Merge pull request #19 from ZIMkaRU/feature/add-min-max-utils

Add max and min utils

CHANGELOG

@@ -1,3 +1,7 @@
+# 1.8.0
+- feat: max
+- feat: min
+
 # 1.7.0
 - feat: freezeDeep
 

README.md

@@ -15,7 +15,9 @@ Currently supported utils:
 - `isNil` - checks whenever value is null or undefined
 - `isObject` - checks if the input is not a nullable object instance
 - `isPlainObject` - checks if input is object, not null object and not array object
+- `max` - computes the maximum value of array. If array is empty or falsey, undefined is returned
 - `merge` - deep merge functionality for objects
+- `min` - computes the minimum value of array. If array is empty or falsey, undefined is returned
 - `omit` - provides new object that omits only specific fields of source object
 - `omitBy` - provides new object that omits only specific fields of source object depending on predicate function filter
 - `pick` - provides new object that picks only specific fields of source object

index.d.ts

@@ -10,7 +10,9 @@ export function isFunction (val: any): boolean
 export function isNil (val: any): boolean
 export function isObject (verifiable: any): Boolean
 export function isPlainObject (val: any): boolean
+export function max (array: Array<any>): any
 export function merge (obj: Object, ...sources: Object[]): Object
+export function min (array: Array<any>): any
 export function omit (obj: Object, keys: Array<string>): Object
 export function omitBy (obj: Object, predicate: (val: any, key: string) => boolean): Object
 export function pick (obj: Object, keys: Array<string>): Object

index.js

@@ -12,7 +12,9 @@ const isFunction = require('./src/isFunction')
 const isNil = require('./src/isNil')
 const isObject = require('./src/isObject')
 const isPlainObject = require('./src/isPlainObject')
+const max = require('./src/max')
 const merge = require('./src/merge')
+const min = require('./src/min')
 const omit = require('./src/omit')
 const omitBy = require('./src/omitBy')
 const pick = require('./src/pick')
@@ -32,7 +34,9 @@ module.exports = {
  isNil,
  isObject,
  isPlainObject,
+ max,
  merge,
+ min,
  omit,
  omitBy,
  pick,

package.json

@@ -1,6 +1,6 @@
 {
  "name": "@bitfinexcom/lib-js-util-base",
- "version": "1.7.0",
+ "version": "1.8.0",
  "description": "general utils",
  "main": "index.js",
  "scripts": {

src/max.js

@@ -0,0 +1,12 @@
+'use strict'
+
+const determineExtremumValue = require('./util/determineExtremumValue')
+
+const max = (array) => {
+ return determineExtremumValue(
+ array,
+ (value, other) => value > other
+ )
+}
+
+module.exports = max

src/min.js

@@ -0,0 +1,12 @@
+'use strict'
+
+const determineExtremumValue = require('./util/determineExtremumValue')
+
+const min = (array) => {
+ return determineExtremumValue(
+ array,
+ (value, other) => value < other
+ )
+}
+
+module.exports = min

src/util/determineExtremumValue.js

@@ -0,0 +1,29 @@
+'use strict'
+
+const isNil = require('../isNil')
+
+const determineExtremumValue = (array, comparator) => {
+ if (
+ !Array.isArray(array) ||
+ array.length === 0
+ ) {
+ return
+ }
+
+ return array.reduce((prev, curr) => {
+ if (isNil(curr)) {
+ return prev
+ }
+ if (
+ prev === undefined &&
+ !Number.isNaN(curr) &&
+ typeof curr !== 'symbol'
+ ) {
+ return curr
+ }
+
+ return comparator(curr, prev) ? curr : prev
+ }, undefined)
+}
+
+module.exports = determineExtremumValue

test/max.js

@@ -0,0 +1,36 @@
+'use strict'
+
+/* eslint-env mocha */
+
+const assert = require('assert')
+const max = require('../src/max')
+
+describe('max', () => {
+ it('should return the largest value from a collection', () => {
+ const actual = max([4, null, 2, 8, 6])
+
+ assert.strictEqual(actual, 8)
+ })
+
+ it('should return `undefined` without arguments', () => {
+ const actual = max()
+
+ assert.strictEqual(actual, undefined)
+ })
+
+ it('should return `undefined` for empty collections', () => {
+ const sources = [null, undefined, false, 0, NaN, '', Symbol('a'), []]
+
+ for (const source of sources) {
+ const actual = max(source)
+
+ assert.strictEqual(actual, undefined)
+ }
+ })
+
+ it('should return the largest value from a string collection', () => {
+ const actual = max(['cd', null, 'ab', 'gh', 'ef'])
+
+ assert.strictEqual(actual, 'gh')
+ })
+})

test/min.js

@@ -0,0 +1,36 @@
+'use strict'
+
+/* eslint-env mocha */
+
+const assert = require('assert')
+const min = require('../src/min')
+
+describe('min', () => {
+ it('should return the smallest value from a collection', () => {
+ const actual = min([4, null, 2, 8, 6])
+
+ assert.strictEqual(actual, 2)
+ })
+
+ it('should return `undefined` without arguments', () => {
+ const actual = min()
+
+ assert.strictEqual(actual, undefined)
+ })
+
+ it('should return `undefined` for empty collections', () => {
+ const sources = [null, undefined, false, 0, NaN, '', Symbol('a'), []]
+
+ for (const source of sources) {
+ const actual = min(source)
+
+ assert.strictEqual(actual, undefined)
+ }
+ })
+
+ it('should return the smallest value from a string collection', () => {
+ const actual = min(['cd', null, 'ab', 'gh', 'ef'])
+
+ assert.strictEqual(actual, 'ab')
+ })
+})