Ways to ensure the type of the value passed to the string indexOf function is correct?

There is a constant defined as follows:

const PageTypes = [
  'type1',
  'type2',
  'type3'
] as const;

export type PageType = typeof PageTypes[number]

If I have a string that I want to check for the index of type1,

mystring.indexOf('type1') - I'm unsure how to enforce the usage of PageTypes in this scenario. What if I accidentally misspell it as 'tpe1'? Is there a way in TypeScript to receive an error or highlight incorrect spellings like 'tpe1'' in IDE?

Is it possible to achieve this level of enforcement in Typescript?

typescripttypescript2.0

Answer №1

An error will be triggered when an attempt is made to assign a value to the constant variable x in the code snippet provided below.

const PageType = [
    'type1',
    'type2',
    'type3'
  ] as const;
  
  export type PageType = typeof PageType[number]

  const x: PageType = 'tpe1';

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