CODEWITHSUNDEEP
typescript
PengProgrammer
PengProgrammer

Reputation: 164

Typescript type string is not assignable to type keyof "Interface"

I have the following code

export interface A {
  redApple: props[];
  yellowApple: props[];
  redYellowApple: props[];

}

export type FruitColour = "red" | "yellow | "green";
export type Fruit = "apple" | "banana | "cherry";

const x = [
  "redApple",
  "yellowApple",
  "redYellowApple",
  "greenCherry"
]

export const changeFruit = (
  fruit: Fruit,
  colour: Colour
): keyof A => {
  return x
    .filter((string) => string.match(colour + fruit))
    .splice(0, 1)
    .toString();
};

I keep getting Type 'string' is not assignable to type 'keyof IndexViewDataItem'. I can use myFunction(someField: keyof A | string) but then I lose type guarding.

Any help or guidance would be greatly appreciated.

Upvotes: 0

Views: 1031

Answers (1)

PengProgrammer
PengProgrammer

Reputation: 164

Managed to get a work around for this by

export const changeFruit = (
  fruit: Fruit,
  colour: Colour
): keyof A => {
  const y = x
    .filter((string) => string.match(colour + fruit))
    .splice(0, 1)
    .toString();
    return y as keyof A;
};

Not sure if this still enforces type guarding but I imagine so. If not I would still appreciate a better approach.

Upvotes: 1

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