Update extension by changing file path

[froddd]

setting file.extname = '.js' seems to only work on Vinyl file objects, meaning tests are passing but precompiling produces .html files when run on actual templates. Updating the file path using the Node path module works on all files.

[sindresorhus]

The file there is a Vinyl file object, though.

[froddd]

When the tests are run, file is a Vinyl object. The file passed from through2 isn't.

[froddd]

$ npm install gulp through2 vinyl
$ echo '<h1>test</h1>' > template.html

gulpfile.js:

const gulp = require('gulp');
const through = require('through2');
const vinyl = require('vinyl');

gulp.task('default', () =>
  gulp.src('template.html')
    .pipe(through.obj(function (file, enc, cb) {
      console.log('File is Vinyl:', vinyl.isVinyl(file))
      cb(null, file)
    }))
);

$ gulp
[14:02:24] Using gulpfile ~/test-nunjucks/gulpfile.js
[14:02:24] Starting 'default'...
File is Vinyl: false
[14:02:24] Finished 'default' after 20 ms

[sindresorhus]

Returns a stream of Vinyl files that can be piped to plugins. - https://github.com/gulpjs/gulp/blob/master/docs/API.md#gulpsrcglobs-options

The problem is that Vinyl is outdated in Gulp v3.

[sindresorhus]

I've fixed this in a patch release.