feat: has

README.md

@@ -146,6 +146,18 @@ fromIterable(new Set([1, 2, 3]))
 ```
 </details>
 
+<details>
+<summary>has</summary>
+
+```javascript
+import { has } from '@ilteoood/re-flusso/has';
+
+.pipeThrough(
+    has(new Set([1, 2, 3]))
+)
+```
+</details>
+
 <details>
 <summary>last</summary>
 

src/equals.ts

@@ -1,12 +1,12 @@
 import { filter } from "./filter";
 
-export const equals = (
-	value: unknown,
+export const equals = <T>(
+	value: T,
 	writableStrategy?: QueuingStrategy,
 	readableStrategy?: QueuingStrategy,
 ) => {
 	return filter(
-		(chunk: unknown) => chunk === value,
+		(chunk: T) => chunk === value,
 		writableStrategy,
 		readableStrategy,
 	);

src/has.ts

@@ -0,0 +1,13 @@
+import { filter } from "./filter";
+
+export const has = <T>(
+	values: Set<T>,
+	writableStrategy?: QueuingStrategy,
+	readableStrategy?: QueuingStrategy,
+) => {
+	return filter(
+		(chunk: T) => values.has(chunk),
+		writableStrategy,
+		readableStrategy,
+	);
+};

test/has.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, test } from "vitest";
+import { fromIterable } from "../src/fromIterable";
+import { fromRange } from "../src/numbers/fromRange";
+import { pipeline } from "../src/pipeline";
+import { toArray } from "../src/toArray";
+import { has } from "../src/has";
+
+describe("in", () => {
+	test("should work with empty list", async () => {
+		const destinationArray = [];
+
+		await pipeline(
+			fromIterable([]),
+			has(new Set([0, 1, 2])),
+			toArray(destinationArray),
+		);
+
+		expect(destinationArray).toEqual([]);
+	});
+
+	test("should correctly filter numbers", async () => {
+		const destinationArray = [];
+
+		await pipeline(
+			fromRange(1, 3),
+			has(new Set([0, 1, 2])),
+			toArray(destinationArray),
+		);
+
+		expect(destinationArray).toEqual([1, 2]);
+	});
+});