Microbundle Versions Save

Features & Improvements

• New onStart, onError callbacks for programmatic Microbundle usage! (#668, thanks @katywings!)
• allow multi-file output and code splitting (#674, thanks @katywings!)
• Strip comments from output (#548)

Bug Fixes

• don't mark --alias modules as externals (#671, thanks @katywings!)

• Updated Babel and preset-env to 7.10 (#660)
• Fixed an version conflict caused by multiple copies of Babel (#664)
• Fixed globals generation when --external values include dashes (#667, thanks @katywings!)

Features

• New --no-pkg-main option for disabling filename inference (#658, thanks @katywings)
• Allow the use of import.meta (#627, thanks @developit)

Bugfixes

• Fix non-alphanumeric values for --external (#650, thanks @katywings)
• Preserve comments when --no-compress is enabled (#648, thanks @developit)
• Fix TypeScript issue when "module" is set to "CommonJS" (#638, thanks @marvinhagemeister)
• Fix TypeScript declaration emit target (#629, thanks @marvinhagemeister)
• Fix TypeScript declarationDir option so it respects the cwd (#643) (#646, thanks @katywings)
• Fix TypeScript Fragments breaking when jsxFactory is set (#623, thanks @marvinhagemeister)

General Improvements

• Dependency updates (#634 #616, thanks @teodragovic, @merceyz)
• Documentation updates for 0.12 and --externals (#636 #628 #625 #609 #611 #614, thanks @gtrufitt, @developit, @SeanBannister, @adrienpoly & @i-like-robots)

• Output modern JavaScript with --format modern (#413, thanks @JoviDeCroock & @marvinhagemeister)
• --define can now replace expressions (#348, thanks @jviide)
• a new --css-modules option controls whether .css files are modular by default (#370, thanks @maraisr)
• the "source" package.json field can now be an Array (#372, thanks @maraisr)
• no more warnings about deprecations or built-ins
• moved to Rollup 2 (#361, thanks @ForsakenHarmony)
• switched from Bublé to Babel (#362, thanks @wardpeet & @ForsakenHarmony)
• added support for babel-macros (#268, thanks @FezVrasta & @ForsakenHarmony)
• Add support for customizing the mangle.json file path (#432, thanks @andrewiggins & @ForsakenHarmony)
• Improvements and corrections for generated TypeScript filenames and definitions (#587 etc)

Breaking Changes

• .babelrc is now detected and supported - it was previously ignored.
• Microbundle now requires Node 10+

• Fix accidental bundle size increase due to core-js version (#550)
• Use preset-modules for modern output (#557, thanks @JoviDeCroock)
• Add --css-modules option for *.css files in addition to *.module.css (#370, thanks @maraisr)
• Fix a bug that caused modern output to be not modern (#570)
• Add support for --define @expression=replacement (#588)
• Silence a bunch of unnecessary warnings
• Reduce bundle size when using async/await, in particular for await () (#596)
• Fix output filename generation when using .ts entry modules (#587)

New mangle.json / package.json configuration for Terser!

{
  // "minify" for Terser (https://github.com/terser-js/terser#minify-options-structure)
  // Note: works as a key in both package.json or mangle.json
  "minify": {
    // Legacy/convenient way to set mangle.properties.{regex,reserved}:
    "properties": "^_",
    "reserved": ["_dom", "_constructor"],

    // Optionally specify Terser compress configuration.
    // Supported values: https://github.com/terser-js/terser#compress-options
    "compress": {
      "hoist_vars": true,
      "reduce_funcs": false
    },

    // Optionally specify Terser mangle configuration
    // Supported values: https://github.com/terser-js/terser#mangle-options
    "mangle": {}
  }
}

🐧 new --define option! Inlines constants (great for Dead Code Elimination):

microbundle --define process.env.NODE_ENV=production,DEBUG=false

🐺 new --alias option! Remap imports from one module to another:

microbundle --alias react=preact,react-dom=preact

🦊 Lovely refactoring from @MatiasOlivera and @ForsakenHarmony :)

🦑We turned minification up to 11!! (#321, thanks @jviide)

Breaking Changes

• Remove import pruning: #265 (thx @marvinhagemeister ❤️)

(also added bors to not break master)

Patches

• Fix importing superagent: #245 (thx @luisrudge ❤️, sorry for not releasing a minor)
• Fix tests and async not being transpiled in Typescript: #262 & #269 (thx @marvinhagemeister ❤️)
• Fix hoisted packages: #271 (thx @FezVrasta ❤️)
• Update snapshots to fix tests and add cross-env for windows: 🙃

• Upstream fix: pin tiny-glob to 0.2.4 while we wait for a fix for terkelg/tiny-glob@cc4a295.