enum validation

[markusbohl]

enum validation

[markusbohl]

I don't know yet. But I'll figure out, if it's doable or not.

[markusbohl]

Okay. I've implemented a possible solution in a feature-branch as you can see from the commits above.
It would work like this:

enum StringColors {
    Red = "RED",
    Green = "GREEN",
    Blue = "BLUE"
}

enum NumColors {
    Black = 0,
    White = 1
}

class SomeColors {
    color1: StringColors;
    color2: NumColors;
    color3: string;
    color4: number;
}

class ColorValidator extends AbstractValidator<SomeColors> {
    constructor() {
        super();
        this.validateIf(dto => dto.color1) // type StringColors
            .isIn(StringColors);
        this.validateIf(dto => dto.color2) // type NumColors
            .isIn(NumColors);
        this.validateIf(dto => dto.color3) // type string
            .isIn(StringColors);
        this.validateIf(dto => dto.color4) // type number
            .isIn(NumColors);
    }
}

const someColors = new SomeColors();
someColors.color1 = StringColors.Blue;
someColors.color2 = NumColors.Black;
someColors.color3 = "GREEN";
someColors.color4 = 1;

new ColorValidator().validate(someColors); // valid

Since enum members can either be of type number or of type string (since TypeScript 2.4) I think it is useful to use the more general validateIf() method instead of validateIfNumber() or validateIfString(). This makes the validator more robust in case of type changes within the enum (i.e. switching from number to string initializers).

The enum fields as well as string or number fields of your object under validation can now be validated against the members of enums. Actually, this would not only work for the isIn() case but also for the opposite isNotIn() case.

What do you think? Would such an implementation meet your needs? Or do you think, we should do something different? Let me know what you think.

[jezzsantos]

Thanks for this @markusbohl I'll try it out shortly.
But in terms of design as you point out, I am happy with which way you want to go.

[markusbohl]

I've published a release candidate [email protected] on npm. This should make it a bit easier for you to test.

[markusbohl]

Just released version 3.0.0 with the solution as shown above.