Actually, rather than test for Node, let’s specifically check that require(‘fs’) returns something before we try to use it

Author: GeoffreyBooth

lib/jison.js

@@ -966,7 +966,7 @@ lrGeneratorMixin.generateCommonJSModule = function generateCommonJSModule (opt)
     opt = typal.mix.call({}, this.options, opt);
     var moduleName = opt.moduleName || "parser";
     var out = this.generateModule(opt)
-        + "\n\n\nif (typeof require !== 'undefined' && typeof exports !== 'undefined' && new Function('try{return this===global;}catch(e){return false;}')()) {"
+        + "\n\n\nif (typeof require !== 'undefined' && typeof exports !== 'undefined') {"
         + "\nexports.parser = "+moduleName+";"
         + "\nexports.Parser = "+moduleName+".Parser;"
         + "\nexports.parse = function () { return "+moduleName+".parse.apply("+moduleName+", arguments); };"
@@ -1280,7 +1280,12 @@ function commonjsMain (args) {
         console.log('Usage: '+args[0]+' FILE');
         process.exit(1);
     }
-    var source = require('fs').readFileSync(require('path').normalize(args[1]), "utf8");
+    var source = null;
+    var fs = require('fs');
+    var path = require('path');
+    if (typeof fs !== 'undefined' && fs !== null) {
+        source = fs.readFileSync(path.normalize(args[1]), "utf8");
+    }
     return exports.parser.parse(source);
 }