A NestJS app

A web server with NestJS, written exactly as on Node, compiled into a native executable. Each block below can be copied into a terminal as it is.

1. Install xisto, start a project, add NestJS

brew install xistolang/tap/xisto
xisto init hello-nest && cd hello-nest     # xisto.json, src/main.ts, .gitignore
xisto run                                  # Hello, world!
xisto add @nestjs/common @nestjs/core @nestjs/platform-express

xisto init creates xisto.json, src/main.ts (a hello world) and .gitignore. xisto run compiles and runs the project's entry and prints Hello, world!.

xisto add fetches the packages from xistolang/packages and their dependencies with them (here express, rxjs, class-validator and class-transformer). It does not touch your code: src/main.ts is still the hello world from xisto init.

2. Write the app

Replace src/main.ts with the app, written as on Node:

cat > src/main.ts <<'EOF'
import { Controller, Get, Module } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';

@Controller()
class AppController {
  @Get()
  hello(): string {
    return 'Hello from xisto';
  }
}

@Module({ controllers: [AppController] })
class AppModule {}

async function bootstrap(): Promise<void> {
  const app = await NestFactory.create(AppModule);
  await app.listen(3123);
}
bootstrap();
EOF

3. Run it while developing

xisto run compiles to a temporary file and starts it, with no build step:

Run it in one of two ways. While developing, xisto run compiles to a temporary file and starts it, with no build step (the first compile of a Nest app takes a few seconds; wait for Nest application successfully started):

xisto run                        # the server, on port 3123; Ctrl+C stops it

For the server, xisto build makes an optimised executable (-O2) that runs on its own, with nothing installed. It only compiles; the executable is what you start:

xisto build                      # ./hello-nest, a native executable of about 1 MB
./hello-nest                     # the server, on port 3123; Ctrl+C stops it

Either way, from another terminal:

curl localhost:3123              # Hello from xisto

A fresh checkout restores the packages from xisto.lock:

rm -rf .xisto && xisto install   # as after a git clone
xisto build

xisto add copies each package into .xisto/pkgs/ and pins it in xisto.lock (source, folder, commit); xisto install restores exactly that, like npm ci. The last two lines show what a fresh checkout does: .xisto/ is in .gitignore, so the packages come back from xisto.lock.

Next

• Projects and packages: xisto add, xisto.lock, other sources.
• The language: the rules xisto adds to TypeScript.
• The NestJS packages available (and the exact subset each one implements) are listed in xistolang/packages; the header comment of each package's index.ts says what it implements and what it does not.