In typescript how would I create a conditional type that states:

If array has x then it must also have y and z.

Example:

const allGroups = [ 'w', 'x', 'y', 'z']

const group1 = [ 'w' ] // valid
const group2 = [ 'x' ] // invalid
const group3 = [ 'x', 'y' ] // invalid
const group4 = [ 'x', 'y', 'z' ] // valid