Made an interface for all key-value iterables out there

src/utils/collections/key-value-iterable.ts

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+/**
+ * Represents an object that contains key-value pairs and exposes an `entries()` method
+ * to iterate over those pairs.
+ */
+export interface KeyValueIterable<K, V> {
+    /**
+     * Returns an iterable containing the key-value pairs of the object.
+     */
+    entries(): Iterable<[K, V]>;
+}
+
+/**
+ * Type guard to check if the given object implements the {@link KeyValueIterable} interface.
+ *
+ * @template K - The key type.
+ * @template V - The value type.
+ *
+ * @param obj - The object to check.
+ *
+ * @returns `true` if the object implements the {@link KeyValueIterable} interface; otherwise, `false`.
+ */
+export function isKeyValueIterable<K, V>(obj: unknown): obj is KeyValueIterable<K, V> {
+    return typeof (obj as KeyValueIterable<K, V>)?.entries === "function";
+}

tests/unit/utils/collections/key-value-iterable.spec.ts

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+import { isKeyValueIterable } from "@/utils/collections/key-value-iterable";
+
+describe("isKeyValueIterable", () => {
+    test("returns true for objects that have entries", () => {
+        expect(isKeyValueIterable(new Map())).toBe(true);
+        expect(isKeyValueIterable(new Set())).toBe(true);
+        expect(isKeyValueIterable([])).toBe(true);
+        expect(isKeyValueIterable({ entries: () => [] })).toBe(true);
+    });
+
+    test("returns false for objects that has no entries", () => {
+        expect(isKeyValueIterable({})).toBe(false);
+        expect(isKeyValueIterable(new Date())).toBe(false);
+    });
+
+    test("returns false for null and undefined", () => {
+        expect(isKeyValueIterable(null)).toBe(false);
+        expect(isKeyValueIterable(undefined)).toBe(false);
+    });
+});