Types: derive actions type from the symbiotes type

[Finesse]

Resolves #28

Sorry for the long delay, I was quite busy.

Now one doesn't need to write the action types, TypeScript does it automatically:

interface State {
  value: string;
}

const symbiotes = {
  foo(state: State) {
    return {...state, value: 'foo'};
  },
  bar(state: State, value: number) {
    return {...state, value: `bar ${value}`};
  }
};

const {actions, reducer} = createSymbiote({value: 'Hi'}, symbiotes);

actions.bar('cocktail'); // TS error, a number is expected
reducer({ value: 42 }, actions.foo()); // TS error, the value property must be a string
reducer({ value: 'Hi!' }, actions.bar(12)); // TS: 👍

I failed to implement the symbiotes optional arguments support in TypeScript 2.8 so I had to set the minimal TypeScript version to 3.0 in daacb43. Also this upgrade has allowed to implement a more simple and robust solution. I think this change is not critical because the version 3.0 is only 2 month younger than 2.8 and migrating from TypeScript 2 to 3 is not a big deal.

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IssueHunt Summary

Referenced issues

This pull request has been submitted to:

• #28: Types: derive actions type from the symbiotes type

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[ghost]

DeepCode Report (#bce8d1)

DeepCode analyzed this pull request.
There are no new issues.

[coveralls]

Pull Request Test Coverage Report for Build 148

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 145:	0.0%
Covered Lines:	110
Relevant Lines:	110

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💛 - Coveralls

[sergeysova]

Have you finished?

[Finesse]

Have you finished?

Yes

[sergeysova]

Thank you

[sergeysova]

@all-contributors please add @Finesse for code

[allcontributors]

@sergeysova

I've put up a pull request to add @Finesse! 🎉

[Finesse]

@sergeysova How to get my $5 from IssueHunt?

[sergeysova]

@Finesse done

[Finesse]

@sergeysova Thank you!