A function that returns a React.Context and a mapContextToProps HOC so that you can inject context onto props, like react-redux's `connect` function

initContext.tsx

import * as React from 'react';

const defaultMapper = (ctx) => ctx

export function initContext<CtxType>() {
  const Context = React.createContext<CtxType | null>(null);
  function mapContextToProps<Props>(Component: React.ComponentType<Props & CtxType>, mapper: (ctx: CtxType) => any = defaultMapper): React.ComponentType<Props> {
    return (props: Props) => (
      <Context.Consumer>
        {(ctx) => <Component {...props} {...mapper(ctx)} />}
      </Context.Consumer>
    )
  }
  return {
    Context,
    mapContextToProps,
  };
}