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
