reergymerej / peer-dep-state

exploring state in peer dependencies

Peer Dependency State

Does a dependency share state across a project?

Hypothesis

Yes. The code will only be interpretted once.

Test

Create a package that has a singleton state. (shared-dep)

feature

• uses shared-dep as a peer dependency
• set/read state in shared-dep

host

• uses shared-dep as a dependency
• set/read state in shared-dep

If the state persists across app, peer dep state is shared.

Result

~/code/js/peer-dep-state/host$ yarn start
yarn run v1.3.2
$ node ./index.js
I am shared-dep.
initial state 1234
I am host.
get 1234
set 200
get 200
I am feature.
get 200
set 100
get 100

Conclusion

State is shared across the app.