Allow returning arbitrary data from the handleAction function

[cinnabarcaracal]

Useful for completely replacing the state when it makes more sense than modifying the current state. Acts as a sort of escape hatch for when more traditional reducer logic, including the use of higher-order array functions, is desired.

e.g.

handleAction(actions.storeFooArray, (draft, { payload }) => {
  return payload;
}),
handleAction(actions.storeUpdatedFooInArray, (draft, { payload }) => {
  return [...draft.filter(f => f.x !== payload.x), payload]
}),

[cinnabarcaracal]

New PR updated for the new version. From my testing it is able to detect if you have also changed the draft, and will ignore any return value if that is the case. The return value undefined will be ignored (much like how immer ignores undefined return values)

I won't have time to add tests to this PR until later tonight, sorry.

[codecov-io]

Codecov Report

Merging #7 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master     #7   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           4      4           
  Lines          31     32    +1     
  Branches        5      4    -1     
=====================================
+ Hits           31     32    +1

Impacted Files	Coverage Δ
src/handle-action.ts	100% <100%> (ø)	⬆️
src/create-action.ts	100% <0%> (ø)	⬆️

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[knpwrs]

One more request -- could you add something to the README and maybe example.ts? Thanks!

[cinnabarcaracal]

No problem, and happy to fix any issues with those

[knpwrs]

Published as 3.1.0. Thanks!