【bug】ThisType is invalid when using param on generic object

Bug Report

🔎 Search Terms

ThisType Object Generic

🕗 Version & Regression Information

I was unable to test this on prior versions because I was not using this feature previously

⏯ Playground Link

Playground link with relevant code

💻 Code

type ILifetime = {
  onShareTimeline: () => string
}

function createObject<D>(obj: D & ILifetime & ThisType<D>) {
  console.warn(obj)
}

// working
createObject({
  title: 'demo',
  onShareTimeline() {
    return ''
  }
})

// not working
createObject({
  title: 'demo',
  onShareTimeline() {
    return this.title
  }
})

🙁 Actual behavior

The generic type is broken

🙂 Expected behavior

The generic type should contain the object properties as those are finally included into the result

Start with the linked TypeScript Playground and the createObject generic example, comparing the working callback with the version that reads this.title. Investigate how ThisType is applied during generic object contextual typing; done means the inferred object type includes title and the callback can return this.title without an error.