readme.md

Transforming state

Read the guideline before start

❗️❗️❗️ DON'T FORGET TO PROOFREAD YOUR CODE WITH CHECKLIST BEFORE SENDING YOUR PULL REQUEST❗️❗️❗️

Task description

Implement a function accepting 2 arguments: state and actions. The function should change the state basing on the given actions array.

• state is an object. You are supposed to add, change, or delete its properties instead of creating a new object

• actions is an array of objects. Each object in this array has the next properties:

  • type contains a string: either 'addProperties', 'removeProperties' or 'clear';
  • The second property of each object depends on type and may be one of the following:
    • if type is addProperties, second property is extraData. It contains an object with key: value pairs to add to the state;
    • if type is removeProperties, second property is keysToRemove. It contains an array with the list of property names (keys) to remove from the state; (Not existing properties should be ignored)
    • if type is clear you should remove all the properties from the state. No second property in this case;

Example of usage:

If state is {foo: 'bar', bar: 'foo'}, then

 transformState(state, [
   {
     type: 'addProperties',
     extraData: {
       name: 'Jim',
       hello: 'world',
     }
   },
   {
     type: 'removeProperties',
     keysToRemove: ['bar', 'hello'],
   },
   {
     type: 'addProperties',
     extraData: { another: 'one' },
   }
 ])

should modify the state, doing the following:

• add two properties to the state
• then remove keys bar and hello from the state
• and finally add another one property to the state

After these operations the object state will have the following look

{
  foo: 'bar',
  name: 'Jim',
  another: 'one',
}

Another example:

 const state = { x: 1 };

 transformState(state, [
   { type: 'addProperties', extraData: { yet: 'another property' } }
   { type: 'clear' },
   { type: 'addProperties', extraData: { foo: 'bar', name: 'Jim' } }
 ]);

// state === { foo: 'bar', name: 'Jim' }