Refactor vm.runInContext

lib/util/vm.js

@@ -1,48 +1,56 @@
 "use strict";
 
-const VM_VARS = {
+const code = ( () => {
 
-    "module": true,
-    "process": true,
-    "VM_VARS": true,
-    "PREFACE_VARS": true,
-    "generateDeclaration": true,
-    "runInContext": true,
-    "code": true,
-    "preface": true,
+    let preface = "";
+    const MODULE_VARS = {
 
-};
+        "module": true,
+        "process": true,
+        "code": true,
+        "runInContext": true,
+        "source": true,
+        "preface": true,
+
+    };
+
+    Object.keys( MODULE_VARS ).forEach( name => {
+
+        preface += `var ${ name } = void 0;`;
 
-const PREFACE_VARS = Object.keys( VM_VARS )
-    .map( name => `var ${ name } = void 0;` )
-    .join( " " );
+    } );
 
-function generateDeclaration( name ) {
+    function generate( name ) {
 
-    return ( ! VM_VARS[ name ] ? "var " : "" )
-        + `${ name } = vm$context.${ name };`;
+        return `${ ( MODULE_VARS[ name ] ? "" : "var " ) + name } = __context.${ name };`;
 
-}
+    }
+
+    return { generate, preface };
+
+} )();
 
 module.exports = {
 
-    // `eval` the given code, using properties found in `context` as top-level
-    // variables, while hiding some variables in this module from the code.
+    // `eval` the given source, using properties found in `context` as top-level
+    // variables, while hiding some variables in this module from the source.
     //
     // Based on `vm.runInContext` found in Node.js, this is a cross-env solution.
-    runInContext( code, vm$context ) {
+    runInContext( source, __context ) {
+
+        let preface = code.preface;
+
+        if ( typeof __context === "object" ) {
 
-        let preface = PREFACE_VARS;
+            Object.keys( __context ).forEach( name => {
 
-        if ( typeof vm$context === "object" ) {
+                preface += code.generate( name );
 
-            preface += Object.keys( vm$context )
-                .map( generateDeclaration )
-                .join( " " );
+            } );
 
         }
 
-        return eval( preface + code );
+        return eval( preface + source );
 
 
     },