From 55ff7c66a364cdcbc45ed0f695994e0be441d879 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sascha=20K=C3=BCnstler?= <sascha.kuenstler@moccu.com>
Date: Tue, 20 Feb 2024 09:45:37 +0100
Subject: [PATCH] Provide `event` utils

---
 README.md      | 18 ++++++++++++++++++
 index.js       |  1 +
 src/event.d.ts |  2 ++
 src/event.js   | 31 +++++++++++++++++++++++++++++++
 src/filter.js  | 46 +++++++++++++++++++++++-----------------------
 5 files changed, 75 insertions(+), 23 deletions(-)
 create mode 100644 src/event.d.ts
 create mode 100644 src/event.js

diff --git a/README.md b/README.md
index 7887302..273413b 100644
--- a/README.md
+++ b/README.md
@@ -234,6 +234,24 @@ Get the number of days in a month.
 
 Format a date as YYYY-MM-DD or a custom format.
 
+### Event
+
+#### `debounce(fn, delay)`
+
+Debounce function to prevent multiple calls in a short period of time.
+
+```javascript
+import { debounce } from '@schascha/brabbelback';
+```
+
+#### `throttled(fn, delay)`
+
+Throttle function to reduce the trigger rate.
+
+```javascript
+import { throttled } from '@schascha/brabbelback';
+```
+
 ### Filter
 
 #### `compare(a, b, operator = '')`
diff --git a/index.js b/index.js
index ffcbd03..aa6399a 100644
--- a/index.js
+++ b/index.js
@@ -3,6 +3,7 @@ export * from './src/classnames';
 export * from './src/cookie';
 export * from './src/copy';
 export * from './src/date';
+export * from './src/event';
 export * from './src/filter';
 export * from './src/scroll';
 export * from './src/text';
diff --git a/src/event.d.ts b/src/event.d.ts
new file mode 100644
index 0000000..334d3f1
--- /dev/null
+++ b/src/event.d.ts
@@ -0,0 +1,2 @@
+export declare function debounce(fn: Function, delay: number): Function;
+export declare function throttled(fn: Function, delay: number): Function;
diff --git a/src/event.js b/src/event.js
new file mode 100644
index 0000000..72e35de
--- /dev/null
+++ b/src/event.js
@@ -0,0 +1,31 @@
+/**
+ * Debounce function to prevent multiple calls in a short period of time
+ * @param {Function} fn - The function to debounce
+ * @param {number} delay - The delay in milliseconds
+ * @returns {Function} The debounced function
+ */
+export function debounce(fn, delay) {
+	let timer = 0;
+	return (...args) => {
+		window.clearTimeout(timer);
+		timer = setTimeout(() => fn(...args), delay);
+	};
+}
+
+/**
+ * Throttle function to reduce the trigger rate
+ * @param {Function} fn - The function to throttle
+ * @param {number} delay - The delay in milliseconds
+ * @returns {Function} The throttled function
+ */
+export function throttled(fn, delay) {
+	let timer = 0;
+	return (...args) => {
+		const now = (new Date).getTime();
+		if (now - timer < delay) {
+			return;
+		}
+		timer = now;
+		return fn(...args);
+	};
+}
diff --git a/src/filter.js b/src/filter.js
index b0f1c64..d07543f 100644
--- a/src/filter.js
+++ b/src/filter.js
@@ -1,11 +1,11 @@
 import { has } from './array';
 
 /**
- * Compare a with b.
- * @param  {String|String[]} a
- * @param  {String|String[]} b
- * @param  {String} [operator='']
- * @return {*}
+ * Compare a with b using the given operator
+ * @param  {String|String[]} a - The value or array of values to compare
+ * @param  {String|String[]} b - The value or array of values to compare with
+ * @param  {String} operator - The operator to use, default is ''
+ * @return {Boolean} Returns true if the comparison is true, otherwise false
  */
 export function compare(a, b, operator = '') {
 	if (!a || !b) {
@@ -29,32 +29,32 @@ export function compare(a, b, operator = '') {
 }
 
 /**
- * Filters an array of objects with multiple criteria.
- * @param {Object[]} obj
- * @param {{field: string, value: any, operator: string}[]} filters
- * @return {Object}
+ * Filters an array of objects with multiple criteria
+ * @param {Object[]} obj - The array of objects to filter
+ * @param {{field: string, value: any, operator: string}[]} filters - The filters to apply
+ * @return {Object} The filtered array
  */
 export function filter(obj, filters) {
 	return filters && filters.length
 		? obj.filter((el) => {
-				return filters.every((filter) => {
-					if (Array.isArray(filter.field)) {
-						return filter.field.find((item) =>
-							compare(el[item], filter.value, filter.operator)
-						);
-					} else {
-						return compare(el[filter.field], filter.value, filter.operator);
-					}
-				});
-			})
+			return filters.every((filter) => {
+				if (Array.isArray(filter.field)) {
+					return filter.field.find((item) =>
+						compare(el[item], filter.value, filter.operator)
+					);
+				} else {
+					return compare(el[filter.field], filter.value, filter.operator);
+				}
+			});
+		})
 		: obj;
 }
 
 /**
- * Group array items by key.
- * @param  {Object[]} array  An array with objects to query.
- * @param  {String} key The key to group the array items.
- * @return {Object} Returns a object with grouped arrays by the given key.
+ * Group array items by key
+ * @param  {Object[]} array - The array with objects to group
+ * @param  {String} key - The key to group by
+ * @return {Object} The grouped array
  */
 export function groupBy(array, key) {
 	return array.reduce((rv, x) => {