make props overridable by composition. In the end might be better to make this explicit otherwise it becomes hard to follow.

composeProps.js

const composeProps = (leftProps, rightProps) => {
  const composedProps = { ...rightProps }

  Object.keys(leftProps).forEach((key) => {
    const leftValue = leftProps[key]
    if (key in rightProps) {
      const rightValue = rightProps[key]
      composedProps[key] = composeProp(leftValue, rightValue)
    } else {
      composedProps[key] = leftValue
    }
  })

  return composedProps
}

const composeProp = (leftValue, rightValue) => {
  if (typeof leftValue === "function") {
    if (typeof rightValue === "function") {
      return (...args) => {
        leftValue(...args)
        rightValue(...args)
      }
    }
    return leftValue
  }
  if (typeof leftValue === "object") {
    if (typeof rightValue === "object") {
      return { ...leftValue, ...rightValue }
    }
    return leftValue
  }
  return rightValue
}