feat(financial-calculating): add calculateDiscountParentage method (#…

…33)

* feat(financial-calculating): add calculateDiscountPercentage function for discount percentage calculation

* docs(financial-calculating): add tsDoc for new method

* docs(financial-calculate): add Documentation for the new method

* test(financial-calculating): write three test for calculate discount percentage

* test(financial-calculating): update tests for calculateDiscountAmount and calculateDiscountedPrice functions

* refactor(financial-calculating): separate calculateDiscountPercentage for calculate profit and discount

* refactor(financial-calculating): rename discount percentage functions for clarity

* lint: Make Happy :)

packages/financial-calculate/README.md

@@ -36,3 +36,12 @@ Calculate the discount amount from the original price.
 ```ts
 calculateDiscountAmount(100, 10, 1); // returns 10.0
 ```
+
+### calculateDiscountPercentage
+
+Calculates the discount percentage between the market price and the sale price.
+
+```ts
+calculateDiscountPercentage(100, 80); // Returns 20.00
+calculateDiscountPercentage(100, 80, 1, false); // Returns 25.0
+```

packages/financial-calculate/src/main.test.js

@@ -1,39 +1,34 @@
 import test from 'ava';
 
-import {calculateDiscountAmount, calculateDiscountedPrice} from '@nexim/financial-calculate';
-
-test('calculate discount from price with: 3, 4 input', (test) => {
+import {
+  calculateDiscountAmount,
+  calculateDiscountedPrice,
+  calculatePercentageDiscount,
+  calculatePercentageProfit,
+} from '@nexim/financial-calculate';
+
+test('calculate discount from price', (test) => {
   test.is(calculateDiscountAmount(3, 4), 0.12);
-});
-
-test('calculateDiscountAmount(100, 10) returns 10.00', (t) => {
-  t.is(calculateDiscountAmount(100, 10), 10);
-});
-
-test('calculate price from discount with: 3, 4 input', (test) => {
-  test.is(calculateDiscountedPrice(3, 4), 2.88);
-});
-
-test('calculate discount from price with: 587, 629 input', (test) => {
+  test.is(calculateDiscountAmount(100, 10), 10);
   test.is(calculateDiscountAmount(587, 629), 3692.23);
-});
-
-test('calculate price from discount with: 587, 629 input', (test) => {
-  test.is(calculateDiscountedPrice(587, 629), -3105.23);
-});
-
-test('calculate discount from price with: 15034, 73 input', (test) => {
   test.is(calculateDiscountAmount(15034, 73), 10974.82);
+  test.is(calculateDiscountAmount(54205, 1332, 5), 722010.6);
 });
 
-test('calculate price from discount with: 15034, 73 input', (test) => {
+test('calculate price from discount', (test) => {
+  test.is(calculateDiscountedPrice(3, 4), 2.88);
+  test.is(calculateDiscountedPrice(100, 10), 90);
   test.is(calculateDiscountedPrice(15034, 73), 4059.18);
+  test.is(calculateDiscountedPrice(587, 629), -3105.23);
+  test.is(calculateDiscountedPrice(54205, 1332, 5), -667805.6);
 });
 
-test('calculate discount from price with: 54205, 1332, 5 input', (test) => {
-  test.is(calculateDiscountAmount(54205, 1332, 5), 722010.6);
+test('calculate discount percentage for profit and discount', (test) => {
+  test.is(calculatePercentageProfit(100, 80), 25);
+  test.is(calculatePercentageProfit(100, 53), 88.68);
 });
 
-test('calculate price from discount with: 54205, 1332, 5 input', (test) => {
-  test.is(calculateDiscountedPrice(54205, 1332, 5), -667805.6);
+test('calculate discount percentage for profit', (test) => {
+  test.is(calculatePercentageDiscount(100, 80, 1), 20);
+  test.is(calculatePercentageDiscount(100, 53), 47);
 });

packages/financial-calculate/src/main.ts

@@ -42,3 +42,45 @@ export function calculateDiscountAmount(price: number, discount: number, decimal
   const discountAmount = (price * discount) / 100;
   return parseFloat(discountAmount.toFixed(decimal));
 }
+
+/**
+ * Calculates the discount percentage between the market price and the sale price for profit.
+ *
+ * @param marketPrice - The original market price of the item.
+ * @param salePrice - The sale price of the item.
+ * @param decimal - The number of decimal places to round the result to(optional with default value = 2).
+ * @param upSide - Determines the denominator for the percentage calculation (optional with default value = true).
+ *
+ * @example
+ * ```
+ * calculateDiscountPercentage(100, 80); // Returns 20.00
+ * calculateDiscountPercentage(100, 80, 1, false); // Returns 25.0
+ * ```
+ */
+export function calculatePercentageProfit(marketPrice: number, salePrice: number, decimal = 2): number {
+  logger.logMethodArgs?.('calculatePercentageProfit', {marketPrice, salePrice, decimal});
+
+  const percentage = ((marketPrice - salePrice) / salePrice) * 100;
+  return parseFloat(percentage.toFixed(decimal));
+}
+
+/**
+ * Calculates the discount percentage between the market price and the sale price for discount.
+ *
+ * @param marketPrice - The original market price of the item.
+ * @param salePrice - The sale price of the item.
+ * @param decimal - The number of decimal places to round the result to(optional with default value = 2).
+ * @param upSide - Determines the denominator for the percentage calculation (optional with default value = true).
+ *
+ * @example
+ * ```
+ * calculateDiscountPercentage(100, 80); // Returns 20.00
+ * calculateDiscountPercentage(100, 80, 1, false); // Returns 25.0
+ * ```
+ */
+export function calculatePercentageDiscount(marketPrice: number, salePrice: number, decimal = 2): number {
+  logger.logMethodArgs?.('calculatePercentageDiscount', {marketPrice, salePrice, decimal});
+
+  const percentage = ((marketPrice - salePrice) / marketPrice) * 100;
+  return parseFloat(percentage.toFixed(decimal));
+}