feat: implement isEmptyObject guard

src/guards/isEmptyObject.ts

@@ -0,0 +1,30 @@
+import { isPlainObject } from './isPlainObject';
+
+/**
+ * Check whether the given value is an empty object or not
+ *
+ * @param x any value
+ * @returns {boolean} true if the value is an empty object
+ *
+ * @example
+ *
+ * isEmptyObject({})                    // true
+ * isEmptyObject([])                    // false
+ * isEmptyObject(10)                    // false
+ * isEmptyObject(true)                  // false
+ * isEmptyObject(null)                  // false
+ * isEmptyObject("bar")                 // false
+ * isEmptyObject({a: 1})                // false
+ * isEmptyObject(() => {})              // false
+ * isEmptyObject(new Map())             // false
+ * isEmptyObject(new Set())             // false
+ * isEmptyObject([1, "foo"])            // false
+ * isEmptyObject(new Set([1, true]))    // false
+ * isEmptyObject(new Map([["a", 1]]))   // false
+ */
+
+export function isEmptyObject(x: unknown): x is boolean {
+  if (!isPlainObject(x)) return false;
+
+  return Object.keys(x).length === 0;
+}