TypeScript Version: 4.0, nightly

Search Terms:
Generic, refinement, refine, extends boolean

Code

function foo<TValue extends boolean>(value: TValue) {
  if (value === true) {
    const truthy: true = value
  }
}

Expected behavior:
TValue should be refined to true. At the very least, the value variable should.

Actual behavior:
Error:

Type 'TValue' is not assignable to type 'true'.
  Type 'boolean' is not assignable to type 'true'.(2322)

Playground Link:
https://www.typescriptlang.org/play?ts=4.1.0-dev.20201030#code/GYVwdgxgLglg9mABMOcA8AVAagQwDYgCmihAHlIWACYDOiARqnoTmAHwAUAbvkQFyJsvQgEpEAbwCwAKESIYwRN2GIAvOsRQATkTFTZcxBAQ0omnVAAWATwHaiaxDwKEZcgL4zP0oA