text: (function() {
    // Tests in this module only work in the node.js environment.
    if (typeof require !== 'function') return;
  
    var fixturePrefix = __dirname + '/../test-treeshake/';
    var moduleName = __dirname + '/../underscore-umd.js';
    var fs = require('fs');
  
    QUnit.module('Tree-shaking');
  
    QUnit.test('should have an effect', function(assert) {
      var done = assert.async();
      var fixtureName = fixturePrefix + 'map-umd.js';
      fs.stat(moduleName, function(error, moduleStats) {
        assert.equal(error, null);
        if (error) return done();
        fs.stat(fixtureName, function(error, fixtureStats) {
          assert.equal(error, null);
          if (error) return done();
          // _.template depends on the entire underscore object, so all of the
          // source code should be included.
          assert.ok(fixtureStats.size < moduleStats.size);
          done();
        });
      });
    });
  
    QUnit.test('should not be overzealous', function(assert) {
      var done = assert.async();
      var fixtureName = fixturePrefix + 'template-umd.js';
      fs.readFile(moduleName, {encoding: 'utf8'}, function(error, moduleData) {
        assert.equal(error, null);
        if (error) return done();
        fs.readFile(fixtureName, {encoding: 'utf8'}, function(error, fixtureData) {
          assert.equal(error, null);
          if (error) return done();
          var moduleLines = moduleData.split('\n').length,
              fixtureLines = fixtureData.split('\n').length;
          // _.template depends on the entire underscore object, so all of the
          // source code should be included. Allowing for up to 9 lines of
          // difference; this is the size of the noConflict logic plus the
          // copyright intro, both of which are present in the official module but
          // not in the fixture.
          assert.ok(moduleLines - fixtureLines <= 9);
          done();
        });
      });
    });
  }());
  