feat(utils): create appendProps utility function

conditionally append properties as the're defined

src/app/utils/appendProps/appendProps.js

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+/**
+ * @desc: conditionally append properties as they're defined
+ */
+const appendProps = (...args) => (action) => (
+  args.reduce((acc, arg) => ({
+    ...acc,
+    ...action[arg] && { [arg]: action[arg] },
+  }), {})
+);
+
+export default appendProps;

src/app/utils/appendProps/appendProps.test.js

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+import appendProps from './appendProps';
+
+describe('footer action', () => {
+  it('should return a function', () => {
+    const fn = appendProps('yeah');
+    expect(typeof fn).toEqual('function');
+  });
+
+  it('should return an object with property "a" and ignore the rest', () => {
+    const fn = appendProps('a');
+    const obj = fn({ a: 1, b: 2 });
+    expect(obj).toEqual({ a: 1 });
+  });
+
+  it('should return an object with properties "a" and "b"', () => {
+    const fn = appendProps('a', 'b');
+    const obj = fn({ a: 1, b: 2 });
+    expect(obj).toEqual({ a: 1, b: 2 });
+  });
+
+  it('should return an object with property "b"', () => {
+    const fn = appendProps('b');
+    const obj = fn({ a: 1, b: 2 });
+    expect(obj).toEqual({ b: 2 });
+  });
+
+  it('should return empty object if the given object doesn\'t match with properties to reflect', () => {
+    const fn = appendProps('a', 'b');
+    const obj = fn({ c: 3, d: 4 });
+    expect(obj).toEqual({});
+  });
+
+  it('should return empty object if there\'s not properties to append', () => {
+    const fn = appendProps();
+    const obj = fn({ a: 1, b: 2 });
+    expect(obj).toEqual({});
+  });
+
+  it('should throw if there\'s not object to reflect', () => {
+    const fn = appendProps('a', 'b');
+    expect(() => { fn(); }).toThrow();
+  });
+});

src/app/utils/appendProps/index.js

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+// eslint-disable-next-line import/prefer-default-export
+export { default as appendProps } from './appendProps';