Type inference with map & (otherMap | otherMap2) fails

[marcesengel]

TypeScript Version: Nightly

Search Terms: None (I couldn't come up with any, please excuse me)

Code

type Entity = {
  someDate: Date | null;
} & ({ id: string; } | { id: number; })

type RowRendererMeta<TInput extends {}> = {
  [key in keyof TInput]: { key: key; caption: string; formatter?: (value: TInput[key]) => string; };
}
type RowRenderer<TInput extends {}> = RowRendererMeta<TInput>[keyof RowRendererMeta<TInput>];

const test: RowRenderer<Entity> = {
  key: 'someDate',
  caption: 'My Date',
  formatter: (value) => value ? value.toString() : '-' // value: any
}

const thisIsNotTheIssue: Partial<RowRendererMeta<Entity>> = {
  someDate: {
    key: 'someDate',
    caption: 'My Date',
    formatter: (value) => value ? value.toString() : '-' // value: Date | null
  }
}

Expected behavior:
TypeScript inferes the argument of formatter to be Date | null.

Actual behavior:
When removing the & ({ id: string; } | { id: number; }) part of the Entity type definition, everything works as expected. However including it breaks type inference, resulting in an implicit any error/warning (depending on configuration), though it does not break the RowRendererMeta<...> type, as shown in the second const declaration.

Playground Link: Playground Link

Related Issues: None found.

Edit: Inference for id sadly does not seem to work at all.

Edit 2: Even though TS seems not to infer the type of the function argument, it complains when you try to use an invalid type (in this example string to name one).

[orta]

Just in case someone is blocked on this, you can switch from ({ id: string; } | { id: number; }) to { id: string | : number; } as a work around

Or allow for lazy propagation of the types via a type AllKeys<T> = T extends unknown ? keyof T : never; in here