;
         }
-        value = globalObj[key];
 
         // key may be an invalid variable name (e.g. 'a-b')
         try {

test/getImportGlobalsSrc.test.js

@@ -3,6 +3,7 @@ var expect = require("expect.js"),
     getImportGlobalsSrc = require("../lib/getImportGlobalsSrc.js");
 
 describe("getImportGlobalsSrc", function () {
+
     it("should declare all globals with a var", function () {
         var context = {
                 global: global
@@ -28,34 +29,43 @@ describe("getImportGlobalsSrc", function () {
         delete global['__core-js_shared__'];
         delete global['a-b'];
 
-        expectedGlobals = Object.keys(global);
+        const ignoredGlobals = ["module", "exports", "require", "undefined", "eval", "arguments", "GLOBAL", "root", "NaN", "Infinity"];
+
+        const globals = Object.getOwnPropertyNames(global);
+        expectedGlobals = globals.filter((el) => !ignoredGlobals.includes(el));
 
         vm.runInNewContext(src, context);
-        actualGlobals = Object.keys(context);
+        actualGlobals = Object.getOwnPropertyNames(context);
+
         actualGlobals.sort();
         expectedGlobals.sort();
         expect(actualGlobals).to.eql(expectedGlobals);
         expect(actualGlobals.length).to.be.above(1);
     });
+
     it("should ignore the given variables", function () {
         var context = {
                 global: global
             },
             ignore = ["console", "setTimeout"],
             src,
             actualGlobals,
-            expectedGlobals = Object.keys(global);
+            expectedGlobals = Object.getOwnPropertyNames(global);
+
+        const ignoredGlobals = ["module", "exports", "require", "undefined", "eval", "arguments", "GLOBAL", "root", "NaN", "Infinity"];
+        ignore = ignore.concat(ignoredGlobals);
 
         // getImportGlobalsSrc modifies the ignore array, so let's create a copy
         src = getImportGlobalsSrc(ignore.slice(0));
-        expectedGlobals = expectedGlobals.filter(function filterIgnoredVars(value) {
-            return ignore.indexOf(value) === -1;
-        });
+        expectedGlobals = expectedGlobals.filter((el) => !ignore.includes(el));
+
         vm.runInNewContext(src, context);
         actualGlobals = Object.keys(context);
+
         actualGlobals.sort();
         expectedGlobals.sort();
         expect(actualGlobals).to.eql(expectedGlobals);
         expect(actualGlobals.length).to.be.above(1);
     });
+
 });