From 85bc226e88b2bec9f56e5b5a3111b385ee4627b6 Mon Sep 17 00:00:00 2001
From: Guotong Liao <37015336+GlintonLiao@users.noreply.github.com>
Date: Sat, 15 Oct 2022 07:13:30 -0700
Subject: [PATCH] feat(math): adding several math functions and math test
 modules (#6)

---
 src/math/index.ts | 19 +++++++++-
 test/math.test.ts | 97 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 test/math.test.ts

diff --git a/src/math/index.ts b/src/math/index.ts
index 1887ed9..33ca982 100644
--- a/src/math/index.ts
+++ b/src/math/index.ts
@@ -1,4 +1,4 @@
-import { reactify } from '@vueuse/shared'
+import { MaybeRef, reactify } from '@vueuse/shared'
 
 export * from './generated'
 
@@ -24,3 +24,20 @@ export const divide = reactify((a: number, b: number) => a / b)
 
 /*@__PURE__*/
 export const subtract = reactify((a: number, b: number) => a - b)
+
+/*@__PURE__*/
+export const mod = reactify((a: number, b: number) => a % b)
+
+/*@__PURE__*/
+const pureGcd = (a: number, b: number): number => {
+  if (b === 0) return a
+  else return pureGcd(b, a % b)
+}
+
+/*@__PURE__*/
+export const gcd = reactify(pureGcd)
+
+/*@__PURE__*/
+export const lcm = (a: MaybeRef<number>, b: MaybeRef<number>) => {
+  return divide(multiply(a, b), gcd(a, b))
+}
diff --git a/test/math.test.ts b/test/math.test.ts
new file mode 100644
index 0000000..d68ba90
--- /dev/null
+++ b/test/math.test.ts
@@ -0,0 +1,97 @@
+import { ref } from 'vue-demi'
+import { is, set, negative, sum, multiply, divide, subtract, mod, gcd, lcm } from '../src'
+import { $expect } from './utils'
+
+describe('reactiveMath', () => {
+  it('negative', () => {
+    const a = ref(9)
+    const c = negative(a)
+    $expect(is(c, -9))
+    $expect(is(a, 9))
+
+    set(a, 10)
+    $expect(is(c, -10))
+  })
+
+  it('sum', () => {
+    const a = ref(1)
+    const b = ref(2)
+    const c = ref(3)
+    const d = sum(a, b, c)
+    $expect(is(d, 6))
+
+    set(a, 10)
+    set(b, 15)
+    $expect(is(d, 28))
+  })
+
+  it('subtract', () => {
+    const a = ref(1)
+    const b = ref(2)
+    const c = subtract(a, b)
+    $expect(is(c, -1))
+
+    set(a, 20)
+    set(b, 15)
+    $expect(is(c, 5))
+  })
+
+  it('multiply', () => {
+    const a = ref(1)
+    const b = ref(2)
+    const c = ref(3)
+    const d = multiply(a, b, c)
+    $expect(is(d, 6))
+
+    set(a, 4)
+    set(b, 5)
+    $expect(is(d, 60))
+  })
+
+  it('divide', () => {
+    const a = ref(1)
+    const b = ref(2)
+    const c = divide(a, b)
+    $expect(is(c, 0.5))
+
+    set(a, 20)
+    set(b, 10)
+    $expect(is(c, 2))
+  })
+
+  it('mod', () => {
+    const a = ref(15)
+    const b = ref(9)
+    const c = mod(a, b)
+    $expect(is(c, 6))
+    $expect(is(b, 9))
+
+    set(a, 3)
+    set(b, 2)
+    $expect(is(c, 1))
+  })
+
+  it('gcd', () => {
+    const a = ref(9)
+    const b = ref(15)
+    const c = gcd(a, b)
+    $expect(is(c, 3))
+    $expect(is(a, 9))
+
+    set(a, 14)
+    set(b, 21)
+    $expect(is(c, 7))
+    $expect(is(a, 14))
+  })
+
+  it('lcm', () => {
+    const a = ref(2)
+    const b = ref(3)
+    const c = lcm(a, b)
+    $expect(is(c, 6))
+
+    set(a, 7)
+    set(b, 14)
+    $expect(is(c, 14))
+  })
+})