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Accessing property on super should be a type error #35314
Description
TypeScript Version: 3.7.2
Search Terms:
typescript property access super undefined
Code
class Base {
n = 3
}
class Foo extends Base {
test() {
console.log(super.n) // type system says it should be a number, but it is undefined
}
}
new Foo().test() // logs "undefined"Expected behavior:
Should be some sort of type error, because clearly it is undefined
Actual behavior:
no error until runtime
Activity
fatcerberus commentedon Nov 24, 2019
This might be a design limitation - TypeScript can’t currently distinguish between prototype properties and own properties of a class type. The type of
superisBase, andBase-the-type has a propertyn, so the typechecker is satisfied.Jack-Works commentedon Apr 29, 2023
#54056