Handle missing dynamic chunks after new deployment with Webpack - javascript

I have an AngularJs (1.7) SPA with Webpack (4.x).
This is how we create chunknames:
config.output = {
path: PATHS.build,
publicPath: '/dist/',
filename: `[name]${isDev ? '' : '.[contenthash:8]'}.bundle.js`,
chunkFilename: `chunks/[name]${isDev ? '' : '.[contenthash:8]'}.chunk.js`
};
The lazyloading is done in the state definitions in ui-router basically like this:
$stateProvider
.state('reports', {
url: '/projects/:project_id/reports',
lazyLoad: function($transition$) {
const injector = $transition$.injector().get('$injector');
return import(/* webpackChunkName: "admin.reports.module" */ './reports')
.then(mod => {
injector.loadNewModules([mod.default]);
})
.catch(err => {
throw new Error('An error occured, ' + err);
});
}
})
After a deployment due changes to a module in a "dynamic" chunk - the filename will change of this chunk ([contenthash] has changed).
When a logged in user (where all bundled assets are loaded before the last deployment) now tries to open a route with the new chunk - the chunk is not there (404) and it will fail with:
Transition Rejection($id: 4 type: 6, message: The transition errored, detail: Error: An error occured, Error: Loading chunk 14 failed.
(error: admin.reports.module.8fc31757.chunk.js))
Is there a common way to circumvent/deal with this?
Maybe more in general: How can changes to a bundled web app be detected? Is there a common way to trigger a reload? Is a manual refresh always neccessary?

I think there are a few ways to circumvent this, since the javascript in the current context isn't aware of the new hash of the content generated by the latest build you could try:
1.) You could try setting up an http redirect on the hashed files: https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections
The browser will request the old file and the server can point to the new file instead of returning 404. If all of your files follow a convention and only store one of the file at a time ex: component.hash.js then this should be pretty easy.
2.) A hacky client approach would be handling the transition-rejection in a try catch and reload the page, without the cache to get the new assets. https://developer.mozilla.org/en-US/docs/Web/API/Location/reload
There's always more than one approach, but this is what I could think of to solve the issue.

Related

how to redirect to error page if path has a .(dot) in Nuxt 2?

I created error.vue in layout directory and it work almost corectly, but if path has a dot like(http://localhost:3000/for.m) i see "Cannot GET /PATH" instead my custom error page.
Cannot GET /PATH
If i change in nuxt.config.js file target to 'server' this problem disappear but adding new problems in path (http://localhost:3000/_nuxt/) i see default 404 message from browser instead my custom error page and actually i need target static.
I don`t now can i fix this with Nuxt settings or i should write custom error handler
can anyone help me with this problem. Thanks for your help!
I found in nuxt github similar request
https://github.com/nuxt/nuxt.js/issues/8715
where someone writes that it's not a bug, that is a features of static nuxt app. Either you resign this, either change 'static' to 'server'. I choose second way, with error where in _nuxt path browser return default 404 message, fixed it like this:
in nuxt.config added
build: {
publicPath: 'store', // changed '_nuxt' way to 'store'
}
serverMiddleware: ['~/server-middleware/errorhandler'], // added middleware for handling error before render page
in server-middleware/errorhandler.js
import { readFileSync } from 'node:fs';
export default function (req, res, next) {
// if it's a stuff path for take
if (decodeURI(req.url).match(/\/_ipx.*/) || decodeURI(req.url).match(/\/store.*/)) {
// try to find file
try { // if the file is found, show it
readFileSync('static/'+ req.url.match(/img.*/)[0])
next()
} catch (error) { // if the file hasn't been found, rederect to custom error page
res.writeHead(301, { Location: '/404' })
res.end()
}
} else {
next()
}
}

Why doesn't Webpack emit chunks when using webpackMode: "weak"?

I'm transitioning a legacy app to Webpack. I'm using Webpack 5.56 (latest at time of writing).
My app is localised and I have a folder with a handful of locale files,
locales
- locale.en.ts
- locale.de.ts
- etc
Each of these locale files is an ES module and they all export (different implementations of) the same functions — getText, printNumber, etc. I have a wrapper module which dynamically imports the correct locale for the current user:
// localization.ts
interface LocaleModule {
getText(text: string): string;
// etc
}
let module: LocaleModule;
import(`locales/locale.${currentUser.language}`).then(m => {
module = m;
});
export function getText(text: string): string {
return module.getText(text);
}
I know the current user's language when the page is being rendered. I want to include the correct locale.*.js script as an initial chunk, so that:
The browser doesn't have to wait for the main chunk to load before it can start downloading the locale file.
The functions in localization.ts can be synchronous.
This seemed like it'd be a good fit for webpackMode: "weak", since I'd like to get an error in the console if the locale file is missing for whatever reason (rather than silently degrade performance). The docs seem to explicitly call out my use case:
This is useful for universal rendering when required chunks are always manually served in initial requests (embedded within the page).
Here's my code:
let module: LocaleModule;
import(
/* webpackMode: "weak" */
/* webpackChunkName: "locales/[request]" */
`./locales/locale.${currentUser.language}`
).then(m => {
module = m;
});
However, it seems webpackMode: "weak" causes Webpack to emit no chunks for the referenced modules at all. There aren't any locale files in Webpack's output folder. I can’t very well include a chunk in the HTML if it was never emitted!
What's the reason for this behaviour? Is there a clean way to get Webpack to emit chunks for dynamically imported modules but not download them asynchronously? (I know that I could use webpackMode: "lazy" and just include the chunk upfront in a script tag, but I'd like to get an error if the locale file is missing.) Or do I have an XY problem, and there’s some better way to do this which I’m unaware of?
I have similar issues and resolve this.
My local file looks like:
import dictionary from './locales/en.json'
const en = dictionary
window.__default_dictionary__ = en
module.exports = en
My locales structure looks like:
enter image description here
You must add new cacheGroup for splitChunks.cacheGroups in webpack config
locales: {
enforce: true,
reuseExistingChunk: true,
priority: 50,
chunks: 'all',
test(module) {
if (/[\\/]src\/i18n[\\/]/.test(module.resource)) return true
return false
},
name(module) {
const moduleFileName = module
.identifier()
.split('/')
.reduceRight((item) => item)
.replace('.json', '')
.replace('.js', '')
return `locales~${moduleFileName}`
},
},
Now all of your locales files will be extracted to another chunk files.
You can use any handler for load locales, for example:
loadLocaleHandler: async (locale: Locale) => {
let localeModule: { default: Dictionary } = await import(`i18n/${locale}`)
return localeModule.default
},
And for everything to work correctly you must
Add locale chunk for result html
<script src="/assets/webpack/js/runtime.js" defer="defer"></script>
<script src="/assets/webpack/js/vendors.js" defer="defer"></script>
<!-- For example it maybe value from cookie or context of app -->
<script src="/assets/webpack/js/locales~(en|it|es).chunk.js" defer="defer"></script>
<script src="/assets/webpack/js/entry.js" defer="defer"></script>
Add magic webpack code to entry point
const defaultLocale: Locale = cookies.getItem('locale') || process.env.DEFAULT_LOCALE
if (__webpack_modules__[`./src/i18n/${defaultLocale}.js`]) {
__webpack_require__(`./src/i18n/${defaultLocale}.js`)
}
Totally:
you don't need wait loading locales by runtime import for first request
you can organize locales for multilocale and multidomain app
all of your locales remain dynamic modules and can be loaded at runtime
I can't post such long comment, so it has to be an answer...
So it looks like there isn't a real link between the modules and the bundler can't resolve them compile time so they aren't emitted. The only think I changed in your code is how modules are imported and it worked out of the box:
const langCode = getLangCode();
let mod;
import("./locales/locale.en")
switch (langCode) {
case "en":
import(`./locales/locale.en.js`).then(m => {
mod = m;
console.log("loaded locale");
})
break;
case "de":
import(`./locales/locale.de.js`).then(m => {
mod = m;
console.log("loaded locale");
})
break;
default:
}
export function getText(text) {
return mod.getText(text);
}
function getLangCode() {
return "de";
}
I know the switch case is not ideal, but the bundler can't automatically guess that pattern: ./locales/locale.${langCode}.js and add all files in the directory that match .js.
The doc says the following:
'weak': Tries to load the module if the module function has already been loaded in some other way (e.g. another chunk imported it or a script containing the module was loaded). A Promise is still returned, but only successfully resolves if the chunks are already on the client. If the module is not available, the Promise is rejected. A network request will never be performed. This is useful for universal rendering when required chunks are always manually served in initial requests (embedded within the page), but not in cases where app navigation will trigger an import not initially served.
From what I understand this means the chunks are expected to be already on the page and generated through some other means.
I hope that helps you resolve your issue.
In order to use weak you have to already manually served the chunks as stated in the docs. This means that adding it in a dynamic import as comment does not create any chunks (in contradiction with lazy and lazy-once).
Is there a clean way to get Webpack to emit chunks for dynamically imported modules but not download them asynchronously?
For synchronous loading:
You can either:
Use webpackMode: "lazy" and include the chunk upfront in a script tag as you stated (the Promise returned is rejected in case of missing chunk).
You can define the locale js files as dynamic entry points and load them manually by yourself.
For your example, creating an entrypoint for each locale could be something like:
const glob = require('glob')
module.exports = {
devtool: false,
entry: {
...glob.sync('./src/locales/*').reduce((acc, module) => {
const name = module.replace('./src/locales/', '').replace('.js', '')
acc[name] = module
return acc
}, {})
}
};
This would emit locale.de.js and locale.en.js bundles and then you should somehow manually load a <script defer src="locale.<locale>.js"></script>, but that depends on how you serve your app.
For asynchronous loading:
You can use webpackMode: "lazy" along with webpackPreload: true in order to decouple main and locale chunk requests.
As stated in the docs
A preloaded chunk starts loading in parallel to the parent chunk.

How do I initialize a webworker in NextJS 10?

I have a Next 10 project where I am trying to use WebWorkers. The worker is being initialized like so:
window.RefreshTokenWorker = new Worker(new URL('../refreshToken.worker.js', import.meta.url))
I also have the Worker defined as
self.addEventListener('message', (e) => {
console.info("ON MESSAGE: ", e)
// some logic with e.data
})
Its also being called like this:
const worker = getWorker() // gets worker that is attached at the window level
worker.postMessage('start')
My next.config.js file is defined as
const nextConfig = {
target: 'serverless',
env: getBuildEnvVariables(),
redirects,
rewrites,
images: {
domains: []
},
future: { webpack5: true },
webpack (config) {
config.resolve.alias['#'] = path.join(__dirname, 'src')
return config
}
}
// more definitions
module.exports = nextConfig
The issue I have is the console.info in the Web Worker definition does not receive the message being sent from postMessage on the build version (yarn build && yarn start) but it does on the dev version (yarn dev). Any ways to fix this?
This is not a solution. But can be a messy way to do the job. This turned out to be a nightmare for me.
I have the same setup as yours. I was initializing web worker as you have shown in your question. I got this idea from the nextjs doc itself: https://nextjs.org/docs/messages/webpack5
const newWebWorker = new Worker(new URL('../worker.js', import.meta.url))
Everything working correctly when I work in dev mode. it is picking up the worker.js file correctly and everything looks alright.
But when I build the nextjs and try it, then web worker won't work. When I dive deeply into the issues, I found out that the worker.js chunk file is created directly under the .next folder. It should come under .next/static/chunk/[hash].worker.js ideally.
I could not resolve this issue in a proper way.
So what i did, i placed my worker.js file directly under public directory. I put my worker.js file transpiled and optimized and put the code in the public/worker.js file.
After this, I modified the worker initialization like this:
const newWebWorker = new Worker('/worker.js', { type: 'module' });
it is working in the production build now. I will report once I get a cleaner solution for this.

Sapper/Svelte.js - How to specify client-side assets location?

I have a Sapper.js application that I have successfully running on AWS Lambda. Lambda is able to deliver the server-side generated HTML created by Sapper to AWS API Gateway which then serves the app to the user. I am using S3 to host the client side assets (scripts, webpack chunks, etc). The S3 bucket is on a different domain than API Gateway.
The issue I'm having is that I need to set an asset prefix for these scripts so that Sapper can find them. Currently all of my client side scripts include relative links and look like this: <script src="/client/be33a1fe9c8bbaa6fa9d/SCRIPT_NAME.js"></script> I need to have them look like this: <script src="https://AWS_S3_BUCKET_ENDPOINT.com/client/be33a1fe9c8bbaa6fa9d/SCRIPT_NAME.js"></script>
Looking in the Sapper docs, I see that I can specify a base url for the client and server. However, changing this base url breaks my app and causes the Lambda rendering the pages to return 404 errors.
I know that when using, say, Next.js, I can accomplish this by modifying the next.config.js file to include the following:
module.exports = {
assetPrefix: "https://AWS_S3_BUCKET_ENDPOINT.com/client",
}
But I don't know how to do this in Sapper. Do I need to modify the bundler (using webpack) config? Or is there some other way?
Thank you.
I think I've figured it out.
I had to change two sapper files. First I went into sapper/dist/webpack.js and modified it like so:
'use strict';
var __chunk_3 = require('./chunk3.js');
var webpack = {
dev: __chunk_3.dev,
client: {
entry: () => {
return {
main: `${__chunk_3.src}/client`
};
},
output: () => {
return {
path: `${__chunk_3.dest}/client`,
filename: '[hash]/[name].js',
chunkFilename: '[hash]/[name].[id].js',
// change this line to point to the s3 bucket client key
publicPath: "https://AWS_S3_BUCKET_ENDPOINT.com/client"
};
}
},
server: {
entry: () => {
return {
server: `${__chunk_3.src}/server`
};
},
output: () => {
return {
path: `${__chunk_3.dest}/server`,
filename: '[name].js',
chunkFilename: '[hash]/[name].[id].js',
libraryTarget: 'commonjs2'
};
}
},
serviceworker: {
entry: () => {
return {
'service-worker': `${__chunk_3.src}/service-worker`
};
},
output: () => {
return {
path: __chunk_3.dest,
filename: '[name].js',
chunkFilename: '[name].[id].[hash].js',
// change this line to point to the s3 bucket root
publicPath: "https://AWS_S3_BUCKET_ENDPOINT.com"
}
}
}
};
module.exports = webpack;
//# sourceMappingURL=webpack.js.map
Then I had to modify sapper/runtime/server.mjs so that the main variable points to the bucket like so:
...
const main = `https://AWS_S3_BUCKET_ENDPOINT.com/client/${file}`;
...
Testing with the basic sapper webpack template, I can confirm that the scripts are loading from the s3 bucket successully. So far this all looks good. I will mess around with the sapper build command next to make it so I can pass these hacks in as command line arguments so I don't have to hardcode them every time.
Now, I'm not sure if this will hold up as the app becomes more complicated. Looking into the sapper/runtime/server.mjs file, I see that the req.baseUrl property is referenced in several different locations and I don't know if my hacks will cause any issues with this. Or anywhere else in sapper for that matter.
If anyone with more experience with the Sapper internals is reading, let me know in the comments if I screwed something up 👍

sw-precache-webpack-plugin webpack service worker default template

I'm using the sw-precache-webpack-plugin to generate a service worker for my project, I can see all my fonts, js and css files in the cache storage but not the index / html file and its not working when i go offline. I also get a 'site cannot be installed: no matching service worker detected.' when i try and add to homepage on the App manifest.
My stack is a universal React + redux app, with Express + ejs for index file. I'm not sure if its because I'm using ejs rather than a default html file, but it doesnt seem to find the file. Is there a way I can specify a template? My sw-precache-webpack-plugin webpack setting is:
new SWPrecacheWebpackPlugin({
cacheId: 'tester',
filename: 'my-service-worker.js',
directoryIndex: '/',
}),
Any advice would be appreciated
You are missing a specification of a caching strategy in the plugin config.
plugins: [
new SWPrecacheWebpackPlugin({
cacheId: 'tester',
filename: 'my-service-worker.js',
runtimeCaching: [
{
urlPattern: '/',
handler: 'cacheFirst',
}
]
})
]
Documentation: https://github.com/GoogleChrome/sw-precache#runtimecaching-arrayobject

Categories