Partial Type Argument Inference

type.ts

declare function get<Doc, Key extends keyof Doc = infer>();
declare let unknownObj: unknown;
declare let obj: { title: string; description: string };

// CASE 0
const case0 = get(obj, 'description'); 
// Unchanged: string

// CASE 1
const case1 = get<{ title: string; description: string }>(unknownObj, 'description'); 
// Current: TS Error
// Proposal: string

// CASE 2
const case2 = get<{ title: string; description: string }, 'title'>(unknownObj, 'description');
// Current: ❌ missing type argument
// Proposal: ❌ 'description' cannot be assigned to 'title'

// CASE 3
// Currently, you have to write
declare function floatingGenericTypeArgument<A, B = any>(b: B): [A, B]

// With this proposal, you could write
declare function floatingGenericTypeArgument<A, B = infer>(b: B): [A, B]

const case3 = floatingGenericTypeArgument<'a'>(null);
// Current: ['a', any]
// Proposal: ['a', null]

Submit your case with the following :

• Function signature
• Function call
• Expected return type