Incompatible union types

Issue

I have these union types:

type Role = 'x' | 'y' | 'z' | 't'
type Entity = { personId: string } | { organizationId: string }
type RoleEntity = { role: 'x', personId: string } | { role: 'y', personId: string } | { role: 'z', organizationId: string } | { role: 'y', organizationId: string } 

and this function that inserts a RoleEntity into an array when passing a role and an entity

function laFunc(r: Role, entity: Entity) {

  const nard: RoleEntity[] = []
  switch (r) {
    case 'x':
    case 'y': {
      if ('personId' in entity) {
        nard.push({
          role: r,
          personId: entity.personId
        })
      }
    }
  }
}

But I am getting this error:

Argument of type '{ role: "x" | "y"; personId: string; }' is not assignable to parameter of type 'RoleEntity'.
  Type '{ role: "x" | "y"; personId: string; }' is not assignable to type '{ role: "y"; personId: string; }'.
    Types of property 'role' are incompatible.
      Type '"x" | "y"' is not assignable to type '"y"'.
        Type '"x"' is not assignable to type '"y"'.(2345)

How can I fix this?

Solution

Have a union on the role itself !

type RoleEntity = { role: 'x'|'y', personId: string }  | { role: 'z'|'y', organizationId: string }

Playground

Answered By - Matthieu Riegler