refactor(utils): add merge function (#45)

* perf(utils): extract `lodash.merge`

* test: add test case

* refactor: optimize

* chore: revert `gitignore`

* refactor: update

Co-authored-by: John <John60676@qq.com>

src/__tests__/utils-merge.test.ts

@@ -0,0 +1,165 @@
+import { merge } from '../core/utils/lodash';
+
+describe('utils', () => {
+  beforeAll(() => {});
+
+  beforeEach(() => {});
+
+  test('no other object are passed', () => {
+    const obj1 = {
+      a: [{ b: { c: 1 } }],
+    };
+
+    expect(merge(obj1)).toStrictEqual(obj1);
+  });
+
+  test('merge should work: case 1', () => {
+    const obj1 = {
+      a: [{ b: { c: 1 } }],
+    };
+    const obj2 = {
+      a: [{ b: { d: 2 } }],
+    };
+    expect(merge(obj1, obj2)).toStrictEqual({ a: [{ b: { c: 1, d: 2 } }] });
+  });
+
+  test('merge should work: case 2', () => {
+    const obj1 = {
+      a: [{ b: { c: 1 } }],
+    };
+    const obj2 = {
+      a: [{ b: { d: undefined } }],
+    };
+    expect(merge(obj1, obj2)).toStrictEqual({ a: [{ b: { c: 1 } }] });
+  });
+
+  test('merge should work: case 3', () => {
+    const obj1 = {
+      a: [{ b: { c: 1 } }],
+    };
+    const obj2 = {
+      a: [{ b: { c: undefined } }],
+    };
+    expect(merge(obj1, obj2)).toStrictEqual({ a: [{ b: { c: 1 } }] });
+  });
+
+  test('merge should work: case 4', () => {
+    const obj1 = {
+      a: [{ b: { c: 1 } }],
+    };
+    const obj2 = {
+      a: { b: { c: undefined } },
+    };
+    expect(JSON.stringify(merge(obj1, obj2))).toBe(`{"a":[{"b":{"c":1}}]}`);
+  });
+
+  test('merge should work: case 5', () => {
+    const obj1 = {
+      a: { b: { c: 1 } },
+    };
+    const obj2 = {
+      a: { b: { c: undefined, d: 2 } },
+    };
+    expect(merge(obj1, obj2)).toStrictEqual({ a: { b: { c: 1, d: 2 } } });
+  });
+
+  test('merge should work: case 6', () => {
+    const obj1 = {
+      a: { b: { c: 1 } },
+    };
+    const obj2 = {
+      a: 1,
+    };
+    expect(merge(obj1, obj2)).toStrictEqual({ a: 1 });
+  });
+
+  test('merge should work: case 7', () => {
+    const obj1 = {
+      a: { b: { c: 1 } },
+    };
+    const obj2 = {
+      a: {
+        b: {
+          c: () => {
+            console.log(123);
+          },
+        },
+      },
+    };
+    expect(merge(obj1, obj2)).toStrictEqual(obj2);
+  });
+
+  test('merge should work: case 8', () => {
+    const obj1 = {
+      a: [{ b: { b1: 123 } }],
+    };
+    const obj2 = {
+      a: [{ b: [1, 2] }],
+    };
+
+    expect(merge(obj1, obj2)).toStrictEqual({
+      a: [{ b: { 0: 1, 1: 2, b1: 123 } }],
+    });
+  });
+
+  test('merge should work: case 9', () => {
+    const object = {
+      a: [{ g: 3 }, { f: 5 }],
+      b: 123,
+    };
+
+    const other = {
+      b: null,
+    };
+
+    expect(merge(object, other)).toStrictEqual({
+      a: [{ g: 3 }, { f: 5 }],
+      b: null,
+    });
+  });
+
+  test('merge should work: case 10', () => {
+    const object = {
+      a: [{ g: 3 }, { f: 5 }],
+      b: 123,
+    };
+
+    const other = {
+      b: undefined,
+    };
+
+    expect(merge(object, other)).toStrictEqual({
+      a: [{ g: 3 }, { f: 5 }],
+      b: 123,
+    });
+  });
+
+  test('multi object merge should work', () => {
+    const object = {
+      a: [{ b: 2 }, { d: 4 }],
+    };
+
+    const other1 = {
+      a: [{ c: 3 }, { e: 5 }],
+    };
+
+    const other2 = {
+      a: [{ g: 3 }, { f: 5 }],
+      b: 123,
+    };
+
+    const other3 = {
+      b: {
+        my: 'name',
+      },
+    };
+
+    expect(merge(object, other1, other2, other3)).toStrictEqual({
+      a: [
+        { b: 2, c: 3, g: 3 },
+        { d: 4, e: 5, f: 5 },
+      ],
+      b: { my: 'name' },
+    });
+  });
+});

src/core/utils/index.ts

@@ -8,6 +8,7 @@ export const isString = (val: unknown): val is string =>
   toTypeString(val) === '[object String]';
 export const isPlainObject = (val: unknown): val is Record<string, any> =>
   toTypeString(val) === '[object Object]';
+export const isArray = (val: unknown): val is any[] => Array.isArray(val);
 
 export const isObject = (val: unknown): val is Record<any, any> =>
   val !== null && typeof val === 'object';

src/core/utils/lodash/index.ts

@@ -1,7 +1,4 @@
-/**
- * source by `lodash`
- * https://github.com/lodash/lodash.git
- */
 /* istanbul ignore next */
 export { default as debounce } from './debounce';
 export { default as throttle } from './throttle';
+export { default as merge } from './merge';

src/core/utils/lodash/merge.ts

@@ -0,0 +1,37 @@
+import { isPlainObject, isArray, isObject } from '../index';
+
+type MergeObject = Record<string, any>;
+
+function baseMerge(origin: MergeObject, target: MergeObject) {
+  for (const key in target) {
+    if (target[key] === undefined) {
+      continue;
+    }
+
+    if (
+      !isObject(target[key]) || // `target[key]` is not an object
+      !isObject(origin[key]) || // `target[key]` is not an object
+      !(key in origin) // `key` is not in the origin object
+    ) {
+      origin[key] = target[key];
+      continue;
+    }
+
+    if (isPlainObject(target[key]) || isArray(target[key])) {
+      baseMerge(origin[key], target[key]);
+    }
+  }
+}
+
+function merge(origin: MergeObject, ...others: MergeObject[]): any {
+  const result = Object.assign({}, origin);
+  if (!others.length) return result;
+
+  for (const item of others) {
+    baseMerge(result, item);
+  }
+
+  return result;
+}
+
+export default merge;