Q:

Stateless component is not rerendering when prop changes

This code is working good in one environment:
const RenderAuthors = ({ fields }) => {
  const addAuthorField = () => { fields.push({}) }
  if (fields.length === 0) {
    addAuthorField()
    console.log("Enter here")
  }
  console.log("Fields************:" + fields.length)
  return (
    <ul style={style.authorsList}>
      {fields.map((member, index) =>
        <li key={index}>
          <Field
            name={`${member}.firstName`}
            type='text'
            component={RenderField}
            dataSource={nameList}
            hintText='Introduce el nombre del autor'
            muiComponent={AutoComplete}
            floatingLabelText='Nombre'
            openOnFocus={true}
            filter={MUIAutoComplete.fuzzyFilter}
          />
          <Field
            name={`${member}.lastName`}
            type='text'
            component={RenderField}
            dataSource={surnameList}
            hintText='Introduce el apellido del autor'
            muiComponent={AutoComplete}
            floatingLabelText='Apellido'
            openOnFocus={true}
            filter={MUIAutoComplete.fuzzyFilter}
          />
          <FloatingActionButton mini={true} style={style} onClick={() => fields.remove(index)} >
            <Delete />
          </FloatingActionButton>
          <FloatingActionButton mini={true} onClick={addAuthorField} >
            <PersonAdd />
          </FloatingActionButton>
        </li>
      )}
    </ul>
  )
}

fields is empty, and addAuthorField function is executed. As I debug my code (Chrome debug tools & webpack) y see RenderAuthors is rerendered (I guess is becasuse fields prop has changed) and  is rendered with fields.
My console.log is:
Enter here
Fields************:0
Fields************:1

In another environment (same React, redux-form, but not webpack, small differences in Babel), when I debug my code:
addAuthorField is executed, but no rerendered. My console.log is:
Enter here
Fields************:0

Any idea about how to guess where the error is?

A:

Upps!  I forgot the reducer in the other environment!

