Fixes#5845
Implement tslint for core files
**What is this?**
Implements tslint for both next and next-server, but keeps standardjs/eslint for the .js files that are still there, we're gradually migrating to Typescript.
**How does it work?**
Before every commit (pre-commit) we execute the following `tslint` command:
`tslint -c tslint.json 'packages/**/*.ts`
**TSLint Rules**
In order to avoid as much changes as possible I marked some rules as false. This way we can improve the linter but making sure this step will not break things. (see tslint.json)
**Note**
After merging this PR, you'll need to update your dependencies since it adds tslint to package.json
**This does not change existing behavior.**
building to serverless is completely opt-in.
- Implements `target: 'serverless'` in `next.config.js`
- Removes `next build --lambdas` (was only available on next@canary so far)
This implements the concept of build targets. Currently there will be 2 build targets:
- server (This is the target that already existed / the default, no changes here)
- serverless (New target aimed at compiling pages to serverless handlers)
The serverless target will output a single file per `page` in the `pages` directory:
- `pages/index.js` => `.next/serverless/index.js`
- `pages/about.js` => `.next/serverless/about.js`
So what is inside `.next/serverless/about.js`? All the code needed to render that specific page. It has the Node.js `http.Server` request handler function signature:
```ts
(req: http.IncomingMessage, res: http.ServerResponse) => void
```
So how do you use it? Generally you **don't** want to use the below example, but for illustration purposes it's shown how the handler is called using a plain `http.Server`:
```js
const http = require('http')
// Note that `.default` is needed because the exported module is an esmodule
const handler = require('./.next/serverless/about.js').default
const server = new http.Server((req, res) => handler(req, res))
server.listen(3000, () => console.log('Listening on http://localhost:3000'))
```
Generally you'll upload this handler function to an external service like [Now v2](https://zeit.co/now-2), the `@now/next` builder will be updated to reflect these changes. This means that it'll be no longer neccesary for `@now/next` to do some of the guesswork in creating smaller handler functions. As Next.js will output the smallest possible serverless handler function automatically.
The function has 0 dependencies so no node_modules are required to run it, and is generally very small. 45Kb zipped is the baseline, but I'm sure we can make it even smaller in the future.
One important thing to note is that the function won't try to load `next.config.js`, so `publicRuntimeConfig` / `serverRuntimeConfig` are not supported. Reasons are outlined here: #5846
So to summarize:
- every page becomes a serverless function
- the serverless function has 0 dependencies (they're all inlined)
- "just" uses the `req` and `res` coming from Node.js
- opt-in using `target: 'serverless'` in `next.config.js`
- Does not load next.config.js when executing the function
TODO:
- [x] Compile next/dynamic / `import()` into the function file, so that no extra files have to be uploaded.
- [x] Setting `assetPrefix` at build time for serverless target
- [x] Support custom /_app
- [x] Support custom /_document
- [x] Support custom /_error
- [x] Add `next.config.js` property for `target`
Need discussion:
- [ ] Since the serverless target won't support `publicRuntimeConfig` / `serverRuntimeConfig` as they're runtime values. I think we should support build-time env var replacement with webpack.DefinePlugin or similar.
- [ ] Serving static files with the correct cache-control, as there is no static file serving in the serverless target
As I detailed in [this thread on Spectrum](https://spectrum.chat/?t=3df7b1fb-7331-4ca4-af35-d9a8b1cacb2c), the dev experience would be a lot nicer if the server started listening as soon as possible, before the slow initialization steps. That way, instead of manually polling the dev URL until the server's up (this can take a long time!), I can open it right away and the responses will be delivered when the dev server is done initializing.
This makes a few changes to the dev server:
* Move `HotReloader` creation to `prepare`. Ideally, more things (from the non-dev `Server`) would be moved to a later point as well, because creating `next({ ... })` is quite slow.
* In `run`, wait for a promise to resolve before doing anything. This promise automatically gets resolved whenever `prepare` finishes successfully.
And the `next dev` and `next start` scripts:
* Since we want to log that the server is ready/listening before the intensive build process kicks off, we return the app instance from `startServer` and the scripts call `app.prepare()`.
This should all be backwards compatible, including with all existing custom server recommendations that essentially say `app.prepare().then(listen)`. But now, we could make an even better recommendation: start listening right away, then call `app.prepare()` in the `listen` callback. Users would be free to make that change and get better DX.
Try it and I doubt you'll want to go back to the old way. :)
This message is from @timneutkens after making changes:
- Convert executables to Typescript
- Remove `minimist` in favor of `arg`
- Implement `--node-args` usage: `--node-args="--throw-deprecation"`
- Adds tests for usage of the `next` cli
This PR will
- allow nextjs export to use all available CPU cores for rendering & writing pages by using child_process
- make use of async-sema to allow each thread to concurrently write multiple paths
- show a fancy progress bar while processing pages (with non-TTY fallback for CI web consoles)
The performance gain for my MacBook with 4 CPU cores went from ~25 pages per second to ~75 pages per second. Beefy CI machines with lots of cores should profit even more.
* Add node_modules bundling under the —lambdas flag for next build
* Run minifier when lambdas mode is enabled
* Add lambdas option to next.config.js
* Add test for lambdas option
