feat: add Immer class

[aleclarson]

Closes #254

Every instance of the Immer class provides a bound produce function. As explained in #254, this class makes room for advanced configuration (if we need it) and allows for interop between Immer-using libraries that have different needs.

I took the time to refactor while I was implementing this, so the diff may look
more overwhelming than it is. :)

Summary

1. Renamed immer.js to index.js so the Immer class can have immer.js

2. Use the word "draft" in place of "proxy" in most places, because "draft" is
   a higher level of abstraction. It also makes sense to use the same semantics
   both internally and externally.

3. Moved finalize logic to the Immer class

4. Inlined the freeze function as only one callsite existed

5. Inlined the createState functions in both proxy.js and es5.js

6. Extract repeated code from produceEs5 and produceProxy (which have since
   been removed) into the Immer class

7. The es5.js and proxy.js modules now have different exports:

   • scopes: an array of nested produce calls, where each value is an array
     of unrevoked proxies
   • currentScope(): shortcut for getting the last value of the scopes array
   • createDraft(): a renamed createProxy with the arguments swapped
   • willFinalize(): called right after the recipe function returns (only
     used by ES5 proxies)

8. Changed some "draft state" properties:

   • removed hasCopy in ES5 state (checking for truthiness of copy does the job)
   • renamed proxy to draft in ES5 state
   • renamed finished to revoked in ES5 state
   • renamed proxies to drafts in Proxy state
   • added revoke method (called by the Immer class)
   • added draft property to Proxy state
   • use null literals instead of undefined (for brevity)

9. Delay creation of patches and inversePatches arrays until the recipe
   function returns. This avoids array allocations when a rollback is performed
   by throwing.

10. Simplified generatePatches by removing the last two arguments, since they
    can be obtained from the state argument.

[mweststrate]

That's fast! Quick question, any impact on build size? Op vr 30 nov. 2018 om 16:53 schreef Alec Larson <notifications@github.com>:

…

@aleclarson <https://github.com/aleclarson> requested your review on: #258 <#258> feat: add Immer class. — You are receiving this because your review was requested. Reply to this email directly, view it on GitHub <#258 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABvGhEa2S1iWHSTxkDYo8spQvvngdKY9ks5u0VRfgaJpZM4Y76aN> .

[mweststrate]

(if it is not too much effort, otherwise will check myself when reviewing) Op vr 30 nov. 2018 om 17:12 schreef Michel Weststrate <mweststrate@gmail.com

…

: That's fast! Quick question, any impact on build size? Op vr 30 nov. 2018 om 16:53 schreef Alec Larson ***@***.*** >: > @aleclarson <https://github.com/aleclarson> requested your review on: > #258 <#258> feat: add Immer > class. > > — > You are receiving this because your review was requested. > Reply to this email directly, view it on GitHub > <#258 (comment)>, or mute > the thread > <https://github.com/notifications/unsubscribe-auth/ABvGhEa2S1iWHSTxkDYo8spQvvngdKY9ks5u0VRfgaJpZM4Y76aN> > . >

[aleclarson]

@mweststrate Looks like the UMD bundle went from 8.88KB (3.29KB minified) to 9.8KB (3.56KB minified). Disappointing; I thought this would reduce the size. :(

edit: Probably from inflating the class declaration.

[coveralls]

Coverage decreased (-0.7%) to 96.931% when pulling c1a548b on aleclarson:factory into d157d7a on mweststrate:master.

[coveralls]

Coverage decreased (-0.7%) to 96.931% when pulling c1a548b on aleclarson:factory into d157d7a on mweststrate:master.

[coveralls]

Coverage decreased (-0.3%) to 97.293% when pulling 1caaebd on aleclarson:factory into 9345f13 on mweststrate:master.

[coveralls]

Coverage decreased (-0.7%) to 96.931% when pulling c1a548b on aleclarson:factory into d157d7a on mweststrate:master.

[aleclarson]

Tests passing! :)

I wonder if the Coveralls bot can be fixed?

[aleclarson]

I separated the diff noise out, so you can use 1fc76a7 for easier reviewing.

[aleclarson]

Updated the .d.ts but not the .js.flow since I'm not using Flow currently.

[mweststrate]

Great PR @aleclarson !

Made some minor comments, but beyond that all LGTM. Thanks a lot!

[aleclarson]

🎉 This PR is included in version 1.9.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀