Prerequisites

• I have read the documentation.

Description

I believe the shouldRender function in utils.js is returning true in too many instances, particularly for nested ArrayFields or ObjectFields, because it's unnecessarily requiring function equality in props and state.

Steps to Reproduce

1. In your clone of this repository, add this line to shouldRender: console.log(comp.props, nextProps, !deeper(comp.props, nextProps) || !deeper(comp.state, nextState));
2. Start the development server with npm start
3. Go to localhost:8080 and click on the "Nested" tab
4. Start typing in the "Task list title" field
5. Look in the console logs for something like Object {name: "tasks".... This is where shouldRender was called for the "tasks" ArrayField
6. Observe that the objects logged on that line are structurally equivalent, but that shouldRender is still returning true. I believe that this is happening only because the onChange functions in those objects are referentially non-equal.

Expected behavior

I would expect that shouldRender for the "tasks" ArrayField would return false and that the component does not re-render, because none of the data that affects how the component renders has changed. Re-rendering all ArrayFields or ObjectFields when none of the data in that component has changed, particularly in large forms, is a performance drain.

Actual behavior

ArrayField re-renders when making a change to another part of the form.

Version

0.34.1

Proposed Solution

I think that a function like the one below should be added to utils.js and called on comp.props and nextProps before they're passed to deeper

function _removeFunctionsFromObj(obj) { var newObj = {}; for (var key in obj) { if (typeof obj[key] !== 'function') { newObj[key] = obj[key]; } } return newObj; } 

I'd be happy to submit a PR, but I thought it might be better to start a discussion first in case there's another way to solve this problem.