Extracting type from block results in "never", always (hehe)

steveninety

last month

2

• 

  diesieben07

  last month

  Page['blocks']

  is an array, which has no overlap with

  { blockType: "collectionItems" }

  , that's why you get

  never

  .

  
  

  What you want is

  Page['blocks'][number]

  to get the elements of the array. This however doesn't work either, because

  Page['blocks']

  is optional. You can fix that with

  NonNullable

  :

  
  

  type Hero = Extract<NonNullable<Page['blocks']>[number], { blockType: "collectionItems" }>

• 

  steveninety

  last month

  That answers my question, thanks for this typescript lesson 🙂