In TypeScript 3.9, the compiler is able to re-use (i.e. not invalidate) the previous program if only external templates (i.e. no TS files) have changed. PR Close #36989
In TypeScript 3.9, the compiler is able to re-use (i.e. not invalidate) the previous program if only external templates (i.e. no TS files) have changed. PR Close #36989