Class Example{
constructor(
public x: number,
public y: string
) {}
}
let e = new Example();
Is there a way to programmatically determine the data type of e.x or e.y in TypeScript?
Class Example{
constructor(
public x: number,
public y: string
) {}
}
let e = new Example();
Is there a way to programmatically determine the data type of e.x or e.y in TypeScript?
TypeScript is great at catching errors at compile time, but when dealing with external data, it falls short. This is where runtime type checking comes in handy - enter io-ts.
Here's an example using io-ts:
const Person = t.type({
name: t.string,
age: t.number
})
// Perform a runtime check
const result = Person.decode({ name: 'Giulio' })
console.log(PathReporter.report(result))
// => ['Invalid value undefined supplied to : { name: string, age: number }/age: number']
ThrowReporter.report(result)
// => throws 'Invalid value undefined supplied to : { name: string, age: number }/age: number'
interface IPerson extends t.TypeOf<typeof Person> {}
function getName(person: IPerson): string{
return person.name;
}
// Check at compile time
getName({ name: 'Giulio' });
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