I had this problem Why do I always have to fill in the details

type Doc = Record<string,any>


type DocFilter<T extends Doc> = {[k in keyof T as T[k] extends (()=>void) ? never:k]:T[k]}



const doc1 = {aaaa:'',bbbb:1,c:()=>{}} 


function test1 <T extends Partial< typeof doc1>,>(opt:{prop:T}){}

test1({
  prop:{
    aaaa:'',
    bbbb:1, // When I enter the "bbbb" field, there is a prompt .This was to be expected
  }
})

test2 I want to filter out the function field // Why do I always have to fill in the details

function test2 <T extends Partial<DocFilter< typeof doc1>>,>(opt:{prop:T}){}

test2({
  prop:{
    aaaa:'', // When I enter the first field, the correlation keyword prompts all fields.  For example, enter a to prompt aaaa and b to prompt bbbb  
    b   //But I couldn't get a prompt when I entered the second field .The cause was found because of the ''as' keyword. How to solve this problem?  
  }
})
 

Playground

CodePudding user response：

I'm not really sure why your solution doesn't work, but this other way of defining DocFilter seems to do what you want. Instead of using as to re-map the keys, you can use Omit to exclude the ones you don't want. I borrowed KeysMatching from this other answer.

type KeysMatching<T, V> = {[K in keyof T]: T[K] extends V ? K : never}[keyof T];
type DocFilter<T> = Omit<T, KeysMatching<T, () => void>>

Playground Link