filter over Map

[davetapley]

For ramda/ramda#3507

[Harris-Miller]

// filter(() => boolean) was correct as is. More accurately it's // filter(() => boolean)(list | dict)

[davetapley]

@Harris-Miller thanks for feedback, fixed and rebased

[Harris-Miller]

Suggested change

	// filter(() => boolean)(list | dict)
	// filter(() => boolean)

[Harris-Miller]

Suggested change

	<K>(map: Map<K, T>): Map<K, T>;
	<P extends T, C extends readonly P[] | Record<string, P>>(collection: C): C;
	// filter(() => boolean)(map)
	<K>(map: Map<K, T>): Map<K, T>;
	// filter(() => boolean)(list | dict)
	<P extends T, C extends readonly P[] | Record<string, P>>(collection: C): C;

[Harris-Miller]

Github doesn't let you add suggests to unchanged code, but you need to add type support for Map here too. This whole things should be:

// filter(() => narrow)
export function filter<A, P extends A>(
  pred: (val: A) => val is P,
): {
  // filter(() => narrow)(map)
  <K, B extends A>(map: Map<K, B>): Map<K, P>;
  // if we put `Record<string, A>` first, it will actually pic`A[]` as well
  // so it needs to go first
  // filter(() => narrow)(list)
  <B extends A>(list: readonly B[]): P[];
  // filter(() => narrow)(dict)
  <B extends A>(dict: Record<string, B>): Record<string, P>;
  // but we also want `A[]` to be the default when doing `pipe(filter(fn))`, so it also needs to be last
  // filter(() => narrow)(list | dict)
  <B extends A>(list: readonly B[]): P[];
};

[Harris-Miller]

First, these tests are for // filter(() => narrow, map)

Second, you need to be far more exhaustive with your test additions. This file has test coverage for all curry varieties and argument type overloads. You added support for a new argument type, so you need to add tests for each curry call variation