gulpfile.js

import fs from 'node:fs'
import { fileURLToPath } from 'node:url'
import path from 'node:path'
import gulp from 'gulp'
import { deleteAsync } from 'del'
import log from 'fancy-log'
import webpack from 'webpack'
import babel from 'gulp-babel'
import { mkdirp } from 'mkdirp'
import { cleanup, iteratePath } from './tools/docgenerator.js'
import { generateEntryFiles } from './tools/entryGenerator.js'
import { getAllFiles, validateChars } from './tools/validateAsciiChars.js'

const __dirname = path.dirname(fileURLToPath(import.meta.url))

const SRC_DIR = path.join(__dirname, '/src')
const BUNDLE_ENTRY = `${SRC_DIR}/defaultInstance.js`
const HEADER = `${SRC_DIR}/header.js`
const VERSION = `${SRC_DIR}/version.js`
const COMPILE_SRC = `${SRC_DIR}/**/*.?(c)js`
const COMPILE_ENTRY_SRC = `${SRC_DIR}/entry/**/*.js`

const COMPILE_DIR = path.join(__dirname, '/lib')
const COMPILE_BROWSER = `${COMPILE_DIR}/browser`
const COMPILE_CJS = `${COMPILE_DIR}/cjs`
const COMPILE_ESM = `${COMPILE_DIR}/esm` // es modules
const COMPILE_ENTRY_LIB = `${COMPILE_CJS}/entry`

const FILE = 'math.js'

const REF_SRC = SRC_DIR + '/'
const REF_DIR = path.join(__dirname, '/docs')
const REF_DEST = `${REF_DIR}/reference/functions`
const REF_ROOT = `${REF_DIR}/reference`

const MATH_JS = `${COMPILE_BROWSER}/${FILE}`
const COMPILED_HEADER = `${COMPILE_CJS}/header.js`

const PACKAGE_JSON_COMMONJS = '{\n "type": "commonjs"\n}\n'

const AUTOGENERATED_WARNING = `
// Note: This file is automatically generated when building math.js.
// Changes made in this file will be overwritten.
`

// read the version number from package.json
function getVersion () {
 return JSON.parse(String(fs.readFileSync('./package.json'))).version
}

// generate banner with today's date and correct version
function createBanner () {
 const today = new Date().toISOString().substr(0, 10) // today, formatted as yyyy-mm-dd
 const version = getVersion()

 return String(fs.readFileSync(HEADER))
 .replace('@@date', today)
 .replace('@@version', version)
}

// generate a js file containing the version number
function updateVersionFile (done) {
 const version = getVersion()

 fs.writeFileSync(VERSION, `export const version = '${version}'${AUTOGENERATED_WARNING}`)

 done()
}

const bannerPlugin = new webpack.BannerPlugin({
 banner: createBanner(),
 entryOnly: true,
 raw: true
})

const babelConfig = JSON.parse(String(fs.readFileSync('./.babelrc')))

const webpackConfig = {
 entry: BUNDLE_ENTRY,
 mode: 'production',
 performance: { hints: false }, // to hide the "asset size limit" warning
 output: {
 library: 'math',
 libraryTarget: 'umd',
 libraryExport: 'default',
 path: COMPILE_BROWSER,
 globalObject: 'this',
 filename: FILE
 },
 node: false, // to make sure Webpack doesn't generate 'new Function("return this")' in the bundle output, see https://github.com/josdejong/mathjs/issues/3001
 plugins: [
 bannerPlugin
 // new webpack.optimize.ModuleConcatenationPlugin()
 // TODO: ModuleConcatenationPlugin seems not to work. https://medium.com/webpack/webpack-3-official-release-15fd2dd8f07b
 ],
 module: {
 rules: [
 {
 test: /\.js$/,
 exclude: /node_modules/,
 use: {
 loader: 'babel-loader',
 options: {
 ...babelConfig,
 presets: [
 ['@babel/preset-env', {
 useBuiltIns: 'usage',
 corejs: '3.15'
 }]
 ]
 }
 }
 }
 ]
 },
 devtool: 'source-map',
 cache: true
}

// create a single instance of the compiler to allow caching
const compiler = webpack(webpackConfig)

function bundle (done) {
 // update the banner contents (has a date in it which should stay up to date)
 bannerPlugin.banner = createBanner()

 compiler.run(function (err, stats) {
 if (err) {
 log(err)
 done(err)
 }
 const info = stats.toJson()

 if (stats.hasWarnings()) {
 log('Webpack warnings:\n' + info.warnings.join('\n'))
 }

 if (stats.hasErrors()) {
 log('Webpack errors:\n' + info.errors.join('\n'))
 done(new Error('Compile failed'))
 }

 // create commonjs package.json file
 fs.writeFileSync(path.join(COMPILE_BROWSER, 'package.json'), PACKAGE_JSON_COMMONJS)

 log(`bundled ${MATH_JS}`)

 done()
 })
}

function compileCommonJs () {
 // create a package.json file in the commonjs folder
 mkdirp.sync(COMPILE_CJS)
 fs.writeFileSync(path.join(COMPILE_CJS, 'package.json'), PACKAGE_JSON_COMMONJS)

 return gulp.src(COMPILE_SRC)
 .pipe(babel())
 .pipe(gulp.dest(COMPILE_CJS))
}

function compileESModules () {
 return gulp.src(COMPILE_SRC)
 .pipe(babel({
 ...babelConfig,
 presets: [
 ['@babel/preset-env', {
 modules: false,
 targets: {
 esmodules: true
 }
 }]
 ]
 }))
 .pipe(gulp.dest(COMPILE_ESM))
}

function compileEntryFiles () {
 return gulp.src(COMPILE_ENTRY_SRC)
 .pipe(babel())
 .pipe(gulp.dest(COMPILE_ENTRY_LIB))
}

function writeCompiledHeader (cb) {
 fs.writeFileSync(COMPILED_HEADER, createBanner())
 cb()
}

function validateAscii (done) {
 const Reset = '\x1b[0m'
 const BgRed = '\x1b[41m'

 getAllFiles(SRC_DIR)
 .map(validateChars)
 .forEach(function (invalidChars) {
 invalidChars.forEach(function (res) {
 console.log(res.insideComment ? '' : BgRed,
 'file:', res.filename,
 'ln:' + res.ln,
 'col:' + res.col,
 'inside comment:', res.insideComment,
 'code:', res.c,
 'character:', String.fromCharCode(res.c),
 Reset
 )
 })
 })

 done()
}

async function generateDocs (done) {
 const all = (await import('file://' + REF_SRC + 'defaultInstance.js')).default
 const functionNames = Object.keys(all)
 .filter(key => typeof all[key] === 'function')

 if (functionNames.length === 0) {
 throw new Error('No function names found, is the doc generator broken?')
 }

 cleanup(REF_DEST, REF_ROOT)
 iteratePath(functionNames, REF_SRC, REF_DEST, REF_ROOT)

 done()
}

function generateEntryFilesCallback (done) {
 generateEntryFiles().then(() => {
 done()
 })
}

/**
 * Remove generated files
 *
 * @returns {Promise<string[]> | *}
 */
async function clean () {
 await deleteAsync([
 // legacy compiled files
 './es/',

 // generated browser bundle, esm code, and commonjs code
 './lib/',

 // generated source files
 'src/**/*.generated.js'
 ])
}

gulp.task('browser', bundle)

gulp.task('clean', clean)

gulp.task('docs', generateDocs)

// check whether any of the source files contains non-ascii characters
gulp.task('validate:ascii', validateAscii)

// The watch task (to automatically rebuild when the source code changes)
gulp.task('watch', function watch () {
 const files = ['package.json', 'src/**/*.js']
 const options = {
 // ignore version.js else we get an infinite loop since it's updated during bundle
 ignored: /version\.js/,
 ignoreInitial: false,
 delay: 100
 }

 gulp.watch(files, options, gulp.parallel(bundle, compileCommonJs))
})

// The default task (called when you run `gulp`)
gulp.task('default', gulp.series(
 clean,
 updateVersionFile,
 generateEntryFilesCallback,
 compileCommonJs,
 compileEntryFiles,
 compileESModules, // Must be after generateEntryFilesCallback
 writeCompiledHeader,
 bundle,
 generateDocs
))