Anti-Patterns

React

• Accessing props in getInitialState. (link)
• Creating new objects or functions in the render method (link)
• Checking for existance of a prop. Should use defaultProps instead. (link)
• Side effects in render method.
• Inheritance using Mixins.

React Redux and Immutable JS

• Calling toJS inside of state selectors.
• Doing anything in a reducer that doesnt modify the state. Make use of side-effects if you need to fire another action, or do the work in the action itself.