rollup.config.mjs

// @ts-check
import { createRequire } from 'module'
import { fileURLToPath } from 'url'
import path from 'path'
import ts from 'rollup-plugin-typescript2'
import replace from '@rollup/plugin-replace'
import json from '@rollup/plugin-json'
import commonJS from '@rollup/plugin-commonjs'
import { nodeResolve } from '@rollup/plugin-node-resolve'
import terser from '@rollup/plugin-terser'
import chalk from 'chalk'

if (!process.env.TARGET) {
  throw new Error('TARGET package must be specified via --environment flag.')
}

const require = createRequire(import.meta.url)
const __dirname = fileURLToPath(new URL('.', import.meta.url))

const masterVersion = require('./package.json').version
const packagesDir = path.resolve(__dirname, 'packages')
const packageDir = path.resolve(packagesDir, process.env.TARGET)
const resolve = (p) => path.resolve(packageDir, p)
const pkg = require(resolve(`package.json`))
const packageOptions = pkg.buildOptions || {}
const name = packageOptions.filename || path.basename(packageDir)

// ensure TS checks only once for each build
let hasTSChecked = false

const outputConfigs = {
  'esm-bundler': {
    file: resolve(`dist/${name}.esm-bundler.js`),
    format: `es`,
  },
  'esm-browser': {
    file: resolve(`dist/${name}.esm-browser.js`),
    format: `es`,
  },
  cjs: {
    file: resolve(`dist/${name}.cjs.js`),
    format: `cjs`,
  },
  global: {
    file: resolve(`dist/${name}.global.js`),
    format: `iife`,
  },
}

const defaultFormats = ['esm-bundler', 'cjs']
const inlineFormats = process.env.FORMATS && process.env.FORMATS.split(',')
const packageFormats = inlineFormats || packageOptions.formats || defaultFormats
const packageConfigs = process.env.PROD_ONLY
  ? []
  : packageFormats.map((format) => createConfig(format, outputConfigs[format]))

if (process.env.NODE_ENV === 'production') {
  packageFormats.forEach((format) => {
    if (format === 'cjs') {
      packageConfigs.push(createProductionConfig(format))
    }
    if (/^(global|esm-browser)/.test(format)) {
      packageConfigs.push(createMinifiedConfig(format))
    }
  })
}

export default packageConfigs

function createConfig(format, output, plugins = []) {
  if (!output) {
    console.log(chalk.yellow(`invalid format: "${format}"`))
    process.exit(1)
  }

  const isProductionBuild =
    process.env.__DEV__ === 'false' || /\.prod\.js$/.test(output.file)
  const isBundlerESMBuild = /esm-bundler/.test(format)
  const isBrowserESMBuild = /esm-browser/.test(format)
  const isNodeBuild = format === 'cjs'
  const isGlobalBuild = /global/.test(format)

  output.exports = 'named'
  output.sourcemap = !!process.env.SOURCE_MAP
  output.externalLiveBindings = false

  if (isGlobalBuild) {
    output.name = packageOptions.name
  }

  const shouldEmitDeclarations =
    pkg.types && process.env.TYPES != null && !hasTSChecked

  const tsPlugin = ts({
    check: process.env.NODE_ENV === 'production' && !hasTSChecked,
    tsconfig: path.resolve(__dirname, 'tsconfig.json'),
    cacheRoot: path.resolve(__dirname, 'node_modules/.rts2_cache'),
    tsconfigOverride: {
      compilerOptions: {
        target: isNodeBuild ? 'es2019' : 'es2015',
        sourceMap: output.sourcemap,
        declaration: shouldEmitDeclarations,
        declarationMap: shouldEmitDeclarations,
      },
      exclude: ['**/__tests__', 'test-dts'],
    },
  })
  // we only need to check TS and generate declarations once for each build.
  // it also seems to run into weird issues when checking multiple times
  // during a single build.
  hasTSChecked = true

  let entryFile = `src/index.ts`

  let external = []

  if (isGlobalBuild || isBrowserESMBuild) {
    external = ['react', 'react-dom', 'use-sync-external-store/shim']
  } else if (isBundlerESMBuild || isNodeBuild) {
    // Node / esm-bundler builds.
    // externalize all direct deps
    external = [
      ...Object.keys(pkg.dependencies || {}),
      ...Object.keys(pkg.peerDependencies || {}),
      // submodule used by react-doura
      'use-sync-external-store/shim',
    ]
  }

  const nodePlugins =
    format === 'cjs' && Object.keys(pkg.dependencies || {}).length
      ? [
          commonJS({
            sourceMap: false,
            ignore: [],
          }),
          nodeResolve(),
        ]
      : []

  return {
    input: resolve(entryFile),
    // Global and Browser ESM builds inlines everything so that they can be
    // used alone.
    external,
    plugins: [
      json({
        namedExports: false,
      }),
      tsPlugin,
      createReplacePlugin(
        isProductionBuild,
        isBundlerESMBuild,
        isBrowserESMBuild,
        // isBrowserBuild?
        isGlobalBuild || isBrowserESMBuild || isBundlerESMBuild,
        isGlobalBuild,
        isNodeBuild
      ),
      ...nodePlugins,
      ...plugins,
    ],
    output,
    onwarn: (msg, warn) => {
      if (!/Circular/.test(msg)) {
        warn(msg)
      }
    },
    treeshake: {
      moduleSideEffects: false,
    },
  }
}

function createReplacePlugin(
  isProduction,
  isBundlerESMBuild,
  isBrowserESMBuild,
  isBrowserBuild,
  isGlobalBuild,
  isNodeBuild,
  isCompatBuild,
  isServerRenderer
) {
  const replacements = {
    __COMMIT__: `"${process.env.COMMIT}"`,
    __VERSION__: `"${masterVersion}"`,
    __DEV__: isBundlerESMBuild
      ? // preserve to be handled by bundlers
        `(process.env.NODE_ENV !== 'production')`
      : // hard coded dev/prod builds
        !isProduction,
    // this is only used during Doura's internal tests
    __TEST__: false,
    // If the build is expected to run directly in the browser (global / esm builds)
    __BROWSER__: isBrowserBuild,
    __GLOBAL__: isGlobalBuild,
    __ESM_BUNDLER__: isBundlerESMBuild,
    __ESM_BROWSER__: isBrowserESMBuild,
    // is targeting Node (SSR)?
    __NODE_JS__: isNodeBuild,
  }
  // allow inline overrides like
  //__RUNTIME_COMPILE__=true yarn build runtime-core
  Object.keys(replacements).forEach((key) => {
    if (key in process.env) {
      replacements[key] = process.env[key]
    }
  })
  return replace({
    // @ts-ignore
    values: replacements,
    preventAssignment: true,
  })
}

function createProductionConfig(format) {
  return createConfig(format, {
    file: resolve(`dist/${name}.${format}.prod.js`),
    format: outputConfigs[format].format,
  })
}

function createMinifiedConfig(format) {
  return createConfig(
    format,
    {
      file: outputConfigs[format].file.replace(/\.js$/, '.prod.js'),
      format: outputConfigs[format].format,
    },
    [
      terser({
        module: /^esm/.test(format),
        compress: {
          ecma: 2015,
          pure_getters: true,
        },
        safari10: true,
      }),
    ]
  )
}