A code generation system.

Usage

import { IS_AOT, IS_BUILD } from 'runtime-compiler/env';
import { evaluate } from 'runtime-compiler';

// Only log when building
IS_BUILD && console.log('Building...');

// Only emit code if not in AOT mode
const fn = evaluate<() => void>(IS_AOT || `return()=>console.log("Hi")`);

// Run only when not in build mode
IS_BUILD || fn();

Build with rolldown:

...
import rtc from 'runtime-compiler/rolldown';

export default defineConfig({
  plugins: [rtc()]
});

Or Vite:

import rtc from 'runtime-compiler/rolldown';

export default defineConfig({
  // Only run this plugin on build
  build: {
    rolldownOptions: {
      plugins: [rtc()]
    }
  }
});

If you have dependencies marked as external that uses runtime-compiler:

// package: external-pkg
import { IS_AOT } from 'runtime-compiler/env';
import { evaluate } from 'runtime-compiler';

export const fn = evaluate(IS_AOT || '()=>console.log("Hi")');

// index.ts
import { fn } from 'external-pkg';
fn();

// build
export default {
  ...,
  external: ['external-pkg', ...],
  plugins: [
    rtc({
      // Chunks that import 'external-pkg' will output loader instead
      useLoader: (pkg) => pkg === 'external-pkg';
    });
  ]
}

Limitation

Library code and startup code that uses runtime-compiler cannot be mixed together in the same chunk.

import { IS_AOT } from 'runtime-compiler/env';
import { evaluate } from 'runtime-compiler';

const fn = evaluate<typeof console.log>(IS_AOT || `return console.log`)('Hi');

// AOT build will break this export
export const createFn = () => evaluate<typeof console.log>(IS_AOT || `return console.log`);