Rollup Plugin: Pug

package.json

{
    "license": "UNLICENSED",
    "dependencies": {
        "fastify": "^3.9.2",
        "fastify-cookie": "^5.1.0",
        "fastify-sensible": "^3.1.0",
        "google-auth-library": "^6.1.3",
        "lodash": "^4.17.20",
        "pug": "^3.0.0",
        "pug-runtime": "^3.0.0"
    },
    "devDependencies": {
        "@babel/core": "^7.11.6",
        "@babel/preset-env": "^7.11.5",
        "@babel/preset-typescript": "^7.10.4",
        "@rollup/plugin-auto-install": "^2.1.0",
        "@rollup/plugin-babel": "^5.2.1",
        "@rollup/plugin-json": "^4.1.0",
        "@rollup/plugin-node-resolve": "^11.0.1",
        "@rollup/plugin-replace": "^2.3.4",
        "@rollup/plugin-run": "^2.0.2",
        "@types/jest": "^26.0.19",
        "@types/node": "^14",
        "@types/pug": "^2.0.4",
        "builtin-modules": "^3.1.0",
        "dotenv": "^8.2.0",
        "jest": "^26.6.3",
        "pino-pretty": "^4.3.0",
        "pkg-dir": "^5.0.0",
        "rollup": "^2.35.1",
        "rollup-plugin-node-externals": "^2.2.0",
        "typescript": "^4.0.3"
    },
    "scripts": {
        "dev": "rollup -cw --watch.buildDelay 200",
        "build": "rollup -c",
        "test": "jest"
    },
    "jest": {
        "testEnvironment": "node",
        "bail": true,
        "verbose": true
    }
}

rollup-plugin-pug.js

import Pug from 'pug'
import {promises as FileSystem} from 'fs'
import pkgDir from 'pkg-dir'
import Path from 'path'

export default (options = {debug: false}) => ({
    name: 'pug',
    async load(absPath) {
        if(!absPath.endsWith('.pug')) return null

        const source = await FileSystem.readFile(absPath, 'utf8')
        const filename = Path.relative(await pkgDir(), absPath)

        const fn = Pug.compile(source, {
            filename: filename,
            inlineRuntimeFunctions: false,
            compileDebug: !!options.debug,
            debug: false,
            pretty: false,
        })

        for(const dep of fn.dependencies) {
            this.addWatchFile(dep)
        }

        return {
            code: `import pug from 'pug-runtime';\n${fn};\nexport default template;`,
            moduleSideEffects: false,
        }
    }
})

rollup.config.js

import babel from '@rollup/plugin-babel';
import nodeResolve from '@rollup/plugin-node-resolve';
import nodeExternals from 'rollup-plugin-node-externals'
import * as tsconfig from './tsconfig.json';
import json from '@rollup/plugin-json';
import run from '@rollup/plugin-run';
import auto from '@rollup/plugin-auto-install';
import replace from '@rollup/plugin-replace';
import pug from './rollup-plugins/rollup-plugin-pug'

const extensions = ['.ts']
const isWatch = process.env.ROLLUP_WATCH === 'true'
const isDev = process.env.NODE_ENV === 'development'
const debug = isWatch || isDev

export default {
    input: tsconfig.files,
    plugins: [
        nodeExternals({
            builtins: true,
            deps: true,
            devDeps: false,
            peerDeps: true,
            optDeps: false,
        }),
        json(),
        pug({
            debug: debug,
        }),
        babel({
            include: 'src/**',
            extensions,
            comments: false,
            babelHelpers: 'bundled', // https://github.com/rollup/plugins/tree/master/packages/babel#babelhelpers
        }),
        nodeResolve({
            extensions
        }),
        replace({
            'process.env.NODE_ENV': process.env.NODE_ENV,
            __DEV__: isWatch || isDev,
        }),
        isDev && auto({
            manager: 'yarn',
            pkgFile: `${__dirname}/package.json`
        }),
        isWatch && run({
            execArgv: ['-r', 'dotenv/config', '--enable-source-maps']
        }),
    ],
    output: {
        dir: 'dist',
        format: 'cjs',
        sourcemap: debug,
        inlineDynamicImports: true,
    },
}