@applicaster/zapp-react-native-utils/objectUtils/__tests__/objectUtils.test.js

Applicaster Zapp React Native utilities package

import { filterObj, mapKeys } from "../index";

const obj = {
  prop: "foo",
  arr: ["foo", "bar"],
  bool: true,
  meaningOfLife: 42,
};

describe("filter object", () => {
  it("is a curried function", () => {
    expect(filterObj(jest.fn())).toBeFunction();
  });

  it("filters an object based on the provided predicate", () => {
    const predicate = jest.fn((key, val) => Array.isArray(val));
    const result = filterObj(predicate, obj);

    expect(predicate).toHaveBeenCalledTimes(Object.keys(obj).length);
    expect(result).toEqual({ arr: ["foo", "bar"] });
  });

  it("filters on the object keys too", () => {
    const predicate = (str) => str.length === 4;
    const result = filterObj(predicate, obj);

    expect(result).toEqual({
      prop: "foo",
      bool: true,
    });
  });
});

describe("mapKeys", () => {
  it("maps over the keys of an object", () => {
    const mapper = jest.fn((key) => key.toUpperCase());
    const result = mapKeys(mapper, obj);

    expect(mapper).toHaveBeenCalledTimes(Object.keys(obj).length);

    expect(result).toEqual({
      PROP: obj.prop,
      ARR: obj.arr,
      BOOL: obj.bool,
      MEANINGOFLIFE: obj.meaningOfLife,
    });
  });
});