[#88] ✅ add test

Author: sungryong.park

src/sortBy.test.ts

@@ -0,0 +1,117 @@
+import _sortBy from 'lodash/sortBy'
+import {describe, it, expect} from 'vitest'
+
+import {sortBy} from './sortBy'
+
+function expectsEqual<T>(...args: Parameters<typeof sortBy<T>>) {
+    expect(sortBy(...args)).toEqual(_sortBy(...args))
+}
+
+describe('sortBy', () => {
+    it('sorts an array of objects by single property', () => {
+        const data = [
+            {user: 'fred', age: 48},
+            {user: 'barney', age: 34},
+            {user: 'fred', age: 40},
+            {user: 'barney', age: 36},
+        ]
+        expectsEqual(data, 'user')
+    })
+
+    it('sorts an array with multiple property iteratees', () => {
+        const data = [
+            {user: 'fred', age: 48},
+            {user: 'barney', age: 34},
+            {user: 'fred', age: 40},
+            {user: 'barney', age: 36},
+        ]
+        expectsEqual(data, ['user', 'age'])
+    })
+
+    it('sorts an array with function + property iteratees', () => {
+        const data = [
+            {user: 'fred', age: 48},
+            {user: 'barney', age: 36},
+            {user: 'fred', age: 40},
+            {user: 'barney', age: 36},
+        ]
+        expectsEqual(data, (o) => o.user, 'age')
+    })
+
+    it('stably sorts items with the same criteria', () => {
+        const data = [
+            {id: 1, group: 'alpha', order: 2},
+            {id: 2, group: 'alpha', order: 1},
+            {id: 3, group: 'beta', order: 1},
+            {id: 4, group: 'beta', order: 1},
+        ]
+        expectsEqual(data, ['group', 'order'])
+
+        expect(
+            sortBy(data, ['group', 'order'])
+                .filter((d) => d.group === 'beta')
+                .map((d) => d.id),
+        ).toEqual(
+            _sortBy(data, ['group', 'order'])
+                .filter((d) => d.group === 'beta')
+                .map((d) => d.id),
+        )
+    })
+
+    it('sorts the values of an object as if it were an array', () => {
+        const dataObj = {
+            a: {user: 'fred', age: 48},
+            b: {user: 'barney', age: 36},
+            c: {user: 'wilma', age: 40},
+        }
+        expectsEqual(Object.values(dataObj), 'user')
+    })
+
+    it('handles empty array', () => {
+        expectsEqual([], 'age')
+
+        expectsEqual([], (x) => x)
+    })
+
+    it('returns a new sorted array (does not mutate original)', () => {
+        const data = [
+            {user: 'fred', age: 48},
+            {user: 'barney', age: 36},
+        ]
+        const dataClone = [...data]
+        expect(data).toEqual(dataClone)
+        expectsEqual(data, 'age')
+    })
+
+    it('sorts numbers or strings properly', () => {
+        const numericData = [10, 2, 5, 2]
+        expectsEqual(numericData)
+
+        const stringData = ['pear', 'apple', 'banana', 'Apple']
+        expectsEqual(stringData)
+    })
+
+    it('sorts numbers by value', () => {
+        expectsEqual([5, 2, 9, 1], (x) => x)
+
+        expectsEqual([3, 1, 2])
+    })
+
+    it('sorts using function iteratee', () => {
+        const users = [
+            {name: 'Alice', age: 32},
+            {name: 'Bob', age: 24},
+            {name: 'Charlie', age: 29},
+        ]
+        expectsEqual(users, (u) => u.name.length)
+    })
+
+    it('handles duplicate values correctly', () => {
+        expectsEqual([3, 1, 2, 1], (x) => x)
+    })
+
+    it('handles null values', () => {
+        expectsEqual([{val: 2}, {val: undefined}, {val: 1}], 'val')
+        expectsEqual([{val: null}, {val: 2}, {val: 1}], 'val')
+    })
+})