feat(useMin): new function (#1934)

packages/math/useMin/index.md

@@ -0,0 +1,25 @@
+---
+category: '@Math'
+---
+
+# useMin
+
+Reactive `Math.min`.
+
+## Usage
+
+```ts
+import { useMin } from '@vueuse/math'
+
+const array = ref([1, 2, 3, 4])
+const sum = useMin(array) // Ref<1>
+```
+
+```ts
+import { useMin } from '@vueuse/math'
+
+const a = ref(1)
+const b = ref(3)
+
+const sum = useMin(a, b, 2) // Ref<1>
+```

packages/math/useMin/index.test.ts

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+import { ref } from 'vue-demi'
+import { useMin } from '.'
+
+describe('useMin', () => {
+  it('should be defined', () => {
+    expect(useMin).toBeDefined()
+  })
+
+  it('should accept numbers', () => {
+    const v = useMin(50, 100)
+    expect(v.value).toBe(50)
+  })
+
+  it('should accept refs', () => {
+    const value1 = ref(10)
+    const value2 = ref(100)
+    const value3 = ref(1000)
+
+    const v = useMin(value1, value2, value3)
+    expect(v.value).toBe(10)
+
+    value1.value = 8
+    expect(v.value).toBe(8)
+
+    value2.value = 7
+    expect(v.value).toBe(7)
+
+    value3.value = 6
+    expect(v.value).toBe(6)
+  })
+
+  it('should accept numbers and refs', () => {
+    const value1 = 10
+    const value2 = ref(100)
+
+    const v = useMin(50, value1, value2)
+
+    expect(v.value).toBe(10)
+
+    value2.value = 0
+    expect(v.value).toBe(0)
+  })
+
+  it('should accept single arg', () => {
+    const v = useMin(50)
+    expect(v.value).toBe(50)
+  })
+
+  it('should accept zero arg', () => {
+    const v = useMin()
+    expect(v.value).toBe(Infinity)
+  })
+})

packages/math/useMin/index.ts

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+import type { ComputedRef } from 'vue-demi'
+import { computed } from 'vue-demi'
+import type { MaybeComputedRef } from '@vueuse/shared'
+import type { MaybeComputedRefArgs } from '../utils'
+import { resolveUnrefArgsFlat } from '../utils'
+
+export function useMin(array: MaybeComputedRef<MaybeComputedRef<number>[]>): ComputedRef<number>
+export function useMin(...args: MaybeComputedRef<number>[]): ComputedRef<number>
+
+/**
+ * Reactive `Math.min`.
+ *
+ * @see https://vueuse.org/useMin
+ * @param values
+ */
+export function useMin(...args: MaybeComputedRefArgs<number>) {
+  return computed<number>(() => {
+    const array = resolveUnrefArgsFlat(args)
+    return Math.min(...array)
+  })
+}