modernator modernator - 28 days ago 10
Javascript Question

ERR_CONTENT_LENGTH_MISMATCH on browsersync.reload

I'm using browsersync.reload() when bundling is done.
At first time, it worked well but after App is grew bigger, web page failed to load JavaScript on reload with this message:


GET http://localhost:4000/js/bundle.js net::ERR_CONTENT_LENGTH_MISMATCH


This is my gulpfile.js code:

function serve() {
let serverStarted = false;

nodemon({ script: 'server.js' })
.on('start', () => {
if(!serverStarted) {
serverStarted = true;

browserSync.init(null, {
proxy: `localhost:${config.port || 3000}`,
port: config.proxyPort || 4000
});

gulp.watch(`${SRC_DIR}/html/**`, buildHtml);
gulp.watch(`${SRC_DIR}/scss/**`, buildScss);

gulp.watch(`${BUILD_DIR}/html/index.html`).on('change', browserSync.reload);

// return empty stream
return gutil.noop();
}
});
}


I'm using browser-sync with express, so I used proxy. Below code is bundling part for script:

function buildJs() {
const b = persistify()
.add(`${SRC_DIR}/js/index.js`)
.on('update', bundle)
.on('log', gutil.log)

function bundle() {
let stream = b.bundle()
.on('error', swallowError)
.on('end', () => {
gutil.log(`Building JS:bundle done.`);
browserSync.reload();
})
.pipe(source('bundle.js'));

return stream.pipe(gulp.dest(`${BUILD_DIR}/js`));
}

return bundle();
}


I'm using persistify for fast builds, it works with watchify, so I didn't used watch. As you can see the 'end' event, which fires when bundling is done, I invoked browerSync.reload to reload the page.

Reloading itself is not a problem, but it fails load JavaScript as I title said.

Does persistify triggered end event so earlier? or is that somekind of issue from express/browser-sync?

Only I can guess is that end event was fired but stream is still writing the file, so actual file size is not correct and refuse to get.

Intentionally I gave some delays before browsersync.reload(), it works but I don't wanna do this.

Is there a something that I missed? Or am I did wrong approach? Any advice will very appreciate.

Answer Source

I was solving this problem by executing transpiling JavaScript after browser-sync started.

I still don't know why that was happen but it seems script was transpiling and browser try to access while it is still working.