anchor.diff:          text = ''
             var fs = require('fs');
             var url = require('url');
  -          
  +
             /*
              * Replaces an impure version specification by *
              */
             function replaceImpureVersionSpec(versionSpec) {
                 var parsedUrl = url.parse(versionSpec);
  -              
  +
                 if(versionSpec == "latest" || versionSpec == "unstable" ||
                     versionSpec.substr(0, 2) == ".." || dependency.substr(0, 2) == "./" || dependency.substr(0, 2) == "~/" || dependency.substr(0, 1) == '/')
                     return '*';
  
positive.code:         EOF
          chmod +x $out/bin/shell
        '';
        
        # Provide the dependencies in a development shell through the NODE_PATH environment variable
        inherit nodeDependencies;
        shellHook = stdenv.lib.optionalString (dependencies != []) ''
  
negative.code:                 done
              done
          fi
  
          # Run post install hook, if provided
          runHook postInstall
        '';
  