Implementing only a Setter is enough to implement an Interface

[willemneal]

TypeScript Version: 3.6.3

Search Terms: only setter in class implements interfaces. Interface property bugs.

Code

interface Properties {
  val: number;
}

class BadProps implements Properties {
  private _val: number = 42;
  set val(newVal: number) {
    this._val = newVal;
  }
}

Expected behavior:
A type error that the implementing class is missing the getter.

Actual behavior:
Just runtime error of undefined.

Playground Link:
Above example

Related Issues:

[j-oliveras]

Probably related to PR #33509 by @sandersn

[RyanCavanaugh]

Duplicate #30852; others

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.