feat@fix r.diff.with

source/differenceWith.js

@@ -5,7 +5,7 @@ export function differenceWithFn(
   fn, a, b
 ){
   const willReturn = []
-  const [ first, second ] = a.length > b.length ? [ a, b ] : [ b, a ]
+  const [ first, second ] = a.length >= b.length ? [ a, b ] : [ b, a ]
 
   first.forEach(item => {
     const hasItem = second.some(secondItem => fn(item, secondItem))

source/differenceWith.spec.js

@@ -1,13 +1,15 @@
-import { differenceWith } from './differenceWith.js'
+import { differenceWith } from './differenceWith.js';
 
-test('happy', () => {
-  const foo = [ { a : 1 }, { a : 2 }, { a : 3 } ]
-  const bar = [ { a : 3 }, { a : 4 } ]
-  const fn = function (r, s){
-    return r.a === s.a
-  }
-  const result = differenceWith(
-    fn, foo, bar
-  )
-  expect(result).toEqual([ { a : 1 }, { a : 2 } ])
-})
+const fn = (a, b) => a.x === b.x;
+
+test('same length of list', () => {
+	const result = differenceWith(fn, [{ x: 1 }, { x: 2 }], [{ x: 1 }, { x: 3 }]);
+	expect(result).toEqual([{ x: 2 }]);
+});
+
+test('different length of list', () => {
+	const foo = [{ x: 1 }, { x: 2 }, { x: 3 }];
+	const bar = [{ x: 3 }, { x: 4 }];
+	const result = differenceWith(fn, foo, bar);
+	expect(result).toEqual([{ x: 1 }, { x: 2 }]);
+});