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The next thing I would like to do is to apply a better type invitation to this action argument.

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Remember, in general, whenever we have a type of any as an annotation inside a typescript, that's

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usually a bad sign because it means that typescript isn't going to really try to figure out what this

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action thing is or what different properties it has.

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So let's try defining or better annotating better describing what this action argument really is to

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do.

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So I'm going to make an interface above my reducer called action.

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Remember that entire script, every action is always going to be an object that must have a type property

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and optionally it can also have a payload.

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So I'm going to reflect that inside of our interface right here.

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I'm going to say that in action is something that must have a type that is a string and optionally can

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have a payload.

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So the question mark right here says that it may or may not have a paler property, and if it does have

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one, it can be of any type.

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Now, I'm going to say that this action argument is of type action like so.

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That's definitely a reasonable improvement now TypeScript is aware that this action will have a type.

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So if we ever write out right here inside of our switch statement, something like Action Dot, t.P,

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Wii, it will jump in and say, hey, you don't actually have a Wii property, but you do have a type

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property.

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In addition, if we ever try to access Actionist payload and we accidentally typed out something like

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why load like so once again we would get an error and we would be told there is no payload property.

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Instead it is payload like so.

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Well, that's definitely a reasonable improvement, but now once again, we have a type of any and like

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I just mentioned, wherever possible, we want to avoid having types of any.

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So although this is an improvement, we still can fix this up a little bit more.

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Let's take a look at some further improvements in just a moment.