Multiply

CHANGELOG.md

@@ -1,5 +1,11 @@
 # deverything
 
+## 0.31.0
+
+### Minor Changes
+
+- multiply
+
 ## 0.30.0
 
 ### Minor Changes

README.md

@@ -52,10 +52,11 @@ Contributions always welcome!
 
 ### Math
 
-- `average()`
-- `max()`
-- `min()`
-- `sum()`
+- `average()` numbers of an array
+- `max()` numbers of an array
+- `min()` numbers of an array
+- `multiply()` numbers of an array
+- `sum()` numbers an array
 
 ### Helpers
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "deverything",
-  "version": "0.30.0",
+  "version": "0.31.0",
   "description": "Everything you need for Dev",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",

src/math/index.ts

@@ -1,4 +1,5 @@
 export * from "./average";
 export * from "./max";
 export * from "./min";
+export * from "./multiply";
 export * from "./sum";

src/math/multiply.test.ts

@@ -0,0 +1,10 @@
+import { describe, expect, test } from "@jest/globals";
+import { multiply } from "./multiply";
+
+describe("multiply", () => {
+  test("simple", async () => {
+    expect(multiply([1, 2])).toBe(2);
+    expect(multiply([1, 0])).toBe(0);
+    expect(multiply([0.5, 0.5])).toBe(0.25);
+  });
+});

src/math/multiply.ts

@@ -0,0 +1,3 @@
+export const multiply = (numbers: number[]) => {
+  return numbers.reduce((total, num) => total * num, 1);
+};

src/math/sum.test.ts

@@ -1,28 +1,8 @@
 import { describe, expect, test } from "@jest/globals";
-import { sum, sumBy } from "./sum";
+import { sum } from "./sum";
 
 describe("sum", () => {
   test("simple", async () => {
     expect(sum([1, 2])).toBe(3);
   });
 });
-
-describe("sumBy", () => {
-  test("simple", async () => {
-    expect(
-      sumBy([{ a: 1 }, { a: 2 }], (item) => {
-        return item.a;
-      })
-    ).toBe(3);
-  });
-  test("string", async () => {
-    expect(sumBy([{ a: 1 }, { a: 2 }], "a")).toBe(3);
-  });
-  test("complex", async () => {
-    expect(
-      sumBy([{ a: 1 }, { b: { a: 2 } }], (item) => {
-        return item.a || item.b?.a;
-      })
-    ).toBe(3);
-  });
-});

src/math/sum.ts

@@ -1,13 +1,3 @@
-import { PropertyAccessor, getProp } from "../_internals/getProp";
-import { PlainObject } from "../types";
-
 export const sum = (numbers: number[]) => {
   return numbers.reduce((total, num) => total + num, 0);
 };
-
-export const sumBy = <T extends PlainObject>(
-  items: T[],
-  prop: PropertyAccessor<T>
-) => {
-  return items.reduce((total, item) => total + getProp<T>(item, prop), 0);
-};