title: Full Gulp Istanbul Coverage Report
body: <p>I am using gulp-istanbul to generate JavaScript unit test coverage reports through Gulp.  Is there a way to configure Istanbul to generate a full coverage report of all the JS files in my gulp stream, and not just the files touched by a test case.</p>
  
  <p>I'm working on a project with a lot of JS, but no unit tests, and we are trying to increase the test coverage.  I would like to have a coverage report that starts by show 0% coverage for most of our files, but over time will present an increasing coverage percentage.</p>
  
  <pre><code>gulp.task( 'test', function () {
      gulp.src( [ my source glob ] )
          .pipe( istanbul() )
          .on( 'end', function () {
              gulp.src( [ my test spec glob ] )
                  .pipe( mocha( {
                      reporter: 'spec'
                  } ) )
                  .pipe( istanbul.writeReports(
                      [ output location ]
                  ) );
          } );
  } );
  </code></pre>