union of enum literal value type converse to union literal value type in typescript

To convert an Enum literal value type to a Union literal value type in TypeScript, we can use the keyof operator along with a type assertion. Here are the steps:

1. Define an Enum that you want to convert to a Union type.

index.ts
enum MyEnum {
    A = "A",
    B = "B",
    C = "C",
}
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2. Define a type MyEnumKeys that represents the keys of MyEnum using the keyof operator.

index.ts
type MyEnumKeys = keyof typeof MyEnum;
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3. Define a type alias MyEnumValues that represents the values of MyEnum using the MyEnumKeys type defined above.

index.ts
type MyEnumValues = typeof MyEnum[MyEnumKeys];
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4. Now you can use MyEnumKeys or MyEnumValues to define a Union type.

index.ts
// Union of Enum keys
type MyEnumUnionKeys = "A" | "B" | "C"  // same as MyEnumKeys

// Union of Enum values
type MyEnumUnionValues = "A" | "B" | "C"  // same as MyEnumValues
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Note that if you add or remove keys from the MyEnum Enum, the MyEnumKeys, MyEnumValues, and MyEnumUnion types will automatically update to reflect the change.