replace-gitter-troupe-env-and-context-env-with-client-env.js

var gulp = require('gulp');
var through = require('through2');


gulp.task('replace-dep', function() {
  var replaceDep = function() {
    return through.obj(function(chunk, enc, callback) {
      if(chunk.isBuffer()) {
        var contents = String(chunk.contents);

        // Replace the usage to the new syntax and reference to new package
        var foundMatch = false;
        contents = contents.replace(/context.env\(('|")(.*?)(?:'|")\)/g, function(match, quote, property) {
          foundMatch = true;

          return 'clientEnv[' + quote + property + quote + ']';
        });

        if(foundMatch) {
          console.log('Found usage in', chunk.path);
        }

        // If we found a match in here, we need to add the `clientEnv` dep
        // And check to make sure `context` is still being used
        if(foundMatch) {
          var foundContextUsage = false;
          contents.replace(/context\./, function(match, property) {
            foundContextUsage = true;
          });


          contents = contents.replace(/var\scontext(\s*?)=\s?require\(('|")utils\/context(?:'|")\);/, function(match, spacing, quote) {
            var packageNameLengthDifference = 'clientEnv'.length - 'context'.length;
            var clientEnvRequireSpacingLength = spacing.length - packageNameLengthDifference;
            clientEnvRequireSpacingLength = clientEnvRequireSpacingLength >= 0 ? clientEnvRequireSpacingLength : 1;

            //console.log('|' + spacing + '|', spacing.length, packageNameLengthDifference);
            var replacement = 'var clientEnv' + new Array(clientEnvRequireSpacingLength+1).join(' ') + '= require(' + quote + 'gitter-client-env' + quote + ');';
            if(foundContextUsage) {
              replacement = 'var context' + spacing + '= require(' + quote + 'utils/context' + quote + ');' + '\n' + replacement;
            }

            console.log(replacement);

            return replacement;
          });

        }


        chunk.contents = new Buffer(String(contents));
        this.push(chunk);
      }
      callback();
    });
  };

 return gulp.src([
    //'./test/fixtures/**/*.js',
    '/Users/eric/Documents/github/gitter-webapp/**/*.js',
    '!/Users/eric/Documents/github/gitter-webapp/node_modules/'
  ])
    .pipe(replaceDep())
    //.pipe(gulp.dest('./test/output/'));
    .pipe(gulp.dest('/Users/eric/Documents/github/gitter-webapp/'));

});