feat(array): isDeepEqual and uniqueBy (#24)

Co-authored-by: Anthony Fu <[email protected]>

src/array.ts

@@ -69,6 +69,20 @@ export function uniq<T>(array: readonly T[]): T[] {
   return Array.from(new Set(array))
 }
 
+/**
+ * Unique an Array by a custom equality function
+ *
+ * @category Array
+ */
+export function uniqueBy<T>(array: readonly T[], equalFn: (a: any, b: any) => boolean): T[] {
+  return array.reduce((acc: T[], cur: any) => {
+    const index = acc.findIndex((item: any) => equalFn(cur, item))
+    if (index === -1)
+      acc.push(cur)
+    return acc
+  }, [])
+}
+
 /**
  * Get last item
  *

src/base.ts

@@ -3,4 +3,10 @@ export const assert = (condition: boolean, message: string): asserts condition =
     throw new Error(message)
 }
 export const toString = (v: any) => Object.prototype.toString.call(v)
+export const getTypeName = (v: any) => {
+  if (v === null)
+    return 'null'
+  const type = toString(v).slice(8, -1).toLowerCase()
+  return typeof v === 'object' || typeof v === 'function' ? type : typeof v
+}
 export const noop = () => {}

src/equal.ts

@@ -0,0 +1,27 @@
+import { getTypeName } from './base'
+
+export function isDeepEqual(value1: any, value2: any): boolean {
+  const type1 = getTypeName(value1)
+  const type2 = getTypeName(value2)
+  if (type1 !== type2)
+    return false
+
+  if (type1 === 'array') {
+    if (value1.length !== value2.length)
+      return false
+
+    return value1.every((item: any, i: number) => {
+      return isDeepEqual(item, value2[i])
+    })
+  }
+  if (type1 === 'object') {
+    const keyArr = Object.keys(value1)
+    if (keyArr.length !== Object.keys(value2).length)
+      return false
+
+    return keyArr.every((key: string) => {
+      return isDeepEqual(value1[key], value2[key])
+    })
+  }
+  return value1 === value2
+}