message: Improve value propTypes warning
  ref
diff: @@ -23,10 +23,13 @@ function valueType(props, propName, componentName) {
  `shape of \`{ key: string | number, label?: string | number }\`.`
  );
  }
  - } else if (props.multiple && props[propName] === '') {
  + } else if (
  + (props.mode === 'multiple' || props.mode === 'tags' || props.multiple || props.tags)
  + && props[propName] === ''
  + ) {
  return new Error(
  `Invalid prop \`${propName}\` of type \`string\` supplied to \`${componentName}\`, ` +
  - `expected \`array\` when \`multiple\` is \`true\`.`
  + `expected \`array\` when \`multiple\` or \`tags\` is \`true\`.`
  );
  } else {
  const validate = PropTypes.oneOfType([
  