Monolith?

still bad

monorepo ≠ monolith

Modularity

Unix Philosophies

• Write programs that do one thing and do it well
• Write programs that work together

https://en.wikipedia.org/wiki/Unix_philosophy

a key to JavaScript's growth and success

npm 🧡 modularity

Orchestrating
high modularity

Repository proliferation

🐇🐇🐇🐇🐇🐇🐇🐇🐇🐇🐇🐇🐇

• where is it
• what's in it
• who owns it

inter-dependency management

• tracking compatibility between versions
• updating downstream version strings

Testing

• Find and clone related modules
• run npm install & npm link
• run all the tests

☑️
☑️
☑️
☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

☑️

Publishing

• Build
• Publish
• Tag & push
• ...all the right modules

Solutions

More developers  👨‍💻
more discipline 🏋️‍♂️

more process 🚦
and
more managers 🐒😱

Custom automation

monorepo

Monorepos in the Wild - Markus Oberlehner

./my-component-library
    /packages
        /Component1
        /Component2
        /Component3
        /Component4
        /Component5

monorepo

monorepo

Solves

• git repository proliferation

Yarn Workspaces

https://yarnpkg.com/lang/en/docs/workspaces/

 a new way to setup your package architecture

Yarn workspaces

./my-component-library
    /Component1
    /Component2
    /Component3
    /Component4
    /Component5

🍓🍊

🥓🥦

✔️

✔️

🍏🍎

✔️

Yarn Workspaces

Solves

• git repository proliferation

Doesn't Solve

• inter-dependency management
• publishing complexity
• testing complexity

Pros

• One source of truth
• Sweeping changes in 1 commit
• Shared metadata & config
• Dependency optimization

Cons

• Slow git
• Slow builds
• Permission management

Bolt

https://github.com/boltpkg/bolt

Super-powered JavaScript project management

once we get around to implementing it

Bolt

• command-line tools for multi-module orchestration
  • running tests
  • compiling code
  • publishing modules
  • lots more
• for your yarn worksapces

Solves

Doesn't Solve

• inter-dependency management
• publishing complexity
• testing complexity

Bolt with Yarn Workspaces

Pros

• One source of truth
• Sweeping changes in 1 commit
• Shared metadata & config
• Dependency optimization
• Automated testing
• Easier dev env setup & contribution

Cons

• Slow git
• Slow builds
• Permission management

{

• git repository proliferation

Lerna

https://lernajs.io

A tool for managing JavaScript projects with multiple packages

Lerna

• command-line tools for multi-module orchestration
  • running tests
  • compiling code
  • publishing modules
  • more
• for your monorepo

Lerna with monorepo

Solves

• git repository proliferation
• inter-dependency management
• publishing complexity
• testing complexity

Doesn't Solve

Pros

• One source of truth
• Sweeping changes in 1 commit
• Shared metadata & config
• Dependency optimization
• Automated testing
• Easier dev env setup & contribution

Cons

• Slow git
• Slow builds
• Permission management

Monorepo with Lerna

monorepo with Lerna

• keep all your modules in one git repository
• shared metadata and config resides at the root
• each module remains independent
• Lerna simplifies the orchestration

Lerna commands

lerna init

• creates a lerna.json config file ⚙️
• creates a packages folder 📂
• adds lerna as a dev dependency in package.json
• -i for independent versioning

Create a new Lerna repo or upgrade an existing repo to the current version of Lerna

lerna bootstrap

• installs external dependencies
• symlinks internal dependencies
• ...

Links dependencies in the repo together

lerna updated

list which packages have changed since the last release

lerna run/exec

• run npm scripts in some or all modules
• execute arbitrary commands in some or all modules

lerna publish

• Update the version updated packages
• Update all dependencies of the updated packages with the new versions
• Commit and tag the new version
• Publish updated packages to npm

publish packages in the current Lerna project

other lerna commands

• clean
  delete all node_modules folders
• diff
  diff packages since the latest release
• ls
  list all the public packages in the repo
• import
  import an existing module including git history
• link
  symlink together all packages that are dependencies of each other in the current repo
• ...

Almost The End

https://www.youtube.com/watch?v=lV8-1S28ycM

https://www.youtube.com/watch?v=kwhOI4mmqnM
https://medium.com/@maoberlehner/monorepos-in-the-wild-33c6eb246cb9

http://slides.com/olegskl/lerna#/2

http://slides.com/clickclickonsal/deck-8#/2/3

http://danluu.com/monorepo/

https://github.com/babel/babel/blob/master/doc/design/monorepo.md

https://graphcommons.com/graphs/a7ec343d-2a0c-47bb-9658-bb8315e8a096

https://macwright.org/2016/07/08/lerna-npm-organizations-new-wave-modularity.html

https://github.com/lerna/lerna/blob/master/doc/hoist.md

...

The End

https://en.wikipedia.org/wiki/Unix_philosophy

https://yarnpkg.com/blog/2017/08/02/introducing-workspaces/

https://www.drmaciver.com/2016/10/why-you-should-use-a-single-repository-for-all-your-companys-projects/

https://en.wikipedia.org/wiki/Monolithic_application

https://github.com/boltpkg/bolt

https://slides.com/chrisweight/monorepo#/2/3

http://danluu.com/monorepo/

https://yarnpkg.com/lang/en/docs/workspaces/

https://github.com/boennemann/alle

https://github.com/lerna/lerna/blob/master/doc/hoist.md