indexedAccessWithVariableElement.ts(7,7): error TS2322: Type 'number | undefined' is not assignable to type 'number'.
  Type 'undefined' is not assignable to type 'number'.
indexedAccessWithVariableElement.ts(13,7): error TS2322: Type 'number | undefined' is not assignable to type 'number'.
  Type 'undefined' is not assignable to type 'number'.


==== indexedAccessWithVariableElement.ts (2 errors) ====
    // repro from https://github.com/microsoft/TypeScript/issues/54420
    
    declare const array1: [...number[], number]
    const el1: number = array1[0]
    
    declare const array2: [...number[], number]
    const el2: number = array2[1]
          ~~~
!!! error TS2322: Type 'number | undefined' is not assignable to type 'number'.
!!! error TS2322:   Type 'undefined' is not assignable to type 'number'.
    
    declare const array3: [number, ...number[], number]
    const el3: number = array3[1]
    
    declare const array4: [number, ...number[], number]
    const el4: number = array4[2]
          ~~~
!!! error TS2322: Type 'number | undefined' is not assignable to type 'number'.
!!! error TS2322:   Type 'undefined' is not assignable to type 'number'.
    